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CHEMISTR V DIVISION ANNUAL PROGRESS REPORT
for Period Ending May 20.1970
E. H. Taylor, Director SheWon Datz, Associate Director Ralph Livingston, Associate Director B. H. Keteile, Assistant Drector
G. E. Moore, Editor of Annual Report
LEGAL NOTICE This report was prepared as an account of work sponsored by the United States Gowt- meat. Neither u;? United States nor the United States Atomk Energy Commission, nor any of their employees, nor any of their contractors, subcontractors, or tfces employees, makes any warranty, express or impbec, or assumes any legal Uab'lhy or nsponsibflrty for the accuracy, com pleteness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights.
SEPTEMBER 1970
OAK RIDGE NATIONAL LABORATORY Oak Ridge, Tennessee opyttiby UNION CARBIDE CORPORATION forth* U. G. ATOMIC ENERGY COMMISSION
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\ Reports previously issued in this series are as follows:
ORNl-2386 Period Ending June 20,1957 ORNL-2584 Period Ending June 20,1958 ORNL-27S2 Period Ending June 20,1959 GRNL-2983 Period Ending June 20,1960 ORNL-3176 Period Ending June 20,1961 ORNL-3320 Period Endi^s June 20, :%2 ORNL-3488 Period EndmgJunc20,I963 ORNL-3679 Period Ending June 20,1964 ORNL-3832 Period Ending May 20,1965 ORNL-3<*94 Period Ending May 20,1966 ORNL-4164 Period Ending May 20,1967 ORNL-4306 Period Ending May 20.1968 ORNL-4437 Period Endir^ May 20,1969 Contents
INTRODUCTION ix 1. Nuclear Chemistry
A Reexamination of the Decay of 4* na 1 Energy Levels in "Sr from the Decay cf 14.6-hr 86 Y ! Search for the 0* Memler of the Two-Phonon Triplet in '' °Cd 3 Properties of'' °Cd L*veb f'opuhted in the Decay of 69-min ' i0*In 4 Decay of* 37Nd. ,3*N& and13*Pr 6 Search for the Occurrence of * **Sm in Na ure 6 Production of Rare-Earth Alpha Emitters with Energetic 'He PartkSes 7 New Isotopes: ISI Er. ,56Yb.and ,57Yb 10 Alpha-Decay Energy SystematJcs 13 Coulomb ExciUtion of l$4Gd. I5'Gd,and ,6'Er 14 Coulomb Excitation Experiments at OR!C 15 Some Properties of Vibrational Bands in ' s*Gd and ' 5*Gd 15 Ml Admixture in the 2* •* 2* Transition in ' 78Hf 17 Fragment Energy Correlation Measurements for the Fission of *32Th by 8- to 13-MeV Protons 18 Fiagment Energy Correlation Measurements in the Fission of Spontaneously Fissioning Isomers 21 Primordial Radionuclide Abundances. Solar-Proton and Cosmic-Ray Effects, and Ages of Apollo 11 Lunar Samples 23 Radionuclide Concentrations in Apollo 12 Lunar Samples by Nondestructive Gamma-Ray Spectrometry 25
in \
iv
2. Chemistry and Physics of Transuranium Elements
Large Yields for Charged-Partide Emission in Reactions of Protons with Actinide Targets 28 Inclusion of Charged-Partide Emission and Fission in Nudear Reaction Calculations 30 The Decay of the Isomers of 240Np and 244Cm snd the Resultant States of 240Pu 32 A Two-Phonon Octupole Vibrational Band in 240Pu 34 Long-lived Spontaneous-Fission Isomerism in 24! Pu? 36 The Fission Thermai-N-uiron Cross Section and Resonance Integral of 2*s Cm, 247Cm, and 249Cf 37 Energy Spectrum of Delayed Neutrons from the Spontaneous Fission of 2S2Cf 40 Alpha-Decay Studies of Neutron Deficient Californium Isotopes 41 States in 2S0Bk Populated in the Alpha Decay of 2$4Es 43 The Neutron Absorption Cross Section of 2S7Fm 4? Studies on the Separation of Recoil Atoms of Heavy Elements 44 K X Rays of the Higher Ac ainides 45 Studies of Pleodiroic Halos 45 Search forSuperheavy Elements in Nature: Ekaptatinum 46 Search for Superheavy Elements in Nature: Ekaosrraum 46
Ekctron-Transter Absorption in Some ActimdHUl) and Laathanide(Iir) Tricydopentadienides and the Standard IMC Cation Oxidation Potentials 48 Theory of the Tetrad Effect in the Lanthanide (IH) and Actinide (III) Series 48 Investigations on the OrganometaBic Chemistry of Actinides and Lanthanides 52 An Improved Synthesis of Tricydopentadienyl Complexes in ftfcroquantities 52 The Formation of Dkydopentadienyfberkelium Chloride 53 Rare-Earth and Americium Chdates 55 Reaction of Aqueous Lanthanide Chloride Solutions with 2,2-Dirnethoxypropane 55
2> Photochemical Reactions Initiated by U02 . Reaction of Butyraldehyde with Diethyl Makate 55 The Crys'al and Molecuhr Structure of Tris(2,2,6,6-tetramethyl-3,5-heptanedionato)- neodymium(III) and -ameridum(II0 56 Trisindenylsamarium: Synthesb and Crystal Structure 57 Crystallographic Studies of Anhydrous Transplutonium Trichlorides 57 The Transuranium Research Laboratory Isotope Separator 58 A Mass Indicator for Sector Isotope Separators 58 A Fail-Closing Valve to Protect ORIC from Radioactive Contamination 59 3. Isotope Chemistry
Deuterium Enrichment 62 Fractionation of Carbon Isotopes: The CYANEX System 62 The CYANEX BenchScale Pilot Plan* 63 170 Facility 63 Photochemical Separation of Isotopes 64 Molecular Spectroscopy 65 Isotooic Mass Soectrometrv Preparation of' 3C0 69 4. Radiation Chemistiy
Flash Photolysis of Aqueous Nitric Oxide Solutions 70 Pulse Radioiysis of Sodium Nitrate Crystals 70 Pulse Radiolysis of Gases 71 Density and Reflectivity of Amoiphous Ice 72
Reduction of CeriumflV) in Aqueous 4.0 MH2S04 Solutions Induced by Hydrolysis of Peroxydisulfuric Acid 73
Kinetic Evidence for a Primary Yield of N03 Radicals in the Radiolysis of Aqueor* Nitric Acid Solutions 74 Primary Processes in the Radiolys* of Water 75 Energy Transfer and the Radiolysis cf Liquid Aliphatic Carboxyljc Acids 76
RADUTION AND HOT ATOM CHEMISTRY OF INORGANIC CRYSTALLINE SOUDS
Chemistry' of' 28I and ' 3°I Recoik in Neutron-Irradiated Crystalline Potassium lod*te and Potsssium Periodate 78 Investigations on the Thermal and Radiolytic Decomposition of Anhydrous Crystalline Potassium Chlorite 78 Further Observations on Products Formed in the Radiolysis of Alkali-Metal Halates and Perhalates by 60Cc Gamma Rays 79 Microanalyiical Method for the Determination of Perbromate !on in the Presence of Macro Amounts of Other Bromine Anions 82
! Radiolysis of "O-Enricbed Po'ycrystalline KN03 82
5. Organic Chemistry Preparation and Deamination of S-exo-Plienyl-S-hydroxy^-fx^-norboniylamine and 5-ena0-Phenyl-5-hydroxy-2-*x
Anion Contol of Stereoselectivity During Deaminations 37 Determination of the Stereochemistry of 1,2 Glycols by Nuclear Magnetic Resonance 87 Isothermal Analysis of Graphite-Impregnated Teflon 88 Wet Oxidation of Cellulose 89
6. Physical Chemistry
AQUEOUS SYSTEMS Free Energies of Electrolyte Mixtures 90
The Thermodynamic Properties of HCi-NaCi-MgCi2 Mixtures 93 Salt-Induced Critical-Type Transitions in Aqueous Solution. Heats of Dilution of the Lithium and Sodium Halides 97 Variation of Osmotic Coefficients of Aqueous Solutions of Tetraalky!ammonium Halides with Temperature. Thermal and Solute Effects on Solvent Hydrogen Bonding 98 Thermodynamic Studies on Aqueous Solutions of Salts of Carboxylic Acids 99 Tracer Diffusion Coefficients in Aqueous Solutions of Organic Ion Exchanger Model Compounds: Comparison of Aqueous Sodium p-Ethylbenzenesulfonate with Cross-Linked Polystyrenesulfonates 100 Mass Transfer in Ion Exchange Tubes 103 Mass Transfer in Shallow Ion Exchange Beds 104 Swelling of Low-Cross-Linked Ion Exchange Resins 106 Hyperfiltration with Dynamically Formed Membranes 108 Polymer Studies Ill Application of Cross-Flow Filtration to Pollution Control Problems 112 "Polywater," Raman and Infrared Spectra 112 On the Existence of So-Called "Anomalous Water" 115
MOLTEN SALTS AND RELATED NONAQUEOUS SYSTEMS
Heat Content of Alkali Metal Fiuoroborates 116 The Solubility of Thorium Metal in Thorium Tetrafluoride 118 The System Yttrium Mctai-Yttrium Trichloride at High Temperatures 119 A Reference Electrode System for Use in Fluoride Melts 119
CALORIMETRY
Low-Temperature Heat Capacity of Potassium Hexachlorotechnetate(IV) 121 Enthalpies of Fusion and Transition of Lead Fluoride 122
F»ee Energy and Enthalpy of Formation of K2ReBr6 123
ELECTROCHEMISTRY
Kinetics of the Charge and Discharge of the Film of Superpassive Iron 123 T^e Electrochemistry of Technetium 124 vn
Electrochemical Behavior of Titanium 125 Chronopotentiometry and Voltammetry of the Ag-AgCl Electrode in Flowing Streams - Experimental 126 Chronopotentiometry and Voltammetry of the Ag-AgCl Electrode in Flowing Stieams - Theoretical 129 Instrument and Cell Development for Rapid Chronopotentiometric Analysis of Chloride Ion 129 7. Chemical Physics
NEUTRON AND X-RAY DIFFRACTION
Interpretation »-f the Structures of Some Alkaline Earth Chlorides in Terms of Interionic Forces 131 Site Symmetry Restrictions of Thermal-Motion Tensor Coefficients 132 A New Structure-Factor Equation frr Analyzing Skewness and Kurtosis in Thermal-Motion Density Functions 133 A Preliminary Study of the Use of Position-Sensing Detectors in X-Ray and Neutron Diffraction Studies 134 A Least-Squares Method for the Absolute Scaling and Normalizing of Observed Structure Factors 135 The Addition Product of an Isocyanide with a Steroidal a^-Unsaturated Ketone: Structure Determination 137 Structure and Stereochemistry cf a- and 0-Cubebene from the Crystal Structure of Nor-0-cubebone 140 A Single-Crystal Neutron Diffraction Study of Urea—Phosphoric Acid 143 Crystal Structure of TrKp-biphenylyl)aminium Perchlorate 145 X-Ray Diffraction Study of Krypton Difluoride 150 Neutron and X-Ray Diffraction Studies of Xenon Hexafluoride 150 Diffraction Pattern and Structure of Liquid Trimethylamine Decahydrate at 5°C 151
INFRARED AND RAMAN SPECTROSCOPY
Spectrophotometry of Soluiions over Wide Ranges of Temperature and Pressure 153
8 Infrared and Raman Spectral Studies on ' 0-Enriched Polycrystalline KN03 155
Ionic Interactions in Crystals: Infrared and Raman Spectra of Powdered Ca(N03)2,
Sr(N03)2,Ba(N03)2,andPb(N03)2 l:"6 Transverse Optical Frequencies from Multiple Attenuated Total Reflectance Infrared Spectroscopy 157 Correlation Field Coupling of Nondegenerate Nitrate Vibrations 157
Raman Spectrum of Crystalline MoF4 159
Paman Spectrum of Polycrystalline MoF5 160
Polarized Raman Spectra of Single Crystal NaBF4 161
The Raman Spectra of Liquid and Gaseous H20 and D20 at Elevated Temperatures and Pressures . 164 vi n
Raman Spectrum of Molten NaN03 «65
Raman Spectra of Solid and Molten BeF2 and L«2BeF4 166
Raman Spectra of Molten NaBF4 to 556°C 168
Dynamics of a Polymer Model for Molten Li2 BeF4: Some Preliminary Results 170 A Furnace for Molten-Salt Raman Spectroscopy to 80C°C 171 A Windowless Cell for Laser Raman Spectroscopy of Molten Fluorides 172 Multiple-Sampling Cold Cell for Laser-Excited Raman Spectrophotometer 174
MICROWAVE AND RADIO-FREQUENCY SPECTROSCOPY
Paramagnetic Resonance Studies of Liquids During Photolysis 175
Paramagnetic Resonance Study of Gamma-Irradiated Single Crystals of KHC03 and
KDC03 176
ELECTRON SPECTROSCOPY
Use of Soft X Rays in Chemical Analysis 176 Angular Distribution of Photoelectrons 178
MASS SPECTROMETRY AND RELATED TECHNIQUES
Characterization of Volatile and Nonvolatile Solids Obtained from the Gas-Phase Radiolysis of Pentaborane-9 180 The Two-Stage Mass Spectrometer 181
MOLECULAR BEAM STUDIES
Cross-Molecular-Bcam Studies of Biomolecular Association and Unimolecular Decomposition Reactions 181 Cross-Molecular-Beam Studies of Reactions of Atomic Deuterium with Halogen Molecules 181
PUBLICATIONS 133
PAPERS PRESENTED AT SCIENTIFIC AND TECHNICAL MEETINGS 189
LECTURES 195
SUPPLEMENTARY ACTIVITIES 198 Introduction
Again this y^ar, we intend the Table of Contents to Table of Contents and the body of this report provide serve also as the summary of this report. We have also evidence for this continuing and evolving effort. We again modified the arrangement of topics by intro note two items about new directions, one of which will ducing a new heading, "Physical ChemJstrv." This certainly influence our future plans and results and one provides a place for a number of subgroups of topics of which may or may not: At about the end of the which had previously seemed a little inconsistent as report period a beam of about 15 mA of Os+ was separate chapters. obtained at ORIC in a combined effort by the This has been a year in which the Laboratory has Electronuclear and the Chemistry Divisions to develop a explored with considerable intemity possible new direc high-intensity, high-charge-state source of carbon, nitro tions for part of its effort. Two division members, S. gen, oxygen, and neon. This flexible, intense source Datz and J. S. Johnson, have been directly concerned together with our unequaled choice of targets from the with this planning, and many more have examined how operations of the HFIR-TRU-calutron complex gives; us these new directions might affect their areas of re a unique capability for producing and for identifying as search. It should perhaps be noted that the Chemistry to Z isotopes of elements around 104, a capability Division has from the beginning been a major contribu which we shall certainly exploit. tor to the first and largest of these new directions; As to the other new direction, we have begun during accounts of the Water Research Program have been this year actual search for superheavy elements in appearing ir. our annual report since 1963. Any heavier nature. We have been using fission counting and mass involvement of the Division in environmental and similar spectroscopy for detection following various kinds of programs seems most likely to fall in this area, separation. Early in fiscal year 1971 (corresponding particularly sinre some aspects of it, hyperfiltration and roughly to our report year) we expert to have in certain applications of electrochemistry, give promise of operation a neutron coincidence counter that will early practical usefulness and ?re therefore in need of accept 50-kg samples without the necessity of prior expanded effort. chemical separation. Whether the search will be success Although the needs of applied projects are therefore ful depends, of course, on whether such elements do taking somewhat more of our time and effort than exi;f. We think that we are bringing to the search formerly, we have no intention of abandoning those enough enthusiasm to find them if they are there, and are-us of research in which we have productive programs we are counting on a variety of experts, in and out of nor of ceasing to look for new areas in which we can house, to ensure that we examine the most promising make important contributions to pure science. The samples.
IX I. Nuclear Chemistry
A REEXAMINATION OF THE DECAY OF 49Ca separate bombardments yielded an A 2 parameter of about —0.1. Such a value is consistent with a %~ E. Eichler assignment, with the reasonable assumption of little or Mann and Bloom1 have recently measured beta- no El admixture. An assignment of \ ~ would only He gamma correlations in *"Ca decay to determine the possible with 50% or more E2 component, unlikei}' in mixing between analog and antianalog states. Analysis such a shell-model nucleus. of their results depends profoundly on the absence of spreading of the p3f2 strength away from the anti- analog 3084-keV level in 45Sc. Erskineef a/.2 observed 1L. C. Mann and S. G. Bloom, Sud. Phys. A»40, 598 (1970). in their 48Ca(3Ke,d) studies a state at 4507 keV with 2 J. R. Erckine, A. Marinov, and J. P. Schiffer. Phys. Rev. 142, an / -• I character suggesting a % or % spin assignment, 633(1966). in our earlier study3 we tentatively identified a 3G. Chiloa, G. D. O'KeUey, and ¥.. Eichler, Nud. Phys. A136, 1409-keV transition which might deexcite the suspect 649(1969). 4507-keV level. With our new high-resolution large- volume GefLi) detector, I restudied the 49Ca gamma- ray spectrum. The 1409-keV gamma ray was readily 86 shown to decay with the 8.8-min 49Ca half-life. I ENERGY LEVELS IN SrFROM THE DECAY 86 observed additional new gamma rays; the energies and OF 14.6-hr Y intensities of all the newly observed transitions are A. V. Ramayya1 D. Krmpotic1 *3 given in Table 1.1. Most of these transitions seem to B. van Nooijen1 *2 J.H.Hamilton1 deexcite previously known levels. J. W. Ford1 J.J.Pinajian4 To establish the spin assignment oi the 4507-keV Noah R. Johnson level, I measured the 1409-3084 keV gamma-ray direc tional correlation using two Nal detectors. Since the An experimental investigation of the 86Sr levels intermediate spin (that of the 3084-keV level) is \, the populated in the decay of 14.6-hr 86Y has been in
A4 parameter is zero. Thus an explicit A2 value could progress for the past several years. This work, which has be extracted from a two-angle experiment. Twenty now been completed, has revealed a wealth of new information on the excited states of 86Sr. Many types of experimental techniques have been utilized in this Table 1.1. Newly Observed 49Ca Gamma Rays research. These included performing internal and ex ternal conversion measurements with an iron-free E (keV) /" double-focusing beta-ray spectrometer, gamma-ray 144.5 10.7* 0.038 measurements with Ge(Li) spectrometers, and gamma- gamma coincidence experiments with Nal-Nal, Nal- 380.8+0.7* 0.018 Ge(Li), and Ge(Li)-Ge(Li) coincidence arrangements 856.4 10.5 0.14 coupled to two-parameter analyzers. 987.5 ±0.5 0.083 For the energy measurements, several runs were taken 1K4.5+0.5 0.12 with standards mixed into the source to eliminate any 1283.6+0.5 0.080 shifts due to source-strength variations. In this manner 86 1408.910.2 0.68 the energies of the stronger Y lines were determined, and in turn these served as internal calibration points. "Relative to the 3084.4-keV gamma rav •%. 100 units. The energy calibration was accomplished by a computer *TIiese transitions could net be verified by half-life because of least-squares fit of the standard lines to a third-degree their low inten««!:cs. polynomial.
1 BLANK PAGE 3*. *
Fig. 1.1. Proposed ODY Decay Scheme. The dashed leveb and dashed transttiojl evidence. £ I
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3CSafl6±0J7 2997.34* 0.V -287*26*0.10 2788.2 * a? 2672.76* 2229u66*0.;4 5273 k«V l854.2O±0,*O 1C7SJ53* 0.10 T Thy dashed level* and dashe*.' transitions indicate ca$s» for wh»ch f;icre n only wta!: 3 The coincidence spectra resulting from gating on 38 2229.68-keV level could be the 4* member. Computing different transitions were analyzed. As a result of these the ratio of reduced E2 transition probabilities of the extensive coincidence measurements along with the 777.37-keV stopover to the 1854.2CMceV crossover numerous other types of experiments performed, a transitions, one obtainsB(E2: T2 -> 2\)IBiE2:T2^Q*) highly consistent and detailed picture of the decay = 102, where it is assumed that the 777.3"-keV line K properties of the 86Y nucleus has evolved. This decay pure £2. The 2481.91-keV •' level probably can be scheme is shewn in Fig. 1.1. interpreted as the one-phonon octupole level because of With the detailed knowledge of the 86Sr levels a relatively strong transition to the ground state. It is achieved here, 't seems somewhat unfortunate that not possible to m?ke any predictions about the higher there are not extensive theoretical calculations with excited states until unique spin assignments become which to compare experiments. Talmi and Unna5 have possible. made sheii-modei calculations for a few of the excited states. Their calculations were based on the assumption Vanaerbiit University, Nashviiie, ; enn. that the closed l/s 2 subshdl is stable ?.s far as the Permanent address: Technological Uiweraty of Delft. De low-lying levels are concerned. Note that the R6Sr partment of Physics. Delft, Holland. nucleus consists of 38 protons which fill the l/s/2 and "Permanent address: Boris Kklnc Institute of Nudear Sci lower-lying sutshells and of 48 neutrons which leave ence, Belgrade, Yugoslavia. 4 two holes in the lg9/2 subshell. These calculations, Isotopes Division. 5 which considered only the neutron holes in the 2pl ,2 1. Talmi and I. Unna, NucL Fkys. 19. 225 (I960). and lg9f2 sabshelis, predict excited states at 1.08 (2* ), 1.98 <4* ), 2.33 (0* ), 2.35 (6+ ), 2.49 (8"), 2.58 (5 " ), SEARCH FOR THE 0+ MEMBER OF THE and 2.62 (4") MeV. As seen, the agreement with TWO-PHONON TRIPLET IN 11 °Cd experiment is not very good. M.C.Ketley1 R. G. Lanier2 It is probable that collective effects also are very J. R. Van Hise1 Noah R. Johnson important in the 86Sr levei structure. The 1076.63-keV 2* level may be described as a one-phenon vibrational Our search for the 0* member of the two-phonon level, whereas the 1354.2-keV 2* level nay be de state in * Cd and study of the decay properties of scribed as a member of the two-phonor- triple:, and the 25-sec '' °*Ag(I* ) have been completed. The experi- i+ 24.7 sec ORNL-DWG. 69-12742 »o«A _ \ Ag ca %0 k>$ft 71 V {kcV} (keV) 1107 0.029 6.7 {2,1} 1783.6 ±0.3 1415 0.017 7.4 2* 1475.72 ±0.05 1418 0.044 7.0 (0*) , * 1473.2 ±0.3 783 n (0.<7) It25.9 (0.3-5) •47S.73 (0.11) 818.00 (0.19) i 815.5 | (0.79) 2233 5.5 5.6 2* 657.71 ±0.03 S57.71 (100) i891 9*.4 4.7 0* * "0„ . 00 Fig. I.?. Decay Scheme of * °*Ag. The nunicers in parentheses below the transition eneneirs are relative gamma-ray intensities. 4 mental measurements were carried OJI with the use of measurements were made with both Nal(Ti) and Ge(Li) Nal(Tl) and Ge(Li) detectors •« both singles and detectors. The spectra in coincidence with every coincidence arrangements. A ^immary of the obser prominent gamma-ray transition have been measured. vations is best presented in the 'l ogAg decay scheme From these experiments a total of 72 transitions were shown In Fig. 1.2. assigned to the decay of1l °*In, and most of these have As we have already pointed out,3 the low-lying states been placed in the level scheme shown in Fig. 1.3. With of rruny medium-weight even-even nuclei have proper the log// values and the gamma-rey intensity informa ties which are reasonably well characterized ?s quadru tion determined in this work, it has been possible to ple surface vibrations. Currently there is considerable p»-i~ limits on the spin and parity values foi many of concern with understanding the behavior of the three the levels. members of the two-phonon quadrupole vibrations in The low-lying states at 657.5 (2* ), 1475.2 (2* ), and these nuclei. From the present measurements it has 1540.0 (4+) keV have been studied by means of been concluded with reasonable certainty that the 0* Coulomb excitation by McGowan etal? and by Milnei member of this triplet in ii0Cd exists at 1473.2 keV. et ai* These authors have determined B(E2) values for The 2* member lies only 2.5 keV higher. Both the 2* the 4t -* 22, 22 -* 2f, and 2J"-* 0* transitions and haye and 4* members were seen in the * 10?ln investigation compared the;r results with the predictions of ihe which is discussed in the following contribution. asymmetric rotor model and the vibrational model. The observation of all three members of the two- Miiner et aL* have determined the ratio B(£2, 27 -*• phoncn state in ,I0Cd thus: gives support to a 2t )fB(E2, 2f - 0* ) to be 1.08 ± 0.29 using a branch vibrational interpretation for this nucleus. However, ing ratio of 1.83 ± 0.13 for/(818)//(1475.5). This iatio th*re are other data which raise serious questions on of B(E2) values is only about half that predicted by the thip interpretation; these are discussed in the following vibrational model and raises some serious question contribution, "Properties of '' °Cd Levels Populated in about the validity of this model. These authors* also J! the Decay of 69-min : ,0*In. found a large B\M\) value for the 2i -*• 2\ in °Cd as well as for other even-yl cadmium nuclei. This raises further question about the vibrational description of ChemKtry Department. Andrews University, Berrien Spring. these medium-weight even->l nuclei, since in this picture Mich. M\ transitions should be strictly forbidden. Our data on MS. Atomic Energy Commission Postdoctoral FeBow under the bet? population of the 2* and 22 states in l t0Cd appointment with Oak Ridge Associated UniversUies. also indicate probable differences in the structures of 3M. C. KeBey, J. R. Van His*, R. G. Lanitr. arid Noah R. these two states. We find a log fr value of 7.0 to the 2£ Johnson. Chem. Dh: Ann. Progr. Rept. May 2>'f, /969, state at 1475.1 keV. In contrast, we find that the log ft ORNL-4437, p. 3. to the 2f state at 657.5 keV is 5.6. Tnis same pattern of log ft values for allowed beta transitions to the corresponding two 2* states has been observed in other similar nuclei. PROPERTIES OF ! * »Cd LEVELS POPULATED IN THE D*CAY OF 69-mir '' °*In 1 Washington University,St. Louis, Mo. 1 L>. G. Sarantltes Noah R. Johnson "Oik Ridge Associated LViver • » to Q sis -J o 2 • *> c T3 C > .a* 41 t! —5 >» - .* "S "» e r» 3 **» >© » u « *» s s 5 o £ "» 9 W Si c fr > — >> « tt. g 6 DECAY OF '37Nd,! 36Nd, AND ! 36Pr even though they appeared to decay with the same half-life. This work has shown that the most intense B.H.Ketelle A. R. Brosi gammas are in coincidence with praseodymium x rays More information on the decay schemes of 13.5-min and that they depopulate level; witli lifetimes of less 136Pr, 37-rnin ,37Nd. and ^O-min I36Nd is of interest than a nanosecond. The high-intensity gammas were because these isotopes are usually present in cyclotron shown to be emitted in the same relative intensities in 136 targets which have been bombarded to produce new targets with different Ce isotopk enrichments and isotopes of praseodymium and neodymium on the regardless of whether the activity was produced by a 3 4 neutron-deficient side of stability. In recent work He or a He reaction. These experiments confirm our 136 emphasis has been on the accumulation of sufficient earlier conclusion that Nd decays by electron I36 gamma-gamma coincidence data to deduce energy level capture to several different levels in Pr. The fact diagrams In the past this has been impossible, because that gamma-gamma coincidence counting rates are low the short-iived sources decayed before data could be indicates that most ekctron captures occur to energy acquired. When rates were increased to compensate for levels which are depopulated by decay to the ground the short time available for data acquisition, the loss in state. energy resolution was intolerable. Recent developments in solid state circuitry have made it possible to resolve SEARCH FOR THE OCCURRENCE OF ! 4 6Sm these difficulties. IN NATURE The coincidence counting system used consists of two 1 C. E. Bemis H. R. Gwinn 40-cc germanium detectors, pulse rejection circuitry, 1 J. Halperin R. L. Bailey amplitude and rise-time compensated coincidence 1 R. W. Stoughton L. T. Newman riming, and a multiparameter pulse analyzer which K. Spainhour1 stores both related coincidence addresses and singles spectra on magnetic tape. In order to accumulate The nuclide M6Sm with an alpha half-life of (1.026 ± coincidence data on short-lived isotopes as rapidly as 0.048) X 108 ye^rs2 has previously been produced in possible, the germanium detectors were mounted as 4He ion bombardments of Nd2,3 and in the close to the source as the positron absorbers would I47Sm(/i,2/z) reaction.4 This nuclide has the longest permit. The pulse rejection circuitry eliminated pileup half-life of all artificially produced radionuclides, al in the last stages of the amplifier and permitted the use though l46Sm has never been observed in naturally of high-intensity sources. This circuitry was also used to occurring samarium. discard coincidences between annihilrtion gamma rays We have estimated that if 146Sm was produced and most of the coincidences due to Compton scat approximately 4.5 X 109 years ago in the same yield tering between detectors. and manner as 144Sm, presumably a charged-particle With I3f'Pr and l37Nd sources, spectra of satis reaction, the natural abundance of !46Sm today is factory energy resolution were taken with singles rates approximately 2.5 X I0"15 g per gram of natural as high as 5 X 10*/sec on each side and coincidence samarium. rates as high as 2 X ICrVsec. These rates are about an Approximately 16 kg of naturally occurring samarium order of magnitude higher than could be achieved with was processed during the period 1967-1968 in the earlier equipment. A total of 107 coincidence events calutron facilities at Oak Ridge National Laboratory as could be accumulated using sources made from a single part of the regular program to replenish the samarium cyclotron iarget. Well over a hundred pairs of coinci stable-isotope inventory. Special collection pockets dent transitions were observed in the decay ol both were fabricated and installed to collect the ion beam l37Nd and l36Pr. From these data an energy level occurring at the mass 146 position for the entire run. diagram with more than 50 levels was constructed for Approximately 17 g of Sm203 was recovered, chemi ,37Pr, and another with more than 20 levels was cally processed to remove Nd, and mass analyzed. The constructed for' 36Ce. average isotopic enhancement factor for this first In the case of sources of 136Nd, coincidence rates calutron pass was ~200. were much lower relative to the singles rates than for All of the first-pass material was processed in a second i37 l36 sources of Nd or Pr. Several experiments have calutron run, and about 13 mg of Sm203 was recovered been done tc learn whether the low coincidence rates from the mass 146 pocket. The results of the mass were the result of delayed gamma emission or whether assays of the samarium recovered from the two suc the gammas were emitted by totally different nuclides, cessive calutron runs are listed in Table i.2 together / Table 1JL. Abundances of Naturally Occurring Samariu n PRODUCTION OF RARE-EARTH ALPHA Isotopes and Abundances After Electromagnetic EMITTERS WITH ENERGETIC 3He PARTICLES Isotope Separation in the Mass 146 Position K.S.Toth1 M. A. ljaz2 Natural First-Pass Second-Pass R.L.Hahn W. M. Sample2 Isotope Abundance Abundance Abundance (at.CT) (at. 7<) (at. 7r) The work reported here and in the following section is part of a program that deals with the production, and 144 3.09 3.65 1.40 characterization of new rare-earth alpha emitters with N 146 <0.005 <0.6 ± 0.2 ppm = 86 and 87. Earlier publications3,4 discussed the s3,154 ss 147 14.97 50.02 76.07 properties of * Ho and ' Er? nuclides produced S6 148 11.24 14.23 10.80 by bombarding enriched targets of * Dy with protons 4 4 149 13.83 10,88 5.78 and He ions. The maximum proton and He energies available at the ORIC are ~65 and ~80 MeV respec 150 7.44 4.28 1.77 tively These energies are not high enough to produce 15? 26.72 10.16 2.79 the thulium and ytterbium isotopes with N = 86 and 87 154 22.71 6.78 1.37 by bombarding the most neutron-deficient stable iso tope of erbium, 162Er. Reaction energetics indicated, however, that 100-MeV 3He ions incident on 162Er with the abundances of the isotopes of natural samar couid induce the (3He,8n) and (3He,9/i) reactions ium. necessary to produce the ytterbium nuclides of interest. We are currently measuring the alpha-particle spec A beam of several microamperes of doubly charged trum of a small portion of the second-pass material 100-MeV 3He ions was developed at the ORIC, and a prior to a third isotope separation which will use the search for ,S6Yb and l57Yb was initiated. It soon laboratory-size 150-cm sector separator at the Trans became clear that a separate investigation with 156Dy uranium Research Laboratory.5 as the target nucleus was necessary to establish excita At this present stage we can conclude that the natural tion functions for(3He^rn),(3He/>xn),and(3He,oic/i) isotopic abundance of14 6Sm is less than ~2.9 X ! 0~l 2 reactions that would lead to known erbium, holmium, g per gram of natural samarium based on the mass and dysprosium nuclides.5 These excitation function assays of the second-pass material. The alpha-particle data could then be used in the mass assignments of the 146 measurements, where the laiio of Sm (Ea = 2.55 new ytterbium nuclides. 4 7 MeV) to ' Sm (Ea = 2.23 MeV) alphas is determined, The experiments were performed with a gasket are perhaps more sensitive than the rmss sj ictrccopic system.6 The radioactive nuclei that recoil out of thin measurements because of large difference in half-lives. targets are stopped in helium gas in a "high-pressure" After the third stage of isotopic separation in which we chamber (~0.2 to 2 atm) and then carried by the gas expect an enhancement factor of ~1000 in the through a very small orific* into a "low-pressure" 146Sm/,47Sm atom ratio, we should be able to chamber (~0.2 to 0.5 torr), where they are deposited measure an abundance for 146Sm in the range of on a catcher to*1 for essay. Targets consisted of thin ^10-16 g per gram of natural samarium. layers (~0.6 mg/cn2) of rare-earth oxide electro- Although we expect I46Sm to be produced via the deposited onto platinum or nickel supporting foils. The 147Sm(»,2n) reaction with cosmic-ray neutrons to the isotopic compositions of the enriched oxides were such extent of ~10~14 g per gram of natural samarium, an that the target nuclei of interest, ,56Dy and ,62Er, abundance of * 46Sm greater than this value might serve made up 12.6 and 20.4% of the target materials as a sensitive geochronological indicator. respectively. During irradiation, targets were positioned so that first the backing fofl and then the oxide deposit intercepted the beam. Alpha-particle spectra were meas Isotopes Division, ured with Si(Au) detectors coupled through a !ow-noise 2 A. M. Friedman etal, Radiochim. Acta 5,192 (196J). charge-sensitive preamplifier, linear amplifier, and post- 3D. C. Dunlavey and G. T. Seaborg, Phys. Rev. 92, 206 (1953). amplifier to a multichannel analyzer, which was used to M. Nurmia, D. Geissing, W. Sievers, and L. Varga, Ann. store spectra as a function of decay time. The full width Acad. Sci. Fennicae, Ser. A, VI(167), 1 (1965). at half maximum for the various alpha-particle peaks 5L. D. Hunt and C. E. Bemis, Jr., Chem. Div. Ann. Proxr.observe d during the experiments was typically 30 to 35 Rept. May 20,1969, ORNL-*437, p. 37. keV. 8 A series of 20-sec bombardments followed by 6 min ene"gv; this increase should not be large in going trom of counting was made on a 156Dy target to obtain 70 ro 100 MeV. and the data shown in Fig. 1.5 are noi relative yields for the various alpha emitters produced corrected for this effect. as a function of 3He bombarding energy. While the Curves shown in Fijj. 1.5 2re excitation functions initial rHe energy was 102.1 MeV, the maximum calculated by using the statistical theory7 of compound available energy without any absorbers was 97.3 MeV, nuclear reactions and are normalized to the data points. since the 3He ions had to pass through an aluminum It is seen that the energy dependence exhibited by the window foil and a 2.5-mil platinum target-backing foil. (3He,x/i) and (3He,px«) data is reproduced reasonably Figure 1.4 shows spectra taken over a period of time well by the calculated excitation functions. The particu following the bombardment of ls6Dy with 97.3-MeV lar values of the level density and radius parameters 3 He ions. Part a represents the sum of the first two used in the calculations were a = 4/20 and r0 = 1.5 F; 10-sec counts, part b the sum of four spectra measured these same values were used in our previous studies on ever the next 110 sec of counting, and part c the sum hoiinium3 and erbium4 isotopes produced in bombard of a i -min and a 2-min count. Eight main alpha groups ments of 1S6Dy with protons and 4He ions. The were observed, and on the basis of alpha energies and (3He,pjt/i) yields appear to be 3 or 4 times greater than half-lives these were assigned to: 152Er, 153Er, lslHo, those from the (3He,Jwi) reactions, while the calcu 15lm 152 152/« ISOjjy jl51 3 3 Ho Ho Ho an( Dy lations indicate that the ( He,.xw) and ( He,pjt/i) Yields as a function of incident energy are shown in products in the region of 70 to 100 MeV should have Fig. 1.5. The experimental counting rates were cor comparable cross sections. Part or all of this discrep rected for differences in beam intensity, bombardment ancy may be due to uncertainties in available aipha- time, and available5 alpha/total branching ratios. The decay branching ratios.5 (The alpha/total branching ordinate scale is expressed in relative units because the ratios for I52Er and 's3Er have been reported to be efficiency for ejection of the recoil products from the 0.90 and 0.95, while those for the holmium alpha ,56Dy target and their subsequent collection or. the emitters are reported to be between 0.20 and 0.30.) platinum catcher foil is not known. Furthermore, the Another possible explanation is that recoils originating recoil range is expected to increase with bombarding from (3He,pjcn) reactions have greater forward momen- CWl-WG 70-4375 200 (a) (c) ,560y+97.3 MeV'He 150 1 i 100 1 2! a> 4.6 7 * !• T T I o<0 I| ! 1 1 1 1 ! ^- 1 i CO 1 i >4.0 6 * \ ft—J ! I ,A I 150 KX> 150 100 150 CHANNEL NUMBER Pfe M. Spectra Obtained from Reactions of 97.VM«V 3He Ions with ' 56Dy. Part a is the sum of the first two 10-sec counts after end of bombardment, p*rt b n the sum of four spectra taken over the next 110 sec, and part c n the sum of a K and a 2-min count. 9 ''•V-OWO-O? •00 : '5«D, + 3; r<">\« •M. (HIGH SPlfc)j _ •SUM I luJ* <°:\i | o^5* Oy a? 60 TO 80 90lO0rG80 90 WO ?0 80 90 WO 6C TO 80 90«CC 3H« EStW (McVl Fig. US. Excitatioa Fractions for Reactions of 3He Particles with 156Dy. The cuives are results of stttistical-niodet calculations, normalized to the data. -%c-DWG TO-874A turn than those resulting from (3He,jr#i) reactions. This —i !—1 162- ;-u«v additional momentum could be due to the effect of 150 proton evaporation on the velocity of the recoils or to the fact that a mechanism other than compound- nucleus decay is involved in(3He,pjr>t) reactions. Since % the 1S6Dy target used was thicker than the ranges of the recoil nuclei, the additional momentum would 100 mean that a greater portion of the target material would •+— -rV be available for (3He,pxn) products. 1S0 * life The counting statistics for the 6-min ( Dy) and 151 I 1 18-min ( Dy) activities were rather poor, as evi I denced by the large scatter in the ,50Dy and ,5'Dy i 50 data points. Nevertheless it is clear that their yields are (O comparable with those of the (3He,pxn) products. The calculations, on the other hand, predict tnat the \ I 1 \\ i ! (3He,a>rH) yields should be smaller than the (3He,jrn) i y yields by about a factor of 5. Here again part of the discrepancy may be due to uncertainties in alpha/total **s3T i i i i ratios5 (0.18 and 0.06 for ,50Dy and iS1Dy respec 25 50 75 100 1% 150 tively) or to a greater forward momentum imparted to CHANNEL NUMBER the (3 He, corn) recoils. But, in contrast to the Fig. 1.6. Spectral Ohttm'l Cram Reactions of 100-MeV (3He,pxn) and (3He,x/i) results, the shapes of the 3He low with'"Er. calculated curves do not reproduce the (3tie, can) data points. A further complicating factor here is that part most of the observed ls0Dy ind l5,Dy yields are of the observed yields for*$0Dy and '5' Dy could be produced not by radioactive decay but by (3He, can) due to either electron-capture decay from lsoHo and reactions. l$lHo or alpha decay from f,*Er and !?5Er. Hew- Similar irradiations of ih« ''*Er target with 100-MeV ever, detailed analysis of the data clearly indicates that 3He particles yielded the spectra smmit in Fig, i.o. 10 Thirty 15-sec irradiations were done, each followed by curve. Also, *he ls3Er yield is significantly larger than 3 min of counting. Three alpha groups stand out at that for *he (3 i!e **i) reaction 4.80,4.67. and 430 MeV. Two smaller peaks appear at These results are of special interest because ihey &*A and 4.38 MeV. Decay curve analyses for the main indicate th?.t charged particles, both protons and slphs-, three peaks indicated that (1) the 4.80-MeV group had are emitted in hrgc yield relative to neutron emission in a 24-5ec half-life and thus could not be * 52Er. (2) trie reactions of 3He particles with rare-earth nude*, fur intense 4.67-MeV peak had ihe 36-sec half-life of thermore, the emission of alpha parties* in fairly 15 3Er, and (3) the 4.50-MeV alpha particle had \ 34-sec complex reactions in which several neutrons are also half-life. The assignment of these peaks will be dis emitted apparently cannot be explained by the usual cussed in the following contribution. The count rates notions of compound-nuclear reactions. for the peaks at 4.46 and 438 MeV were low; the drcay curves, however, were consistent with the half-lives of the I52Ho isomers. Eiectroirjdear Drawn. 2Piiysic$ Department, Vienna Polytechnic Institute. Excitation functions for the 4.67-, 4.50-. and Bbcksbunj. 4.80-MeV peaks are shown in Fig. 1.7. Statistical model 3R. L. Hahn, K. S. Toth, and T. H. Handtey, Phn. Rev. 163, 3 3 calculations for the( He,8n) and ( !Ie.°n) reactions are 1291 (1967). in agreement with *hc data for the 4.50- arid 4.80-MeV 4K- S. Tolh, R. L. Hahn, M. F. Roche, and D. S. B-sacr, pesks. But the yield of ,53Er. produced by the Phys Rev. 183,1004 (1%9). (3 He, ate) reaction, cannot he tiited by the calculated *P. EskoU, A, kh Fysik 36,477 (1967). 6P. L. Hahn et «?., Chan. Dh: Ann. Ptogr. Rep*. *&v 20, 1969, ORNL-4437, p. 37. 7 0RNL-DW6 70-8765? 1. DostrovAy, Z. Fracnkd, and G. Fiiedlander. Phys. Rev. 20 116,683(1960. 10 NEW ISOTOPES : MEr.' S6Yb, AND ' 57Yb K.S.Toth1 MA !jaz2 R. L. Haha WM. Sample2 The data discussed in the preceding contribution were used tc characterize three new rare-earth nuclides. 15 * Er, because it contains 83 neutrons, should decay ~ 2 l~ primarily by electron capture to '5' Ho. Indeed, the two alpha-decaying isomers of '$' Ho at 4.52 and 4.60 MeV were clearly seen in the reactions IS6Dy + 3He. % 1 Accordingly, a search for an initial growth period in the 1 $ l Ho peaks due to the decay of 's' Er was under taken. None was observed for the more intense 4.52- 0.5 MeV alpha peak (see Fig 1.4). The 4.60-MeV group, contrastingly, at 3He incident energies above 90 MeV did show an initial increase in intensity, with the growth period being most pronounced at the highest 0.2 bombarding energy. A separate experiment was undertaken to emphasize the period immediately after bombardment so that an 0.1 accurate determination could be made of the initial 80 85 90 95 100 <05 growth and decay relationships. Twenty 10-sec bom 3H« ENERGY (MeV) bardments were made, foiiowed, within M).2 sec, by forty 10-sec counts. The decay data for the 4.60-MeV Fij. 1.7. Excitation Fnctioa* for Ike 447-, 4JS0-, and 4jsa-*tv realu Otaerod ta die bndntiomoT *•*& with JHe peak, snuwn in Fig. i .o. are characteristic of radioactive arc statistical-model calculations, normal- growth and decay. Least-squares analyses of these data !S,m teed to the data. indicated that the 47-sec Ho arises in par* from 11 ORNL-OWG. 70-5&56 The assignment of the 4.50-MeV peak to '$ 7 Yb from the read ton l62Cr T 'JIC icquires considerably more discussion than in the previous cases, '5' Er and '5 6 Yb. Aitno-igh the experimental excitation function (Fig. 1.7) is certainly consistent with that for the ,62Er(3He,8/i) reaction required to make ,57Yb, analysis of the decay data for the 4.50 ± 0.01 and 4.67 ± 0.01 MeV alpha peaks is not as straightforward as it wasforI5lErand,56Yb. First of all, as shown in the lower part of Fig. 1.10, die 4.50-MeV peak decays with a half-life of 34 ± 3 sec. This combination of energy and half-life agrees reason ably well with that known for 's' Ho. So one must O adequately demonstrate that the 4.50-MeV alpha peak cannot be due to ! 5! Ho before considering its assign ment to15 7Yb. The experimental excitation function for the 4.50- WeV group (Fig. 1.7) dearly peaks at ~98 MeV, a result that is unreasonable for the (3He,ap9n) reaction needed to produce '5' Ho in light of the data shown in Fig. 15 for the (3He/on) and (3He/wn) reactions. Furthermore, if the 4.50-MeV peak were due to '5' Ho, then the 4.60-MeV alpha group of'5 imHo should also be evident in Fig. 1.6. It was not seen. 0 100 200 3O0 400 The possible production of '5' Ho from the alpha lss SECONDS AFTER IRRAOIATION decay of the unknown nuclide Tm, as well as the suggestion that the 4.50-MeV alpha group is due to the F*. IA. Decay Data for Ike 4^0-MeV Alpha Peak of 's *m Ho, UntntM Its Grow* fro* "$" Et 3 OmtL-0»G- 70- K) T •—I '"I T -r—, . 1— the decay of a nudide with a half-life of 23 ± 2 sec. 4.80 M»V « PEAK This new activity, based or. the unequivocal nrent- daughter relationship, was assigned to l s' Er. The 4.80-MeV alpha peak observed in the reictions 24 sec ,5*Yb 1 *2Er + 3He (Figs. 1.6 and 1.7) also representee a new >^ alpha-decaying isotope. Its exdtatkm fund on in dicated that it was produced in the i62Er(3Hc$n) reaction leading to ' 56Yb. Corroboration of this assignment was sought in the decay data for the 4.80-MeV peak. One hundred irradiations of 10 sec duration followed by 160 sec of counting for each were performed. The summed decay dati. are shown i.i Fig 1.9. Least-squares analysis indicated a generic relationship between two radioactive components, one with a half-life of 24 ± 1 sec and the other with a 9.8-sec half-life. Because this ,S3 latter value is that of Er, the parent-daughter X _L X^_L J i_ relationship clearly establishes the existence of its 20 40 60 80 (00 120 140 alpha-decay parent, the new ytterbium nudide ' 56Yh. SFCOMQS AFTER ^RACiATiOw (The aipTia-devay cncigy, 4.30 i 0.0i i»ieV, within the Fif. 1.9. Decay Date for the 4M-Me\ A'j** Peak, resolution capabilities of the detection system used, is Iw flie Decay of l$*Yb aad Ae Growth of Its the same as that of its alpha-decay daughter,'s 2 Er.) 'EI. 12 ORNL-CWC. 7Q-13A9 the decay of I$7Yb, then its daughter I53Er should also be observed. The 4.67-MeV alpha peak, decaying with 36-sec half-life,can indeed be attributed to ' s3Er But because ,S3Er is essentially a pure alpha emitter, for every ' s7Yb alpha decay one should see one alpha event due to ls3Er; radioactive growth and decay- should be apparent. The counts observed at 100 MeV (see Fig. 1.6) were such that the ,53Er produced independently in the (3Heva8/i) reaction obscured any counts that would have grown in from the 4.50-MeV alpha group which we have assigned to '5 7 Yb. Ai energies below 90 MeV, count rates for both the 4.50- and 4.67-MeV groups were extremely low. An attempt was made to observe growth in the 4.67-MeV alpha peak at a 3He energy of 90J MeV. Sixty 20-sec irradiations were made, each followed by 320 sec of counting. The decay data from these experiments are shown in the upper part of Fig. 1.10. Note that the 4.67-MeV alpha peak no longer exhibits the characteristic half-life of IS3Er; instead, the apparent half-life is appreciably 0 40 80 120 160 200 240 280 longer than 36 sec. SECONDS AFTER IRRADIATION One can perhaps argue that the 4.67-MeV peak S3 Fig. 1.10. (Lower) Decay Data for the 4.50-MeV Peak, observed at 903 MeV is due not only to 36-sec ' Er, flaijpnl to the Decay of ls7Yb; (Upper) Decay Data for the but also to some other nuclide with a half-life of ~70 1S3 4j67-MeV Peak, Ascribed to Ei. Curve At(t) is that sec. The combination of these two components could calculated for the ' S3Er present at the end of the irradiation. l53 lead to the experimental decay curve if'he intensity of The calculated growth and decay curve of Er due to parent 1 S7 the longer component were comparable with that of Yb is curve A2U). The sum of these curves, Atit)+ A2(f), > quite weH with the data. 1 S3Er. One would expect to see this result reflected in the behavior of the excitation function for the 4.67- MeV peak (see Fig. 1.7). Nothing striking, however, 9?pha decay of ,ssTm itself, can also be ruled out occurs in the excitation function at 90 MeV to indicate because the thulium nuclide would have to be made in a that another nuclide besides ' 53Er is making a marked Cttep9n) reaction. Again the shape of the observed contribution to the yield of the 4.67-MeV peak. yield curve is inconsistent with the data shown in Fig. We can explain the results ir> Fig. 1.10 by assuming 1.5. Also, the half-life of'5 sTm should be >5 sec (that that the 4.67-MeV peak is due to ' 53Er. growing from reported3 for 154Tm), but no initial growth period was the decay of ' 57Yb. Furthermore, this expUna^on is observed for the 4.50-MeV peak. consistent with our assignment of the 430-MeV peak to In the series of 100 irradiations at 100 MeV, no alpha the decay of ,57Yb. In Fig. 1.10 it is 5een that the activity was observed due to the known3 1.65-sec initial intensities of the 4.50- and 4.67-MeV peaks are 1 $$Yb nuclide, even though measurements were begun comparable, so that the ' s3Er growing from the alpha within ~0.2 sec after the end of the bombardment. decay of ! 5 7Yb can have a striking effect upon the Thus the 4.50-MeV alpha group cannot be due to either observed decay curve for the 4.67-MeV alpha peak. of the two decay sequences: Because parent and daughter have approximately the same half-life, the equation for the growth and decay i*SYb°-*l$lErE* isi Ho for *s3Er has a special form: or -kt AJi) = Ap{G)\ie ,55YbE4.C' iss Tm isi Ho Here A^t) is the daughter activity at some time t after Another problem associated with rh? m?« a««!gr.n^r.t the end vi ilic iuaciatiun, Ap(G) is the parent activity is due to the fact that if the 4.50-MeV peak arises from at the end of bombardment, and A is the decay 13 Table 1 J. New Rare-Earth Nuclides energies. Alpha-decay energies available2 for rare-earth nuctei are plotted in Fig. 1.11 as a function of neutron Half-Life Alpha-Particle Isotope number. Decav energies for new isotopes reported in (sec) Energy (M«V) 3 the preceding contributions and in refs. 4 and 5 are 151 Er 23 ±2 indicated by larger points. With the exception of the :s& Yb 24 ±1 4.80 ±0.01 data shown for X = 83 nuclides, only experimentally 157 Yb 34±3 4.50 ±0.01 determined decay energies are plotted in Fig. 1.11. •Decay is primarily by decrron capture to mHo. Energies given for ,47Gd, l4sSm, and l43Nd were calculated by means of closed energy cycles. The method consists in constructing an energy-balance cyck constant, which is taken to be equal for parent and from twe alpha- a id two beta-decay energies, {f three daughter. It is significant that this expression contains of the four pieces :>f information that constitute a cycie the multiplicative factor A/: it does not exhibit the are known, then the fourth can be calculated. In all simple exponential dependence upon t that is usually thiee hKtances the alpha-decay energy of a given N ~ S3 associated with radioactive decay. 53 isotope is ~l .5 MeV less than that of the corresponding The calculated growth and decay curve for ' Er, r I5, A = 84 nuci.de. (In Fig. 1.11 the Er alpha-decay consistent with the observed intensity of the 4.50-MeV s 7 energy is thus estimated to be —1J5 MeV less than that peak that we assign to ' Yb, is labeled A (t) in Fig. IS2 2 of Er.) This sudden drop in energy shows the 1.10. The curve labeled A , (r) with characteristic 36-scc T influence of the closed 82-neutron she!!. As a result of half-life, is that ascribed to the * S3Er present at the end the major closed shell, the n*»3Ei*nun: :dphs-dc£2 of bombardment. [The ' 53Er is produced in two ways during the irradiation: b" the (3He,o8/i) reaction and ,57 by decay of Yb.] 'Che sum of the two curves, CRKL-0WG 7G-877R labeled Ai(t) + A^t), L< seen to agree quite weD with the data; at decay times >120 sec, the growth of's3Er Hf 157 Lu from Yb [curve A7(t)] has an important effect Yb upon the shape of the observed decay curve. 156 Tm Yb In conclusion, we assign the 4 50-MeV alpha particle r to the new nuclide l57Yb because (1) the excitation :^N< function is typically that for the (3He,8«) reaction, (2) the d£ta do not support the assignment of the activity to other nuclides, such as l$1 Ho, and (3) the decay data for the 4.67-MeV peak are consistent with what is expected for ' 53Er growing in from the alpha decay of 157Yb. The data for the three new nuclides are summarized in Table 13. Electronudear Division. Physics Department. Virginia Polytechnic Institute, Black; TTElkok»^4Wt/F Fysik 36,477 (1967). ALPHA-DECAY ENERGY SYSTEMA7ICS K.S.Toth' R.L.Hahn The discovery of unknown isotopes is of significance because it contributes to the understanding of the 84 36 systematica of radioactive decay and provides measure NEUTRON NUMBER ments of decay energies which can then be used to Fig. 1.11. Alpha-Particle Energies for Rare-Earth NucWes as determine precise values of nuclear masses and binding a Function of Neutron Numbers. i4 energy for 2 given elenacm is reached a- <4 neutrons. \. S. T^> R. ! . Hahn. *t. A. I«I. and *. M Saisr-i* owing to the abnormally \o% ncu*«-->»» binding en-tgjes -fh«u^!ior. *•-•* Rare tirth Al»na EmiKen. *ith LnercetK- JHe l54 : , T ju»i beyond the closed shell. fansc**-sad-S«» Isotopes 5:*. **Yb.a3d *' >b.**rtie no »»e».-edinf -.-o£.;iiK;»k>fiv -las report. The data, for the new Ho, cr, and Yb iso«epes, with 4 ?. L. K^Sr. k 5. Tou-. T*i I. K. Hindi*}./*-1 *f.\ »*3, neutron number ;V = 86 and fc7,a s wtii is V.. Gd and I2S- <19*^>. iJy nuclides, are in-Jicstiv* of a pairing ciergy tft'cc ;A SK. S. loth. S». L. Kahn, ¥.. F. Roche, and D. S. Brenner. ssater pairing effect L*s been noted* ior alpha emigre Pint. Per. 183. i004«i96)i. in the .* = i 26 region.) V?hflt nuclides with $ = 84 ar»d *K. VaBi. IVSefwty of California Radiation wabonetory ,V = 85 hare simitar decay energies, the additional pair ReportNo. 1772 j. 5-67 (aepubushcdl. of neucrorts in ;V = 86 nuclides seems to result in added 'j. O. Ras&aseiu S. U Thompson, and A. Cfcior*-. Phys. stability and a consequent extra decrease in alpha-decay Rir. 89.33 < 195 *». energy. The effect is even more pronounced in going from iV = 87 to A' = 83 nuclides; this would zccount for 4 COULOMB EXCITATION OF the fact that a rather extensive search for alpha l54 l5 1 Gd. 'Gd,AND ^Er activity due to the 88-oeutron nuclide ,5SHo proved fruitless. A straight line drawn through the energies for L. L. Rktdinger2 J. Fugkang3 3 isi.isa.is3.is4Ho wou,d yicW a ^^^y ^^ ror E. Eich'er G. B. Hagemann 1 ssHo of ~3.7 MeV. Based on the sharp drop in enctgy B Herskmd3 between the 87- and 88-neutron isutopes of dyspro Coulomb excitation involving ! 5-MeV alpha and 30- sium, however, cne wo»»!d ^stim*!* the ,ssKc alpha- to 55-MeV oxygen ions from the Niels Bohr Institute decay energy to be only ~33 MeV. A decrease of 0.4 tandem accelerator hss been used to study rotational MeV in *Ipha-d*cay energy would lead to a greatly ,s4 ,s and vibrational states in Gd, *Gd. and ***Er. increased alpha-decay half4ife, which in turn would The alpha particles weie detected in a heavy-partide make the aloha/total branching ratio for ' 45Ho much spectrograph. Gamma rays from decay of the states kss than expected. I6 Coulomb exdted by die 0 ions were detected in The one dear exceptior in Fig. 1.11 to t>.ts pairing r coir 1 Work performed at the Nie's Bohr Institute. University of Copenhagen. Denmark. 1 Electronuckar Division. 2 Present address: Physics Department. Notre Dam Uni 3Nuclear Data Sheets, B. Academic, New York. versity. South Bend. fnd. 15 N«fc T-oJii iooiittte. Unrcersit.- e*"Cc|>«i*af£... Dcturuk. Al*hough the detailed decay properties of these two * L. L. Rirdtnctr. Noah fc. iot>'.w«_ and J. H. HiraiUo* Pkys. isotopes are being determined, our experurvnts hare tier. !?*. !214; 196*5. been coocemed primarily with the study of the $I. A. Fra*r itaL, Fhrs Re. Letters 23. i"M7 < 1969?. branching ratios o:" the gamma-ray :ran*it!«nis between the f*- and 7-vibr>i:o<;al Jevets and the 0+. 2>. and 4+ COULOMB EXCITATION EXPERIMENTS mersbers of +.e groand-statr rotation** band. In par ATOR1C ticular, we are concerned with the ration of reduced ete.uric ^uadrupok !ransak>n probabilities from the 6 E. Eichier >ioah R. Johnson band. 1 C-EBamis M.Schmo.ak Earlier it was found3"5 that these raiia- in ! 5*Sm and 54 The recent development of heavy-ion beams at the Gd. which are just at {he onset of permanent Oak Ridge bochror-cus Cydotron (ORIC) ha* ooe»*d nuclear deformation, were not accounted for by theory. up a new ares }f nuclear research using the technique of The theory which had seemed to give an adequate Coulomb excitation. The currently available beam of aescripuon of the &£2) ratios from the 7 band coc*isu 80-MeV ' *0 is near the barrier height of the heaviest of a first-order perturbatioral treatment of '-«e simple elements and thus quUt suitable for Coulomb excita adiabatic model of an axally sy.nmr'.ic deformed tion Li this icexpiored region at the outer Hints of the nucleus. This treatment is necessary *j accoua: for the periodic system. mixing of the wave functions K the vibrational and rcutionai bat"** These mirjigs of bands result in We have constructed a reaction diambes ar,d acquired corrections to the gamma-ray branching intensity ratios annular silicon surfcobarrier detector* ?nd coincidence which are proportional to the ratios of the spin- circuitry needed for gairaa-fsy-backscattered-oxygen- independent part of the matrix elements. The pro ion coincidence measureoients. In our first three runs portionality factor can be determined as a function ef a we attempted to optimize the beam optica! parameters term called a mixing parameter, Z. which according tc so as to maximize the intensity on the target and the theory should have a consistent value for aG minimize that striking me collimator- Even in the branching ratios from a given band. singles mode we observed excitation of the ground-state It was felt that since !S6Cd is a somewhat better roiation.il band up to the 10*- state as weD as members i52 I$ r«f the 0- and y-vibratkmal bands. In o>*r most recent deformed nucleus man Srr and *Gd. the same disagreement may not be present here. However, our run we recorded gZiiima-ray spectra from Codomb ls exatation of 23*U in coincidence with backseattered high-resolution work with *Eu indicates that similar ' *0 ions with excellent sipul-tG-backpovr.d ratios. anomalies do exist in the branching intensity ratios from the 0 band of '* **Gd. The band mixing parameter is given in Table 1.4 for u;e various transitions from the ' Nuclear OaU Project- 2* member of the f, band. (The Of- band head is at 1049.45 kcV. and the 2+ member is ai 1129.47 keV.) As seen in Table 1.4, there is a large variation in *he SOME PROPERTIES OF VIBRATIONAL three Z0 values. In the last column we show the BANDS IN s S6Gd AND * 5*Gd corresponding Z„ value from the (n.y) work of Green 6 A.F.fCuk1 N.R.Johnson wood and Reich. We also observed another Kit - 0+ J. H. Hamilton3 band with the 0+ level at 1168.12 keV and 2+ levsl at 1258.02 keV. This band likewise was recently reported The decay properties of 15-day IS6Eu and 45-min by Greenwood and Reich.6 The data on this band are IS,Eu are being investigated with large-volume, high- siso given in Table . ** und are found to be inconsistent fc*oitt*ipi? Ge(Lj) detectors. Both gamma cay singles with theoretical predictions. experiments and multiparameter Ge(Li)-Ge{Li) coin These discrepancies may be partially explained by cidence experiments have been done on each isotope. recent Coulomb excitation work7'8 which showed Several computer programs have been developed for relative magnitudes of the El matrix elements as accutab' analysis o' the gamma-ray singles spectra and sociated *ith the decay of the ^-vibrational band in tor sort ng related address pairs from coincidence several deformed nuclei. It was found7'8 that the experiments. In addition, an Si(Li) spectrometer system probability for deexcitation of the 2+ level by £7 has been developed for multichannel pulsed eight anal radiation to die 4+ level of the ground-state rotational ysis of election spectra. band is comiders.b!y less enhanced than that predicted 16 by the rotational model modified to include nixing of ground states) and compared with those of PaperieUo et the ir.u^isic and totational wave functions to firs? al..9 whicn were obtained from ' sSTb decay. In l s*Gd order-3-4 The reason for this lower B(£2) viiue is noi the 2+ level of the y band was considered to be at known. i 154.01 UeV. The wide variation in the three Z2 values Our vaiues tor the Z-* mixing parameter for the obtained from this !?vd is most surprising, since l $ ^-vibrational band of *Gd are given in Table L5 \Zl previous experience with olher deformed nuclei has is the mixing parameter between the 7-vibrational ml shown much better agreement in the respective vilues. TaWe 1.4. Redact* Traasooft Probabttty Patios for Traos&oos from die K* - 0+ Baad of t '"G5*, d hnafy Reduced Transition Experiment^; Theoretic?! Lerr! ikcY) Frobabiiitv Ratio Value Value* This Greenwood Wot*? ttaL" X10 -3 X10 -3 £-V9»ratioaa! Baad BiEl. 2** -0^ 1129.47 O.I81I) 0.70 -82(7) 74(4) BiEl. 2** -2*» BiEl. V -0^) 0.14fl» 0.39 28«3* 18(2) BiEl. •»«* -4*) »E1. 2" -4*) I.2W) 1.79 12(2) -15i 2) HE2,r 2 ) Other K* == 0* Baad BiEl. 2 -»C ) 1258.02 0.25(2) 0.70 -68<7> 7.H5- BiEl. ?** -2*) BiEl. 2V -0+) V 0.0?<1> 0.39 -55<6) 47(4) BiEl, 2 -4*> + BiEl, JL. -*4 > 3.28<24) 1.79 -25(5) 18(4) ff(£-2,2v-»2+) *Ba3ed on adiabarir asymmetric rotor model. ^The difference in the s%ns on our values from those of Greenwood et at6 arises merely from the sign convention used in writing the wave functions of the srates. TaWel-5. RedacedTtaastjoa Probabany Ratios far rnasitiomfrom the *» = 2 Bandof !3!S8*G, d Zl Energy Reduced Transiticn Experimental Theoretical Level (keV) Probability Ratio Value Value* This Paperiel!o Work et<>Lb xio"3 S%E2. 2*"-* 01 1186.8 0.448 0.699 77(8) ~40 BiEl. ~*" •2*> BiEl, 2+"-4+) 0.046c 0.050 -10(1) ~0.0 BiEl, 1 •" 2*) BiEl, 2*"-0*) i3.»* JJ(4) BiEl, 1" 4*) 'Based on the adiabatic symmetnc rotor model. bC. J. Paperiello. B. G.l-unk. and J. W. Mihelkh. Univ of Notre Dame, to be published. 'The 2 —4 * transition intensity was obta^d 'rom G. Ewan, R. L. Graham, and J. S. «erGc«.i Nucl. Piiyt. 29,153 (1962). 17 Our feelings at this time are that additional experiments Nielsen. Nielsen, ind Ruds have reoened mote recently must be done to clarify the situation. Tim ts very tha» tor 3r even better deformed nudejs.' ?BHf. there iinporla.nl in that ihe presently listed values seem to is »83 * 10Y7: A/1 admixture in th- orrespouding nrtph/ for ihe first time a highly impure 7-vibrat!on2't trcnsitiGtt from the 2* state at I27*>.t> keV. From our band. Detailed data analyses on the 7-vibrationai band results and oihc resuits .i-ported6-7 recently for o!" * 56Gd have not been completed. ! s 2Sm. it seemed somewhat surprising that s~*ch a large Afl component should be present in : '*Hf. Therefore u* decided 10 repeat the l78Hf experiments using an ! Oak Ridee Graduate h'tttaw from V'anderbilt '.'niversity. Nal detector in conjunction *vith a high-resolution Nashville. T;nn. unJcr appointment with Oak Ridge tssoctated Universities. Ge( Li) detector. 2Vanderbilt University. Nashville. Tenn. Our preliminary results are similar to those of Nielsen 4 3L. L. Riedinger. N. R. Johnson, and J. H. Hamilton. Phys. et al.* in that we find 87.4 l V- A/I radiation in this Rer. Letters 19,1243 ,'1967). 2 J -*• 2* transition. Whereas the vaiue of Nielsen evaf.* L. L. Rkdtnger. N. R. joiuison. and J. H. Hamilton. Fhys. gave a consistent picture for the B{E2) ratios based on a Rei. 179. 1214*1969). general perturbationai treatment for the mixing of the 5I. Liu. •>. B. Niefcen. P. Selling, and O. SUbreid. /rr. Akod. two bands, our result is just outside that needed for Souk SSSR. Ser. Fir. 31.63 (1967). agreement with the theory. The present value has error 6R. C. Greenwood and C. W. Reich, Vici Technoi. Branch limits a factor of 2 smaller than those of Nielsen etal..* Ann. Projr R"f-- January 1970, IN-I317. p. 78; A.Backiin*f but we are repeating the measurements in order to at. presented at the symposium on Neutron Capture Gamma- reduce these still further. Ray Spectroscopy. Aug. 11-15.1969. Stndsvik. Sweden. J. S. Grcenberg, presented at International Conference on The absence of sizable A/1 components in the 2£ -*• 2* ! S2 S4 Radioactivity in Nuclear Spectroscopy. Vanderhit University. transitions in Si 1 and ' Gd, which are just at the Aug. 11-15.1969. beginning of a deformed region, and their presence in *L. L. Rfcdinger. E. Eichler. J. Fugisang. G. B. Hagentann. similar transitions in more strongly deformed nuclei like and B. Herskind. presented at the International Conference on l7SHf presents an even greater dilemma than that Nuclear Reactions Induced by Heavy Ions. Heidelberg. emphasized earlier by Mottelson.5 The accumulating Germary, Jury 15-18. 1%9. experimental evidence on lowest excited K = 0 states 'c. J. Paperiello. B. G. Funk, and J. W. Mihdich. University and the rotational bands built on them in the above of Notre Dame, to be published. three nuclei suggests that their usual description as collective quadrupole vibrations of the 0 type may be in error. It appears that the wave functions describing Ml ADMIXTURE IN THE 2j - 2* these states are strongly admixed with other com TRANSITION IN ' ?*Hf ponents and that probably this admixture is quite 7B b2 54 1 1 different in ' Hf from that in ' Sm and ' Gd. The J.H.Hamilton A. V. Ramayya 1 need for a detailed theoretival understanding of these P. E. Little Noah R. Johnson nuclei is obvious, although it may have to await the In some of our previous work2*3 on levels in IS2Sm accumulation of additional data on excited 0* states in and ,54Gd aimed ut a better understanding of the other deformed nuclei. ^-vibrational bands in deformed nuclei, there existed considerable question about the nature of the electro magnetic radiation from the 2* numbers of the bands. ' Vanderbilt University, Nashville, Tenn. Specifically, it appeared that the reduced electric 2L. L. Riedinger. N. R. Johnson, and J. H. Hamilton. Phys. quadrupole transition probability for the 2^ -* 2* Rev. Letters 19,1243(1967). transition was about twice the value expected for the 3L. L. Riedinger, N. R. Johnson, and J. H. Hamilton. Phys. apparent degree of mixing between the wave functions Rev. 179,1214 (1969). of the ground and 8 bands. It was surmised that there 4J. H. Hamilton. A. V. Ramayya, I. C. Whitlock. and A may be a large A/1 component present to account for Meulenberg. Proc. Intern. Conf. on Nuclear Structure, Tokyo, this apparent discrepancy. Sept. 7 13. 1967, ed by J.Sanada. p. 667. SH. L. Nielsen, K. B. Nielsen, ar.d N. Rud./Viys. Letters 2/h. However, Hamilton et ai* did angular correlation 150(1968). 54 measurements for the 2£ -*• 2* -*• Og cascade in ' Gd J. o. Greenbeig, International Conference on Radioactivity and found that the 692-keV 2^ -* 2* transition had less in Nuclear Spectroscopy: Modem Ttz'mique:- and Applications. than a 2% A/1 admixture. Using two Nal detectors, Gordon and Br^Sv 1969; I. A. Fra^r J. 3. Greenbenj. S. H, 18 Sk. R. G. Stokstad, ^nd D. A. Bromley, Contribution - thorium-plus-proton system would allow exploration of International Conference on Properties of Nuclear States. a transition region between the distinctly triple-peaked Montreal. 1969. radium fission and normal heavy-element asymmetric 7 F. k. McGowan. International Conference on Radioactivity fission. in Nucletr Spectroscopy: Modern Techniques and Applications, Gordon and Breach, 1969; F. K. McGowan, R. O. Sayer, P. H. General features of the functions and distributions Stelson, R. L. Robinson, and W. T. Milner.Bu//. Am. Phys. Soc. obtained in this work are qualitatively consistent with 13,845(1968). our earlier results o.i uranium and plutoniuri3'4 (see *B. R. Mottebon, Proc. Intern, Conf. on Nuclear Structure. Fig. 1.13). Note that the symmetric peak is not Tokyo. Sept. 7-13.1967. ed by J. Saaada, p. 87. apparent in these mass distributions, even at 13 MeV bombarding energy. When ratios of peak to valley yields in the mass FRAGMENT ENERGY CORRELATION distributions are plotted against bombarding energy, as MEASUREMENTS FOR THE FISSION in Fig. 1.14, we observe a break between 8 and 9 MeV OF 232Th BY 8-TO 13-MeVPROTONS1 which may be indicative of the onset of second-chance fission. At 9 MeV bombarding energy the compound- Robert L. Ferguson Franz Plasil2 nucleus excitation energy may be sufficiently high to H. W. Schmitt2 allow the emission of a neutron before iission, thus In order to complete our study of the systematics of lowering the average excitation energy relative to that heavy-element proton-induced fission, we have carried at 8 MeV bombarding energy and increasing the out two-parameter fragment energy correlation meas contribution from asymmetric fission. In '>pite of the urements on the fission of 232Th bombarded by occurrence of a symmetric peak in both he thorium protons at several energies in the range 8 to 13 MeV. and radium results, we note that values of the peak-to- Previously we reported studies on the fission of 233U, valley ratio for thorium follow more closely those 235U, 238U, and 239Pu by protons of 7 to 13 MeV.3-4 found for uranium and plutonium isotopes than those Experimental details and methods of analysis in the for radium. present work were essentially identical to those de 5 scribed earlier. This work was performed in collaboration with the Physics Thoriun>232 has the lowest values of Z and A amon.; Division and has also been reported in Phys. Div. Ann. Progr. the target nuclei included in our survey, and it exhibits Repu Dec. 31, J 969, ORNL-4513, p. 79. Similar collaborative features not shown by the uranium and plutonium efforts were aLo reported on pp. 76-84 of that report 2 isotopes. In the mass distributions ihown in Fig. 1.12 Physics Division. 3 for E - 8 and 13 MeV, a third peak centered about R. L. Ferguson, S. C. Burnett, Frances Pleasonton, F. Plasil, p and H. W. Schmitt, Chem. Div. Ann. Progr. Rept. May 20, symmetric mass division appears at low values of the 7 96S. ORNIM306, p. 12. total fragment kinetic energy. This symmetric peak 4R. L. Ferguson, F. Plasil, Frances Pleasontcn, and H. W. becomes more prominent as the bombarding energy is Schmitt, Chem. Div. Ann. Progr. Rept. May 20, J 969. ORNL- increased, as has been observed previously in the fission 4437, p. 26. of radium6 (where it actually predominates at higher 5 R. L. Ferguson, S. C. Burnett, Frances Pkasonton, F. Plasil, bombarding energies) and of thorium.7 ai.d H. W. Schmitt,/%>* Wv. Ann. Progr. Rept. Dec. 31,1967, ORNL-4230, p. 79. Because this feature is apparent at relatively low 6 232 See E. Konecny and H. W. Schmitt, Phys. Rev. 172, 1213 excitation energy in Th, a relatively heavy nucleus, (\96*);Phyx. Rev. 172,1226 (1968);and references therein. it may become attractive to attempt an analysis of our 7See, for example, I. F. Croall and J. G. Cuninghame. Nucl. results in terms of a two-component hypothesis in Phys. A125,402 (1969). cluding molecular-model considerations, as proposed by *E. Konecny, W. Norenberg, and H. W. Schmitt, Nucl. Phys. Konecny, Norenberg, and Schmitt.8 In this context the AI39,513(1969). 19 OANL-OWG 70-l€<« *CO i- OT 400 - ui > I z 200 - 140 ^ 100 120 140 FRAGMENT MASS (amu) eoo,- 100 120 140 FRAGMENT MASS (ami) 232 Fl* 1*12. Isometric Projection of TMpJ) Urn Vmny Comiatk»». Ep « 8 MeV, lower portion; E - 13 MeV, upper portion. Mam distributions, given as a function of the total fragment Uaetk energy, were smoothed by averaging over boxes* by 5 MeV and symmetrized by reflection about fragnw* man 116.5. 20 0RNL-DWG7O~t6t7 Of 300 *!* It Ui §y OT Ul i Z i* "§ > s g z ui O z -i o U < X 140 FRAGMENT MASS (omw) JTf.1.13. M«oiI>toiHioot^A*otoyTotolKio> ORNL-OWG 70-WW "*Pu(«/\2»?3,wAm, 2i*mdf)2"mV. 13*\Md.np) 2i m ,37 237, * Vt and Np(: were measured by a pair of silicon surf»cc-barrier detectors located downstream from the target. The detectors were so arranged that 3 their active surfaces were shielded from the target. The l number of events ranged from about 1000 in the case o as m t of """Am to about 200 in the case of * U. The < pulse-height data were transformed to mass and total ill kinetic energy data in the usual manner.* The masses obtained here are related to pre-oeutroa-emission masses. They are the "provisional masses** of ref. 9, but since neutron emission data are not avertable in these cases, it is not possible to make the small corrections 10.0 C.5 CO which give "final** masses. PROTON ENERGY fUtV) The mas distributions are showr in Fig. 1.15. AQ Fij. 1.14. distr&utkkts are shown to be peaked at asymmetric of '"Til « s fawUon <* msss divisions and have the general appearance of mass Show* for romp whoa an marts for &e distributions from low-excration^nergy prompt fis fWonof"*ta.aiiU.a*l"*rV sion. The number of events is ins**&k)ent to determine peak-to-vaRey ratios. Table 1.6 gives the average light- fragment and heavy-fragment masses, 1 OF SPONTANEOUSLY FISSIONING ISOMERS kinetic energy dsiribution, off In the case of "••*u> Robert L. Ferguson G. D. Atom1 for comparison purposes, values are also given for the f Frani Ptasia H.W.Sdmitt2 thermal-ikwtrorHnduced fission of " "U. In this case me fission of the isomer is. «ritha the accuracy of our in recent yean a large number of spontaneously measurements, ident&di to '.he low-excitation prompt- fissioning isomers have been discovered.4 Theoretical fission csss Two different methods were used to obtain calculations of Sirutinsky* and others predict the """Am; these results are also identical within ex existence of a second minimum in the nuclear perimental errors. Uncertainties are not givm in the potential-energy surface, giving rise to a double fatten table because enor estimates are not completed. The barrier. A popular explanation of the observed isomers error in the average kinetic energies, however, is is that they are due to nuclear states in this second expected to be of the order of ±2.0 MeV, white the potential-energy minimum. Data on spontaneously fis error in the average masses is expected to be about ±13 sioning isomers consist largely of half-life measurement* arras. The position of the hmy-fraement peak of the (typically in the nanosecond to microsecond region) and mass distributions, characterized by ORNL-ONG 70-16*9 50 2t CD 2*Vtt (/»,2/»)23S*AJH 237Np (^.2/»)237mPu •• 23*Pu {*,2/»)239*A»B ! I 40 16 I- l 30 5 I 5 " ( i 1 20 K 1 8! I l t i I » i J i ! I I I ; i I •O IT La^iiL *ma.U ! 0 JLL VJ 11 2*5 i 12 r -J el i j n§>l.tS. Mm PbUMwHtaw from liomric Radon. Reactt m* by which •omen were obtained are ritown. 23 Table 1.6. Mess Vatoesand Widths of Fi i Fragment DMtribatiom 4 237«p """Am """Am* 236fttij "*u* 238m <*/.> 101.6 101.8 96.9 96.6 lUlU 10U.4 <•*> 137.8 138.3 138.8 139.4 138.5 136.2 °n 6.1 5.9 5.4 5.4 6.1 5.3 'Obtained from the reaction 240Pu(/?.2*)239mAm. ^Obtained from the reaction 73,Pu(he samples. Radionuclide concen G. D. O'KeOey V. A. McKay5 trations of breccias were obtained by calibration with J. S. Eldridge2 R. T. Rosebeny5 extended sources of iron powder containing the radio E. Schonfeld3 R. E. Wintenberg5 nuclide standards. 4 2 P. R. Bell K. J. Northcutt BiJk densities for seven samples were obtained from The high-sensitivity gamma-ray spectrometer with low the sample weights and the volumes of accurate replica background described in previous reports6 was em shells. It wiO be noted that the crystalline rocks, 24 Table 1.7. Gaama-Rjy Analyses of Whole Rocks awl Fws from ApoBo 11 Values fot short-lived nuclides have been corrected for decay to 0000 hours, COT, July 21,1969 Sample No. (type)* 10057,1(4) 10072,1(4) 10003,0(4) 10017,0(4) 10018,1(0 10019.1(0 10021,1(0 10002.6(D) Weight (g) 897 399 213 971 2113 234 157 301.5 Buk density (g/cc) 2.73 ± 0.14 2.37 ±0.24 2.88 ±0.35 3.00 ±0.15 2.0 ±0.2 2.02 ±0.15 1.55 ± 0.05 K *Petrologic classification: A, fine-grainedcrystallin e rock;£. medium-grained crystalline rock; C. breccia; D, fine material. ^Standardisation fot assay of K, Th, and U with reference to terrestrial isotopic abundances. Equilibrium of thorium and uranium decay scries abo assumed. 'Upper limits are la evaluated from least-squares analyses. breccias, and fines show a distinct correlation between melting of the lunar stuface to depths >100 km; bulk density and sample type. however, the source of the heat is at present open to The breccias and fines are very similar in their question. chemical compositions, as evidenced by their similar Radionuclide concentration gradients at the surfaces concentrations cf K, Th, and U. This substantiates the of rocks were shown to have arisen from intense hypothesis that the breccias were compacted mostly bombardment by the low-energy protons of solar flares, from the fin.; material. especially the flare of April 12, 1969. Solar proton With the exception of sample 10003, the crystalline activation is the principal source of 4t,V and 56Co; in rocks from the Apollo i 1 landing site form a distinct addition, 3*A1, 2*Na, and 54Mn are produced both by group w»th K, Th, and U contents significantly higher solar and cosmic-ray protons. The steep concentration than those of the breccias and fines. Sample 10003 is a gradient of 56Co was us^d to identify the surface of coarsely crystalline rock which resembles in texture the rock 10017 that had faced the sun. This orientation terrestrial gabbro and differs from the other crystalline information was needed so that oriented samples of rocks in its lower concentrations of K, Th, and U. This 10017 could be distributed to other investigators for suggests that it may have come from another region of analysis. Ti * long half-life of 2*A1 (0.74 X 10* years) the moon, that it may be the product of an igneous and its surface concentration gradient due to solar-flare process different from that which formed the other effects suggest that the erosion rate of the rocks due to crystalline rocks examined, or that it may have origi micrometeoroid bombardment must be less than about nated in a stratigraphically different location in the 3 mm/10* years. same general region. Some of the information obtained in this study may The concentrations of potassium are low compared be combined with gas analysis data to provide estimates with the average value for the earth's crust, but the of crystallization and cosmic-ray exposure ages. In thorium and uranium contents are near those of Table 1.8 we show gas retention ages for four rocks, terrestrial basalts. Thus the contribution by potassium derived from elemental analyses for K, Th, and U to radiogenic heating of the moon must be small reported in fable 1.7, combined with concentrations of relative to that of thorium and uranium. The degiee of radiogenic 4 He a:iu 40 Ar from the literature. differentiation required to produce the apparent de Except for rock 10003, for which the U,Th-4Heage pletion oi potassium and enrichment of thorium and is only about half the K-40Ar age, both gas retention uranium seen here must have come about through ages are concordant. These results suggest that radio- 25 22 2 TaUe 1.8. Estimation of Gas Retention Ages aad Na- *Ne Sponsored by the National AerondStics -ad Space Adminis Expomre Ages for Crystakne Rocks of Apoflo 11 tration through interagency agreements «ith the VS Atomic b Energy Commission. Sample No. 10003* 10017* 10057 !0072* 2 Analytical Chemistry Division. 3 Gas Reteatioa Ages (1116 years)* NASA Manned Spacecraft Center. 4 ninM-tor't Division. U,Th- He 2300 2450 ±150 2700 ± 150 2750 ±150 5 40 Instrumentation and Controls D vision. K- Ar 3970 2220 ±150 2400 ±150 3200 ±230 *Chem. Dhr. Ann. Progr. Rept. Shy 20, 1969, ORNL-4437, Exposue Ages (10* ytaaf pp. 16-19, and references therein. 22Na-2lNe 90 340 ±40 38 ±5 160 ± 20 7G. D. O'Kedey, J. S. EMridge, E. Schonfdd, and r. R. Bd, 3 He 110 310 44 190 Geochim. Cosmodiim. Acta, Suppl. I, VOL 2, pp. 1407-23 (1970). 8 'Gas contents from ref. 13. The Lunar Sample Analysis Planning Team (hvtuding P. R. *Gas contents from ref. 12. Bel. J. S. EUridge. andG. D. O'Keley). Science 165,1211-27 Errors quoted for K-4°Ar and 22Na-2' Ne ages are combined (1969). analytical errors ol gas concentrations and our radioactivity- 9G. D. O'Keley, ,. S. bridge, £. Schonfdd, and P. R. Bel, determinations of K, Th, U, or 22Na. Errors for gas Science 167,580-82 (1970). concentrations of samples 10017,10057, and 10072 were taken 1 °A. L, Afoee et at. Science 167,463-65 (1970). as JS (J. G. Funkhouser, O. A. Schaeffer, D. D. Bogaid, and J. 1 *G. Spannage! and C. Sonn'ag, in Radioactive Dating and Zahringer, private communication, January 1970). Methods of Low-Level Counting, ed. by IAEA, pp. 231-38, lnteru.tk»al Atomic Cncrgy Agency, 1967. 12 }. G. Funkhoeserer at.. Science 167,561-63 (1970). 13H. Hintenbeiger et aL. Science 167,543-45 (1970). genie *Hc b located in retentive sites but that rock 10003 may have undergone some significant heating not experienced by the other rocks. RADIONUCLIDE CONCENTRATIONS IN APOLLO Gas retention methods are generally found to give 12 LUNAR SAMPLES BY NONDESTRUCTIVE somewhat shorter ages than other methods, due to loss GAMMA-RAY SPECTROMETRY' 7 7 of gas from interstitial phases. The * Rb-* Sr internal G.D.O'Kefley P.R.Bel4 isochrons for rocks 10017 and 10057 yield an age of J. S. Eldridje3 V. A. McKay3 9 10 3.65 X 10 years. If the event which formed the E. Schonfeid* R. T. Roeebeny* mare materials did occur 3.65 X 10* years ago, the K. J. Northcutt3 K-40Ar age of 4.0 X I09 years determined here for rock 10003 is quite remarkable. This result suggests that Eleven samples were analyzed ,by nondestructive the origin of rock 10003 may be different from tliat of gamma-tay spectrometry during the preliminary exami the other rocks examined. nation of the Apollo 12 lunar samples6 at the Lunar Estimates of cosmic-iiy exposure ages were made by Receiving Laboratory, Houston, Texas. The gamma-ray the 33Na-2lNe method. From similar work on mete spectrometer, on-line computer data acquisition system, orites' l it was assumed that the effective cross sections and general technique were the same as described for production of 33Na and 33Ne were equal, that is, a previously for Apollo 11 studies.7 AD samples were ratio of production rates ^N./C^N, • ^N<) " 0.50. The mounted in thin-walled stamles* steel cans with indium ratio of these production fates would not be expected gasket seals. to vary greatly with chemical composition, since botii For preliminary study, calibrations were obtained spallation products have the same mass and differ only with a series of radioactive standards prepared by by one atomic number. Specific activities of 33Na from dispersing known amounts of radioactivity in quantities the present work were used m combination with neon of iron powder. Time did not permit recording a library concentrations ootained by Funkhouser et a/.12 or of standard spectra with the standard sources placed Hintenberger et a/.13 The 3He exposure ages were inside the steel containers actually used. Empirical calculated on the basis of 10"* cm3 of 3 He per gram corrections for the effects of the containers were per million years exposure. The variations in cosmic-ray applied; these corrections were least important for the exposure ages of a factor of 10 teen here are consistent 40K data and most serious fa the "Al and "Na with the concept of a continual series of disturbances of results. The results are summarized in Table 1.9. the lunar surface '»uet o impact. Because of the preliminary nature of the investigation. 26 TsfcH 1.9. GWMM4U]r AMtymof L»M l Tlfltl ftom Apofto 12 w«npte Wtfcht K TJ» U "AJ 2lNa Otbrr Ra&onuciides So. (g) CsyjfBMM Rocfa $*M- $*M~ «*^ **C^ 4»V !2«02 1530 0.043 ± 0.004 0.95 t0.!0 0.23 ± 0.03 72 ± !4 53 ± 10 •*•••* «*••«• •*-•*» **-^» * 12004 S02 0.048 ± 0.004 088*0.09 025 ±0.03 !12i22 65±U 54M*,5'Co.4*Sc.4SV 12039 255 0.060 ±0.005 I.20±OI2 0.3110.04 80 ±16 45 ±9 5 Yo. '•Sin 12053 879 0.051 ±0.004 o.89 sao* 0.25 ±003 85 ±17 42 ±9 56Co.48V,4*Sc.*4^ 12054 68? 0.052 ±0.0*4 0.77+0.08 O21±O03 50±ll 42 ±9 4iV,$*Co.$4*».4'Sc 48 s $4 46 12062 730 O052±O034 a«i ±o.os 021 ±003 65±*3 34±7 V, Vol Mc Sc 12064 1205 0.053 ±0.(04 as8±oov 0.24 ±0.03 58 ±12 44±9 5*Co,4fc 12034* 154 0.4410.04 13.2 ± 1.3 3.4 ±04 58 ±12 27 ±6 54Ms 12073* w5 02/B ± 0.022 8.2±0.8 2.0 ±0.3 125±25 60112 $*Co.54Ma.4*Sc 4, 4 ,4 12C70* 354 0.206 ±0.016 6.0 ±06 1.5 ±0.2 140 ±25 65 ±13 "Ca. V. *Sc. »ln 120l3< 80 2.02 ±0.16 34.3 ± 3.4 107 ± 1.6 *Breccn. nffcbfy fetopathfe bncdt of complex onpn. rather bug? enors have been assigned. These errors rocks and meteorites than did the surface material from include, in addition to the statistical errors of counting, Tranquility Base. Although toe ratio Th/U remains at estimates of potable systematic errors due to un about 4, the concentrations of all the radioactive certain ie* in the detector efficiency calibration. dements are much higher in the breccias than in the Although there are many qualitative similarities be* crystalline rocks. This is the reverse of the situation tween the radiation counting data on samples from observed at Tranquility Base, and poses an interesting Apoflo 11 and ApoUo 12, there are also some notable problem: If the fines and breccias are derived from difference* The potassium concentration of the crys crystalline rocks, why do the crystalline rocks from the talline rocks of Apollo 12 is remarkably constant at Ocean of Storms (Apollo 12) show such differences in about 0.05 wt %, and the ratio K/U is about 2200. their chemistry? The answer may lie in sampling bias or These properties appear significantly lower titan the in different origins of these materials. typical crystalline rocks7 from Apollo 11; however, one Sample 12013 exhibits dramatic differences in chem of the coarsely crystalline ApoBo 11 rocks (sample istry from all lunar samples examined so far. The 10003) did resemble very closely the chemical composi sample is * sns!' feldspar-rich specimen which appears tion of the crystalline rocks shown in Table 1.9. The to be a broccia made up of material characteristic of the ratio Th/U is about 4 for all typical materials in Table rate stage of crystallization from a mci;. Accordingly, it 1.9, as found for the materials from Tranquility Base contains higher amounts of K, Th. and U than (Apollo 11). The concentrations of the radioactive previously encountered. elements K, Th, and U in the crystalline rocks of Table In general ihearaovnuofcosniogentc'*Aland"Na 1.9 are all remarkably constant and on the average appear nturaied but show variations which may be much lower than comparable Apollo 11 rocks. Because related to chemical composition or to cosmic-ray so few samples from the two sites can be compared, it is exposure. For example, sample 12034 was recovered not possible to discount biased sampling of the lunar from a trench dug during the iunar surface activities. surface material as a factor. When colected, it was buried lo a depth of IS to 20 The breccia and fines are quite different from the cm. The saturation activities of **AI and "Na are crystalline rocks in several respects. The ratio K/U b reduced by the amount expect*) due lo attenuation of only 1400 lo 1500. compared with an average value of the irradiation flux in the lunar soil. about 2700 for the Apollo 11 materials. Thus ihese Cosmic-ray exposure ages tod pweteniion ages for samples show even greater differences from terrestrial four rocks were computed from the data of Table 1.9 27 and rare-gas data published by the Preliminary Exami- Analytical Chemistry Drrision. nation Team.6 Exposure ages ranged from 3? to 200 3 NASA Maaned Spacecraft Center, Houston, Tex. million years, and 40K/**Ar gas-retention ages ranged *D»*ctoc*5 Dninoe, from 2400 to 2700 million years. The cosmic-ray Instrumentation and Controls Division. exposure history of the ApcUc 12 rocks appears to be 6L^oar Sample PreUnunaiy Examination Team (including F. sanilar to that of the Apofio 11 materials; however, the ». Bel, J. S. Ektridfe. V. A. McKay. G. D. O'Xefcy. and R. T. average age of the Apollo 12 rocks is about 500 million RmcUityi.SiicRR 167, J325- 39(i*7C). 7 years youngev than those of Apollo 11. G. D. O'KeSey et at. "Pranocdial Radionudide Abundances, Soar-FrotM and Cosmic-Rsy Effects, and Ages of Apoto 11 Lunar Samples," preceding contribution, tins report. 'Spawned by the National Aeronautics and Sr«x Admion- tatton through tnteiagency agreements with tne VS. Atomic Energy Coram bron. 2. Chemistry and Physics of Transuranium Elements LARGE YIELDS FOR CHARC D-FARTKLE the recoil nudei knocked out of a 23' Pa target during EMISSION IN REACTIONS v PROTONS irradiation with protons. The catcher foil was then WITH ACTTN1DE TARGETS assayed with an alpha spectrometer to give spectra such as those shown in Fig. 2.1. Because 33,Pa is radio R.L.Hahn K.S.Toth' M F.Roche1 active, one has to be certain that the products of 335 Theoretical treatments, usually based upon the interest, such as Th, arc not formed in (p,xn) 327 pound-nucfeus model, have been developed for complex reactions on Ac, which is the alpha-decay daughter 33 23 nudear reactions in heavy dements.3 Because of the of ' Pa. So special care was given to preparing ' Pa large Coulomb barriers encountered in these reactions, separated from its daughters; the main step in the the thcoTes have often neglected the emission of separation scheme involved extracting the Pa from an charged panicles; the two modes of nuclear breakup HN03 solution into 0.5 M TTA in xylene. After the usually considered are neutron emission and fission. separation the concentration of radioactive daughters 33, 7 In our studies at ORIC of proton-induced reactions to from the Pa decay chain was ~10~ relative to 331 produce alpha-emitting nuclides of neptunium3 and Pa; the reaction products observed are clearly due 231 uranium,4 we luve observed that the yields of products to nudear reactions induced in Pa, not in its from reactions ^ivotving the emission of protons or daughters. alpha particles art comparable with or even larger than The yields shown in Fig. 2.2 have not been corrected the yields from reactions involving only neutron emis for effects related to target thickness. That is, the 5 331 sion. For example. *»*» stow in Fig. 2.1 some alpha calculated range in Pa of a heavy lecoil such as 33 spectra obtained fro ORNL-OWG. 69-680A (d) 63 MeV 223, 120 80 40 —•—I—•—r (c) 63 MeV i- z z> o (b) 44 MeV 228, o 100 80 - 60 229, h 226TI. 6.37 MtV 40 20 (o) 44 MeV 7.46 M*V 60 223-. 40 20 —r —i—i—i—•—r T 20 40 60 80 100 120 140 160 180 200 CHANNEL NUMBER Pip 2.1. Spectra of Alpha-Active Prodact* front the Reactions of "*H + p at 44 and 63 MeV. Spectra a and c were takea shortly after the end of bombardment; spectra b and d were taken at later counting time*. See text for details. 30 0*NL- D*G. 70-5302 energies, r*ages, and yields of the products of reactions too involving charged-parficle emission can be greater than thns* of products of ip.xn} reactions; for * (taction involving proton evaporation, this effect can con ceivably increase the observed yields of ip.pxn) products by as much as 50% (this value is based upon expressr MIS given in ref. 7). It should be noted that although these effects upon the observed relative yields can't be evaluated ven* precisely, the yields of ip.pxn) products relative to (pjen) products have been enhanced at most by no more than a factor of ^3. Even if we correct the yields jy this factor, it is apparent that the ip,pxn) and (p.axn) yields are still not negligible. Nuclear reaction calculations are currently being done to see if we can interpret our data. Two modeb are being tried: (I) compound-nucleus formation and de cay, and (2) an intranuclear cascade initiated by the incoming protor, followed by compound-nucleus de cay. In both models the processes of ctorged-partide evaporation and cr fission are explicitly considered during the compound-nucleus phase of the reaction; some of die details of the theoretical treatment are discussed in the next section. Electtomdetf Driacn. 2See. for example. J. D. Jackson. Out J. Pity*. 34, 767 (1956/: T. Sfckdand. A. GWO.TO, am M. J. Nunria. fftj* Rev. F* 2J. YMfe of fkcol ftufec* •> 172,1232(1968). *R. L Halm. H. F. Roche, and K S. Toth. Hurt toys. Al 13, 206(1968). *R. L. Hahn. M. F. Roche, and K. S. Toth, Pkys. Rer 182, was produce J. In a compound-nucleus reaction, t'.te full 132* (1969). 5 Momentum of the projectile is imparted to the com J. Lindhaid. M. Scharff. and H. E. Sckiott. Kgl. Damke Vldemksb. Sdtktb. MatFys. MtdtL 33. No. 14 (1963). pound system, whereas in outer. •«onrompound proc- *G. B. Sato and N. T. Porik. Phys. Per. 149.880 (1966). eaes less li-am the fuli value is transformed into recoil 7 221 L Wmsbeig and J. M. Alexander. Phys, Rev. (21, 518 momentum.* if Pa, the (p^*i) product, were (19611). fanned in some noncompourid process, then its recoil energy, and Kcordinglv i*.s recoil yield, would be les thai* if it were made hy compound-nucleus formation (note that this effect would mean that the 2,,Pa cr «s INCLUSION OF CHARGED-PART1CLE EMISSION tecttun. relative to ;hat for 22*U. which we might AND FISSION IN NUCLEAR REACTION auume i* a compound-nuclei's product, would be even CALCULATIONS br|ef than that shown in Fig. 2.2). R. L. Hah? And yet. even if all of the products observed were formed in compound-nucleus reactions* their recoil The compound-nucleus and intranuclear-cascade ranges could still differ from nt another. Because of modeb present f**> very different physical pictures of the large fouiomb barriei in protactinium, the average how protons interact with nuclei. In the former model energy oi an evaporated proton or alpha paitick is of 'he proton reacts with (lie target nucleus as a whole to neosiiiy much greater than that for a neutron. The form a system whose decay can be treated by statistical kinetic energr? of the recirfl b related to the kinetic mechanical methods. In the latter case the proton is energy of the evaporated particle.' thus the re '„- (I) / J P r*P (7) rP.f r> where V- is the emission width for particle / and the f Now, instead of taking T * 0 as is usually done,2 we sum in the denominator is over all possible decay p modes., except fission. After the emission of the use the less severe approximation 2)1/ * IV Then neutron, a new compound nudeic is formed whose decay is independent of its mode of formation. So the l | r r probability that a first and then a second neutron is V* rlV< -* />! «) emitted is given by the product of the probabilities that We see that the fission factor has the same form as in each neutron is emitted, Eq. (4), irrespective of the partide being evaporated. Then for the case of pn emission we have ^-V«-1I k/Eri (2) l J /=i / wVain nv small compared with P2n,f- The various Pj terms in the equations are given by the Now in heavy elements the calculated widths for 4 usual Monte Carlo evaporation calculation.** With the emission of charged particles, T_, are usually small 9 aid of O. W. Hermann, we have modified the computer (<10%) compared with neutron emission,3,4 so that V n calculation to multiply these probabilities by the >r ,orJjr *r„,and / / appropriate fission terms, which are evaluated by a simple prescription given by Sikkeland et at.2 The calculations are currently being done for the reactions VMW + ^l. (4) "'Pa+p. 32 1 1.0. Jackson, Cm. / Pkjn. V, 767 < 1956). THE DECAY OF THE ISOMERS OF 24*Nj 7T. Sfcketrad, A. Ghsono. and M. J. Nonwa. Phyt. Re*. 172. AND 24*Cm AND THE RESULTANT 1232 < 1969). STATES OF **•»* *l. Dottrovsky. Z. FneafctL and G. Friedlaader. fkyt. Rrr lies 613(1959) C.E. Bemu.Jr. M.R.Sdunorak1 4'See« . for example. H. W. Bertiai. H. E. l-raack. ud M. I. M.J.Zender3 Gathrk, "lastractfeas for the Operation of Codes Auocated with the Low-Eaergy latnnadear Cascade CakafaKJoa." We have investigated the nuclear energy states in ORNL-*844(1966). 24*Pu by observing gamma rays emitted following the sCoawattas Tedmotoajr Ceater. beta decay of the 24*Np isomers and following the 0RNL-0W6. 69-9630 to' T—«—i—r •|—i—r 1—I—r—1—I—j—i—»—i—i—j—r—i—i—i—m T - • • • i p ****• *44f*~I\iv - 240wU-, t w24N0 p GAMMA- RAY SPECTRUM 3200 3400 3600 3800 4000 CHANNEL NUMBER Faj. 2.3. Gamma-Ray Spectram Observed in the fi~Deca y of the 7.3-min laotnsr oT "^Np with JC/* = 01 ~. J3 \ Of&ttr1 — Ta I * t*r ffiff to •02sa«*.«r r °"t- — - — - — J0.47 06TV, 7.« D?- tua%.*ta/ . tTKtmt *—«VT—, «•» mmmfffh AM •xrr «/<«ss;, £ <•*•{=*: »n **- / #C $** •y LffT H «*<«:> g2-o«i- u>- , —irv- :i^2 t t4* «!&%,>*!! in (155 <«rtfc, *tfl •Co X x i •I *0 09- /CN \*m 'oct%, >**) K'. (2*4 <««, xw B.w 4v*. #.*»; .\C- 2.« tm.rtv Ffc 2A. Complete Lev* Scheme for 348Pa. Derim work), together with the previously pubtisfcd results for * ORt T \ / *o» / r««c-" *0| y • wo* _!*""!!*/ •00 $ tmr»€t 7.4» *%i 100 arMe** * «0y ***Cm .«*• nw 100 0- at 65* **V of SM>h **°*» »v«00*- 23 T w\ o * tfvr Qtsl.>vz*icB) 20 JO - iiws 13 15 Tsar — t ft vJOt* tSSns - jfitjf ,g - to 10 <2«* MW» i' / astro to rcJ JtSCO - OS 03 04MTO a $F'4.9r«r*% trived from the decay of the 24""0w Np isomers and frori to 2*4* /C m decay (this for 24° Am decay. I* •i** ;J • '* V*^^' -' BLANK PAGE 0R3L- DWG. 70- 5968 Y J ^^T *0y 0,'MOT — T»ow«i!iOW» gcr IOC A-dKoyl of €5*i *4°Hp —- Tnmihon* par «0 «-«K«y of 5tO* **°»» £-£K3^ si "^J 25 # / is*> _t -^^ »a** t**zj. .*7*[«aj ZO -909% f»h -"_ «•.!-?- #W# 5tQh yjawo S"—— wn «H» \om* U) - ,'V/; tan Ore"it//* / <2n» 14' !»•) 0900 09 * / / oari tai t I__i H -21. J 1 1 1/. J. * otwo 0.464 M 94 «46 V«4.«»*r«% w the 244Cn decay (this &tj^*&:!-.. .^JkV-' '• r*--::-..'."-, '" "*" ' • ' ~V.-" ' . '" -'" " • ' ."- - " • .**T^2" _;;»*•, M 1 -*. BLANK PAGE 3*5 14 alpha decay of ,44Cm. A 15-mg iiaf«>pe«eparaied states is given in Fig. 2.5. Thesv states were confirmed 44 source of 99% * Fe (/l/a «8JSX 10* years) was in gamma-ray-gamma-ray coinaC-.^ce experiments: (he used as the equjBbrittm grandparent activity for 73-min transitions from these states only populated the / • I' a4#"Np(Jt/» «01) Approximately IO«gof,44Cm and 3" members of the AT • 0 octupoie band, as would was prepared using the Transuranium Research Labo- be expected for coOectrve-oudear vibrational stales of atory isotope separator' tor studies of the gamma rays die iwo-phonon octupok type with X • 3. Although the at "•F* foiowiag the alpha decay of "4Cm. om-phonon vibrational states with X*2andX*3are We have found approximately iOO fammi-ray Iran- weB established in nuclei, only the X • 2 two-phonon sitioQS in the ,4*Np decay wing » Is**** &(V) shape vibrational states have been previously identified, detector. A representative singles gimmnay spectrum with only one such case in permanently deformed is shown m Fig. 2 3 We hive also seed s thm-wmdow sucSes. planar Ge(Li) detector for the investigation of pimne To characterize these states in X4*Pu even further, we rays in the low energy region (20 to 200 keV). have performed gaman-gainme directional correlation Gamma•ymma coinctderKy tr*5*Mrement$ were per- experiments between the gamma rays deexoting these formed with a 3 X 3 in. NalfTT) detector and the states and the transitions deexcitmg the one-phooon 35 -cm1 Ge(U) detector. Ail of the transitions with an octupoie band. Using a rotatabte 2 X 2 in. NalfTI) absolute intensity greater than ~OJ01% per decay were detector set to record only the photopeaks of the placed in the level scheme shown in Fig. 2.4, which 554.6-. 597.6*. S07.I-. and 606.1 -keV transitions, the summarizes essentially all of our work, including the coincidence spectrum was recorded using a 50.4 vm. ••-•sot* 12S»«?7 0* • 9% *SS 14.1 h / 14.« • T 0 + «Jm .^ w» £ 0 9 3 7.4 «K T r I*' !!-* * "? f •*•**>*} •Tata. •40 «4ia« 0*J £•*«** •3ft.1 2+ *>2 •00.3 2*1 K>0 i.:\(7.S4| M0.7 0*J U-4-40UV 4.0% (MS) 2.5% (7.10) *0.1%(2«.7)' / 32% i*2BY > 7.15 ksV 53% Fig. 2.5. Partial Lewi of M0P». The two-phonon octupote bands (1410.8- and 1438.5-keV states) and their resultant decay pattern are shown. 36 2.1. rxpaijawatal DtTrtio—I Conahniiw Coefficwrta for Csarjda turn the I4IAA- atd 14383-teV Lev* m 24#fci Experimental Theoretical Level caeigy <•> Level Sptr» ConeUikM Corrctaiion U10.8 813.4-554.6 4 3 • 0.050(0-*l-^2) 43«0.062 ±0.015 0* 813.4-597.4 /«,« 0.62 ±015 >l,«0.5O0C0-^l-*O) 1438.5 789.6-507.1 vij» 0.1110.05 ^2«0.050<2-^3H4) 789.6-601%. 1 /4j«0.26±0.13 y4 «0.120C2-»3-»2) s 2<*> 841.1-554.6 i42--0.014 ±0.024 42«a005<2-^l-*2) M 1.1-597.4 A2 " -0.14 10.24 ,42«0.050<2-»1-H» *AI of the meastttcd A* values are coasisteat with xero, as expected for spia 1 iatermediste states and for the cascades through the 3' state, which is expected to decay via pare electric dspofe transitions to the 2* and 4* members of the ground band. ^Calculated assuming owe dipote traasitiom and the cascades as given above. Table 7_2. Absoam Gamaa••Ra y lanmiiiai, Ruiaced Tra—Mna-lnaeasiry Ratios, aad Beta toacatag to the TWFhoooa Ocwaoit Baad ia 24ePa Normalized Absomte Gamma- Normalised Lcve* energy Gamma-Ray Transition Theoretical Ray Transition Reduced (teVHir*/) (keV) Reduced Intensities intensity (%)* Intensity* lt>0 K'l i410J<0*0) 813.4310.14 0.21110.025 1438.5 Normalized Level Energy Bete Feeding* Normalized Theoretical tof/f (kcV) /rvalues Reduced Intensititt 100 *:=i 1410.8(0*0) 0.21H0.025 7.32 1.00 1.00 1.00 14383(0*2) 0.37610.023 7.01 0.5OH0.O31 0.500 2.00 "Intensity units are in percent per decay of 140mNp. . ''Assuming electric dipok character. The £^ dependence on the transition rate has been removed. 'Beta feedings were derived from total gamma-ray intensities using theoretical £1 conversion coefficients. 1 Nuclear Data Group. 24' Pu has generated much theoretical and experimental Oak Ridge Associated Universities Research Participant from interest. NUsson and coworkers4 have associated this Fresno State College, Fresno, Calif., summer 1969. isomer with spontaneous-fission isomerism a;.d at 3 Vanderbilt University, Nashvflk, Tenn. tribute the long half-life to the presence of the 4 See C. E. Bemis, Jr., M. R. Schmorak, and M. J. Zender, 1 V[505] neutron orbital at the Fermi surface at the "The Decay of the Isomers of 240Np and 244Cm and the Resultant States of 340Pu,** preceding contribution, this report. large distortion characteristic of fission isomers. The possible presence of a ~0J-year spontaneous- LONG-LIVED SPONTANEOUS-FISSION fission isomer in 24,Pu and the unexcelled oppor ISOMERISM IN 24,Pu? tunities it would afford for detailed studies of shape and fission isomerism in nuclei have prompted us to C.E. Bemis, Jr. J. E. Bigelow' make an exhaustive search for this isomer using a 2 R.J.Silva A.M. Friedman variety of production modes. We have attempted to The recent report by Nisle and Stephan3 of the produce this isomer in the 240Pu(n,y) reaction, the existence of a (0.34 i G.ii)-year isomeric state in 242FU(/I,2/I) reaction, and the 238U(a/i) reaction. 37 ?/c irradiated 240Pu (99 994%) in carefully mon- 1 Chemical Technolocy Division. tored experiments at the Oak Ridge Research Reactor, 2Chen>isny Division, Argotuw National Laboratory. Aiffi—c. examined the plutonium fraction from a 1-5-year I1L 3 irradiation of 242Pu in the High Flux Isotope Reactor, R. G. Nisfc and I. E. Stephan. SucL Sci tng. 39, 257 and bombarded 238U with 40-MeV 4He ions at the (1970). 4 Argonne 60-in. cyclotron. All samples were carefully S. G. Nilsson, G. Ohlen, C. Gustavton. and P. MbDer. Pkyi Utttn 30B.437 (1969). processed chemically after the irradiation to recover the piutcnium fraction, which was assayed for alpha and fission activities. The irradiated 240P»i sample and the 242Pu sample were isotopjcaify enriched in s4' Pu using THE FISSION THERMAL-NEUTRON CROSS the ISO-cm isotope separator in the Transuranium SECTION AND RESONANCE INTEGRAL Research Laboratory. OF 24$Cm, 247G». AND 24»Cf Tne smaii number of fission events observed in these J.Halperin J. H. Oliver R. W. Stoughton experiments was entirely accounted for by the fusion branching decays of 240Pu or 242Pu which were Measurements of the thermal-neutron fission cross present in the samples in known quantities. Upper sections and resonance integrals of 24$Cn\ 2*7Cm,aed limits for the cross sections for the production of a 24,Cf have been carried out employing the method of -*03-year spon?aneous-tissioa activity were derived solid-state track recording. The technique lends itself to from the absence of fission events, from the isotopic picogram (10*'2 gram) and smaller sample sizes and composition of our samples, and from the monitored aliows the measurement of fissionabiiity in various irradiation histories. These values are listed in Table 23. neutron-spectrum configurations. We have irradiated Ou/ data have also been analyzed in terms of a nuclides deposited upon thin nickel foils in contact 03-year isomer of24! Pu which undergoes independent with Lexan film (biphenol-A polycarbonate plastic) in *ipha or beta decay. A limit of <6 X 10~* for the atom selected neutron spectra. Following the irradiation the ratio of 24' mPu/24 '*Pu was determined for an alpha- Lexan film is etched in an KaOH medium to develop decay isomer and a limit of ~10"3 for beta decay. the tracks caused by the fission fragments. The etched Although these values are not a» sensitive as the tracks, approximately 20 fi in length and each repre fissioning-isomer experiments given in Table 2 J, the senting individual fission events, are counted under a values are well below the corresponding ratio reported microscope The efficiency of the system for our by Nisle and Stephan.3 experimental configuration was found to be 92%, In conclusion, we are unable to explain the results of determined by calibrating the film with a known Nisle and Stephan3 in terms of a 0.3-year isomer that fissioning source. decays by spontaneous fission or even by alpha or beta The saniples were each measured a number of times in decay. In light of our negative results, the elegant two distinct neutron spectra. An almost pure- theoretical interpretation by Nilsson et al* seems Maxwellian room-temperature neutron spectrum is somewhat premature. available in the D20 tank adjacent to the BSR (Bulk Table 2 J. Upper Units foi the Prodnctioa of ~0.3-Y« .241 "•P. in Virions Reactions Energy 24i«pu/24i*pu Isomer Formation Cross Section Reaction (MeV) (cm /atom) 240 12 i3 Pll<»!,7> Thermal <7.6X10~ <2.2 X 10~ 240 Pu(n,7) >\ <*.6X10~12* <1.S X 10"3S 242 fu(n,2n) >6.2 <6.6X10",2a <2.9 X 10~33 238 V(a.n) 46 <5.0 X 10"4 <2.5 X 10~35 'These values do not necessarily represent the actual isomer ratios but are the ratios of 24lmPu produced by the indicated reaction to total ^''Pu oroduced by all of the reactions posnble with reactor-spectrum neutrons on 2 °Pu and 242Pu. 38 Shielding Reactor). Here samples were irradiated vith 247Cm gold neutron monitors lo measure thermal cross sec 247 tions. The monitors were dilute (~0.1%) alloys of gold A sample of curium containing 22% Cm, 48% 244 24s in aluminum to minimize self-shielding. The thermal- Cm, and 0.6% Cm was made available from the 1 neutron measurements were normalized to a 2200- calutrcn isotope separations group. Approximately m/sec value of 98.8 b for gold. 30% of the thermally induced fissions were due to the 245 Epithermal reaction rates were measured in the Cm in the sample. However, only some 3% of the 245 pneumatic-tube facility or the GRR, where the ratio of fissions were due to Cm in the epithermal-neutron thermal to resonance flux per unit lethargy is ~35. measurement. There is also a small correction due to Samples were irradiated within 40-mil cylindrical cad the 1-b thermal-fission cross section and 12-b fission 244 mium filters together with gold monitors for short reso" ice integral in Cm. A 2200-m/sec value of the periods of time. The epithermal neutron measurements • cross section oy = 120 ± 12 b and ~ fission were normalized to /(Au) = ! 580 b. resonance integral of It = 1060 ± 110 b are reported here for Cm The value within Ihe iirr;ts of error The accuracy of the method is comparable with the 2 usual activation cross-section measurements of 5 to agrees with that reported by Diamond, oy = 108 b, but is substantially smaller than the HFiR radiation cross 10%. However, the ccumulation of sufficient statistical 3 precision tends to be more tedious in the counting of section of oy = 280 b. The fission resonance integral is consistent with the value of 1000 b used as a events under the microscope. In general all the measure 3 ments listed in Table 2.4 were found to be consistent production cross section for the TRU facility. within the statistics of the number of tricks enumer 249Cf ated. The neutron fluences (which ranged up to 1015 2 13 thermal neutrons/cm and 10 epithermal neutrons A particularly pure preparation of the 352-year 249Cf per unit lethargy per square centimeter) were evaluated was obtained by milking a source of 311-day 249Bk.5 by measuring the 411.8-keV gamma ray in the decay of The sample was assayed by measuring its alpha-decay l98 2.70-day Au. The gold activity was followed over a spectrum. \ 2200-m/scc fission cross section ot - 1690 period of several half-lives to evaluate the amount of ± 160 b and a fission resonance integral of If= 2940 ± 19S Au formed during the irradiation. The efficiency of 280 b are reported here. The thermal cross section may the Nal detector was established by 4n beta-gamma be compared with the 173G-b production cross section coincidence measurements. reported by Metta.6 The resonance integral is consider ably higher than the 1800 b reported by MacMurdo.7 245Cm A sample containing 76.5% 24SCm and 23.1% 244Cm was available from the calutron isotope-separations group.1 It contained a negligible amount of 247Cm. A We are indebted to 1. O. Love and his coworkers lor these separated cunum isotopes. 2200-m/sec fission cross section oy = 1920 ± 180 b and 2H. Diamond ei al, J. Inorg NucL Chenu 30, 2553 (1968). a fission resonance . itegral If - 1140 ± 100 b are 3W. D Burch, J, E. Pigelow, and L. J. King, Transuranium reported here. The thermal cross section within the Processing Plant Se:mann. Rept. of Production, Status, and limits of error agrees with the 2040 b reported by Plans, Dec. 31, 1968, ORNL-4428 (1969). Diamond2 but is distinctly larger than the cross section 4J. Halpenn, R. E. Druschel, and R E. Eby, Ckem. Div Ann. of 1550 b used for production calculations for the TRU Progr. Rept. May 20,1969, ORNL-4437, p. 20. facility.3 We are indebted to R. D. Baybarz, Chemical Technology By combining the value of the capture cross section Division, for making this sample available. 6 and resonance integral previously reported4 the ratio of D. Metta etal, J. Inorg. NucL Chent 27. 33 (1965). 7 a /a = 0.50 (a = ojoj). This ratio is somewhat K. W. MacMurdo, "Measurement or Fission Cross Section epi th and Spontaneous Fission Half Life By Solid State Track smaller than earlier estimates and is in the direction of Recorder," Presented at the 21st Southeastern Regional Meet making a lesonance reactor less attractive than a ing of the American r'»emical Society, Richmond, Va., Nov. thermal reactor for the production of californium. 5-8. 1969. Table 2.4. Fission Cross-Section Measurements 24S Cm 247 Cm 24Yf Type cf Total Total Total ?nadiation Number of °2 200 / Number of a / Number of Tracks Traces 2 200 Tracks °i200 ' Measurements (b) (b) Measurements (b) (b) Measurements Co Counted Counted Counted (*•) vb) v© 2 Thermal neutron 7500 1920 6 1500 120 2800 1690 Epithernial neutron 4 9100 1140 3 1900 1060 2900 2940 40 ENERGY SPECTRUM OF DELAYED the nnvt system from a magnetic-tape transport. NEUTRONS FROM THE SPONTANEOUS Nei iron shielding (consisting of high-density concrete FISSION OF 252Cf blccks, cadmium sheets, and paraffin blocks loaded with lithium and boron) was interspersed between the E.T.Chulick' C. E. Bernis, Jr. 2 5*Cf source 2nd the counting position of our time-of - P. L.Reeder E. Eichler fiight spectrometer to reduce the piompt fission- Delayed-neutron energy spectra from fission product spectrum neutron background precursors are of interest in the field of fast-reactor The time-of-flight spectrometer consisted of a beta kinetics and as a nuclejr spectrcscopic tool for studying detector located 0.5 cm above the tape and a neuiron the properties of nuclear states. As reported pre detecior located 20.0 or 25.0 cm horizontally from the viously,3 we have remeasured the delayed-neutron tape The beta detector was a disk of NE-I02 plastic group half-lives and group abundances from the spon scintillator, and the neutron detector was a stilbene taneous fission of 2 5 2Cf and have briefly described cur crystal; bolb were mounted on RC'A-8575 photo- very preliminary re*uli$ for delayed-neujron energy multipiiers. A block diagnm of the tirne-of-flight measurements using the time-of-fl'ghi technique. instrumentation including the neutron—gamma-ray dis Our experimental procedure in the energy spectra crimination system is shown in Fie. ?.6. The time measurement was to collect fission product recoils resolution of this system under the conditions of the from a ~-10-j*g 252Cf source on Mylar magnetic ripe actual experiments was 1.4 nsec. for 2 predetermined collection time;. After the col Our recoil-collection and counting-time cycle em lection penod the tape containing the fission product phasized mostly the 2-sec and tbe 0.5-sec delayed- recoils was rapidly transferred a distar ce of about 3 m n^utron group. Df the total neutrons that we observed, from the 2S2Cf source to the counting position, using 48% were due to the 2-sec group and 28% were due to ORNL-DWG. 69-5H4 fl 0.5/tsec 12th OYNOOt LINEAR \ DELAY AMP •I SCA j »j • ANODE PILE - UP I ANTI-COINCIDENCE REJECTION ^l_f 200 n ;«c TlMF. FlXioT. 2.5^$*c ft PlCKOFF DELAY |" -f- 0!£c 0 XT L COUNTING !NTEi?VAL NE-102 ^fc Jl Jl Jl T SCA LERJ Jl x ill TIME TO \ L'NEAR J" SLOW 2fisec ~20-30cm PULSE HEIGHT GATE jCCINClOCUCf FLIGHT PATH jSCALER —*- Pb PlLTES LINEAR f V23ZZ JT n 0-16 nsec OUT STILBENEXX D'SC • ADJUSTABLE TIME DELAY lO^iecUJELAYl PM PlCKOFF , v SCALER X f ANODmnnEc !I Jl h2thDVN0DEl J^yL^rL-J^lAY ^^fcrz; ~H LINEAR I _J~" I I/* sac Jy i n-^DiSC. n-V iLXTTTvlX-J TIME TO I ^*J,.. 1GA;JGAY£g ^J ADJUSTABLE QISCRlMlNff>ONi^jPt:{-AY| *| PULSE HEIGHT| *| SC* [ j^ * OILAY rrrrj Fig. 2,6. Block Diagram of the Instrumentation Used for Ddaycd-Neutrcm Time-of-Flight Experiments. 41 the 0.5-set group. Our neutron time-of-flight counting 'Cyclotron Institute. Texas A & M University, College raie was about 1 count /cycle, and the cycles were Station repeated continu-visly for a two-wock ucriou to obtain 'Department of Chemistry, Washington University. St. Louis, statistically significant data. Experiments at 20.0-cm Mo. 3 and at 25.0-cm flight distance were perforrred to E. V. Chulick. P. L. Reeder. E. Eichler. and C. E. Bemis. Jr., Chem. Div. Ann. Rro&. Rept. May 20. 1969, ORNL-4437, p. identify the neutron groups uneouivocally by virtue of 24. dieir shift m time for the two different flight paths. The 4R. Batchelor and H. R. McK. Hyder, / Xuel. .Energy 3. 7 energies of the mo*! prominent discrete neutron energy <195b>. groups for the two different flight paths are given in Table 2.5 together with their average energy. In Fig. 2.7 our 2Q.0-cm-flig!»i-paih time ipectrum has been con ALPHA-DECAY STUDIES OF verted *o an energy spectrum and compaicd with the NEUTRON-DEFICIENT CALIFORNIUM 2-sec group energy spectrum measured by Batchelor ISOTOPES and Hyder.4 Althougli the oatchelor and Hyder 3 R.J.Silva M. L.Mallory spectrum was measured with a He spectronvte; v/jth 25S R. L. Hahn P. F. Dittner pooier energy resolution and for the fission of U. C.E. Bemis, Jr 0. L. Keller the agreement is interesting. K.S.Toth1 This work is being prepared for publication. The recently developed !2C ion beam of the Oak Ridge Isochronous Cyclotron (ORIC) was used to O«KL-0WG.7O-57l2 it produce neutron-deficient californium isotopes for -i T ' r —! ' 1 1 z alpha-decay studies. The carbon-ion energy was 118 z 2 9 MeV but couid be adjusted to lower energies by interposing beryllium foils of appropriate thicknesses. S! The beam intensity varied from V2 to 1 particle co 7 microampere of current. » jMN*: The targets of highly enriched 238U, 235U, 234U, 233 u, 5 and U were prepared by molecular plating cf approximately 1 mg of inatenal onto 1-mil-thick * 3 _L J J L ' beryllium backing foils over a 1-cm-square are2. The 0.1 0.2 0.3 0.4 0.5 0.6 £"„{MeV> uranium targets served as beam-entrance windows for a helium-filled gas-jet chamber. The californium product Fig. 2.7. Comparison of DeJayed-Neutron Energy Spectra for atoms recoiling from the target were stopped in the gas the 2.0-sec Group. Top curve from the work cf batchekr and Hyder; bottom curve, this work. and pumped through a 13.5-mil orifice into an evac uated chamber where the helium gas jet impinged on a platinum disk upon which the atoms were deposited. The platnium disk was attached to the end of & T?We2.5. Energies of DeJayed-Neutron Peaks for 'he 2.0-sec Group from the Spontaneous polyethylene "rabbit" that could be transferred pneu 5 252 Fission of Cf matically through a /8-in.-diam polyethylene tube to the chemistry laboratory in ~5 sec after the irradiation 20.0-cm Flight Path 25.0-cm Flight Path Average Energy period. At the chemistry laboratory end of the tube the (MeV) (MeV) {MeV) "rabbit" was received in a device that allowed it to be 2 0.096 ± 0.005 0.093 ±0.005 0.095 2 0.007 rotated in front of a 2-cm Si(Au) alpha-particle 0.107 ±0.005 0.101 ±0.006 0.104 ±0.008 detector. 0.138 + 0.007 0.132 ±0.007 0.135 ±0.010 After suitable amplification the pulses from the 0.155 ±0.009 0.160 ±0.013 0.158 ±0.016 detector were fed into two pulse-height analyzers where 0.190 ±0.012 0.185 ±0.016 0.188 ±0.020 0.205 ± 0.014 0.205 ±0.018 0.205 ±0.023 alpha-particle pulses in the energy range of 6.00 to 8.S0 0.225 ±0.016 0.225 ±0.021 0.225 ± 0.026 MeV were recorded. One of the analyzers was a 0.240 ±0.018 0.240 ±0.018 1600-channel device which was divided into eight 0.265 ± 0.020 0.265 ±0.027 0.265 ±0.034 200-channel sections in order to follow decay of various 0.340 ± 0.030 0.340 ±0.041 0.340 ±0.051 alpha-partic!e groups through preset time intervals. The 0.440 ± 0.040 0.420 ± 0.050 0.430 ± 0.064 other was a 1024-channel analyzer which provided a <*2 continuous sum spectrum at higher channel resolution prod'.cticn of the interfering 2'*C( activity. In addi than the first analyzer so that accurate energy values tion to the known alpha group of 7.12 MeV2 (re- "uld be obtained. The measured res'Juticn of the measured in this expenment to be 7.135 ± 0.G03 MeV system was ~*8 keV FWHM for the 5.4988-MeV alpha at 93.2% abundance), peaks at 7.103 (3.7%), 7.074 group of :3*?u. (3.1 ?'-), and 6.964 «0.5%) MeV were recorded. Alpha-particte spectra of 245Cf were obtained in Figure 2.8 shows a typical alpiia-par.icle spectrum bombardments cf 238U with 67-MeV ,2C ions. The obtained in the bomburdmeni of 233U with 79.5-MeV low bombarding energy was used to eliminate the l2C ions where bjth the new activities of 7.335 ± 0.005 and 7.590 ± 0.010 MeV can be seen. The former ORNL-DWG. 69-«366e activity was also seen in bombardments of 2?SU and 100 »5, TT Ro "1 234U. The half-lives of these activities were determined 6.74 MeV 233 ,2 U • C to be 3.1 ± 1.2 and 0.90 ± 0.15 min respectively. In 2,3Fr E ., = 79.5 MaV 6.78 addition, we weie able to obtain a more precise energy value for the ground-state decay of 242Cf3'4 of 7.385 ± 0.004 MeV with measured half-life of 3.3 ± 0.4 min. Analysis of die data also showed an alpha group of 0RNL-0WG. S9-H363* 60 70 80 90 60 CARBON ION ENERGY (MeV) Fig. 2.9. Excitation Functions for SProdnct»~n of 242% 24,Cf, and 240Cf. Points are experimental values, and solid lines are theoretical calculation:'. 43 ing energy. As some of the experimental . olieciion observe both members of a give i Gallagher-Moszkowski efficiency paramoteis were not well known, the experi doublet, which should be possible in 250Bk. This mental dat3 for 2i2Cf were adjusted in magnitude but identification would provide information on the neu not energy to fit the calculated curve for the 23SU. The tron-proton interaction in nuclei. same factor was then used for the 234U and 232U cases. The behavior of the 7.335-MeV and 7.590-MeV activities is that expected for the assignment of the 1W. McHarris. F. S. Stephans. F. Asaro. and 1. Periman. Phys. former to the decay of 24lCf and the latter to 240Cf. Rev. 144, 031(1966). 2C. J Gai.aj?her and S. A. Mostkowski. Phys. Rev. 111, 1288 (1958). Electronuclear Division. 2 A. Chetham-Strode, G. R. Choppin. ami B. G. Harvey. Phys. Rev. 102,947(1956). THE NEUTRON ABSORPTION CROSS 3P. R. Fields. R. F. Barnes, rf K. Sjoblom, and J. Malsted. SECTION OF 257Fm /Vf. Letters 24B, 340 (1967). 4T. Sikkeland and A. Ghiorso. Pkys. Letters 248, 331 (1967). C. E. Bemis, Jr. J.Halperin 1 T. Sikkeland. A. Ghiorso, and M. J. Nurmia,Phys. Rev. 1/2, R. E. Druschel R. D. Baybarz 1232(1968). Measurements have been made of the neutron absorp tion cross section and resonance integral of 2S7Fm. STATES IN 2 5 ° Bk POPULATED IN THE This measurement probably involves the heaviest nu ALPHA DECAY OF 2 S4Es clide thus far examined for this properly. 2 7 C.E.Bemis, Jr. E.Eichler A sample of the 97-day alpha-emitting ' Fm con taining some 108 atoms became available as a part of We are currently investigating the states in 2S0Bk that the transuranium production program at the HFIR. A are populated in the alpha decay of 276-day 254Es measurement of the "burnout' of the fermium in a (Kt* = 77+). As was shown in the earlier work of carefully monitored neutron irradiation was used ss the McHarns et al.,x the four low-lying rotational bands method of measuring the absorption cross section. observed in odd-odd 2soBk could be explained by the Curium-244, with a relatively small and well-known 7 + various couplings between the /2 |633t] and cross section, was added to the fermium sample to serve 3 + /2~[521t] proton states and the V2 [620t] and as an internal standard. Aliquot* of this sample were 7 /2*[613t] neutron states according to the Gallaghcr- deposited in quartz ampuls and irradiated in an as Moszkowski coupling rules.* sembly containing cadmium filters designed to measure We have reinvestigated this decay with the much the response to epithermal as well as thermal neutrons. larger sources of 254Es that have been produced at Dilute alloys of cobalt (~0.1%) irradiated with the ORNL. Using silicon surface-barrier detectors for alpha samples were used to measure the neutron fluence. The particles and a thin-window Ge(Li) detector for gamma samples were irradiated in the ORR to a thermal- rays, we have performed alpha-gamma coincidence neutron fluence of 6.27 X 10'9 neutrons/cm2 at a experiments in addition to singles measurements. Al position where the ratio of thermal to resonance flux though these experiments are still in progress, we have per unit lethargy was found to be 9.56. identified two new, higher-lying, rotational bauds in Following the irradiation the samples were dissolved 250Bk which most "obably involve the V[633t] and passed through a "cleanup column." The actinides 3 proton state and the neutron state /2*[622t] for one of were adsorbed onto an anion exchange column and 5 these bands and the /2*(642t] proton and the washed with 0.1 N HCl, which removed various fission 5A+[642t] neutron states for the other band. Our work products and other activated impurities from the is in favorable agreement with most of the assignments irradiated sample. Then elution with 2 N HCl removed of McHarris et al.,x aiihcugh we have not analyzed all the actinides as a group. The washes and the column of our data. Six new alpha groups and ten previously were carefully examined to verify that no loss of unobserved gamma rays have bee I measured in the fermium or curium had taken place. Samples were alpha-gamma coincidence experiments. assayed with a si! icon-detect or alpha spectrometer to An isotopically separated 2S4Es source will be used detcimine the ratio of 257Fm (6.519 MeV, 94%) to for studies of the intemal-conversion-e!' ctron spectrum 244Cm (5.806 MeV, 76.4%) in the unirradiated and the with the it'Jl spectrometer. We ar: attempting to several irradiated samples. 44 Approximately 0.589k of the 244Cm which served as obtaining information about the chemical and energetic a standard of comparison in this burnout experiment state of such recoil nuclei. We especially wished to was calculated to have been transmuted in the un- investigate the possibility of the solid-phase halogena- filt-red irradiation and somewhat less was transmuted tion of the^e nuclei after catching them on thin layers in the epithetinal-neutron experiment. After correcting of '£ri collector and chlorination with CC14 at 650 to 700°C for about 5 min, about 30 to 40% of the ' 70Hf activity Chemical Technology Division. was sublimed, while nearly 100% of the ' 69Lu activity 2 J. R. Huizenga and R. B. Duff-eld, Phys. Rev. 88, 529 remained on the graphite. Experiments are planned in (1952). which attempts will be made to increase the separation 3 A. Prince, private communication, September 1969. efficiency while decreasing the separation time. 4E. K. Hulet, private communication, April 1970. SC. E. Bemis, Jr., t. K. Hulet, and R. W Lougheed, Chem. These investigations also revealed that so-called 95 95 Div. Ann. Progr. Rept. May 20, 1969, ORNIM437, p. 24. "carrier-free" radioactive isotopes (eg., Zr, Nb, l53Gd, and 18,Hf), when deposited on the various surfaces by evaporation of acid solutions, do not serve as good models for the behavicr of recoil atoms in STUDIES ON THE SEPARATION OF experiments of this kind. This may be due to the RECOIL ATOMS OF HEAVY ELEMENTS method of deposition or to the presence in the samples P. G. Laubereau1 R. J. Silva of small but nevertheless "weighable" amounts of the stable isotopes of Zr, Nb, Gd, and Hf used in the Investigations were started to find improved proce reactor productions of ihe radioactive samples. One dures for rapid separation of the heaviest elements (Z > might expect the chemical behavior of a few thousand 100). These elements are likely to be produced as atoms on a foreign surface to be significantly different energetic recoil nuclei ejected from a target a; a result from that of weighable numbers of atoms, depending of a nuclear reaction,2 and we are interested in on the nature of tie experiment. A frontal gas-chromatography apparatus using The K x-ray energies and intensities for elements graphite columns was designed for the rapid separation 99-102 will be determined :;i the same way, using from neighcoring elements of element 106 (eka- parent elements produced with alpha and heavy-ion tungsten), which is predicted to form a volatile hexa- beams at the ORIC. carbonyl. !T. A. Carlson. C. W. Nestor. Jr.. F. B. MaliK, and T. C. Guest scientist from Federal Republic of Germany, Bonn. Tucker,NucL Phys. AI35. 57 (1969). 2See, for example, R. J. Silva etaL, "Alpha-Decay Studies of A. L. Wapsira. G. J. Nijgh, and R. van Lieshout, Nuciear Neutron Deficient Californium Isotopes," a previous contribu Spectroscopy Table, North-Holland, Amsterdam, 1959. tion to the chapter of this report. 3R. L. Hahn, Chem. Div. Ann. :*ogr. Rept. May 20, 1968, ORNL-4306, p. 37. 4R. L. Hahn et al, Chem. Div. Ann. Progr. Rept. May 20, STUDIES OF PLEOCHROiC HALOS 1969, ORNL-4437, p. 37. R.V. Gentry1 J.W.Boyle Russell Baldock K X RAYS OF THE HIGHER ACTINIDES Pleochroic halos (minute regions of discoloration P. F. Dinner C. E. Bemis, Jr. surrounding microscopic inclusions in various minerals) R.J. Silva are usually observed in thin mineral sections as one or more concentric circular rings. These halos are now Recent interest in superheavy elements and in the generally considered to result from alpha-particle bom problem of their identification (atomic number) has bardment over geologic time from the decay of spurred theoretical predictions of the energies of the K uranium, thorium, or other radioactive elements present x rays of elements having Z > 95. These predictions1 in vhe inclusions. Many halos can be explained in this are in part dependent upon experimental values of way—for example, the common uranium and thorium known K x rays. With this in mind we have embarked halos in which the radii of the concentric rings upon a program to measure the K x rays of elements 96 correspond to the ranges of the various alpha particles through 102. Beyond americium (Z = 95) the quantities in the decay chains which end in stable lead. However, of material available are too small to use the method of there are some halos which cannot be explained by any fluorescence excitation. We have measured the Zf-series of the known naturally occurring radioactive elements. emission lines following either alpha, electron-capture, Some of these unexplained halos are larger than or 0~ decay using suitable actinide radioactivities. uranium and thorium halos (giant halos) and some are Production of Kshell vacancies from these processes smaller (dwarf halos). Studies are under way to try to results in the emission of a K x ray as the fluorescence explain the genesis of these anomalous halos. 2 yield is close to 100%. One approach which has been initiated with the rare The x rays are detected by a Ge(U> detector, and the dwarf halos consists in leaching the samples2 containing output pulses are amplified and stored in a 4096- the halos with boiling nitric acid, separating the channcl pulse-height analyzer. The K x-ray spectrum of resulting solution into various fractions by standard ion curium has been recorded using a 24*Cf source, which exchange techniques, and analyzing these fractions for alpha decays to 245Cm. The use of a 254Es source, their atomic composition using the Chemistry Division's which decays by alpha emission to 250Bk which two-stage mass spectrometer. The analyses so far have subsequently beta decays to 2S0Cf, allowed us to shown the presence of both uranium and thorium and record both the berkelium and californium K x-ray have shown that the lead is mainly radiogenic. spectra. These spectra are currently being analyzed to Specifically, the lead isotope of mass 206 is approxi determine the energies of the K x rays and their relative mately one and one-half times more abundant than the intensities for each element. In order to determine the isotope of mass 208, whereas in natural (nonradiogenic) energies, the unknown spectra were simultaneously lead masses 206 and 208 are present in abundances of recorded with well-known standards (>£., Pu K x rays, 23.6 and 523% respectively. Subsequent measurements 182Ta,243 Am and 5 7Co gamma rays). For the relative by another laboratory3 are in agreement with these intensities, the efficiency of the Ge(Li) detector has findings. Work is to continue, with special effort to be been calibrated using the known gamma-ray intensities expended in the rare-earth and actinide regions of the of24,Am,57Co,203Hg,and,60Tb. periooic table and also in the superheavy region. 46 Visiting scientist from the Institute of Planetary Science. Stillwater Complex in Montana; bzzMt from the East Columbia Union CpUege, Takoma Park, Md. Pacif: Rise (Juan de Fuca), basalt from the Mid- A Precambnan biotite from the Ytte^by quarry near Atlantic Ridge (equator). rn?gnetite concentrate from Stockholm, Sweden. 100 lb of basalt from the Snakt River region; gabbro Analyses were made by C. A. Anderson of the Hasler from Ontario; hornblende from Quebec; pyroxenite Research Center, Applied Research Laooratory, Galeta. Calif. from Colorado and North Carolina. Samples were also taken from certain mills in which ore concentration processes were thought likely to concentrate the super- heavy element. SEARCH FOR SUPERHEAVY ELEMI NTS At the time of writing, fission-fragment activity has IN NATURE: EKAPLATINUM been detected in samples from only one source - a flue J. S. Drury dust from a Western lead refinery. The source of this activity has not been identified. An international search is currently in Droeress t."> find certain superheavy elements (atomic numbers 108—120) in nature. Members of several different SEARCH FOR SUPERHEAVY ELEMENTS groups in the Chemistry Division are collaborating in IN NATURE: EKAOSMIUM this effort. The work reported here and in the following D. A. Lee contribution is concerned primarily with the discovery of ekaplatinum, atomic number 110, and ekaosmium, Although the volatility of osmium tetraoxide is well atomic number 108. known, very little general information exists concerning An assumption was made that the chemical properties the solution chemistry of osmium. This information is of element 110 would be as noble as, or more noble desirable, not c '*y to serve as a basis for predicting than, its light predecessor in Group VIII. Using this where in nature ekaosmium might be concentrated but criterion, we sought to identify and select samples in also to suggest how this superheavy element might be which the superheavy element would tend to be further concentrated once a natural or artificial concen concentrated, either naturally, in the earth's rocks, or trate of the element is available. For these reasons we artificially, by man's intervention. The natural or have studied the distribution of osmium between two artificial concentrate would then be concentrated immiscible phases under controlled conditions. Extrac further before being analyzed by some distinctive tion coefficients of Os(VIII), D = [OsJorg/[Os] aq,were analytical technique, such as spontaneous- or indue i determined by measuring the extraction of fission counting, or multiple neutron counting. osmium(VIII) from aqueous solutions by CC14 as a Our first choice for samples judged likely to be function of equilibrium pH, the concentration of naturally concentrated in element 110 was ultrabasic different alkali-metal hydroxides, NIL;* concentration, rocks known to contain platinum values, such as the concentration of various mineral acids, osmium harzburgite or dunite from the Transvaal region. These concentration, CC4 concentration in heptane, and the rocks were finely ground, and by means of the effect of various oxidants added to maintain osmium as "fire-assay" technique, all noble-metal values were OsTVIII). From the slopes of the plots of log D vs the concentrated in a l-rr.g be id of carrier gold. This various parameters, the osmium species involved were operation could be expected 10 concentrate any super proposed. heavy noble elements present in the initial sample by a From the loading isotherm (Fig. 2.10) it was con factor of 15,000. The gold beads were dissolved in aqua cluded that the extracted osmium species was in the regia, and all noble elements were electroplated as thin same polymeric state as the aqueous species Osmium films on nickel disks. These disks were then monitored tetraoxide in organic solvents is monomeric:' therefore for fission in 2ff counters which were set to reject 0sO4 in acid solution is monomeric. particles having energies less than 15 MeV. The limit of Osmium tetraoxide was extracted from solutions of detection of this method was estimated to be about 1 HN03, HCl. H2S04. and HC104 over a concentration ppb. assuming a favorable fission half-life for the range from 0.1 to 5.0 .V for each acid. A slope of 0 was ekaelement. determined for the plo' of the extraction coefficient Fallowing is a list of typical samples examined: against acid activity for each acid, and there was no platinum-bearing rock from the Transvaal' dunite from difference in the magnitude of the extraction coef Nort't Carolina and from New Zealand: norite from the ficient for a particular acid. It was neoe^ary to 47 maintain osmium as Os(VHI) in the tracer solution with 3 10" A/K!04. The effect of ammonium ion concentration on osmium tetraoxide extraction was measured in a series of experiments in which the ammonium ion concentra tion was varied from 0.005 M to 5.0 M in 0.1 Mand 0.5 M HN03. There was no change in the extraction coefficient over the entire range of ammonium ion concentration in either acid concentration. The dependence of Os(VIlI) extraction upon equi librium pH was studied using KOH, NaO^ UOH, and NH4OH. Os(VIII) extracts readily from acidic solu tions; however, from basic solutions the extraction coefficient is smaller. Also, osmium is more easily reduced in basic solutions. A plot of log D vs equilibrium pH for the various bases is given in Fig. 2.1 i. The slope for KOH and NaOH solutions of 0s04 was -1, which indicates that the osmium species in Kg. 2.11. Dependence of Extraction Coefficient 00 pH. those basic aqueous solutions was 0s04K0H and 0s04-Na0H. K[0s04(0H)H20J has been described a-, a possible compound formed by the reaction of 0s04 1 with KOH. For NH4OH solutions of 0s04, the plot of log D vs pH proceeds smoothly from slope 0 to —2, indicating a stepwise addition of two hydroxyls to To determine whether or not CCU formed a complex osmium. The species obtained by using LiOH was not with 0sO4 and thereby extracted osmium, an experi easily determined. At high pH the basicity of the ment was made to determine CC14 dependence. The solution increased very minutely with a large increase in molar concentration of CCU in heptane was vaned LiOH concentration. The best estimate for the slope from 0.00325 M to 10.4 M (100% CCI4 ), and a series of was —4, which indicates a species Os04-4LiOH in the extractions of 0s04 were made from 5 M HN03. Over aqueous phase. the entire CCU concentration range the extraction coefficients were the same. Therefore CC14 is not a complexing reactant but simply extracts Os04 as a neutral species. OBNL-PWO. 70-4979 1—1 1 r 1 111 T 1 I I I I !| 1 1 I I iou In all the«c experiments special precaution had to be taken to keep osmium oxidized to OsfVIII). In early 50- exoennents the osmium tracer assumed to be 0s(VHI), was actually Os(VI), and from acid solutions u SU0P£= 1 the extraction of OsfVI) was first order with acid g20 activity: each osnaum atom extracted w?« hound to one X acid molecule. Usually KI04 was added to the tracer solution and was the most effective oxidant used; (9 however, in basic lithium solutions insoluble UI0 tions. For the lithium systems, H?02 proved effective. (NrLj^SjO, was also tried, but it did not keep osmium O 2 oxidized in all cases. -I I I I I I I l 1 L—i 1 1 : il _i l L_l 0.2 as t 2 «0 20 50 0*(H) IN AQUEOUS PHASE (n*) 1 Fig. 2.10. Londug Isotherm for O>04 Extraction. W. P Griff!**. Qum. Rev. 19, 254 (1965). 48 JRftL-0W6. 70-3*94 ELECTRON-TRANSFER ABSORPTION IN SOME T-T \ ' I ' I I ' I ' I ACTINIDE(III) AND LANTHANIDE(HI) 3 - TRICYCLOPENTADIENIDES AND THE STANDARD IMC CATION OXIDATION POTENTIALS1 L.J.Nugent G.K.Werner3 P. G. Laubereau2 K. L. Vander Sluis3 Electron-transfer absorption bands have been de tected in the reflectance spectrum of a single micro- Fig, 2.12. Example of the Tetrad Effect. Variation of log K crystal of 249CfCp (Cp~ = cyclopentadienyl ion) at with q for lanthanideUH) ?pecies in 0.6 F DEH |C1MP] 3 (benzene) vs 11.4 F LiBr + 0.5 F HBr (from ref. 1). room temperature. The lowest energy band appears near 5510 A; this is assigned as electron-transfer absorption on the basis of a correlation with the californium standard II-III oxidation potential (+2.0 V) half-filled-shell effect in the electronic structure of the and corresponding data in the lanthanide series for the Gd(III) or the Cm(III) ion, there is a minor dip at the EuCp3, YbCp3, SmCp3, and TmCp3 compounds. The % point between elements 60 and 61 and at the % fact that electron-transfer absorption is not observed in point between elements 67 and 68. AmCp3 above 3600 A permits a lower limit of +2.6 V Analogojs tetrad relationships appear in their Ln(III) to be set for the americium standard II-III oxidation and An(III) data for other liquid-liquid systems, in the potential. Prospects for the detection of electron- data of others on reversed-phase partition chroma transfer absorption in the other lanthanide and actinide tography, and in several other comparative properties tricyclopentadienide analogs are discussed' in relation for these series.3"6 Thus the effect is in general well to theoretical estimates of the standard II-III oxidation established for the Ln(III) and An(III) series; this has potentials for these series. led Peppard et al.3 to make the following general hypothesis: "In systems involving all 15 lanthanides(III), the 'Abstract of paper appearing in Proceedings of the 8th Rare-Earth Research Conference. Reno, Nev., Apr. 19-22, points on a plot of the logarithm of a suitable numerical 1970. measure of a given property of these elements vs Z may Visiting scientist from Federal Republic of Germany, Bonn. be grouped, through the use of four smooth curves Physics Division. without inflections, into four tetrads with the gado linium point being common to the second and third tetrads and the extended smooth curves intersecting, additionally, in the 60-61 and 67-68 Z regions. In a THEORY OF THE TETRAD EFFECT IN THE similar plot for actinides(IH), an analogous tetrad ef LANTHANIDE(III) AND ,iCTINIDE methylphosphonate (C1CH2 )P0(0C6 H, 2 C2HS)2 in static theories attemptii to account for the solvation benzene and an aqueous solution of 11.4 F LiBr + 0.5 F energy as a function of these Ln(III) radii, such as the HBr at 22 ± 2°C. The equilibrium constant K \s the simple theory of Born8'9 or others,10 show no tetrad ratio of the concentration of the metal cation in the effect because the corresponding effect is not apparent organic phase to that in the aqueous phase. These in the ionic radii. Cunningham8 has calculated the workers point out that in addition to the expected hydration energies Tor some of the Ln(IH) and An(III) discontinuity at the 72 point, attributable to the ions from the Born equation; he shows this interaction 49 with H20 to be quite large (~36 eV), and similar value minus (% )S(S + I) from Eq. (1) is listed in Table interactions are undoubtedly influential in stabilizing 2.6 as the coefficient of El for the ground state of each these HI oxidation states in most media. There is nc Ln(H!) and An(III) ion. The product of £*' times the evidence from such calculations, however, that classical coefficient of Ll the spin-pairing energy, is plotted vsq solvation-energy variations with the cemmonly ac as a solid line in Fig. 2.13 for the Ln(Ill) series and as a cepted cation radii7 indicate a tetrad effe.i in either the solid line in Fig. 2.14 for the An(III) series. The Ln(lll) or the Au(IlI) series. variation in the spin-pairing energy here with q shews Next in magnitude after the classical solvation energy the half-filled-sheli effect, and this is undoubtedly why is the qu?r. turn-mechanical interelectron-repulsion the latter is observed experimentally. This does not, energy Hr of the q electron* in each fi configuration. however, explain the one-fourth- and three-fourths- This interaction removes the degeneracy of those terms filled-sheli effects. In order to explain the latter we with different L and S, or of the same L and S but must develop Eq. (1) to a better approximation, different seniority quantum number, leaving the J and !n the original development of Eq. (1), the terms 2 3 Mj degeneracy intact. The value of HF is different for linear in the Racah parameters E and E were not the free ion and for the ion in the solution, or in the explicitly considered,1' probably because they are present cases for the two interfaced solutions, and, as mainly smaller and more difficult to generalize than the will be shown, its variation with q or Z has the same symmetry as the tetrad effect. 1 J^igensen ' has developed a convenient treatment of ORNL- OWG. 70-3692 T T Hr by noting that it can be expressed to a good I ' i T T approximation for/1' configurations simply by -10.0 - 1)£<> Hr(q. s) = ^~ + (%) -aWS+DE1 , (1) where S is the total electro., spin angular-momentum quantum number in the usual Russell-Saunders basis for the state of interest in tiie fc configuration (in the present case the ground stele), < > indicates a degen eracy or 27 + 1 weighted jverage over each term in the configuration, and E° and El are the first two Racah parameters of interelectronic repulsion. The first two terms in Eq. (1) represent the degeneracy-weighted average vaiue, or baricemer, of the entire configuration, while the last term gives the deviation of the baricenter of those terms with quantum number S from the Contribution from baricenter of the entire configuration. The first, £"'dependent terms E°-dependent term in Eq. (1) is simply a quadratic monotonically increasing function of q which, as such, cannot account for the tetrad effect; therefore it will not be considered any further here. The test two, £'-dependent terms are what Jdrgensen calls the -^--i»—Contribution from / -j- spin-pairing energy. Experimentally determined values I \ independent term»»' for £*' are listed in Table 2.6 for the Ln(III) and An(III) series. Using these values with the last two terms of Eq. (1), we show next that the variation in the spin-pairing 7 W 13 energy with q has the same symmetry as the half-filled- Q shell effect. Fig. 2.13. Ground-State Intetelectronic-Repulsion-StaV'Jiza- Jdrgensen'' has noted that for any ft configuration tio* Energy for the Ln(Il!) Aqueous Ions vs q for the 4/4 2 (%XS(5 + 1)> =( 732>7(1 -{q- l)/(4/+ 1)1,and this Configurations. 50 first three terms. For the ground electronic states of the 2.6. The product of E3 tunes the coefficient off3 is ff configurations, the coefficients of the E? -dependent plotted vs q as the dotted ine in Fig. 2.13 for the terms are all zero, so they make no contribution here to Lii(U!) series and as the dotted line in Fig. 2.14 for the the tetrad effect. The coefficients of many of the An(UI) senes. It ^n be seen there that the theoretical £3-dependent terms, on the other hand, are not zero, one-fourth- and three-fourths-filled-shell effects have and they display the exact q dependence required to the same sign as the half-filled-shell effect and that they match the one-fourth- and three-fourths-filled-shell ef are about a factor of 6 smaller in magnitude. fects. These coefficients for the ground electronic states The variations in log K at the one-fourth-, one-half-, are listed in Table 2.6; they *re easily obtained with the and three-fourths-filled points, constituting the tetrad aid of .tyrgensen's paper on the refined spin-pairing- effect, can now be shown to follow from simple energy theory for electron transfer bands, where their thermodynamic equilibrium considerations. Thus, tak consecutive differences are presented.12 Experi ing the standard free-energy change mentally determined values for E3 are also listed adjacent to the corresponding values for E1 in Table AG° = Uf - 7*AS° = -230RTlogK (2) Table 2.6. Parameters of Significance for the Theoretical Deve^inent of the Tetrad Effect in the Laathaaide Ground a £*(V)*.b Coefficient Coefficient Element (III) a E' (V) * 1 3 State off off Ce 2F 1 0 0 3 5/2 Pr 2 0.56389 0.0579 -?/13 -9 Nd /9/2 3 0.58758 0.0602 -27/13 -21 Pm ''4 4 0.61019 0.0652 -54/13 -21 Sm hSI2 5 0.68152 0.0689 -90/13 -9 Eu 6 0.69095 0.0691 -135/13 0 Gd 7 0.7142 0.0722 -189/13 0 Tb '*. 8 0.74655 0.0755 -135/13 0 Dy "IS/2 9 0.75872 0.0756 -90/13 -9 Ho X 10 0.79851 0.0774 -54/13 -21 E» 715/2 1! 0.83934 0.0802 -27/13 -21 Tni X 12 0.88552 0.0836 -9/13 -9 Yb F7/2 13 0 0 2 Th /5/F 2 1 0 0 Pa 2 (0.320) (0.032) -?,'13 -9 4/ U '9/2 3 0.3859 0.0355 -27/13 -21 Np '4 4 0.4208 0.0394 -54/13 -21 Pu **5/2 5 0.4621 0.0434 -90/13 -9 Am 7 6 (0.517) (0.047) - 135/13 0 8'„o Cm A7/2 7 0.5730 0.0495 -189/13 0 Bk >6 8 (0.616) (0.0540) -135/13 0 Cf /*15/2 9 (0.667) (0.0577) -90/13 -9 Es (0.0614) !'. 10 (0.716) 54/13 -21 4 Fm i (0.765) (6.0650) -27/13 -21 J\rn r. Md X 12 (0.815) (0.0687) -9/S3 -9 No hT/2 13 0 0 aRef. S3 for the Ln(lll) aqueous ions. bJ. B. Gruber. W. R. Cochran, J. Conway, and A. T. Nicol. / Chem. Phys. 45, 1423 (1966), for the An(III) ions in various crystalline hosts. The values in parentheses '.vere obtained by a linear extrapolation against atomic number. 51 ORNL-DWG. 70-3693 aqueous phase. From Fig. 2.13 the E3-dependent term -9.0 T i contributes to about -1 to -2 eV in the aqueous phase at the one-fourth and three-fourths points, so thi> 3 ±: -8.0 - requires the value of E in the organic phaw to be o smaller than the value of E3 in the aqueous phase by 3 o about 1 to y2%. Since variations in E values by this Id 7.0!- amount are typical for the Ln(III) ions in various z ! 13 UJ media, these considerations account very well for the z o one-fourth-and three-fourths-filled-shell effects. * -6.0 h The half-filled-shell effect in Fig. 2.12 can now be independently estimated from the above results for the -0.U one-fourth- and three-fourths-fiiied-sheii effj*cis, since 3 (A variations of 1 or %% in E between various media are • Z commonly accompanied by corresponding 1 or %% o S -4.0 variations in El.'3 From the latter and from Eq. (4), a3 . (log K)' - — 1 at the half point: this is in reasonable u accord with the data of Fig. 2.12, considering that the a: -3.0 Contribution from dip here is growing in all the way from the q - 1 or q ~ z £~'dependent terms ao: 13 points following the El -dependent contribution i- -2.0 shown in Fig. 2.13. _j Id It is worth noting that observed differences in £*' <£ UJ r- between two media and the corresponding differences Z -1.0 3 13 ^.Contribution f torn £*/ 4 in E are not always of the same sign. This means \ dependent term-*/ that although the one-fourth- and three-fourths-filled- I N I shell effects will always occur in the same direction, ;he 7 11 13 half-filled-shell effect can go either in the same direc 9 tion or it can go in the opposite direction relative in the Fig. 2.14. Ground-State IntereJecrjonk-Repubion-Stabliza- others, depending upon the particular media involved. tion Energy for the An(III) Ions vs q for the Sf* Configuration*. THUS it may be possible to find an experimental arrangement which shows an "alternating" tetrad ef fect. In conclusion, it is emphasized that the theoretical for the Ln(III) or An(III) ion between the aqueous treatment of H above is based on well-defined values phase and the organic phase and talcing r for the L and S quantum numbers, that is, upon Russell-Saunders states. It is well known that the AG°' = AH°' - TA$°' = -2.30/? r (log £)' , (3) Russell-Saunders basis is only an approximation when where by the prime v,e mean only those components in the relativistic spin-orbit (?LS) interaction terms are each term of Eq. (2) which are accounted for by the included in the theoretical treatment of f* electronic l s 13-1 5 E -dependent and the E -dependent interelectron- energies. It is a simple matter to include first- repulsion terms, and making the reasonable assumption order spin-orbit interactions in the above consider that AS°' can be neglected in Eq. (3), we obtain ations, and the coefficients of these terms also display a q dependence matching the one-fourth- and three- U-r = -2.30RT(\ogK)' (4) fourths-filled-shell effects.1! Estimates for both series indicate, however, that these fust-order contributions An examination of Fig. 2.12 shows that at the aie neither as sharply q dependent nor as iarge as those one-fourth- or ihree-fourths-filled points, the tetrad originating from the E3 -dependent term; so it is not a effect diminishes log A by about 0.2. and this must be bad approximation to neglect thern here. A treatment accounted for by the E*-dependent contribution in Fig. of higher-order spin-orbit interactions, on the other 2.13. Accoidingly, setting (log K)' - -0.2 in Eq. (4),wc hand, is not simple, but it isn't necessary either, since obtain AH°' = 0.01 eV for the difference between the the present approximate treatment provides an ade energy of the £3-dependent term in the organic phase quate theoretical substantiation of the observed tetrad and the energy of the E3 -dependent term in the effects for both the Ln(III) and the An(IH) series. 52 1D. F. Peppard. G.V. Mason, and S. Lew)-, / /«©•* AWi scribed by Fischer and Fischer5 for the heavier !an- C*em 31. 227k *1. I idelis and S. Siekierski./. Chroma roe. 17.542 (1965). 1 Supported by Bundesministeriurr: fur wissenschaftliclK J. R. Peterson and B. B. Cunningham. Inorg. Nad. Chem. Fondhung. Bonn. Federal Republic of German.*. Utters 3,327(1967). listing scientist from the Cireinisuy Department. Louisiana ~i? U. Cuf!«w*haai. "Comparative Chernhtry of the Lan State University, Baton Pouge. thanide and Actinide Elements," paper presraicd it th? XVII 3P. G. Laubereau and J K. Bums. Chem. Dir. Ann. Progr. International Ccugress of Pure and Applied Chemistry, Munich. Rept. May 20, 1969. ORNL-4437. p. 34; Inorg. Chem. 9,1091 1959. pp. 64-81. (1970). 9 W. M. L lower. The Oxidation States of the Elements and 4 P. G. Lauberca.-. i. A. Fancy, and J. H. Bums. "An Their Potentials in Aqi..cus Solution, Prentkw-H-ill, New York. Improved Synthesis of Trieydopentadieny; Complexes in 1952. Microquantities," following contribution, this report. 10 E. A. Moerwyn-Kughes. Physical Chemistry, chap. 18. 5 E. G. Fischer and H. Fischer. /. Organometal Chem 6,141 Pergamon, New York, 1%1. '1966). 1 *C. K. J^rgensen, Orbital: in Atoms and Molecules. Aca demic, New York, 1962. ,2 C. K. Jtaensen, MoL Phys. 5,271 (1962), Table II. TaWe 2.7. CiyvtaHoaTaphic Data for Organomeraific 13W. T Camall, P. R. Fields, and K. Rajnak, / Chem, Phys. Compounds of Actaudes and Lanthanidrs 49,4442,4443,4447,4450 (1968). 14J.G.Conway./ Chcm. Phys. 4u, 2504 (1964). Unit-Cell Dimensions (A) Compound Space Group i5J. ^. Gruber and J. G. Conuay, /. Chen Phys. 34, 632 a b c (1961). ftrtCjHsb 14.20 17.62 9.79 Pbcm Nd(C$H$)3 14.24 1T.66 9.77 Pbcm PnHCjHjh 14.12 17.60 9.76 Pbcm INVESTIGATIONS ON THE ORG ANOMETALUC Sm GdfC5Hs)3 14... -f 17.52 9.65 Pbcm P. G. Laubereau1 J. H. Burns L. Ganguly2 TMCsHjb 14.20 17.28 9.65 Pbcm Tm(CsH$)3 19.98 13.82 8.59 Pnam or Pna21 Our studies on the use of cyclopentadiene, C$ H6, as a Cm(C5H$)3 14.16 17.66 9.69 Pbcm ligand for actinide and lanthanide elements have been Bk(C$H5)3 14.11 17.55 9.63 Pbcm Cf(C H ) extended to the synthesis and growth of crystals of the 5 5 3 14.10 17.50 9.69 Pbcm Yb(C5Hs)2Cl 13.57 16.21 13.60 Plxlc following compounds: Cm(C5Hs)3, Nd(CsHs)3, = 92°3C' Eu(C5H5)3, Gd(C$H5)3, Tm(C5H$)3, Yb(C,Hs),CI. 0 a and ?r(C5Hs)3CHIN, where CHIN = cyclohexyl- Pr(CsH5)3-CHIN 8.03 21.65 11.55 /»2i/<- isonitrile. 0 « I05°9' The Cm(Cr,H5)3 was synthesized by the microtech 3 nique used to prepare Bk'C3H5)3 and Cf{C5H5)3; "CHIN = cyclohexylisonitrile. YbtXJ5H5)2Cl resuiie.1 from the same method when YbCl3 and Be(CsH5)2 were employed. Gram quantities of Gd(C5H5)3 and Tm(CsH5)3 were made by reaction AN IMPROVED SYNTHESIS OF of the respective trichlorides with a melt of TOCYCLOPENr ADIENYL COMPLEXES Mg(C$H5>2. Reaction >f EuCl3 and molten Be(C5 H5 )2 IN MICROQUANTITIES at 70°C yielded EuiC H ) ; gram amounts were 2 5 5 3 P. G. Laubereau' J. A. Fahey J. H. Burns subsequently isolated in analytically prre form by 1 4 extraction with pentane. The HSP of NdF3 i«i picparing Previously we prepared CmaVris).,, Bk(C,H,)3 4 4 s Nd(CsH$)3 is described elsewhere. A procedure de Cf(CsH5)3 and [Bk(C;Hs)2CI]2 by reacting the 53 actinide trichlorides with Be actinide oxides to the anhydrous chlorides. Usually this 1 P. G. Laubereau J. H. Burns gave good results, but in some rases th? HCl reacted with the stopcock grease in the system and produced It was found that in the course of a reaction of BkG3 interfering oils. Hence a different path of synthesis was with Be 2MF3 + JB^CjHj), [at 70°C in molten 2BkCl3 +28^0^5^ * [Bk(C$H$)2Cl]2 + 2Be02 . B^CsHs)-.] -2M(C Hs) +3BeF , 5 3 2 The new berkeiium compound was isolated together where M = lanthanide or actinide element, was studied. with BkCCsHs^ in a quartz capillaiy by high-vacuum The fluorination of the lanthanide or actinide oxides sublimation above 220°C. Identification was achieved was carried cut in a separate funuce. The fluorides by comparison of the x-ray powder pattern with that of were stable in air and could be transferred easily into dicydopentadjenylsamarium chloride. This latter com 4 the reaction system described previously;4 there they plex was found by mass spectrometry to exist as a reacted with high yield to form tricydopentaditnyls. dimer. Because of the very similar properties of the berkeliu and samarium complexes, for example, By this method Nd(C5H$)3 and ^AmXCjHs), were synthesized; they were identified by their x-ray diffrac powder p«ii ns, needle-like crystal morphology, and tion pattenis. The d values (A) for the strongest sublimation temperature, the new berkeiium compound is assigned the formula: [Bk(C5 H$ ^CI] 2. powder lines of Am(C$Hs)3 are: 7.42, 7.11,5.92,4.85, 3.98, 2.95, 2.47, in full agrement with the ones Dicyclopentadienylberkelium chloride is amber, somewhat lighter in color than Bk(C H ) . Optical obtained from orthorhombic tricydopentadienyls of s 5 3 5 the actinides and the iaiiiuanides. spectra in the 400 to 990 nm range were recorded and s are shown in Fig. 2.15 with the spectra of Bk(C5Hs)3 ind Bk3* for comparison. 'Supported by the Bundesministerium fur wissenschafthche Forschung, Bonn, Federal Republic of Germany. 2Grad»2ie student. University of Tennessee, Knoxv^le Supported by Bundesministenum fur wissenschattliche 3 Forschung, Bonn, Federal Republic of Germany. P. G. Laubereau and J. H. Burns. Inorg NucL Chan. Letters 2 6,59(1970). P. G. Laubereau and 3. H. Burns. Inorg. Chem. 9, 1091 4P. G. Laubereau and J. H. Burns, Inorg. Chem 9, 1091 (1970); Chem. Div. Ann. Progr. Rept. May 20, 1969. ORNL- 4437, p. 34. (1970); Chem. Div. Ann. Progr. Rept. Max 20, 1969. ORNL- 3 4437. p. 34. P. G. Laubereau. Inorg. Nucl Chem. Letters, submitted. 4 5 P. G. Laubereau, Inorg. Nucl. Chem. Letters, submitted; Mass spectrum recorded by W. T. Rainey, Jr., and W. H. also. P. G. Laubereau and J. H. Burns. "The Formation of Christy, Analytical Chemistry Division. Dicyclopentadienylberkelium Chloride," following contribu SL. J. Nugent, P. G. Laubereau. G. K. Werner, and K. L. tion, this report. Vander Sluis. work in progress. 54 ORNL-DWG. 70-4061A • J" t ~\ S 10 O- «r 8 CD < cc c 3 i I A Z o ^«vy. o UJ o: [BMCgH&Clfe i . L__ 25000 20000 15000 10000 ——WAVE NUMBERS (cm'1) 1 i ' • i I • i i i I i i • • I i i i i I i • • i I • i • • I • i . . I • • i i 1 i i i i I i i i i I i i i—1 i ; | 1 i 400 450 500 550 600 650 700 750 800 850 900 950 1000 WAVELENGTH (nm) —•» 249 249 Fig. 2.15. Reflection Spectra of Bk(CsHs)3 and ( Bk(C5Hshaj2 Microcrystals and Ac Absorption Spectrum of 5.6 X 3 2< 9 3f 20~ M * Bk in 1.0 M DCI04. Spectra A and B recorded with dry-ice-cooled S-l phototube detector, spectra C andD recorded with S-5(1P28) phototube detector. Spectra A and C recorded AA m jfter the isolation of the complex. Spectra B and D recorded 2 hr after '.ne isolation of the complex (no significant changes observed ifter 44 hr;. Data for absorption spectrum of Bk from R. D. bay ban, J. R. Peterson, and J. R. Stokely, personal communication. 55 kARE-EARTH AND AMERJC1UM CHELATES REACTION OF AQUEOUS LANTHANIDE CHLORIDE SOLUTIONS WITH M.D. Danford J.H.3ums 1 2,2-DIMETHOXYPROPANE C. E. Higgins J. R. Stokely, Jr. W. H. Baldwin W.H.Baldwin T.H.Handley1 Pn.-panticn of C"Ln(hfa)^ Using Cation Exchange Existing methods for the preparation of anhydrous Resiu. - Study of these chelates, where Ln is lan lanthanide and actinide trihalides, which are used for thanum or europium and hfa is the anion from the synthesis of many derivatives including some l,l,l,5,5,5-hexafluoro-2,<-pentanedione, has con organometallic compounds, require elevated tempera tinued.2 An aqueous solution of Cs(hfa) was passed tures and sometimes high pressure. In our search for into a column of Dowex 50 loaded with lanthanide ion, milder reaction conditions we found that the well- and the cesium lanthanide tetrachelate was obtained known reaction of ketals with water, from the eluate in 70 to 85% yield. In a modification of this synthesis, the lanthanide was exchanged onto the CH3C(OCH3)2CH3 +H20^ resin, and then resium ions were exchanged onto the CH COCH + 2CH OH, excess resin sites. CsLn(hfa)4 resulted in 83% yield 3 3 3 when the resin was eh ted with Cs(hfa). The identity of has already been applied, however a priori, to the the product was established through its melting point dehydration of several crystalline hydrates. We have anrf through mixed meiting point measurements with studied this reaction and have attempted to extend its authentic specimens prepared earlier.2 use to aqueous solutions of lanthanide chlorides that The advantages of using the cation exchange resin for result from the action of oxide with excess hydro the preparation of lanthanide and actinide compounds chloric acid. An endothermic reaction takes place when include relatively easy separation from other cations 2,2-dimethoxypropane is added to the aqueous solution and from excess acid. of lanthanide chloride. The reaction mixture is dried in vacuo, and in addition to the anhydrou* lanthanide Preparation of Cs2La(hfa). - The monohydrate, s chloride, a small amount of nonvolatile black residue C$La(hfaVH 0, was dissolved in n-butanol, and part 2 also remains. Quantitative estimate; of the amount of of the solvent was removed until crystals separated. The this residue are being made. The ratio of G/Ianthanide product, Css La(hfa)5, mp 226-27°C, was identified by in the product was the expected 3.00 ± 0.05. analysis for C, H, Cs, La, H20, and equivalent weight. Derivative? of this type have considerable interest since the lanthanide atom may be ten coordinated, a rare Analytical Chemistry Division. situation. Cs243Am(lifa)4.2'3 - This cheiate is a yellow crys 6 talline material that sublimes at 130 to 140°C at 10~ PHOTOCHEMICAL REACTIONS INITIATED BY torr and melts at 193-94°C. The product decomposes 2 U02 *. REACTION OF BUTYRALDEHYDE by self-radiolysis; after eight days in air the melting WITH DIETHYL MALEATE point had fallen to 168—174°C. In another instance, in which the compound stood in air foi about one month, W. H. Baldwin the residue contained significant quantities of AmF 3 The condensation (formation of C-C bonds) of (identified by x-ray powder diagram). aldehydes with diethyl maleate, 243 Americaim-trfe(2,2,6,6-tetramethyl -3,5 -beptzne- 2 3 dione). ' - This compound sublimes at 124 to 135°C RCHO + EtOOCCH=CHCOOEt - at 10"5 torr and melts at 216 to 2183C after softening at 205°C. RCOCH(COOEt)-CH2COOEt, has previously been accomplished in the presence of dibenzoyl peroxide.1 This reaction using butyraldehyde A naly tical Chemistry Division. has now been carried out photochemicaUy with uranyl 2M. D. Danford. C. E. Higgins. and W. H. Baldwin. Chem. Div. ion activation. No attempt has been made to find Ann. Progr. Rtpt. May 20, 1969, ORNL-4437, p. 36. optimum vonditions, but a 35% yield of diethyl 3M. D. Danford and J. H. Bums. Chem. Div. Ann. Progr. butyrylsuccinate was obtained along with an equal Rept. May 20, 1968. ORNL4306. p. 44. weight of higher-boiling material, evidence of extensive 56 reaction. Tois reaction is useful for the synthesis of While our vor'c on Nd(thdn was in progress, a high-molecular-weight branched polar aliphatic com completed structure determination of the isostructural pounds whose specific interactions with metallic ions compound Pr(thd}j baser1, on film-recorded data wa* produce metallic salts soluble in organic solvents. reported.2 Using these workers' parameters as a starting point, we refined ihe structure of Nd(thd)3 with our data collected by a diffractometer. There are no !T. M. Patrick,/. Org. Chem. 17,1009 (1952). important differences between the two results withii. the error limits of the two determinations. THE CRYSTAL AND MOLECULAR STRUCTURE The most interesting structural feature is the ex OF TRIS(2^,6,6-TETRAMETHYL-3,5- istence of dimeric molecules, Nd2(thd>6, in which two HEPTANEWONATO)NrODYMlUM(IIl) of the chelating oxygen atoms form bridges between AND AMERICIUM(IiIi neodyirium atoms. Through dimension, each neo- M. D. Danford J. H. Burns dymium atom achieves seven coordination by oxygen, more than possible in the monomer but still less than Our studies on the crystal structures of volatile normal for an ion of this size (0.995 A). Higher chelates of lanthanide and actinide elements1 were polymerization is prevented by the steric hindrance continued with the elucidation of the structure of from the bulky r-butyl groups of the ligands. The Nd(thd>3, where thd= 2,2,6,6-tetramethyl-3,5-heptane- molecular character of this crystal accounts for its dione. The analogous actinide compound Am(thd)3 was volatility and ability to sublime without decomposition. shown by x-ray powder diffraction to be isostructural The bond lengths in one Nd2(thd)6 molecule ob with it. tained from this determination are shown diagram- ORNL-OWG. 70-1456 46 13 ? "76 51 44 | o j* 20 *£S-26 33 " 73 7; >1 " '2 Fig, 2.16. Sclienatic Drawing Snowing fee Bond Lengths in One Nd(thd)j Doner. Atoms I and 41 are neodymhim; the remainder are oxygen and carbon atoms. 57 maticalty in Fig. 2.16. Average values Tor the standard CRYSTALL03RAPHC STUDIES OF ANHYDROUS errors (A) arc: Nd-0 (0.01): 0-C (002V. and C-C TR ANSPLUTON1UM TRICHLORIDES (0.02), except for terminal methyl groups, where the J.H.Burns J. R.Peteison* value is C-C (OJ03). The thermal parameters for the terminal methyl atoms are quite laige and have an A study of the crystal structures of the series of isotropics indicative of large librational motions. Mono- isomoiphous transplutonium trichlorides is in progress, clinic unit-cell dimensions are: Nd(thd)3,a = 1238(1) with the aim of obtaining a useful set of ionic radii for A, b = 28.08(2) A, c = 22.27(1) A.0 = 107.40(3)°:and the trivalen? actinide elements. The hexi^onal unit-cell 2 for Amithd)3, Sm(C9H7;,. by reaction of indenylmagnesium bromide different structure: it is isomorphous with crtho- s with anhydious SmG3 in ether solution, and we rhombic TbCl3. This implies dimorphism in CfCl3> purified the compound by extraction with toluene. and the orthorhombic structure is probably the high- Trisindenyteinarium forms deep red-brown platelike temperature form. The change in structure type occurs crystals which are very sensitive to moisture and air. in the actinide series at about the same ionic size as in Single-crystal studies with a precession camera and a die lanthanide series. It is reasonable that this change corrtputer-controlled x-ray diffractometer yielded the results from the actinide (lanthanide) contraction, since orthorhomt ic unit-cell dimensions and space group: a - in the hexagonal form the metal is nine coordiiated. 15.568(3) A, b = 31.348(8) A. c = 8.265(2) A, Fbca. while in the orthorhombic form it is eight coordinated. Subsequent strucutre analysis by Patterson methods foir.o the samarium n'oms to be locsied in the general Table 2.8 summarizes the results, including the eightfold positions of Ptcf. Electron-density maps then unit-cell dimensions, refined positional parameters, and showed the positions of the 27 independent carbon tentative ionic radii derived from these. atonu. also in general positions. Refinement is still in progress, bui a qualitative description of the structure can be given as follows: Each samarium atom is bonded to the ir-electron system of the cydopenudienyl ring of each of three indenyl moieties. The centers of the five-membered rings form an approximately tqnilateral 1 Chemistry Department. University of Tennessee. KnoxviUe. triangle with the samarium atom at its center. Distances 2 J. R. Peterson and B. B. Cunnu.fhvn. / Inorg. NucL Chen'. between these trisindenylsamarium molecules are 30,823(1968). normal. 3 J. H. Burns and J. R. Peterson. Chem. Dh. Ann. Prop. Rept. May 20, 1969. ORNL-4437. p. 33. *S. L. Green and B. B. Cunningham, Inorg. NucL Chem. 'Department of Chemistry. University of Alabama. Uni- Utters 3, 343 (1967). veisity. 5J. D. Forrester. A. Zalkin. D. H. Templeton. *nd J. C. 2 Supported by the Federal Republic of Germany. Bonn. WaUmann. Inorg. Chem. 3, 185 (1964). 38 TahkZA. Data for' lomc Conpovaa tu * c Space Group X C\ •a Radios (A| AmCh 7.3*2 4.214 Ph^jm 0.38772 0 30187 0.984 Cnn3 7.374 4.1*5 Pfiyfm 0.38790 0.30127 0.973 BfcCI3 7.3*8 4.12V hiyjm CfClj 7.393 4.090 P6y/m CKI3 3.869 11.75 8.56! Cmcm THE TRANSURANIUM RESEARCH LABORATORY and to produce is'Uopica'iy pure 244Cm for the ISOTOPE SEPARATOR investigation4 ot states in 240Pu. -nd it will be used to enhance the ,4*Sm content of a second-pass calutron L.D.Hunt C.E.Bemis,Jr. l4 5 product in an attempt to find *Sm in nature. A description of die 150-crn-radius laboratory isotope separator installed in the Transuranium Research Lab 1 1 L. D. Hunt and C. E. Bonis. Jr.. Chen Dhr. Ann. Progr. oratory has been induded in an earlier report. This RepL Mar 20. 1969. ORNL-4437. p. 37. instrument is now fully operationa! and has been 2C. E. Bonis. Ir. R. J. SiVa J. £ B«dow. and A. M mtegrated into the nudear researd. activities of the Friedman. "Long-Lived Spontaneous-Fission Isomerism ic Transuranium Element Research Group. 24' rV?." another contribution *n this chapter, this report. The majority of our research separations have been 3C. E. Bonis. Jr.. R. E. Druschrf. and J. Halpcrin. \ucl Sn. with the actinide elements to provide isotopically Eng. (in press). enriched sources for nudear spectroscopic investigation 4C E. Beaus. Jr.. M. R. Sduuorak. and M. J. ZtsOa. The 24 244 and snail quantities of enriched isotopes for integral Decay ot the Iso.-nrr> of °N'p and Cm and the Resultant States of 2 Pu." another contribution ia this chapter, this neutron cross-section measurements ihat are of im report. portance in the transuranium element production pro 5C. E. Bonis. Jr.. et *t. -"Search for the Occurrence of' 4*Sm gram at ORNL. in Nature." a contribution in chap. 1. this report. For the transuranic separations the charge material, usually <100 /ig, is evaporated from nitrate solutions onto quartz wool in a quartz sample tube and heated in A MASS INDICATOR FOR SECTOR ISOTOPE air to convert the material to the oxide. The tube is STTARATORS inserted into an outlet hole in the ion source, where the sample at ~500 to 700°C is chlorinated in situ at a J. R. Tarrant L. D. Hunt C. E. Bemis, It. controlled rate with CCL, vapor. Our overall efficiencies using this procedure aveiage S to 6% for the actinides. In a sectorial homogeneous magnetic field of strength B (G) a singly charged ion of ma (CC12F2), Freon-13 (CCIF3). and Freon-22 (CHC1F2) in an attempt to reduce the amount of CC14 breakdown The parameters which determine the position of a products deposited in the vicinity of the ion source. focused ion beam in the focal plane in the Trans The separator has been used in an attempt to identify uranium Research Laboratory Isotope Separator' are tne recently reported 241 Pu fission isomer/ to produce the potential through which the ions are accelerated isotopically enriched 17.8-day 253Cf for nuclear spec and the magnetic field strength of the 150-cm. 90° troscopic; and neutron cross-section measurements.3 homogeneous-field sector magnet. 59 S«nce both of these parameters are independently Protection of the cydotron in the evtnt of such a adjustable for a particular tsotupe separation, we have • upture could be achieved by a fast-acting valve placed designed and constructed an instrument which provides between the radioactive target and the cyciotroa: in a digital indication of the mass in ami throughout .»ic case of target rupture, the vaive would close before the entire range of both the magnetic field and the shock wave could travel past it. The beam line and acceleration potential. This device allows for the rapid assocv2t;d vacuum pum^-s from target to valve would optimization of sli other separation parameters for a iiave to be decontaminated, but the cyclotron itself given experiment. could continue in operation. We use a rotating-coil gaussmeter (Rawson Lush Valves that dose a 2.5-cm opening in ^$6 msec lave model 9221) which provides z 31.25-Hz ac voltage been constructed previously.3 but their rapid operation proportional to the magnet!: field strength over the results from the ignition cf an explosive charge such as range 500 to 6000 G. Thk alternating voltage is gunpowder. These waives havr to be dismantled and converted to a dc voltage level using conunerciui* cleaned frequently 10 remove the residues of tb* available modules. A dc voltage proportional to the explosive mixture, and some of the valve parts become acceleration potential is derived from the reference deformed *fter a few firings because of the great impact divider string for the acceleration power supply (0 to 90 delivered by the moving valve plate when it slams shu* kV). Us-r.g a quadratic traraconductor with ippropriate in the valve sea:. Accordingly, we have built a rd-ible. normalization, the dc analog kvri proportional to the leak-tight valve tltat does not derive its fast ?UK>n from magnetic field strength is squared, and the ratio of this explosives. analog signal to the signal proportional to the accelera tion potential is taken using a four-digit ratio voltmeter according to Eq. (1). The calibration co istznts required to make the digital •"•- -SJ*S voltmeter read direcny in amu are determined experi mentally using known singly charged ion beams in the range 10 to 270 amu. The accuracy of our mass meter ov.f this range is approximately 0.25 ansu, which \s sufficient to determine either the position in the focal piane of a known ion beam or the mass of an unknown ion beam. 1 L. D. Kun! and C. E. Berais. Jr.. Chent DR. Ann. Progr. Rrr:. May 20. 1969. ORNL-4437. p. 37. £ . • C~"*v"*W A FAST-CLOSING VALVE TO PROTECT ORIC FROM RADIOACTIVE CONTAMINATION R. L. Hahn J. R. Tarrant 1 R. L. Stone L. D. Hunt 36«f *f* In our research with transuranium nuclides at the Oak Ridge Isochronous Cyclotron (ORIC). we have often irradiated tarj, *s of alpha-particle-emit ting isotopes2 suchas233U.23,Pa. 24,Am. 2$3Es.and 24*Cm.The Uiget material is usually deposited upon a thin foil, which serves as (he window between the cyclotron vacuum (~10 "* torr) and a chamber containing helium gas at pressures from ~0.2 to 2 atm. Thus the danger exist., should the foil rupture during irradiation.that a shock wave traveling at approximately sonic velocity in helium would carry the gas and some of the alpha-active material into ORIC. Fig. 2.17. DctaMs of til* Construction of the Fast Vshr. 60 This valve, shown in Fig. 2.17, consists of a movable measure of the effectiveness of the method. Timing plate that is held by an electromagnet, against the tests indicate that the valve closes ^30 msec after the tension of two compressed springs, above the cyclotron target foil is broken. beam line, h ihe current to the electromagnet is A closing time of 30 msec is unsatisfactorily slow for interrupted, as by shorting, the magnetic field rapid'v shock waves in helium (sonic velocity = 970 m/sec at collapses, and the springs then drive the plate down N.TP.). However annular baffles arc exnemely effec ward to close off a 2.5-cm opening in the beam line. tive in reducing the velocity and pressure of a shock The valve housing is water cooled to reduce thermal wave,4 and provided that they do not interfere with the effects caused by the cyclotron beam hitting the valve cyclotron beam reaching the target, they may suffi plate after it has closed. ciently impede the progress of a shock wave from target In actual operation the valve must close only if the to cyclotron to make this valve system still useful. target has been broken; otherwise the irradiation should Baffles were designed taking into account the cyclotron not be interrupted. Since target rupture is accompanied beam characteristics along the beam pipe,5 constructed by a rapid rise in pressure along the evacuated beam with concentric holes (2.5 to 5.0 cm) that were twice as pipe, a pressure sensor near the target chamber can large as the calculated maximum beam dimensions to indicate the condition of the target foil. We hzve used assure complete beam transmission, and installed near an automobile spark plug, with an electrode gap of 0.01 the valve and near the target chamber in the mockup at cm and an impressed potential of 2000 V, which wil! intervals of 25.4 cm (Fig. 2.18). discharge in helium at pressures from ~200 n to >1 atm With this arrangement and for helium pressures in the but not at lower pressures. The discharge of the spark target chamber as high as 2 atm, no indication of plug can be made to trigger an electronic circuit that helium having passed the valve was given by the leak shorts the current to the electromagnet and thus detector in mockup tests. The combination of fast valve actuates the closing of the safety valve. and baffles should prevent not only the helium but also A schematic diagram of a mockup that has been any radioactive material carried along by the helium constructed and the course of events following target from getting past the valve. The valve has been tested rupture are shown in Fig. 2.18. A plunger with a sharp hundreds of times v/ithout apparent reduction in its cutting edge is used to break the foil and simulate foil speed or reliability. rupture. A helium leak detector is connected to the The use of the baffles is most significant. A valve system beyond ihe safety valve to obtain a sensitive system that inherently is not fast enough to stop a ORNL-DWG. 70-3349 FAST VALVE L TO ^SPARKPLUG HELIUM ,10.2 cm I.D. /BEAM PIPE 0ETECT0R BAFFLES BAFFLES .HELIUM IN , * » f 1 1 1/ 1 1 +++ ( 111111 } I -H4 FOILA PLUNGER 9.75 ft - -» 0.61m V- HELIUM DETECTOR MAGNET CURRENT OFF; INDICATES NO HELIUM FIELD COLLAPSES. SPARKPLUG PLUNGER HAS GOTTEN PAST SPRING CAUSES FIRES RUPTURES (0,2 torr ). POIL. VALVE. VALVE TO CLOSE. Fig. 2.18, Schematic Drawing of the Complete V.Jve System. The sequence of events from simulated foil rupture to valve closing is indicated. 61 helium shook wave works quite well because of the 'See, for example. R. J. Silva etal.. "Alpha-Decay Studies v,. addition 01 baffles. One is thus not required to build Nei'tron-Deficient Californium Isotopes." another contribution extremely fast valves. This result can be put to general in this chapter, this report. 3 use at accelerators, not only in greatly reducing chances A. Hartwig. Lawrence Radiation Laboratory, Berkeley; of radioactive contamination but also in avoiding private communica.ion. shutdowns caused by accidental loss of accelerator 4L. Dresner and C. V. Chester. "Attenuation of Shock Waves vacuum. in Long Pipes by Orifice Plates. Rough Walis. and Cylindrical Obstacles." ORNL-4288. unpublished (1968). 5Performed with computer code OPTIK. T. J. Devlin. Plant and Equipment Division. UCRL-9727. unpublished (1961). 3. isotope Chemistry DEUTERIUM ENRICHMENT useful in large-scale equipment. It is certain that the separation factor for such a reaction would be smaller D. A. Lee than that for the NH3-H2 or the H20-H2S system, but this disadvantage could well be offset by the prospect Heavy water (D20) is a widely u?ed neutron moder ator for natural uranium reactors. Most of the presently of a greatly simplified refluxing process: available supply of this material was separated chemi cally from natural water by means of the exchange Donor-DOH -^ Donor + DOH , reaction -ool DOH + Donor *DonorDOH . HH0(1) + HDS(g) = HD0(1) + HHS(g) . Experiments to evaluate the suitability of possible In every instance the resulting process streams were systems were carried out using tritium rather than refluxed by the "dual-temperature" technique. This deuterium in order to take advantage of simplified combination of chemical exchange and reflux method analysis by radioactive counting. Of course the separa has been very successful: it has produced D20 at a tion factor i.i the D-K systems would not be expected lower unit cost than any other method. Nevertheless, to be as large as in the T-H systems. The results of even this arrangement .caves, something to be desired. preliminary studies are encouraging. Following ai* the The dual temperature refluxing technique requires measured separation factors (between T and H) for the larger and longer exchange columns and more elaborate first few syste ns examinee: heat exchange equipment than conventionally rcfluxed Separation systems. This appreciably increases the required capital Donor Aqueous Phase Factor at 25°C investment. The effective separation factor for the (T-H System) exchange reaction is much smaller for dual-temperature Trioctylphosphine oxide H 0 1.15 plants thar. for plants refluxed Formally. The fraction 2 of deuterium which can be removed from :he feed in p-xylene O.5.VAICI3 1.05 stream is also reduced in plants employing 'he dual- 0.5 ,V K2C03 1.06 temperature refluxing technique. Furthermore, al 0.5 N HCl 1.08 though the corrosive effects of H2S can be colerated, Tetraheptylammonium H20 I.I: there is no doubt that a less corrosive material would be bromide in p-xylene Trioctylpropylammonium H 0 moie economical. 2 1.13 bromide In view of these conditions, we have begun a search for a chemical exchange reaction which will permit a The observed separation factors are relatively sm?ll new approach \o this problem. Specifically, we wish to (for hydrogen isotope systems). Nevertheless, they are find a reactior, by which water can be reversibly sufficiently large to be encouraging at this stage of the exchanged with a molecular addition compound of investigation. Further studies of this new approach to water, as indicated in the iollowing equation: the problem of separating hydrogen isotopes will be conducted. DonorHOH t HOD = Donor DOH + HOH (I) FRACTIONATION OF CARBON ISOTOPES: If a complex can be found which has ar. enthalpy of THE CYANEX SYSTEM formation of the order of 10 to 20 kcal/mole, it seems L. L. Brown likely that reaction (l) would have :. single-stage isotopic separation factor large enough to be interesting The development of the CYANEX system for the (>l.l) and a short enough half-time of exchange to be fractionation of carbon isotopes continued at the 62 63 bench-scale level. This chemical exchange system is glass pipe. The pipe sections were hand fitted with based on the exchange reaction perforated stainless steel plates which were strung on a '4 -in.-diam stainless steel red alternately with % -in.-i.d. 12 3 _ Teflon spacer*. Several of these assemblies were joined R2C(OH) CN(org) + ' CN (aq) with standard glass-pipe flanges to produce columns of J3 2 = R2C(OH) CN(org) + * CN~(aq>, the required length. The waste-end reflux assembly consisted of two 8-ft wiiich hi'S a single-stag-? fractionation factor of 1.04 at jacketed and insulated pulse columns in series. Plates C 25 C. Reflux of the product stream is achieved by for these columns were stamped from 0.020-in.-thick heating the organic phase to 61°C in the presence of a sheet perforated with 0.030-in.-diam holes (22% open small stoichiometric excess of HC03 . The cyanohydrin area). Plates were spaced 1 in. apart. Heat exchangers in the organic phase is reconstituted in the waste-end were installed on all feed and exit lines. A water-chilling refluxer by countercurrent contact with the aqueous unit furnished coid water to the column jackets and CN~ solution at about 8°C. heat exchangers. Integrated operation of the entire CYANEX system The exchange column ^vas made from 5 ft of (waste-end refluxer, exchange column, and product-end unjacketed pulse column. The plates and spacing were refluxer) was demonstrated during this report period. the same as for the waste-end reflux section. The longest of these runs continued for 72 hr, during The rioduct-end reflux assembly consisted of one 6-ft which time good mechanical operation was achieved. jacketed and insulated pulse column, a high-terrper?.- Each refluxci also performed well chemically. Although ture water bath, and heat exchangers for all feed 2nd the chemical stability of the system was not adequately exit lines. Plates for this column were stamped from tested by such short runs, it appeared that solution perforated stainless sheet 0.0IS in. thick with 0.015- decomposition was not excessive. in.-diam holes and 22% open area. Plate spacing was % Other observations were less favorable. The rate of in. exchange of carbon between the immisciDle phases The pulse generators for all four columns were made decreased rapidly as the stoichiometric excess of HC03~ from seamless stainless steel bellows which were 1 % in. was increased from 0 to 25%. Further, mass transfer of i.d., 1% in. o.d., and 3 in. long. The bellows were carbon-containing species from the aqueous to the actuated by a cam-driven arm attached to a Zero-Mix organic phase was observed as each run progressed. This speed changer. Pulse frequency could be varied from 0 latter objectionable characteristic of the CYANEX to 500 cycles/min at fixed pulse amplitudes of %, 34, system stems from the use of free ketone as 'Jie solvent or V2 in. of the organic phase. An obvious adjustment would be Type 316 stainless steel was used throughout the to dissolve the alkyl cyanohydrin in an inert solvent system for pumps, bellows, sieve plates, valves, and rather than in free ketone. We have ascertained that flanges. Micobellows pumps were used for process xylene is physically suitable for this purpose, and we streams, while centrifugal pumps were used for water are now performing additional integrated column runs circulation. Teflon tubing was used for transfer lines. to establish the usefulness of a modified CYANEX Liquid levels and interfaces in the columns were system. controlled by gravity legs. Once steady state was reached, the apparatus would operate automatically and THE CYANEX BENCH-SCALE continuously for weeks with only occasional minor PILOT PLANT adjustments to operating variables. Twenty thermo A. A. Palko couples monitored temperatures throughout the sys tem, while 18 sample ports were available to monitor A bench-scale pilot plant was constructed to aid in the system chemically. testing the CYANEX system under process operating conditions. The pilot plant consisted of three main parts: a waste-end reflux system, an exchange column, 170 FACILITY and a product-end reflux system. D. Zucker Pulse columns were used in each subsystem to contact the aqueous cyanide solution with the cyanohydrin Last year's efforts to correct the performance of the contained in the organic phase. These pulse columns water distillation cascade appear successful, and the were made from 1-ft-long sections of 1-in.-i.d. jacketed isotopic gradient in this cascade is recovering. Dif- 64 ficulties with regulating the flow of feedwater to by which frequencies of the various activated states distillation column 4 were eliminated by replacing the could be computed. The potential well for the 3Ilo feed line and rotameter and by adding more air excited siate of Cl2 has a depth of approximately 7400 deentrainment. A low-pressuie alarm was also added to cal. and the 5145 A argon laser line will excite the the condenser water system. Removal of product water molecule to a vibrational level 4200 cal below the from the distillation cascade began at a reduced rate dissociation limit. about the middle of the report period. The following reactions were chosen for investigation: The installation of gas circulating pumps in the thermal diffusion cascade, begun last ye?j, was com CO + Cl2-COC!2 , pleted. These pumps consist of annealed Plexiglas U-tubes containing mercury and two check valves. The C4F8 (perfluorobutene-2) + Ci2 ->C4FgCl2 , mercury is pulsed by externally applied air pressure, displacing the process gat in the circula:ion loop. The CH2 =CF2 +C!2 - OH2CCF2C!, only wearing parts contacting the process stream are the check valves; th«*se move so slightly they are expected C2H4 + Ci2-C2H4Cl2 . to last for yesrs. A number of changes were made in the physical plant These molecules do not react with Cl2 in a clean cell at to ^itsure greater working and operating safety. The -oom temperature if light is excluded and the Cl2 icw-ofl-f ;essure and high-temperature cutoff controls pressure is low. Irradiations were made on mixtures of for the emergency power supply were discor.*iected Cl2 wiih CO, C4Hg, and C2H2F2, using a filtered trom the diesel control and connected to an alarm 5145-A beam and a light-tight box so that only 5145-A instead. This protects the emergency power against radiation traversed the sample. Ratios of reactant to Cl2 failure of the sensing element. S!.ould there be diesei pressures were varied from 1:1 to 90:1, and the Cl2 trouble instead of element failure, several additional pressures used were 10, 25, and 30 mm. In all cases the minutes would now be available in which to take reaction proceeded by a chain mechanism. Quantum corrective action. yields ranged from 20 to 100 or more. As noted previously last year's repairs interrupted the The conclusion indicated by the results of these normal operation of *he * 70 facility and decreased its experiments is that a free-radical mechanism is involved productivity. In spite of this, 14.3 g of water enriched in all of these reactions. There are at least two in 180 to 97.3% and 5.4 liters of oxygen gas enriched mechanisms by which this could occur: in ,80 to 99.7% were transferred to Isotope Sales 8 inventory. In addition, 4 liters of gas containing' 0 at 1. The excited Cl2 may form a complex with the a purity of 95<£ were also prepared. The total value of reactant molecule, then lose a CI atom before the these materials exceeded S 18,000. complex can lose its excess energy and become a stable molecule. 2. Repeated collisions of an activated Cl2 molecule with other molecules may cause it to gain the PHOTOCHEMICAL SEPARATION OF ISOTOPES additional 4 kcal it requires to dissociate. This seems W. H. Fletcher1 improbable, but this path cannot be disregarded until more data are in hand. Study of the problems associated with the photo 2 At higher pressures of Cl (0.5 to 1 atm),CH =CF chemical separation of isotopes continued. The work 2 2 2 reacts even in the dark at room temperature. CO does reported here deals with our efforts to excite the Cl2 3 not appear to ieact with 1 atm of Cl if it is in a clean molecule to the discrete t1o state and to cause it to 2 react with selected substrates without generation of the cell and light is carefully excluded. CI- radical, which, if formed, would destroy the desired isotopic specificity of the photochemically induced reaction. Molecular chlorine was chosen for study, not so much Consultant, Departn ent of Chemistry, University of Ten because of interest in the isotopes of this element per nessee, Knoxville. se, but because this was the only molecule of interest 2W. H. Fletcher, Chem. Div. Ann. Progr. Repl. May 20. 1968, for which sufficient spectroscopic data were available ORNL-4306, p. 53. 65 MOLECULAR SPECTROSCOPY1 better than previously reported chokes. We confirm the value reported by Carlson2 of 490 cm"1 for v rather G. M. Begun y than the higher frequencies previously accepted. In The use of Jie laser as a light source has greatly addition we have observed two bauds at —110 and expanded the domain of Raman spectroscopy, in ~310 cm"'. Both bands may be combination bands particular, it has become much easier to obtain Raman (see Table 3.1): alternately, the band at ~310 cm"1 _ spectra of fused salts. We have used this new capabflity may be due to A12C17 (see below). Our spectrum of to study the species present in alkali chloroaluniinate liquid AI2C16 is in reasonable agreement with the melts varying in composition from 50-50 mole 1 literature except at very low frequencies, where we AKTb-NaCl to pure A^Cl*. observed two peaks at 119 and 104 cm-1. Figures 3.1 and 3.2 show the spectra of pure molten The variation of the spectra of the melt with A12CI6 and AKV (AJCI3-NaCl. 50-50 mole 7c) respec composition is shown in Figs. 3.3 and 3.4, and the tively. Although these spectra have been reported frequencies are tabulated in Table 3.2. before the.e is comiderable disagreement in the litera Lines due to A12C17~ can be located if we assume that ture. We believe our laser-excited spectra to be superior the only Raman-active species present in the concentra to any so far reported. Table 3.1 summarizes the data tion range 50-50 to 58-42 mole % are A1CU" and 1 for A12CI6 and the A1CU ion. We believe our assign A12C17~. One peak is easily identified (313 crn* ); it is ment of the low-frequency peak for A1CU" as P7 to be highly polarized and has an intensity similar to the ORKL-OWG. 70-t«49 800 700 600 500 400 3CO 200 too A WAVE NUMBERS (cm1) Fig. 3.'. Raman Spectrum of AI2CI6 Liquid at ~225°C. 0RNL-DWG. 70-1447 700 600 500 400 300 200 100 A WAVE NUMBERS (cm-' ) Fig. 3.2. Raman Spectrum of Molten AJCI3 NaCl (50-50 Mole %) at ~225°C. 66 ORNL-OWG. 70-20678 T T -r RAMAN SPECTRA 4880 A LASER EXCITATION CARY MCNOCHROMATOR (C) ' J > •' -~*~WVJ V-y,^ (8) en z /"> /^' \ v/ (A) /\y "V GOO 500 400 300 200 100 A WAVE NUM8ERS (cm"') Fit> 3.3. Raman Spectra of Molten AK33-NaCl at ~225 C Composition: -4, 52-48 mole %; £, 54-46 mole %; C, 64-36 mole %. TaUe3.1. Raman Fieqaencies of Molten 350-cm_ 1 peak of A1CU~. We also assign the peaks at AhCI^ and AlCLf at 225°C -1 435, ~165, and ~100 cm to A12C17~. The variation Frequency (cm -i, ) Polarization Assignment of the spectra with composition cannot be explained solely on the basis of AlCi./, A12CI7~, and A12C16. The AliCU existence of at least one more Raman-active species 104 s* P may be deduced from the following observations: 119s D 166 w D? 1. The appearance of a new peak near 390 cm-1 for 218.5 vs P 290 m P compositions with high A1C13 content (for example, 341 vs P 73-27 mole % composition). 440 w 1 512m P 2. The presence of the strong 350-cm" peak due to 608 m P? AICI4" in compositions in which AI2C16 (as evi 1 AJC14~ denced by the 218-cm" peak) is either not present (67-33 mole %) or present in very low concentra 121s D v2E 186 s D v4F2 tions (73-27 mole %). ? 268 vw v - v4 (?) ? 306 w v3 + v4 (?) Assuming only A12CI7~ and A12C16 at the composition V A 351 vs P X X 73-27 mole % (certainly an incorrect assumption), the 490 m D V3F2 iatio A12C16/A12C17~ should be 0.35. If the equilibrium a%, strong; m, medium; w, weak; \ , very; D, highly depolarized; P, polarized. 2A12C17" - A12C16 + 2AKV (1) 67 OSNLOWG. ?0-2OSX RAMA* SPECT«A 488Ci LASr't EXC'T^iON IB) CARY MONOCHROMATOa A/' v ! Ij Ui 1 A Ss^/ 600 500 400 300 20C IOC A WAVE NUMBERS (err."1) Fig. 3.4. Raman Spectra of Molten AICl3-NaCI at ~225 C . omposition A. 67-33 mole ~; B. 73-27 mole' Table 3.2. Raman Frequencies of the System AlCh-NaCI at 225 C -1 Composition Frequency (cm ) and Polarization (molc%) D* D P P P P P D? 51-49 119s 184s 313 w 351 vs 490 b,w 52^8 118s 182 s 313m 350 vs 436 w 490 b,w 54^6 116s 183 s 313 m 350 vs 434 w 490 b,w 53-42 108 s 154 sh, 178 s 313s 350 vs 436 w 62-38 58 s 165 s 313 vs 350 vs 436 w 64-36 98 s 165 s 312 vs 350 s 434 w 67-33 97 s 162 s 312 vs 348 s 388 w 432 m 73-27 96 s 159 s 218 vw 310 vs 346 m 388 w 432 m 495 b,w avs, very strong; s, strong; m, medium; w, weak; b, broad; sh, shoulder; D, highly depolarized; P, polarized. is the predominant one, an even larger ratio should are indicated. No definite conclusions may be drawn at result. Since the concentration of A12C16 appears to be this time regarding the nature of the new species much lower than estimated above (in comparison to appearing in compositions of high A1C13 content. The AI2CI7"), other equilibria such as presence of monomelic AICI3 is unlikely, however, since it is not present in appreciable concentrations in 2Ai2ci7~-Ai3Ci1(f+ AlCL^ (2) pure liquid aluminum chloride. Evidence of A13X:0~ species may be inferred from phase diagram studies.3 or We have observed the Raman spectra of solid and melted samples of triphenylene (C8H12) in order to Al2cl7~-AlCv+AK:l3 (3) make comparisons between observed- and calculated 68 >v. :»« *c- •«se RAMAN SPECTRUM T" 1 s 6328 A LfSER EXCITATION CARY-81 MONOCHROMATOR > TRIPMEN^LENE - SOUO i 0) •***. z UJ +* 4 w* I: I t Vw »^»» / •^ U^ h*L X* 1800 1600 1400 120O «C00 SOO Sw* 2-JO A WAVE NUMBERS (cm1) F«>3.S. Spectra of SofcdT oRNL-owa ro-«45i ! ! " RAMAN SPECTRUM 632SA LASER exDTAJCM CA.RY-01 MONOCHR0HA7OR 'TWPHEHYLENE- Mti-TEO en 2 UJ 1^ V \// 1 X _L X X 1800 1600 1400 1200 1000 800 600 400 200 A WAVE NUMBERS (cm1) Fig. 3.6. Raman Spectrum of Melted Triphenylene. vibrational frequencies. Previous observations of the comparisons between calculated and observed vibra Raman spectrum of triphenylene were poor due to tional frequencies have been prepared for publication. fluorr *ence of the sample. Our observations were made using the 6328-A helium-neon laser line for excitation. Figure 3.5 shows our Raman spectrum of solid tri- phenylene, and Fig. 3.6 is a reproduction of the spectrum of the melted compound. Polarization meas 'G. Torsi, G. Mamantov, C. H. King, and W. E. Deeds of the urements were also made on the melted sample. The University of Tennessee, Knoxville, have participated in this research. Raman spectral results are shown in Table 3.3. 2 G. L. Carlson, Spectrochim. Acta 19,1291 (1963). 4 C. H. King performed an 2 priori calculation of the 3J. Kendal], E. D. Crittenden, and H. K. Miller, J. Am. Chem. planar normal vibrations of triphenylene and found Soc. 45,963(1923). good agreement between the calculated and observed 4Ph.D. candidate at the University of Tennessee, Physics frequencies. The results of these calculations and the Department, working under the direction of Dr. W. E. Deeds. 69 Table 3 J. Ramaa Spcctnun of Tripheayteae distillation and the thermal diffusion cascades in the I70 facility. The oxygen samples were also inspected Frequency (cm V Species Assignment for N2. Ar. and CO: to aid in the detection and Solid Melt location of leaks. Samples of CO and C0 were examined by the rat^o 32 s Lattice 2 method to determine I3C eniichment factors in single- 58 m Lattice stage experiments _«d to evaluate the performance of 91 m Lattice the COCO and the CYAN EX systems in column runs 108 m Lattice under different operating conditions. 282 m 279 m A continuing analysis of a set of stan rd C0 408 w 2 £', samples, used to evaluate the mass spectrometer's 420$ 416 sj» Ax performance, now shows a comparison of the 45/44 544 w ratios of the two standards to be 1.03030 ± 0.00008 620 w s 1 (957c CX.). This is the average of 15 sets of measure 698 s 699 %P Ax ments over a period of 11 years. The previous 770 vw average1"3 was 1.03029. 776 w ! s Samples of HCN, Xe, and CO^ enriched in O were 1061s 1061sj A\ analyzed for other groups. A total of 450 samples were 1163 w F' snalvzed. 1172w 1171w,P A'x 1229 m 1231m,F A\ 1340 vs 1336 vsj A'x *Chem. Div. Ann. Prop. kept. June 20, 1963, ORNL-3488, 1457 s 1458 sJP A'x p. 33. 1603 n 1605 m,D 2 A'x Chem. Div. Ann. Prop. Rept June 20, 1964, ORNL-3679, 1616 m p. 29. 2995 w E' 3Chem Div. Ann. Prop. Rept. May 20, i 96 7, ORNL-4164, p. 3034 w A'x 34. 3092 w A'x flw, weak; m, medium; s, strong; v, very; P, polarized; D, highly depolarized. PREPARATION OF 13CO L. Landau ISOTOPIC MASS SPECTROMETRY CO containing 60% 13C was prepared by reducing isotopically enriched C0 ever zinc at 400°C. The C0 L. Landau 2 2 was recycled for several hours through a loop contain During this report period samples of C02 and 02 ing a U-tube filled with heated zinc granules. The mass were analyzed routinely for enrichnu of l70 and spectrometric analysis of the product showed that more 18 0 in order vo monitor the peiformance of the water than 99% of the initial C02 was reduced to CO. 4. Radiation Chemistry FLASH PHOTOLYSIS OF AQUEOUS sient appears to be identical to that observed recently NITRIC OXIDE SOLUTIONS by Seddon2 in the pulse radiolyrs of NO solution. He suggested that the transient is N 0 ~ produced by C. J. Hochanadel J. A. Ghormley 2 2 reaction of NO with NO", which was shown to J. W. Boyle originate from the fast reaction c(aq) + NO -*• NO". The primary processes in the photolysis of aqueous Tire N202" decays by protonation to give N20 and OH, and the OH reacts rapidly with NO to give HNO^. The solutions of NO and 02* have been investigated by flash techniques. Both of these solutions have con comparison with pulse radiolysis indicates that the tinuous absorption spectra which extend to much primary process in photolysis is essentially as written longer wavelengths than the absorptions of the in above. The analogous reaction in 02-saturated water dividual components themselves. These spectra have would produce 02~ and OH. We observed 03 as one of 1 been attributed to charge transfer processes, which, for the final products in this system, whereas the reactions NO solution, can be written as of 02~ and OH generally considered in radiation chemistry and photochemistry would give only 02 and hv H 0 as stable products. Possible mechanisms for 0 NO(aq) -^ NO(*aq) •* NO 2 2 3 formation include: combination of 02~, reaction of H + ,+ / 2° H03 (produced by OH + 02 -*• H03) with itself or with + H20 (——-H30*+ OH). 02", or by reactions of H03~ (produced by OH + 02~ -*• 3 H0 ~). In attempting to learn more about the reactions On flashing NO-saturated water (1.9 X 10" M) wc 3 observe the transient spectrum shown in Fig. 4.1 with of OH in this system we studied the flash photolysis of solutions of H 0 + 0 (OH is produced by photolysis peaks at 3840 and 2520 A. Part of the absorption is 2 2 2 of H 0 ), H + 0 , and CO «• 0 , where the H and produced during the flash, but most of it grows in after 2 2 2 2 2 2 the flash, reaching a maximum in ~250 j/sec. Ai natural CO are OH scavenge:*. However, the results thus far pH the transient decays in ~-6 msec, leaving a residual, have not been conclusive. long-lived absorber with the spectrum of N02~. The decay rate increases with increased acidity. The tran- xChem. Div. Ann. Prop. Rept. May 20, 1969, ORNL-4437, p. 49. W. A. Seddon, AECL-3477, p. 59 (Sept. 30, 1969). OSNL-OVKG. 70-4983 1 1 1 -©- Spectrum of thr Tronsient —o~ Residual, Long-lived Absorber, Presumably N0 " 0.10 2 PULSE RADIOLYSIS OF y-(ordinafe xO.I) /\ SODIUM NITRATE CRYSTALS z \ J \ ' J. A. Ghormley C. J. Hochanadel g 0.05 1 / \ H < ; / \ The pulse technique was used to study ihe radiolysis o 0. of sodium nitrate crystals at room temperature. In the o A^/\ V steady radiolysis of alkali nitrates the final products are 1 *"W> . O L y 2000 3000 4000, 5000 N02" and 02, with 100-ev N02" yields ranging from WAVE LENGTH (A) 1 0.02 for LiN03 to 0.25 for NaN03 and 1.6 for KNO-,. A number of studies2"4 employing optical or esr Fig. 4.1. Absorption Spectra Produced in the Flash Pho detection after irradiation, usually at low temperature, tolysis of Solutions of Nitric Oxide in Water. Solid curve - spectrum of the transient; dotted curve - residual long-lived have indicated several intermediates, the most prom 2 absorber, presumably N02~. inent being N03, N03 ", and N02. 70 71 On irradiating NaN03 crystals with a 30-nsec pulse of oulse and is stable for manv hours. It can be photo- electrons, we observe the formation of transient absorp Dleached, leaving a weak residual absorption in the same tion bands with maxima at 6800, 4100, and 3400 A region (3450 A) due to NO:~. There is some delayed (Fig. 4.2). The absorbers are tentatively identified as light emission in the wavelength region from —3000 to 2- N03, N02, and N03 , based on comparisons with 5000 A for a period of 1 % /usee following a pulse. reported spectra in the gas phase and/or solution5 and Thus far measurements of short-lived species have evidence cited above from esr and optical measurements been limited to wavelengths above 365C A. Therefore it following steady radiolysis. All three absorbers are has not been possible to observe the behavior of other produced most'y during the pulse, and the formation- possible transients such as 0, O", Ch~. 03. NO, N203, 2 decay characteristics of any one species do not seem to N02 ". ONOO". etc.. nor is it possible to observe the b? related to either of the others. The band at 6800 A formation of final products directly. A complete mech anism for formation of products has not yet been (N03) decays by first-order kinetics with a lifetime of established ~0.5 Msec. Apparently it does not decay to N02 '4100 A). The amount produced and the decay kinetics are independent of the orevious history of the sample, for 'C. J- Hochanadel and T. W. Davis, J. Chern. Phys. 27, 333 example, previous irradiation and bleaching. There is a (1957). shoulder on this band at ~5600 A which decays at a 2P. Pringsheim, J. Chem. Phys. 23, 369 (1955). 3J. Cunningham,/. Chem. Phys. 41, 3522 (1964) rate similar to the N03 but appears to belong to a different species, posribly related to a crystal defect or 4H. Zeldes and R. Livingston, J. Chem. Ph^r. 37, 3017 an impurity. The yield of absorber was different tor (1962); R Livingston and H. Zeldes,/. Chem. Phys. 41. AOU (1964); H. Zeldei, Paramagnetic Resonance, vol II, p. 764. three different crystals [two samples grown from the Academic Press, New York, 1963. melt (Harshaw) and one grown from solution], and the 5L. Dogliotti and L. Hayon, /. Phys. Chem. 71, 3809 (1967). shoulder is either greatly reduced or not produced at all on a crystal that had previously been irradiated and bleached. The band at 4100 A (NCVi, produced mostly during the pulse, decays thermally in ~5 sec by PULSE RADIOLYSIS OF GASES something between first- and second-order kinetics. C.J. Hochanadel J. A. Ghormley Approximately the same amount is produced on the P. J. Ogren1 first pulse as on a crystal that had received many pulses, suggesting that NOz~ is not its precursor. The band at 2 Energy Transfer in NG-Ar and 3400 A (N03 ") also reaches its maximum during the NO-N2 Mixtures In studies of energy iiansfer and energy degradation, 0SNL-0WG- 70-4984 1.0 ~i 1 r we measured yields of N02 + N203 (from the rapid -o- Transient with -0.4 ^sec Lifetime (NO3) 0.9- equilibration N02 + NO ** N203) and of NO (v = 1) in -a- Transient with ~5sec Lifetime (N0 ) 2 the above mixtures over the entire composition range at 0.8- •4--Long-lived Transient (NO,") a total pressure of 1 atm, using a 30-nsec electron pulse 0.7 at a dose rate of ~1012 rads/sec. In pure NO the yields 0.6 of N02 + N203 had been evaluated as 10.6 per 100 z 0.5 eV.2 In mixtures with argon the yield remains nearly 0.4 constant down to about 5% NO, below which it falls < o rapidly. In N2 the yield falls slowly with decreasing »- 0.3 h o. partial pressure of NO, but at 0.5% NO it is still ~60% 02- of the full yield. 01 - The principal "energy transfer" reactions are likely to be charge exchange from N or Ar to NO and reaction 3000 4000 5000 6000 7000 8000 2 WAVE LENGTH [1) of NO with excited Ar or N2 or with N atoms produced by dissociation of excited N2. Charge neutralization is Fig. 4.2. Absotpticn Spectra of transients Produced in the likely to be by NO* + NO" -* N + O + NO following Pulse Radiolysis of N;.<03 Crystals. Solid curve - transient electron capture by NO. Regions leading to N02 with ~0.4-jisec lifetime (N03); dashed curve - transient with ""5-sec lifetime (N02j; dotted curve - long-lived transient formation are N + NO -»• N2 + 0 followed by O + NO -* 2- (NO, ). N02. From the W values for NO, N2, and Ar of 27.5, 72 36.3. and 26.4, respectively, and assuming an equal J. A. Ghormley, C. J. Hochanadel, and J. W. Boyle. Chtri yield of excited states leading to N02 formation, the Div. Ann. Progr. Rept. May 20, 196 7, ORNL-4164, p. 41. estimated maximum yields of N02 from energy initially absorbed in NO, N2, or Ar are 14.6, 11.0, and 15.2, respectively, thereby accounting for the high yields of DENSITY AND REFLECTIVITY OF AMORPHOUS ICE N02 + N2C3 even at iow partial pressures of NO. Further refinement in interpretation will require studies J. A. Ghormley C. J. Hochanadel of effects of pressure and dose rate. The yield of vibrationally excited NO (y = 1) in the Ice formed when water vap-v is condensed on a electronic ground state as a function of composition surface cooled to I40°K or beiow gives only broad bands by x-ray diffraction and is generally considered showed behavior similar to the N02 + N203 yields, to be amorphous.1 In studies of the radiation chem both in Ar and in N2. istry, surface properties, and thermodynamics of amor Luminescence and NO Fonnation phous ice. we have visually examined many samples inNj-Oj Mixtures during crystallization and have seen no change in volume or other indication of the existence of ice with In the pulse radiolysis of oxygen at high dose rate a density of 2.3 g/cm3 reported recently.2 This ve^y 12 3 (—lO rads/sec) 03 is produced in high yield. In high density was determined by computing the volume mixtures with N2 the 03 yield is nearly constant down of a known weight of so-called "glassy" ice from 4 to "-10% 02 and then falls rapidly. No oxides of photographs of a copper cone with and without the ice nitrogen were observed in the N2 -02 mixtures, possibly deposit. because of the low sensitivity for their detection by We have now measured directly, by the buoyancy in optical absorption. Light emission is observed in these liquid oxygen, the density of six samples of amorphous systems and interferes with absorption measurements. ice prepared by condensation of water vapor on a Light emission may, however, offer a means to study copper surface at temperatures from 82 to 110°K and NO formation since emission is observed both in the deposition rates from 16 to 69 X 10"6 g cm-2 sec"1, second positive system of N2 (C*Tlu -^B^Ug) for (1,0), conditions comparable with those reported for prepara (0,0), and (0,1), and in the gamma system of NO tion of "superdense" ice. The average density was 0.940 2 3 (A 1* -> **nr) for (0,1),(0,2),(0,3),(0,4), and(0,8). ± 0.012 g/cm , with no evidence for a "superdense" The strongest emission from N2 is in the (0,0) ice. Other samples, prepared under a wide variety of transition and from NO in the (0,2) transition. The conditions by deposition on copper or aluminum or on maximum emission, either from N2 or NO, occurs at glass in an all-glass system, all floated in liquid oxygen very low 02 concentrations [11 ppm 02 or pure N2 (3 and sank in liquid nitrogen, indicating a density 3 pom 02)J. Emission is much less at 495 ppm 02, and between 1.14 and 0.808 g/cm . in air there is no detectable NO emission and only faint When samples of amorphous ice were observed N2 emission. The maximum emission from N2 occurs visually during warming, the change in appearance from during the pulse, followed by decay with a lifetime ~1 translucent to opaque white was so gradual it was not usee. The NO emission reaches a maximum in 2 to 3 possible to determine the time or temperature at which ^sec and undergoes first-order decay with a lifetime of the change occurred. However, by using a photo- 3 to 5 usee; the decay is not very sensitive to 02 multiplier we were able to follow the reflectivity concentration in the range 11 to 1100 ppm. Measure continuously during buildup and warming of the ice; ments of NO (v = 1) quenching in NO-Ar and NO-N2 results from a typical sample are shown in Fig. 4.3. 4 6 mixtures gave/>= 2.1 X 10" for NO and<10" foi Ar Diffuse reflectivity of the ice increased slowly during and N2. Efficiencies of NO, Ar, and N2 as the third deposition and continued a slow increase when deposi body in the reaction O + NO + M were also estimated. tion was stopped and warming begun. At about 150°K a small decrease in reflectivity was usually observable, followed at about 1S3°K, where crystallization occurs, Department of Chemistry, MaryviJle College, MaryvUle, by a small but sudden rise in reflectivity followed by a Tenn. 2 continuous increase to a maximum at 210°K. At this C. J. Hochanadel, J. A. Ghormiey, and P. J. Ogren,/. Chem. Phys. 50, 3075 (1969). point the reflecvivity was about 90% of that of freshly 3J. A. Ghormley, C. J. Hochanadel, and J. W. Boyle,/. Chem. deposited MgO. Any large change in density of the ice Phys. 50,419 (1969). during crystallization would be expected to break up 73 hydrolyzes in sulfuric acid solutions to yield peroxy- monosulfuric acid, which further hydrolyzes to yield hydrogen peroxide. Some typical results are shown in Fig. 4.4. When the initial cerium(III) concentration is 0.026 M, the reduction of cerium(lV) is attributable solely to reduction by hydrogen peroxide according to the following expressions: rf[H2S208]/^ = -*,[H2S208], (0 >r- --IZ i-^, 1 1 1 1 L. 0 5 10 55 60 65 ?0 75 rf[H202JA/f = A:2[H2S05] Fig. 4.3. Diffuse Reflectivity of a Typical Sample of Ice During Initial Period of Deposition on a Black Surface at 101°K -* [CeiV]2rH 0 ]/[Cei»], (III) and During Subsequent Wanning. 3 2 2 ,v 2 rf[Cen/rf/ = -MCe l [H202l/[Ce"i] , (IV) the deposit and cause a significant increase in reflec tivity accompanying the sudden rise in temperature d [Ce111 ] idt = ~d[Cv*v ] \dt. (V) 5 which indicated crystallization. A thin layer of amor We have previously determined the value of k3 in phous ice greatly reduced the specular reflectivity of aqueous 4.0 M H2S04 solutions. Values for kx and k2 polished copper. 1 ORNL-DWG. 70-5294 J. A. Ghormley,/. Chem. Ph-%. 48,503 (1968). 5 J—I—I—|—I—|—I—I—|—I—I—I—I—I—I—J—|—I—I—I— 2 A. H. Delsemme and A. Werner, Science 167,44 (1970). REDUCTION OF CERIUM(IV) IN AQUEOUS 4.0 A/ H2S04 SOLUTIONS INDUCED BY HYDROLYSIS OF PEROXYDISULFURIC ACID H.A.Mahlman T. J. Sworski We previously reported1 evidence for a primary yield of S04" radicals in the radiolysis of aqueous sulfuric acid solutions. This evidence was obtained from a kinetic study of the effect of variations in both cerium(III) concentration and either formic acid or 2-propanol concentration on cerium(IV) reduction in aqueous 4.0 M H2S04 solutions. We assumed for our kinetic study, as previously reported,2 that any peroxy- monosulturic acid and peroxydisulfuric acid formed during inadiation were stabb products. Mariano3 recently reported that both peroxymono- sulfuric acid and peroxydisulfuric acid do react with cerium(IV) in sulfuric acid solutions. To remove any 0 5 10 15 20 doubt in our mind about the validity of our kinetic HYDROLYSIS TIME , hours evidence for a primary yield of SO/" radicals, we investigated the reduction of cerium(IV) induced by Fig. 4.4. Reduction of €es«sm0V) Induced by Hydrolysis of 0.01 M PeroxydHulfuric Acid in Aqueous 4.0 M H2S04 hydrolysis of peroxydisulfuric acid in aqueous 4.0 M Solutions at 25°C. Initial concentrations of cerium(lll): 4 H2SOJ solutions. Peroxydisulfuric acid reportedly 0.026 M\ 0.0026 M; 0.00026 M. 74 are b<*ing determined by numerical integration of Eqs. previously obtained5 from a kinetic study of the effects (I)-(V) and are about 4 X !0"s and 4 X 10"7 sec"1 of boui cerium(Ill) and either formic acid or 2- respectively. propanol concentrations on cerium(IV) reduction. Sim The marked inflection in the curves of Fig. 4.4 for ilarly, a kinetic study of the effects of both eerium(IU) cerium(HI) concentrations of 0.0026 and 0.000263/ is and formic acid concentrations on cerium(lV) reduc attributed to reduction of cerium(IV) by peroxymono tion has now yielded evidence for a primary yield of sulfuric acid, inhibited by high concentrations of N03 radicals in the radiolysis of 4.0 M HN03 solutions. cerium(III), in agreement with Mariano.3 No kinetic At constant cerium(III) concentration, the de UI study of ccriumfJV) reduction by peroxymonosulfuric pendence of G(Ce ) in 4.0 M HN03 on formic acid acid has been previously reported. We have been able to concentration adheres well to: interpret our results quite well by assuming the follow G(CJ") = G(CenI)* + 2G* /( 1 + (*, (Ce^l ing reaction mechanism: H + *2[HN03])/(*4[HCOOH])) . (I) IV III + Ce + H2S05-Ce + H + HS05 , (4) This suggests simple competition for the OH radical 2HSOs + H20 - H2SOs + H2S04 + 02 . (5) according to the following reaction mechanism: ,11 IV If we further assume that ks is negligibly small OH + Ce -*OH~ + Ce , (1) compared with Jfc_4, then the rate of cerium(IV) reduction by peroxymonosulfuric acid is given by: OH+HN03-*H20 + N03, (2) IV 2 2 2 = -2*5^[Ce ] lH2S05] /(fc-4[Ce">J) - (VI) OH + HCOOH - H20 + COOH , (4) The value of ksklllcU is being determined by nu 1v in merical integration of Eqs. (I)-(V), with Eqs. (11) and COOH + Ce - C02 + H * + Ce . (5) (IV) modified to take into account Eq. (VI), and is J11 about 0.01. Values of G(Ce )*, G*H, *nd the kinetic parameter ,,I We do not confirm the reaction between ceriumfJV) (*1lCe j + *2[HN03])/*4 were obtained for each and peroxydisulfuric acid reported by Mariano.3 We cerium(III) concentration by fitting the experimental conclude that reduction of cerium(IV) by both peroxy data to Eq (I) by the method of least squares.4 disulfuric acid and peroxymonosulfuric acid was negli The dependence on cenumflll) concentration of both gible under the experimental conditions employed by G*H, shown in Fig. 4.S, and the kinetic parameter, 2 Boyle and in our determination of Gso - in aqueous shown in Fig. 4.6. is clearly inconsistent with Eq. (I). 4.0 M H2 S04 solutions. ORNL-OWG. 69-10285 *R. W. Matthews, H. A. Mahlman, and T. J. S^orski, Chem. Div. Ann. Progr. Rept. May 20,1969, ORNL-443'\ p. 52. > 2 J. W. Boyle, Radiation Res. i7,427 (1962). 3M. H. Mariano, Anal. Chem. 40,1662 (1968). 4 H. Palme, Z. Anorg Chem. 112,97 (1920). <» 3.C - 5H. A. Mahlman, R. W. Matthews, and T. I Sworski, Chem. Div. Ann. Progr. Rept. May 20. J968, ORNL-4306, p. 61. KINETIC EVIDENCE FOR A PRIMARY YIELD OF N03 RADICALS IN THE RADIOLYSIS OF 1 AQUEOUS NITRIC ACID SOLUTIONS ' 0 0.02 0.04 0.06 R.W.Matthews2 H. A. Mahlman [*•).* T. J. Sworski Fig. 4JS. Dependence of G&H on Cerimnfll) Concentration Evidence for i primary yield of SO*" radicals in the as Determined by Least-Squares Fit of the Experimental Data radiolyas of aqueous 4.0 M H^S04 solutions was to Eq. (I). 75 ORNL-DWG. 69-10286 The experimental data adhere well t^ £4. (ii), ana a 4 least-squares fit yields values of GOH = 2.04 ± 0.09, GSOi - 1.5b ±O.I2,*,/*4 =4.0±0.9,A'2(HNO3]/V;4 = 0.2*1 ±0.03, *.,/*6 = 143 ± 11, and eight values of G(Cenl) for eight cerium(III) concentrations. 3 0.4 - Whereas oar relative reactivities of S04" with Ce(Ii!), formic acid, and 2-propanol agree well with published5 values of absolute rate constants, our relative reactivities of N03 with Ce(IH) and formic acid are in serious disagreement with published5 values which yield k*/k6 = 1.8. 'Presented at the XXII International Congress of Pure and Applied Chemistry, Sydney, Australia, Aug. 20- 27, 1969. 2Visiting scientist from the Australian Atomic Energy Com mission Research Establishnient, Lucas Heights, New South 0.02 0.04 0.06 trltCS. 3R. W. Matthews, H. A. Mahlman, and 1. J. Sworski. Chem. ! Ec« M Die. Ann. Prop. R< v 20,1969. ORNL-4437, p. 52. 4M. H. Lierzke, A Gemraii7zd Lnst-Squares Program for the I,, Fig. 4.6. Dependence of the Kinetic Parameter (A](Ce J + IBM 7090 Computer, 0RNL-3259 (Mar. 21, 1962). * (HN0 J V* on CenwnOU) CoscestntioB as Determuwd by S 2 3 4 L. Dogtiotti and £. Hsyon, 7. Phys. Chen. 71,3802 (1% 7). Leasi-Sqaares Fit of the Experimealal Data to Eq. (I). PRIMARY PROCESSES IN THE RADIOLYSIS OF WATER T. J. Sworski The kinetic parameter should be a linear function of the 1 cerium(HI) concentration, while C*H should be es Kinetic evidence was previously reported for ? sew sentially constant. This inconsistency is only another unobserved primary product in the rsdioivsis of water: example of why crie should vary the concentration of "excited water," which decays by a first-order process. more than orx solute in a kinetic study. Excited %»*C7, instead of e~(aq), was claimed to be the A similar dependence of both G* and kinetic principal precursor of molecular hydrogen in the spur; parameter or. cerium(lH) concentration was previously it was proposed to be electronically excited water in 3 observed in 4.0 M H2SG4 solutions, perhaps for the equilibrium, oy a shift of an H atom :r, a hydrogei same reason. Therefore, we assume for the radkriysis of bond, with the K30-OH radical pair. An inci«»i*e in nitric acid solutions that (1) there is a primary yield of yield of excited water with increase in LET was 2 N03 radicals and (2) the N03 radical csn react N03 + HCOOH -* N03" + H* • COOH (6) ot GHj on solute concentration was consistent with a precursor of hyU;ogen which decays by a first-order Then the dependence of G(Ce,u) on cerium(lll) and process. They proposed that H" was the primary formic acid concentrations should be given by product which reacts with water by a pseudo first-order 2GOK6 +*2[HN05!/(^[HCOOHl{i + kzlCc*»]t(k6[HCOOH))))) G(Cem)*G(Ce» I)* • 2: L ,n \ • (*, [Ce ] +*J[HN03J)/(*4fHCOOHl) 2GHOj/(l+MCe"M/ H20* (precursor of OH radical) to yield the NO? OF LIQUID ALIPHATIC CARBOXYLIC ACIDS radical, A. R. Jones HjO* r MOj- - H 0 + N0 , (2) 2 3 The energy of fast charged particles decelerating in organic matter is thought to be absorbed by the and also with dry e~ to red'ice C , , H electrons of the matter to yieid electronically excited and ionized mokcutes in a variety of states. The e- + N0 --N0 2~. (3) 3 3 stabilization and interaction of these excited and Our dytenrirtaiions of GOH = 2.04 ± 0.09 snd CNO ionized moiecuies is commonly held to produce a 7 = i.56 ±0.12 for 4.0 M HN03 solutions and GOH = conglomeration of chemically active species - atoms, i.78 ± 0.03 and GS04- = 0.9410.03 for 4.0A/H2SO4 free radicals, radical ions, electrons, and stable and solutions (the previously reported* values for 4.0 M excited product molecules - which then interact in H2S04 solutions have been changed as a result of complex fashion. taking into consideration the hydrolysis ot~ the S04~ It has been found, however, that the products of the radica'} may invalidate the proposal of Sawai and radioiytic decomposition of some Ciganic compounds Hamill. With the approximation that energy partition apparently result from a single specific decomposition between water and acid is proportional to the electron of the parent molecule. This effect has been most fraction of each component. GOH for acid water can be extensively investigated for the alpha radiolysis of the calculated from the sulfuric and nitric acid yields: homologous series of normal aliphatic carboxyik acids. 1.78/0.70 = 2.54 ± 0.05 and 2.04/0.79 - 2.58 ± 0 J 2, It was concluded that 90ft* or 95%2 of the carbon-to- equal within standard errors and equal to the reported9 carbon bond breakage caused by the radiolysis occurred vahte for pure water of GOH - 2.59. Th* proposal of ?.t the R-COOH bond and that there was no evidence Sawai and Hamill would be valid only under the of a variety cf free radical decompositions.3 unlfcdy conditions that an ir ORNL-DWG. 69-11166 • • • i i— — ! r- \ 1 ! ' 1 i 1i i |i • 1 1i i i 1i CO ~ 1 /& LIQUI D ACI « O UJ i X <*/ • FO R o *Y *"* m Oi O O O 9r :/ •s o ! i 0.0 0.1 0.2 0.3 0.« 0.* 0.0 9.1 a ELECTRON FRACTION OF COOH IN RCOOH Fig. 4.7. Comtatioa of 0M YkM of Caiboa Dioxide from the Goran of Liojrid Noma! Aliphatic Cafboxyfic Acids wilh theCaiboxyfic Etoctroa Fraction in (he Acid. 78 reactive fragments (oxygen, iodine, or water) doe; not INVESTIGATIONS ON THE THERMAL AND affect the yield of C02. RAMOLYTIC DECOMPOSITION OF ANHYDROUS This proposal is easily tested, since with these CRYSTALLINE POTASSIUM CHLORITE1 assumptions a plot of the carbon dioxide yields from G.E.Boyd L.C.Brown2 each acid vs the electron fractions of COOH in each acid should give s straight line. Such a relationship is Measurements of the radioiysis at ca. 38° of anhy indeed found and is shown in Fig. 4.7. Excluding tiie 60 drous crystalline KCK)2 by Co gamma rays showed points which represent formic and acetic acids, a that the chlorite ion decomposed in the solid (Fig. 4.8) straight line may be drawn satisfactorily through the via the overall reaction remaining yield values; it passes as closely as one might hope through a zero yield of carbon dioxide for an 3CK), Cr+2O0 " electron fraction of COCH equal to zero. 3 Radiolytic yields for a dose of 1.0 X 102 3 eV per mole 1 R. E. Koiug, Science IU4, 2 / (1946). of KCIO2 were: G(-CK)2~) = 33.5 ± 1.7; G 2 C. W. Sheppard and V. L. Burton, J. Am. Chem. Soc. 68, ± 0.2; G(CIO-) = 0.0; G(C103") = 22.5 ± 0.8; and 163f '1946). G 28 30 CHEMISTRY OF • 1 AND * I RECOILS and their addition to CK)2~ ions in the crystal lattice IN NEUTRON-IRRADIATED CRYSTALLINE was suggested. POTASSIUM IODATE AND POTASSIUM PERIODATE1 0WH.-0WG. 69-279A G. E. Boyd Q. V. Larson T T A, UNIRRADIATED KCK>2 l28 ,30 Radioactive I and I recoils formed by neutron 8, ^Co y-RAY IRRADIATED KOOj capture in crystalline KI03 and KI04 appeared as iodide, iodate, and periodate ions on analysis of alkaline aqueous solutions of the irradiated solids. With KI03 more than two-thirds of the radioiodiiie was retained as radioiodate, and small amounts of radioperiodate were found. With K104 nearly 90% of the recoils appeared as radioiodate, while the periodate retention was slightly less than 10%. The relative concentrations of the radiokxtine oxidation states varied with the time and temperature of the neutron bombardment. Radiciodide was readily converted to iodate and periodate on **»-%•*»»#ting* of\ r on exposing the ncuiiun-irradiated soiids to 60Co gamma rays. Iodine-131 added ir tracer concen trations to crystalline K103 or K104 as iodide ion was rapidly ox;dized to iodate and to periodate en heating the solids above room temperature. There was only a 1100 900 TOO 500 300 small isotopic effect in the yields of the iodine valence cm states in which ' 28I and ' 30I were combined. :ss=; d KOOjic} •: Room Temperatue. KBr pellet technique: concentration of 'Abstract of published paper: J. Am. Chem. Soc. 91, 4639 KCIO2 ca. 0.2% by weight; do« to irradiated KCK>2: 1.0 X (1969). 1023 eV/mole. 79 ORN_-DWG 69-6704 TtMPERATURE *C — Fig. 4.9. Thermal Anafyas Data for the i ot KCK>2(c)i 9.0-mg sample heated in ;at6°/i to 120°, at 0_5°/min to 175° and at 6°/niia to 600°C. 'Abstract of pubMied paper: J. toys. Cksm. U. 1691 KI04 (Fig. 4.14) showed that CK)3" and CK)2~, Br03~, (1?70). and I03~ ions, respectively, wer-; formed by radietysis. 2 New with the Isotopes Division. Chemical determinations (Fig. 4.15) of the amounts 3 of BrO , Br02", and Br04~ ions produced in CsBr03 by increasing gamma-ray err.>sure revealed that con FURTHER OBSERVATIONS ON PRODUCTS stant concentrations were approached for large doses, FORMED IN THE RADIOL YSE OF suggesting that decomposition reactions of a thermal ALKALI-METAL HALATES AND PERHALATES snd/or radicSytk* nature must occur. The rate of BY 60Co GAMMA RAYS1 increase in the BrO" ion concentration at very low dose G.E.Boyd L. C.Brown2 suggested that this species is not a primary radiorysis product The ertcess oxidizing power of CsBr03 above Spectroscopic and chemical techniques were em that from hypobrorrrite and bromite ions was attributed ployed to identify and measure the concentrations of to 02~ ion rather than to BrOj 3« 3«u*n^d earlier. the stable radkMytic products formed at room tempera A synopsis of the current state of knowledge about ture in crystalline KCK) , CsBr0 , Csi0 , KCK> , 3 3 3 4 the radiolysts of halate ions in crystals is given. 60 KBr04. and KI04 by Co gamma rays. The ultraviolet absorptions of KCK)3 (Fig. 4.10) and CsBr03 (Fig. 4.11) measured with diffuse reflectance techniques 1 Expanded abstiact of paper submitted to the Journal of indicated the oresence of CIO" CIO," andf)-." and of toyrcal Chemistry (1970). 7 Now with the iw topes Division. BrO" and 03~ ions, respectively, in these solids. The 'Perbtomate km, B«0 ~. was determined by the micro- spectrum of heavily irradiated CsiO*. however, showed 4 anuyiicJ iiwt\\~£ isxrizzi is ikt fcSersing conlr^utK^n, ***** no new features except for a broad band at 460 run report **MicToanalytkal Method for Determination of PeAro- attributable to I2 in the crystal. The infrared absorp- mate Ion in the Presence of Macro 4 mounts of Other Bromine Tr~* *~\ tiens of £CX>4 (Fig. 4.J2), *Bfj4 trig. 4.131, and Anions'* by L. C. Brown and G. E. Boyd. so -t- I RADIATED KCIO, OlFFUSE REFLECTANCE £0.51- SPECTRUM OF _j KC1O3 IRRADIATED <04|— WITH ^Co r-RAYS O 9bQ3»- 1 02 UNIRRADIATED r V\ KCIO, 01 /LNIRRADIATE D KCIO, 00 r. . , . _L X _L • • • • • X 2150 2450 275C 3050 3350 3650 3950 3500 4000 4500 5000 5500 SOOO WAVE LENGTH (A) *o = FK.4.10. KQ03 at35°C Co Rays. Absovbcd dose 4.1 X \ Fig. 4.11. Diffne Reflectance Spectrum of s OBf03 Irodoted at ca. 35 win *°Co Rays. Absorbed dose = 22 X 1024 eV/mote. 2600 3400 4200 5000 5800 6600 1HAM/C • Ckt/!TU /fll 81 ORNL-OWC 69-2045A T T T A, UNIRRADIATED KCl04 B, ^Co y-RAY IRRADIATED KClO, F«. 4.12. laftaied Spcctran of Crystalne KO04 Inaakv* at ca. 35° mlh 6PCo Gam Rays. Absorbed oo*e = 1.7 X 1024 eV/mok; K Br pellet technique. ORWL C=S. 69-2044* T T T A, UNIRRADIATED KflrO* 8, ^Co y-RAY !RRAOlATED K3r04 C, SCALE EXPANSION OF B 1200 1000 800 600 40C WAVE NUMBER (cm") t% 4.13. latnnd Spectra* ofCijilMwi KB1O4 it «*. \5° wi* *°Co C—ill Rays. Absorbed dose »ISX BrU, 10" eV 'mtote: KBr peOet techniooe: 0.2 wt 1 KB1O4 hi KBr. X X 1000 800 600 400 WAVE NUMBER (cm'') 82 CWNL-OWG. 69-2043* MICROANALYTKAL METHOD FOR i—• 1 ' 1 • r DETERMINATION OF PERBROMATE ION A, UNIRRADIATED KIC4 60 IN THE PRESENCE OF MACRO AMOUNTS B, Co 7-RAY IRRADIATED KI04 OF OTHER BROMINE ANIONS1 L.C.Brown2 G.E.Boyd T»»e need for a sensitive, rapid, and convenient analytical method for the determination of perbromate ion in its compounds and in the presence of much larger concentrations of bromate and/or bromide ion arose as a consequence of the discovery of Br04~ ion in 3 radidyzed crystalline KBrO, and CsBr03. 5 Previous analyses4,5 for perbromate have employed (ft Z either reduction to Br/ by 12 M HBr followed bv Br3~ oxidation of 1 to I3~ which was titrated with thio sulfate, or reduction to Br~ by MofVIVcatalyzed SnCl2 in 6 Si HCI followed b> chlorine oxidation of Br" to BrCN in neutral cyanide solution, reduction of BrCN by acid iodide, and titration of If with tftiosulfate. Both rrethods are ace irate, but they are also long and tedious and wotk best for relatively pure Br04~ samples. If appreciable amounts of other bromine oxyaniofis are present, for example. Bi0 ~. a prelimi J3_ 3 900 700 500 300 nary step must be performed in ca 1.5 Si HBr to reduce WAVE NUMBER (cm",-u! those species to Br2. which b then sparged from solution with an inert g2S. Spuliau of CIJIIJWI PQ 4.14. 4 The rrucToaiiaiytical procedure developed in this at cm. 35rO" wtfii ^Co Gwn Rays. Absotbed dose = 1.9 x 24 investigation was an adaptation of the Crystal Violet 10 eV per mole of KK)4; KBr pdfct i sohrent-extraction-spectrophotocietric method for the 6 determination of CK)4"" km. Concentrations of 1 to 10 X 1G~* Si Br04~ ion were determined in the presence of 1000 times larger amounts of bromate or bromide ion with good accuracy. 3*>«.-3K tt-'SSM 25r-' 'Resume of pubibhrd paper: And. Chen. 42, 291 11970). L RAOWLYSiS Of C^rST»i...iK£ CsBrO. I WITH ^Co t^srs. AT c.x 35-C 2 Now with the Isotopes Division. 3L. C. Brawn, G. M. Begun, and G. L. Boyd. / Am. Chem. Soc. 91,22*00 969). 4F. H. Aonrtman J Am Chrm, Snc 90. 190P. H968). 'E. H. Appehnan./fMr]t Chem. 8.223 (1969). *S. Uchfta-a.Bui Chem. Soc. J*pon 40. 798 < 1967). RADIOL YSLS OF ' sO-ENRICHED POLYCRYSTALUNE KN03 M. H. Brooker1 G. E. Boyd The effee s of an oxygen atmosphere of normal isotopic abu. dance on the *°Cc gamma radiolysis of 1 *0-enrich'?d fCN0 are being studied by infrared and fif, 4.15. Dow Dependence of -.- G~cc2tntioas of I 3 lytic Prodncta Fomed it ca. 35° in CIJ ildMni O81O3 by MCo Raman sjyectr.'jcopy. Preliminary cxpennwr.ts shew ,A €-~Mfeys. that atmospheric 02 can be incorporated into the 83 16 ls reactant KN03 and into the radiotysis product KN02. Replacement of 0 for 0 in the N03~ ion dur-iw Infrared and Raman vibrational-band assignments have irradiation in air is not a random process biz; exhibits a been facilitated by earlier investigations3-4 cf the selective isotopic effect. The percent of the total nitrate ,8 I6 ,8 frequency shifts characteristic of nitrate and nitrite ions present as N 03~ and N 0 O2~ is greater ?»:in substituted to different degrees with ' 80. calcu'ated on the ba^is of random distribution, whereas I8 ,6 ,8 Oxygen- 18-enriched KNO, (51.7^ 0) purchased the N 02 0~ aiii N"03~ species arc less concen from Isomet Corporation was used after treatment with trated than calculated (Table 4.1). Previously, this Nont A decolorizing carbon in distilled water and effect had been noted in the form of a 13^ lower subsequent lecrystallization. The I80 enrichment was nitrite yield for the irradiation of 180-enrichea determined by the Raman line intensity method.4 KN0» .s '6 It is unlikely that isotopic substitution could Raman band intensities in the symmetric stretching cnange the N-0 force constant: therefore, it seems region (vi) of the different Motopkally substituted most probable that because of it* greater mass. - KJ nas nitrate ions were in excellent agreement with calculated i lower recoil velocity than * 60 after the reaction band intensities on the basis of a random distribution of the l80 atoms (Table 4.1). Two samples of 51.7 02 20 (1969). Table %.l. Conyarison Between Observed "O-Enriclied N03~ SpeciesConceatiafions and Piedicted Concmtntiom on the Bant of Random Distribatioa Percent of Total Nitrate ,6 l6 18 l6 l8 I8 N 03- N 02 O" N O 02 N 03~ Original KN03 sample. not irradiated. 51J1 ' sO Observed 11.0 36.6 38.5 13.8 CsHzzistsd Irradiated KN03 sample. CM. 2X 1021 tV',g.A\j(,1 l8G Observed 16.2 37 I 34.7 12.0 Calculated 19.9 42.5 30.5 7.2 5. Organic Chemistry PREPARATION AND DEAMINATION OF S-exo- Table 5.1. Yields of Products and Product Ratios on a PHEr^L-S-HYDROXY-l^ro^ORBORNYLAMINE Deanunation of Amines 1 and 2 (See Chart I) AND 5^0-PHENYL-5-HYDROXY- From * From 7 2-ero-NORBORNYLAMlNE Products* Glacial HCAc HOAt-NaOAc HOAc-NaOAc Ben M. Benjamin Clair J. Collins Yields Certain refinements in our measurements1 of the 3 43.5 35.0 29.6 C yields of the products obtained on deamination of the 4 3.4 2.4' 0.039° 41 5 title compounds (I and 2) have now been made. Tne 5 36.7 25.6 6 16.5 19.0 42.6 scheme for deamination of the two reactants is outlined 7 0.075c 0.1i4 2.r in Chart I. The deaminations were carried out either with glacial acetic acid as a solvent or with glacial acetic Ratios acid-sodium acetate mixtures. Yields of the minor 5:6 2.2:1 2.3.1 1:1.7 products were obtained by isotope dilution analysis, 5:4 10.5:1 18:1 650:1 6:7 220:1 166:1' 19:1 starting with labeled reactants 1 and 2. The results are 4:7 45:1 21:1 1:56 summarized in Table 5.1. From these data we can draw the following conclusions: 'Deaminations were performed it ambient temperature. *The monoacetates of 4-7 were obtained on deamination, 1. The carbonium ion intermediates are best inter and these were converted to the diols with bthium aluminum preted as the classical Wagner-Meerwein pah A ^ B hydride. Smaller yields of three other compounds0 (resulting which do not reach equilibrium before they suffer from hydride shift in the ions A and B) were abo obtained. attack to yield the products, for from 1 the ratio 5:6 These products SN 2-1 ike processes. ORNL-OMG. 69-9319 3. The product ratios 6:7 (from 1) of 166 and 5:4 (from 2) of 650 provide the first measurement of a lower limit for the stereospecificity of exoiendo 3 attack by anion or solvent on a classical substituted / "\ norbornyl carbonium ion. *k< 'B. M. Benjamin and C. J. CoOint, Chem. Dbf. Ann. Progr. A * B 2 Repi. Msy 2G, ]<)69. ORNL-4437, p. 57. (XOT.ACIMCNT (MSPUKXMIEN T SYNTHESIS AND DEAMINATION OF i 5^0-HYDROXY-S-PHENYL- 2Wo-NORBORNYLAMINE Ben M. Benjamin Clair J. Collins * OM « 6 7 The title compound (8 in Chart II)1 was synthesized3 Chart I and subjected to deamination in acetic acid-sodium 84 85 OftNL-OWG. S9-I3BS7A 3. The relatively high total yield of 7 and 4 together, obtained from 8, i? significant; the endo diol 7 is OH MC' produced in greater yield than the exo diol 6, whereas deamination of 2 (Chart I) produces 6 and 7 in a ratio of 19:1 (Table S.l). These results, we relieve, offer clear evidence for the configuration- M^-4 - faOH holding ability of the counter acetate ion. 'To preserve continuity and readability, the numbering CXSPLACEMCNT system used in the preceding section is preserved. 2The synthesis was through the following route: norbor- nenone + PhMgBr -* 2-exo-pbenyt-2-norbornenoi (borohydra- H0\[^J HO^W^-OH ** tion) -*• 2 2. The ratio of the yields of diols 5 and 6 was 1:2.1 0NNL-0WC M-««M when they were obtained from 8 and was 1:1.7 (Table 5.!} when they were obtained from the exo amine 2 (Chart I); here we have further evidence for I + CH A P the presence of SN2-lice processes which for 2 CHCHjCJ \ COOH would produce endo diol 7 (2.2%), but for 8 should COOEt result in an increase in the yield of 6 as compared (t) 90O, with 5. In addition, S-^2 attack from the exo direction on 8 should be favored over endo S 2 N 9 ^9 * 12) Arndt- attack on 2; from die data it can be calculated that CHJCHJOH CMjCOOM EhtfWt 2.2% of the exo amine 2 and at least 5% of the endo amine 8 undergo SN2-Jike processes. Chart HI 86 cc-l,4-dichlorobutene-2 and malonic-2-14C ester. The increase 0.25 and 0.15% respectively. From these data tosyiate A was then acetolyzed4'6 in buffered (with we calculate that the ratios of 6,2 hydride shift to 3.2 urea) acetic acid at 50.0 ± 0.2°. The labeled norbornyl- hydride shift in the acetolyses of A and B. are <) 16 14C aceute was isolated, and the distribution of' 4C at and <250 respectively. positions 1 and 2 was determined. The results are given l in Table 5.2. The norborn>i-,4C acetate containing Oak Ridge Graduate Feiow from Vnwtraty of Tcaneawe. moft of its ' *C at C and a known fraction of its ' *C Knoxvnfe, under appointment with Oak Rrdse Asocatcd 4 Unrersities. Present address: Cacnustnes Institut ocr Uw- 2t C, and C was converted to the tosyiate B and 2 veratti, Tobianen, Germany. acetolyzed in buffered acetic acid at SO.O ± 0.2°. The 3V. F. Raaen, C. E. Hafdaig, and C. J. CoMao. Chrm. Diw. l4 product 2-exo-norborny)- € acetate was reconverted Am. hx*r. Rept Mty 20.19**. ORNL-4306, p. 66. ,4 to 2«rxo-norbornyl- C tosyiate and reacetoryred. This *C. E. Harding. V. F. Raatn, and C. J. Cctmn. Chrm. 0f>. procedure was repeated until a total of four acetolysis Aim. fnm. Rrpl. May 20. J 969. OftNL-4437. p. 58. M 4 cycles were completed. The fractions of C in C2 were R. G. Lawton, / Am. Cham, Ser. 83, 2399 (1961): P. D. determined after the second and fourth cycles. The Bartlelt andS. Bank./ Am. Ob**. Sot. 83. 2S9IU9MV fraction of ,4C in C, was also determined after the *S. Winstcin and D. Trifan, /. Am. Cham. Soc. 71, !953 fourth cycle. These results are ah* given in Table S.2. (1949). The ,4C content of the 2 position of product was *K. Humtki. S. Bonac, and D. E. Sunko. Ooti. Cktm. Acta determined by reducing the 2-cca-norborryi-l4C 3?, 3 10(1965) acetate with lithium aluminum hydride to 2-exo* >. von R. ScaJeycr. J.Am. Chrm. Sac. 89.3901 (3987). ncrborneol-,4C, which was oxidized to I-ncxbor- l4 nanone- C. The ketone was treated with phenyl- DEAMINATION OF ^emio^HEHYl^Ui YWOXYL. magnesium bromide, and the resulting product, after 2*xo TaateSJ. Dtorifcitionof ,4Cin Norfcorovl»l4r A*—^» -' t r PCfCMf o e ' Experiment So. of ,4 RcacUnt Cm No. Cycle* I 1 A 1 0J2 0.33 2 • * 0.46 i 3 1 4 IJ2 0.92 Chart IV 87 analysts easier, deuteriums were abo present at the cartxmium ion D. Tms difference in behavio. of D when exc-6 and atti-7 positions.1 Nmr analyses of the deu* produced frost die two different reactants (I and 2) is a terated products 3 and 4 obtained on dearaination of **i-*mory effect** which we ascribe to partial control of appropriately deutented 2 indicate that spproxsRstdy product formation by the counter anion (acetate). 903b of 3 and 75% of 4 are formed from 2 through the ciockwise course. Trus means that approximately 25% 1 of 4 and 10% of 3 are produced through the counter* Abstract of pabtiilnd paper: C. i. CotiM. M. D. Eckan, sad V. F, Ram./. Am. Otem. Soc 92,1787 (1970). clockwise course. The results indicate that ious B and C *Oak Rider Grsdaale Fcsrm in** 3* iiafrcrsity of T«a- are equiibratinf dassicrl ions and not a angle non* •ader appointment with Oak lUfcje Ajtocv cluneal bridged ion. We hqie to refine the measure Jaac 1966-JMK 19*S; ments by nmr analysis of apf wopriate derivatives of the oip.. Kinasport. T dcutented samples of 3 and 4. * V. F. Raaoi and C J. Conm. Ckm. Db. Aim. Pro*. Rtpc Hay 20.1969, ORNL4437. p. 54. The storting point Cor tkt sfilktmi wn Joitlo-ptMwyM- DETERMNATTON OF THE STEM&OCICiaSTIlY netborMMi^S-nro-T^itaWj;S. M. •uiiwiw andC. J.< OF U GLYCOLS BY >UCL£AJt / Am. Ckem. Soc. U. 1554 (19*4). MAGNETIC RESONANCE Ben M. Benjamin Michael S. Green ANKWCONTlrXM.0rSTEItE06EI^C71ViTV 1 In an earlier report data were presented which DUWNG DEAMtKATtONS related the staeothewastiy of a series of a gtycob to Clair I.ColiM Michael D. Edcart1 the nmr chemical shifts of the hydroxy! proton Vernon F. Raaen resonances, ror any oastcreomenc pair oi at pycon me hydroxy! proton of the lajreo (or feremfc) isomer gave a During the dratntnatrftn. in acetic acid—sodium signal at Sower fkM strength man that of the ay thro acetate somtion- of 3«*»*>*hydroxy-3-*x»-pr*eiry"-2- (or MCSO) isomer at the same concentration tn deutero* enoo-norbornyuanine (I in Chart V), the products 3 h^n^^B^B^vvj^r^gfT^f^v^v^^fc A% gaj £^^F AMjL^^M. ^^^t^rft*fffd*t^^t^^*t *ffA^Tns^ ^a^^^^ta^^^n-fn ^h^^^tBhSVva^^tB^^n^sl and 4 were produced in aearlv aaual amounts fme aronaitic groups. Chaff V). Upon deamtnation of the amine 2, however, B™ eg? vjan} BBBSvangw^ajt ey*^ ^B^Bra-*5»#aBBnjan> wernaejpajanaEjej wvaaj> ajasnujan> •jg veajaa, nearly 30% of 4 was produced, and only a trace of 3. is observed (I) in solvents other than CdCl, and (2) in SuonlemetttafY itftttMHf taoetina exoennents f with deu* coonpoundi cMttaMng only atiprittir groups. Table 5 J terium) were performed, and from these cxp^fiments it contains data fee several glycols whose nra was shown that both 3 and 4 are formed from the were observed in carbon tetrauriorrde and I J-dibromoethane, and Table 5.4 contains data for two nans of atirjfejijc alveoli. 23-Bntanodiot* was rjrenured •^aapw-w wi aBv-snw*~.tfnv*^w/ gps/wwens e»fj*^^vrw#vjnff"^a^a>u»w^ ^»w*w arfvifnN *-w# aw-. aj4WjB> aawi*laa#4aWwaa d-ahT alaBVf*dB#w#l an*v#)sW laffsmaaHnan wdmaMaan^aVSMtva "^r wawa> av^a^nBB>4a>v^wa} ^av w#aasaa>^vv^^a ^wn^a*' nvvvaanwaa)a) eee^nvvaejenBjpWauaj hydride. The mixture of nsMnaV and i separated by preparative gas 3,4*Hexanndt0i was prcparad by the a)travio9ct irra diation of Jt-pfopvl alcohol conrainina 1% hvdroaan ~ n.i ippatt at lower field strength. Thai teclunque be uatfal in determining the structure of new pa&s of dnstereomeiic n glycols when both isomers are ChstrtV 88 TxMeSJ. Shafts of Hydroxy! Protons of eric Aromatic Gh/cob as a Fi m Carbon Tetrachloride aad DentefO»i,2-dibro«H>e4hane Concentration, .Mole Chemical Concentration, Mole Chemical Compound Isomer Fracti-M Shift Fraction Shift iaCCLi (PPM) inC2D4BT2 (ppm) 2,3-Oiphe»y*.2J- ateso 0.0207 1.933 0.0026 2.150 batanediol 0.0108 1.835 0.0015 2.!?2 0.0C61 1.803 ncenmte a0076 2.223 0.0033 2.562 aoow 2.233 0.0016 2.495 0.0020 2.213 U-Dsphenyl-U 0.0121 2.217 0.0039 2.372 0.M76 2.008 0.0022 2.348 0.0044 2.044 erythro 0.0091 2.477 0.0045 2.565 0.0058 2.290 0.0025 2.5:2 0C018 2.292 l-Phinyl-2-p-toryi- C.0G47 1.98 0.0030 2.183 a0035 1.95 0.0015 2.159 0.0033 2331 0.0037 2.799 erythro aoois 2.482 0.0019 2.753 0.0012 2.421 BWtO Notsolable 0.0019 2.263 0.0011 2.253 imceimte 0.0034 2.832 0.0021 2.809 Tab** 5.4 Shifts of Hydroxy! Proton* of ISOTHERMAL ANALYSIS OF Ahphatk Glycols as a of GRAnilT&JMFRECNATED TEFLON 1 Concentration C. E. Higgins D. R. Nehnn (mote Shift W.H. Baldwin fraction) (ppm) It has become necessary for work proposed in the moo 0.0539 3.079 Health Physics Division to ascertain the composition 0.02S3 2.473 and uniformity of electrodes made from Teflon impreg 0.0159 2.168 nated with graphite. A method of analysis has been /•cenefe 0.0502 3.234 0.02 Other polymers that can be volatilized without We initiated several runs with filter paper (a sourc* of leaving a residue, for example, polystyrene and poly cellulose with minimum ash) in order to learn some ethylene, can also be analyzed in admixtures with thing of the course of this reaction. graphite. Poh/methy! methacrylate decrepitates during Most of the carbon is converted to caibon dioxide, heating with loss of graphite. Nylon, polyethylene but a measurable quantity remains as compounds of glycol, polyvinyl acetate, polyvinyl alcohol, and poly carbon dissolved in the residual aqueous solution. vinyl chloride leave residues (2-8%) when heated alone Continuous extraction of the aqueous solution with at 530°C for 10 min. diethyl ether was used to concentrate an acidic fraction Commercially prepared electrodes were analyzed by in which acetic and formic acids were identified by gas heating 0.5-to 1-g samples at 750° in a nitrogen stream chromatograpl.y. The ratio of formic to acetic acid is of 65 ml/min for 30 min. Their composition was less at hifntr temperatures, presumably because faster uniform and close to that stated by the manufacturer oxidation of formic arid occur* z* *h«» higher *enr ma (15.1% graphite, the mean of 12 determinations on ture. nominaiiy 15% material). The nonvolatile aqueous-soluble residue that re mained after freeze drying of the aqueous solution was examined by infrared spectrometry. Evidence was H«*lth ifiyscs Division. found for bonded hydroxy! groups, carbonyl groups, 2£. B. Yeltoa Chan. Abstr. 40,4909 (1946). and perhaps vinyl groups. Quantitative volumetric 3E. Abnhamzhflc, Chan. Abstr. 33,2437 (1939). analysis for functional groups revealed, per gram of nonvolatile residue, 1.5 meq acid, 7.3 meq hydroxy!, WET OXIDATION OF CELLULOSE and <0.8 meq carbonyl. Undoubtedly this residue is a mixture of organic compounds. W.E. Clark1 W.H.Baldwin Studies of the mechanisms involved in this reaction, 2 as well as its scope and limitations in practical waste A process is being studied for the treatment of 3 disposal, are being continued. cellulose materials, such as paper, as a means of waste disposal. This is an interesting heterogeneous reaction in which cellulose in the ratio of 10 g to 100 ml of water *Civ9 Defense Project. is placed in an autoclave with twice the theoretical 2F. J. Zimmermano, Chen Eng. 65,117 (1958). quantity of oxygen gas and heated to the temperature 3W. E. Chile, Ctril Defense Project Ann. RepL March rangeof200to250°C. J969-March 1970, ORNL-4566, in press. 6. Physical Chemistry AQUEOUS SYSTEMS component treatment in estimating the activity coef ficient for NaCl in this mixture. The ion-component FREE ENERGIES OF ELECTROLYTE treatment provides a distinctly better fit using only MIXTURES two-ion data. With the addition of terms obtained by fitting osmotic coefficients of three-ion solutions, the J. S. Johnson, Jr. G Scatchard1 ion-component treatment agrees better with direct R. M.Rush DV ew measurements of log 7+naci ^ methods* than the neutral-electrolyte treatment does, particularly with of respect to the curvature at high MgCl fractions. Free Energy Data3 3 The ability of the ion-co^nponent treatment to In a previous annual report3 we discussed the provide an estimate of the activity coefficients in a ion-component treatment of free energy data recently four-ion mixture is illustrated by the results for 4 proposed by Scatchard and preliminary results of the Na2S04-MgC!2 mixtures (Fig. 63). It should be em application to the mixtures involving NaCl, Na2S04, phasized that the solid line was not derived from the MgSO*, and MgCl? m aqueous solution. We have now completed the derivation of 'the equations for the osmotic and activity coefficients and a more detailed z-tom analysis of the data rrentioned above as well as other «--V data. These results haw been submitted for publica 5 - V tion. 2-MN One of the major advantages of the ion-component treatment is the ability to estimate free energies (and osmotic and activity coefficients) for three-ion mixtures > 1 ! > * t » -H 5-JON (common-ion mixtures) for data on two-ion (single salt) ai- omernr 2i" *. i •• i *« o»- —«- •- ©}•- -•1 —w i systems and for four-ton mixtures from data on two- • . .• w and three-ion mixtures. This is illustrated for the •1.1. -at* *• *. • * . -> four-ion mixtures of the systems mentioned above by O 2 t—r^ d—t « s -r NB»SQ>—MtaCU the deviation plots of osmotic coefficients shown in sop fig. 6.1. The plots on the left are for the earlier (neutral •%•.•• • electrolyte) treatment, and those on the right arc for the ion-component treatment. It is clear that the -aof- • 2-KM ion-component treatment gives a much better estimate I- than the neutral-electrolyte treatment when only two- -40*- ion (single salt) data are used. The plots labeled "3-icn" -*5- are estimates using both two- and three-ion data and •f- OMGCT FIT 4 -, 4f involve no direct measurements on the four-ion mix 5-ION tures. These estimates are about as good as the direct fit Oo----^*- » -»••- -•-J Qi...«. • • •• to the experimental data obtained by the neutral- ^J O 2 4« J^ O 2 4 • electrolyte treatment. IONIC STRENGTH Calculations of the activity coefficient of NaCl in F~. 6,!. Dsr*sges Rets UJS Fesf-to* Date. Neatrai- several of the mixtures are shown in Fig;;. 6.2 and 6 J. efectrolyte treatment (left) and ion-tomponeat treatment The results for the NaCl-MgC12 mixtures (Fig. 6.2) (right), look strength fractions for second component: * 0.25, indicate rather clearly the superiority of the ion- • 0.5, ap.J • 0.75. 90 91 (Wk.-0W. «9-t4l«0 measurements on the Na S0 -MgCl mixtures: it was 0.06 — i i i 3 4 2 calculated using only data on the single salts and the ' J appropriate common-ion mixtures. It is not possible to /•6 i lake estimates such as these with the neutral- ao4 electrolyte treatment (except at the ends and the midpoint). o For this system, at least, the ior-component treat o ao2 2 ment provides a better estimate of the osmotic and . .-J activity coefficients when only data on the two-ion 2 (single salt) systems are avaiaMe and provides as good a 0 j^^^ fit to the three-ion (common ion) data. In addition, for any four-ion system, it provides a means of estimating values using only parameters derived from the two- and three-ion data. -ao2 i i i « 02 a* as as 1.0 '"•a, rf*» F«. for die mixtures involving U02(O0«)2 is essentially complete. Experimental work on mixtaies of Ba(CI04)2 with HCK)4 and NaCK)4 is nearing com pletion. 0RNL-0a6. 69-15OT2 The osmotic coefficient data for the systems HCK)4- U0 (Cr0 ):-H 0 and NaCK) 4X^(00^ ^-H 0 nave -O.iO - 2 4 2 4 2 been analyzed by boih the neutral-electrolyte treatment and the more recent iou-component trrttrnent. The relative abilities of die two methods to fit the experi mental data are shown in Table 6.1. When terns characteristic of the mixtures (cro&t term; three-ion terms in the case of the ion-component treatment) are included, both methods provide a quite satisfactory fit to the data. When only terms derived from data on the single salts (without cross terms: two-ion terms in the results indicate a better estimate for the neutral- electrolyte treatment in the case of NaCK)4- UOj(Ci04); and for the ion-component treatment in the case of HC)04-U0,(CI04),. This is rather dis couraging in view of the consistently better fit obtained with the ion-component treatment for the solutions 2 containing Na*, Mg*\ CT. and S04 " (see above). In the case of NaCK^-WjfCK^ the measurements •NCI, covered an extended concentration range (ionic strength / from 0.8 to 12.7). and osmotic coefficients F%. 6J. Ac**? CoarlMaaai of Nad ia Na S0 -MgCl 3 4 3 of the two solutes are very different, as shown in Fig. MbajnMk ——I**vcoojp©aeat tmuiwat, two ioa pansnctcn; 6.4. For Ha0 -U0 (G0 )2 the ionic strength range — kw-compootnt treatnMnt, fhiec-ion pranctcn; • cntf 4 3 4 Q maawtwcwti from Y. C. Wo. R. M. Rw*. Md G. Scatduari. was from 0.6 to .4, and the individual solutes have J. Ptiys. Ckem. 73.2047.4434 (1969). osnotic coefficients relatively dose together. It may be 92 :t.l. 0MM.-0WC. 70-3490 1 1 1 1 »•<*- •«*-> t-5 -- •A of obsenraboas I «10 ^^ Witboat Cross Witfc Cross >^v 1.4 - s — Tenm X - Sotates Tens X\ NX* I.C. NJE. I.C. xJ\ X 1.3 - -^-** 2-iOii «•«•) _ NaCKX,-1X^(004 h 0.0474 0.148© 0.0023 0.0022 o K(3-io« *•»)- HClO^-UOjtCX^fe aoiss 0.0090 0.0031 0.0030 - *NZ. itni-cfcctiotyte tieatmm; I XT. ?I2 X^,' l.l ^ 0RNL-CWG. TO-3530 l l l 1 1 i 1 0 0.2 0.4 OS OS 1.0 Kr>"lC STRCNCTM FRACTON TF UO^CQ^ 3 of 9Q04 uojfoojh-iha xx ' ' 4 X x //wo* + x ' Oft*. 0»C. 70-3499 xX ^ ' 1 1 1 1 3 / x ' * — • X x• ' * a? - X * I-»0 / xX ' ' X ' X ' X * 0.6 /- 2 r / / 0.5 / IC (2- ion doto)-^/ J f ^£ c?04 1 ! 1 / // 3 <0 !5 u e / // IONIC STRtNGTH z - 0.3 / / - Fig. 6 A N»O0, o> r ORNLtfata; Hteiiiiit data. J 0.2 - // - that the neutral<4ectroryte treatment is better able to 0.1 / .sy^~W-Kl-«*4*\*) cope with !he extended concentration range add the / /V^-IC ond HZ {3-ion dofo) wide divergence of the individual osmotic coefficients. 0 We have not yet checked the computations thoroughly, - / together for MG04 (Fig. 6.5) but differ quite a lot for Fig. *>. ActM* Coaftt-li of NoQC4 in NoOO* Na€l04 (Fig. 6.6). UOstOO^h-MiO. 93 0«NL~0V6- 70-5*92 C**L-M»S- 70-3497 T 1 r 0.4 - A O MoCKVUO^aQ^ • 0.2 *» »- < HC»0 -U0^(CIG ) _ -* 0 4 4 2 £ 5 O JC -0.2 o a^ •i & o I -0.4 JC ^* e zIX I -0.6 HCIO4- N0CK44 -0.0 -1.0 o a2 a4 o.« o.e to Ofi€ STRENGTH FRACTION OF M £LBCTROCfTE Ft**.?. w-t.4 ± J. X 4 6 S to IONIC ST*e*6TH The vastly daffcting effects of HO0 and NaO0 on 4 4 tadMHBwSehrifi the activity coefficients of UCMCtQ*), are shown in fig. 6.7. The magnitude of the effect is even more dearly nluttrated by the activity coefficienis them selves. At an ionic strength of 10, for pore UO,(CK)4>7 4C / >4«. Om Soc. 9*. 3124 (lf44):VI. 2410 7± « 5*.4; in "pure- HOO* ftrace" U02(CI04), J yt NaO04 yt * 7.29. a change in the opposition directs by a 'actor of $ *R. D. Lafo./ f»r* OWm Of. 19921lf*5i These great changes at hit> concentrations are abo apparent from the excess free energies of mixing. Figure THE THElMODYNAhfK nttJtERTlES OF 6 J shows the excess free energy of mixing for equal HQ^04lga MIXTUSS ionic strength fraction (r) at constant ionic strength. : M.H.Lietzke R. J. Herdklou' 'CoMahaai; frofaaor of Physical ClMsabtry, rmcfnaK, No extensive study has been made of the thermo MmadMMiU InftiMitte of TcdMotogy. Ciwtrli%<. dynamic properties of aqueous solutions containing 'itcatafeft jofatity yam*mi by t*t Offk* of Sato* Water. four different ionic components. One of the few VS. Dtpmwmmi of it* Interior, and VS. Awmk EMS*? systems studied, has been HO-CsG-BaCJ,. where the oaoVf cootract villi Uaioo CarMdt Corn, and results of emf and isopiestic measurements we*e com contract No. AT(MM>-*aS vita Miami— m Ion*** Of I WWUtPpT- bined to calculate the activity coefficient of each 'ft. U. ftuak rr of.. Onu Dtr. AH*. hu&. Mtpt. May 20. component in the mixtures as a function of tempera- /96*. 0*Nt-4437.p. 69 lure, total ionic strength, and ionic strength fraction of 94 eadi ccmpone*:. Since it will be necessary to have data both cases the amount of curvature increases as the on a variet) of different systems in order to develop total ionic stmgth increases. and test nttfaetuticai rrpresentatiom. a study is being The open dtots in Fig. 6.9 represent activity coef undertaken of four suture each com*ira»g HO. an ficient values computed using the ion-component treat afcah metal cbionde. and the adjacent arkahne earth ment. The agreement with the observed values is very metal chloride. The system reported here, HCl-NaCi good at both total ionic strengths. fttgCh, is the second in the series. Plots of the logarithm of the activity coefficient of Emf measurements of the ceil HO QUO) in the HO-NaCl-MgCl, mixtures at three different temperatures and a total ionic strength of 3D ft4i,i> * I) I HO<«2 ) NaCHm3 )Mga2(ift4) I AgQ, Ag are shown in Fig. 6.11. Note that the amount of curvature decreases as the temperature incresses. At this ionic strength, values of the activity coefficient com were performed over the temperature range 25 to 75° puted using the ion-component treatment (open drdes) £ solutions of total ionic strengths from 05 to 5.0 agree very wef with the observed values only for Js bodk the io«i fractions of add and salt were solutions in which the fractioo of add is 0.75 and 0.50. as wdl as the ionic-strength ratios of the two At the lower fractions of add, the plots of the observed at fixed fractions of total salt bopiestic dau on values show much more curvature don do the values oVe NaO-SfgC* mixtures were taken from the Stera- computed by *he ion-component method, and the The emf Mid isopiestic data were fitted by least and the activity cceflkaents of each corn- 0ftNL-3NC 7C-404S it in the mixtures were calculated using a treat J»t0 ment3 which focuses attention on the "neutral" swedes - MCI - HmO - MfCl. hi solution, for rvjmpk. HO or Nad, rather than on 0.920 - the ions tbemset >**. That wil be referred to as the • Jtj *t.O 4 •'neutral-electroryte*' treatment. An attempt was made JT2 «CL75 to compute the activity coeffideiit of each electrolyte 0.900 in the mixtures at 25* from data on pure HO, Nad and Mga2 solutions as well as on HO-Nad, HO- fttfCI?. and NaO-MgC^ mixtures. The purpose of dm 0.880 cakubtion wss to test t-t abiity of an MMveomponent treatment1 to predict the properties of a more com- ptkated mixture from measurements on simpler sys 0.860 tems. Details of the method of calculation will be u e KM COMPONENT reported elsewhere;* only the resuits of the calculations z J*!jTRAL ELECTROLYTE wm be gyven here. f 0.84O In Fig. 6.9 the solid lines an plots of the logarithm of 0.900 the activity coefficient of HO (X10) in HCl-NtO J«0.5 HgCl, mixtures at / * 03 and I JO at 25° as computed using the neutral-electrolyte treatment. The abscissa x«/(x> * *«) represents the ratio of the fraction of MgCj in the mixtures x4 to the total fraction of salt in the mixtures {JT> • x ), where JT, IS the fraction of 4 0.860 NeO. Note that the curves are concave downward and _1_ that the amount of curvature increases as the fraction 0.25 0.50 0.75 1.0 of acid in the mixtures (JT3 ) decreases. The solid circles in Figs. 6.9-6.12 refer to the activity coefficient of the pure HO at the same total ionic strength. For compari son the corresponding plots in HCI-CsO-BaO mixtures Fie.6.9. PJotiofuM •i of dM Activity CottBcJMt of : HO (XIO) • HO-NaO-MgC]] Mixta*, w x /(x • x \. / « 0.5 are shown in Fig. 6.10. rfere the curves are cencave 4 3 4 and 1.0; temperature - 25 ;x7, x3, and x4 refer to the fracfam upward, but apin the amount of curvature Is greatest in of HC1, Nad, and MgClj icapeUwtly; «oHd dicta refer to pure the mixtures containing the lowest fraction of add. In HO it the same total tank stredfth. 95 !»*;.-0»G. 70-«C5C increases at the same total fra^*on of acid, the activity coefficient of the H*G increases. The same is true with the MgCL activity coefficient: as the fraction of NwCl increases at constant fraction of acid, the activity coefficient of the MgG2 increases. Thi* is exactly tr*e ieverse of the behavior shown in the ifCI-CsCl-Ba€l2 mixtures by the activity coefficient of the CsG when the fraction of add is greater than 0J06 and by the activity coefficient of the BaCl2 at all fractions of add. As cui be seen in Fig. 6.14. addition of Ba€l2 at constant fraction of add above CJ06 decreases the activity coefficient of the CsCI, whfle at any fraction of OMiL-OWG. JO-405I .060 i.OOO - 1.070 = 0.25 0.50 0.75 1.0 1.010 *4 F«.6.10. Hots of to Loganntm of «M Activity Coefficient - 0.950 - TS X /(JC ot HO 1.060 agreement is good only at the extremes. Hence the intermediate values of these computed values are not 1.020 shown at x2 = 0.2S and OX). Pie plots of the logarithm of the activity coefficient of HQ (X10) in the mixtures at / = 5 X) at 25°, shown in 0.960 I— O ION COMPONENT Fig. 6.12, continue the trend of greater curvature at NEUTRAL ELECTROLYTE HCI-NoCl- MgCi higher ionic strength. At this ionic strength, values of 2 the activity coefficient of the HCl computed using the 0.900 I L 0.25 0.50 0.75 1.0 ion-component treatment show good agreement with the observed values only at the highest fraction of acid. The variation of the logarithms of the activity Fig, 6.11. Plots of die Logarithm of the Activity Coefficient coefficients (X10) of NaCl and of MgCl} in the of HO (X10) in Ha-Nsd-Mfa^ M ixtares vs x4/(x3 + xA\ I» HCl-NaG-MgC^ mixtures with x2, the fraction of HG 3.0; temperature = 25, SO, and 75°; x2, *3, andjr4 refer to the in the mixtures, at / = 1.0 and 25° is shown in Fig. fractions of HCl, NaCl, and MgClj respectively; solid circles 6.13. As the fraction of MgCI2 in any or tne mixtures refer to pure HCl at the jame total tone strength. 96 OWWL-MG. 70-4012 *400 HCI - N«r.i - **fZ' Ffe. 6.12. Plote of the Loprithai of the Activity Coefficient of ta (X10) in HONad-MgCl2 Mixture* vs x4/(x3 • *4K / « i.VJ S.0; temperature * 25°; xj, x%, andx4 refer to the fractions of HCI, NaCt. and MfCI2 respectively; solid circles refer to pure HCI at the sane total ionic strength. '200 «- 1*00 i.ooc - e ION COMPQfttLNTv, NEUTRAL ELECTROLYTE ORNL-OWS 70-4054 0.900 Xz «0.0 0900 025 0.50 0.75 10 0.880 - X++X<3~"4 ***** A 0.0 a 0.25 c 0.5O c 0.75 E 1.0 0 740 »%.•.•>. note of *e Lofaritho* of die Activity Cjeffi- cfcafc 25*; x3. t j and '« refer to th* fraction* of HCI. NaO. and Mjfij xe«j>«:tr«ch;. 1.0 97 ORV._-D*G 70-*->St, 1 0.850 :.T il. Lx!?k(. H B. Hupf. and R. W. Stoughton. / I nor*. Sucl. Chent J I. >48l ll%9>. 3R. Y. Platford.7. Phys Chcm. 72.4053 (I968l. 4C. Scatchard./ Am. Chen Soc. 83. 2*36 (I96I >. 5G. Scatchard. R. M. Rush, and J. S. Johnson, sut milled for publication to the Journal o) Physical Chemistry: «r >lv> J. S. Johnson. Jr.. G. Scatrtura. and X. M. Rush. "Free Kncigies of Electrolyte Mixtures." preceding contribution, this report. R. J. iferdklotz, Ph.D. dissertation. University of Tennessee. Knaxville. August !<)70. SALT-INDUCED CRITKAL-TYfE TRANSITIONS IN AQUEOUS SOLUTION. HEATS OF DILUTION OF THE UTMUM AND SODIUM HAUDES FredVasiow Measurements of the heats of dilution of the halide (except fluoride) salts of both lithium and sodium haw been completed. Salt solutions initially between I JO and l .5 M were diluted with water in increments, each of about 4% of the total volume; each diluted solution was the starting point for the next dilution. Ten to twenty dilutions were made on each initial solution, and two runs were made for each salt except NaG, where six were made, although the first three were of a preliminary nature. The precision of the results is ?N?L't ±0.0025 cat in a total heat change ranging from 0.5 io 6 cal, depending on the salt and the concentration. Each measurement gives the change b+ 0.450 H of the apparent molal heat content of the salt, or the average slope ^H\tcjm over the interval &>/m(m h Ftgkit 6.14. Koto of fhe Logarithms of the Activity Cosffi- molality). With the possible exception of one of the preliminary dcato (XiO) af Cad and tUd2 wx2. / = IX); ten.penture = 25°; x}. x3, and x4 refer to the fractions of HCl, CsCI, said NaG curves (£$Hfa*/mv% yjm) ez± of these 16 urves fiaCI2 selectively. shows a small ap> vent discontinuity dose to or within a chord vhere, with the exception of LiG, a dis continuity in Atf'y/A^vs ^"curves (c is molarity) was acid the addition of CsCl also decreases the activity observed previously.' Selected curves for each lithium coefficient of the BaG2. When the taction of acid is salt are shown in Fig. 6.IS and for the Na salts in Fig. less than 0.06 in the HG-CsG-BaG2 mixtures, the 6.16. A vertical arrow shows the position of the activity coefficient behavior of the CsG is the same as apparent discontinuity, and a horizontal arrow indicates that of NaG in HG-NaG-MgG2 mixtures at all frac the position of the discontinuity in the A4r/A\/c tions of acid. curves. The heat of dilution curves that are net thown Further studies in this program will include the are very similar. instigation ot both KCl-KCI-taC^ and HCl-RbCI- For LiG solutions a discontinuity in the AfJ&s/c SrG2 mixtures. curves could not be resolved (i*., the transition ras diffuse). Hie only other significant difference in trie position of the discontinuity between the heat and 'Oak Ridge Graduate I ellow from the University of Tennes volume curves occurs for UBr and amounts to about see, Knoxville, under appointment with Oak Ridge Associated 0.1 unit in V^or y/m. Since hysteresis and lag effects Universities. are a normal occurrence in the measurement of tint- or , i Li* io* is regarded as a water*tructura stabiliser and might be expected to preserve the water structure to a ' LtCi 3» higher conceit*'*'*:^ in agreement with the Semnitav theory. Similarly the relatively high concentration of the transition for NaBr compared with Nad and Nal might be interpreted as indicating an optimum stability for Br' ion in the cavities of water, with CI" and I" being u>o small and too large, respectively, for maxi mum stability. 1V. Vaatow. J. f%TL Chtm. 73. J743 i 1969). J0. Ya. Satttofev. T>t Smtctmt of Aqt$*oms Sokrtkmt and ffcr Hy+mkm of torn. Cwgtiih Trawl, p. 141. Comtahart* g«f*M. New York. I%S. F%. 4.15. iftffew**! Haafc of MotJo* Data lb* LaO, lilt. 3J. G. Xwkwood. Orm. Rer. 19.275 < 1936). •4 Lfl. U«Ms of A^jAy^Tan ^ (kg H3Q)"2 mote "V». VARMTON OF OSMOTK COEFFICIENTS OF AQUEOUS SOLUTIONS OF TETRAALKYL> AIOIO^i1UMIiAUDESWrmreMrElUTl«£. THERMAL AND SOLUTE EFFECTS ON SOLVENT HYDROGEN 60NWNC' S. Lindenbau.-n G.E.Boyd L.Leifcr* ^.Oiase' Osmotic coefficients h»ve been measured at 65* for aqueous solutions of tetn^-butytammoniuiti fluoride; 0JS5 on aes as* iM 1.15 tetramethyl-, tetravt-propyl-, and tetra-n-butyt- ammonium chloride; and tetramethyl- and tetra-n- Ftp, 6.1©. DUUmmt* Hoc* of Dfeioa Cor Nad. Natr, aad propylammonium iodide. These data were combined NaL Units of A+fjAy/man cat (kg H jO)'/2 mote"3/2. with the available thermodynamic data at 25° to estimate relative partial molal entropies of thf solvent. The thermodynajnic properties of symmetric tetra^i- alkylarnrnonium halide volutions have been interpreted higher-order thermodynamic transitions, this small dif in terms of the effect of increasing anion size and ference is not unexpected, and the results are not increasing temperature on the local structure of water. considered to be in disagreement. This interpretation a justified in terms of the recently While the nature of the transition remains highly published x-ray diffraction tesults on water and on speculative, some of the data suggest a closer agreement aqueous ammonium halide and tetra-ff-butylainmonium with the Samoi-ov theory3 (transition of solvent struc fluoride solutions. The concept of '4water-structure- ture from that of pure water) rather than with the enforced ion pairing" has been used to explain the Kirkwood theory1 (change in form of the km radial reversal in the sequence of the magnitude of the distribution function). According to the Kirkwood osmotic coefficients on substituting iodide for chloride theory the transition should occur at wr = 1.03 (K is the ions. It is suggested that this concept is not valid in Debye-Huckel parameter proportional to y/c, and a is cases involving either cations or anions which reduce the distanceof-apprcach parameter), or between 0.4 the amount of local order in the solvent. However, and 0.6 M for the salts studied. While the general osmotic coefficient reversals may be accounted for on concentration predicted is reasonable, the sequence the basis of the competition between increased hydro predicted on the basis of ion sizes h wrong, since the gen bonding of water as the size of the R|N* cation raits with the larger values of a give tie transition at the increases and decreased hydrogen bonding as the size of higher concentration, contrary to the Kirkwood theory. the halide ion inceases. 99 ' \bnrart of fwMnfcrf paper: / fHys. Chrm. 74. 7*1 < l*70i anions are extensively km paired by a ypecial non- 'Mtctiieaa TgdMaokjfk-jl Unarentiy. Honjhlow Coutombk mechanism (Mwater-structure 4L for alkali-metal chlorides and tetra-ff-alkyl- ammonium chlorides in 1 m aqueous solutions. For the alkali-metal ions, $L decreases with increasing crystal logniphic km size, whereas for the large organic ions 4L increases markedly with increasing cation size. Many physical measurements have been reported, all of which demonstrate this remarkable difference between the properties of large organic cations and those of in organic cations. The purpose of this work is to determine whether this difference also exists between inorganic anions and large organic anions. We have measured heats of dilution of aqueous solutions of sodium salts of butyric (C4) and valeric (Cs) acids. These are given in Fig. 6.176, together with and acetate m 1 m solutions. The 4>L values of sodium butyrate (NaBut) and sodium valerate (NaVal) are also IONIC RADIUS, I given in Fig. 6.18 as a function of cctcentration. The inorganic salts show the expectei dependence on ion Ha. 6.17. Apparent MoW Keat Contents of 1 m Aqneow Sotaoom at 25°. (/*) Chloride salts, (B) sodium salts. Ionic radii size, namely, the larger the anion the smaller the value for acetate, butyrate, and valerate were estimated from molecular for 4>L. The sodium salts of the arboxylic acids gave models. Other ioiuc radii are taken from tables in P.. A. large positive values of suggesting that these anions cause increased hydrogen Academic, New York, 1959. *L values of sodium fluoride, bonding in the solvent. chloride, bromide, iodide, and acetate and lithium, sodium, potassium, and cerium chloride are taken from V. 3. Parker, 2 Low values of osmotic and activity coefficients '* of Thermal Properties of Aqueous Uniunivalent Electrolytes, tetraalkylamrnonium iodides in aqueoiu solution have NSRDS-NBS 2, National Bureau of Standards, Washington,, led to the suggestion9 that large cations and large IXC, 1965. iOO the osmotic coefficient! were greater than IJO for aO Table 6.2. Apparent Motal Heat Co«te»ts of concentrations greater than 03 m. This may be taken as I m AqaeowSatatioas at 25° a strong indication that km patring does not occur in Salt Table 6.2 with #>L 'Values of tetrabutybunmonium chioride (BujNCi).) Nafiut, and NaCl for 1 m aqueous solutions. Heats of mixing of I m solutions of Bu*NBut mixtures of Bt^NBut and NaCl. These are given in with NaCl, and NaBut with Bu^NCI, were also obtained Table 6.2 also. The 4>L of Bi^NBut is seen to be from measurements of heats of dilutions of equimolar considerably larger than the sum of $L for NaBut and BU4NC1. This difference is due mainly to the heat of OMNI-0W6. 70-4901 mixing &Hm of Bi^NBut + NaCl and to a lesser ispoo 2 extent the heat of mixing A//m, of BU4NCI and NaBut. These results suggest that in Bu^NBut solutions, both anion and cation cause increased solvent hydrogen bonding, whereas in solutions of NaBut or BU4NG the hydration of the sodium ions and chloride ions com petes with the water-structure promotion caused by the hydrophobic buiyraie or tctrabutylammonium ions. 1H. S. Frank and W-Y Wen, Discussions Faraday Soc. 24,133 (1957). 2 3 2 MCLALtTY, m S. Lindenbaum and G. E. Boyd, /. Phys. Chan. 68, 911 (1964). Fit. 6.18. Appnunt McW Hot Cbafeats of Aopeoas Sofe- 3S. Lindenbaum, /. Phys. Chem. 70,814 (1%6). tioaa ofCartorcytate* at 25°C 4A. H. Narten and S. Lindenbaum, / Chan. Phys. 51, 1108 (1969). ORN'.-OWG. 70-4962 5H. G. Hertz and A. D. Zeid!er, Ber. Bunsengn. Physik. Chan. 68,821 1964). *R. L. Kay, T. Vstuccio, C. Zawoyski, and D. F. Evans, /. Phya Chem. 70, 2336 (1966). 7R. A. Home and R. P. Young, /. Phys. Chem. 72. 1763 (1%8). 8J. Unge, Z. Phyrk. Chem (Leipzig) 139A, 584 (1968). 9R. M. Diamond,/. Phys. Chem 67, 2513 (1963). 1 °S. Lindenbaum, /. Phys. Chem. 73,4334 (1969). TRACER DIFFUSION COEFFICIENTS IN AQUEOUS SOLUTIONS OF ORGANIC ION EXCHANGER MODEL COMPOUNDS: COMPARISON OF AQUEOUS SODIUM p-ETHYLBENZENE- SULFONATE WITH CROSS-LINKED POLYSTYRENESULFONATES M. J.PikaJ1 Fig. 6.19. Molai Oamotic Coefficient! of Tetra-fi- The purpose of this study was to determine facer butytammoniuni Butynte and Valerate at 25°C. diffusion coefficients for inorganic ions in concentrated 101 aqueous electrolyte solutions of "model compounds" increases from zero. This effect is more pronounced for for organic ion exchangers. It was expected that this Y3+, where the data indicate an increase in the diffusion research would yield information on the nature of coefficient between zero and 0.1 m. This unexpected ion-ion and ion-water interactions in aqueous systems behavior is illustrated in Fig. 6.20, where the ratios 3 2 2 containing large organic ions and that information DHM*IDt are plotted: i = Y *, Zn *, Ca *, K*, CI", would be obtained on how these interactions affect the HTO. These data show that at low concentrations the mobilities of inorganic ions in ion exchangers. mobilities of Y3* and Zn2* decrease less rapidly with Tracer diffusion measurements at 25°C with HTO, increasing concentration than does the Na* mobility. 3*G~, 6SZn2*, and 24Na* were carried out in aqueous However, at higher concentrations this trend reverses, sodium p-ethylbenzenesulfonate (NapEBS) solutions of and the mobilities of Zn2* and Y3* ions decrease ivore 0.1, 0.3, 1.0, and 3.0 m concentration using the Stokes rapidly than does the mobfl'ty of Na* ion. The latter diaphragm-cell technique. In addition, measurements in behavior is qualitatively consistent with the effects of 0.1 and 1.0 m NapEBS solutions were completed with long-range electrostatic forces (Le., the relaxation tne species ca , ~~Y , and K. ; measurements effect). A similar trend is found with km exchange with 3.3 m NapEBS are in progress. resins of the Dowex 50 type. We note that the Ca2* From the data accumulated thus far, above 0.1 m the data appear to be quite normal. While the low- diffusion coefficients of all species decreased rapidly concentration behavior found for Y-** and Zn2* is with an increase in NapEBS concentration. In fact, at believed to be real, the physical origin for the effect is 3.0 m sodium p-ethylbenzenesulfonate, the diffusion not understood. It should also be observed, from Fig. coefficients were only about 30% of their respective 6.20, that both the K* and CI" ion mobilities decrease values at infinite dilution. This change is more than slightly faster than does the mobility of Na* ion. This twice the decrease observed with a typical 1-1 sup observation, which is qualitatively consistent with the porting electrolyte such as sodium chloride. One inter relaxation effect, indicates the absence of specific esting feature of the diffusion data is the slow initial non-Coulombic forces between Na* (or K*) and decrease in DZn& as the concentration of NapEBS pEBS~. It seems reasonable to generalize this result aid to assert that no specific non-Coulombic force exists between alkali-metal cations and the sulfonate anion CRN L-DWG. 70-5288 group in organic ion exchangers of the Dowex SO type. The decrease of DHTO with increasing NapEBS concentration was much greater than the corresponding m decrease of 2>H2O NaCl solutions. From this observa tion one might be tempted to conclude that the pEBS" ion is a strong "structure maker." However, all that is observed is that the translational freedom of the water molecules is greatly restricted. Such an effect would also be observed in a solution of large noninteracting spheres in a continuum. The large spheres would effectively block part of the total area available to diffusion and would therefore decrease the mobility of a small species such as H20. This effect is the so-called "obstruction effect" whose magnitude may be calcu lated from hydrodynamic theory. Preliminary calcula tions for HTO diffusion in the NapEBS solutions studied in this research indicate that most, perhaps ail, of the rapid decrease in DHJO may be accounted for by the obstruction effect. The tracer diffusion coefficients of Na* and Zn2* are compared in Figs. 6.21 and 6.22, respectively, in a "typical" 1-1 inorganic electrolyte, in the model com Fig. 6.20. Diffusion Coefficient Ratio* for Various Species at pound (NapEBS), and in cross-linked polystyrene- a Function of Molality of Aqueous Sodium p-Ethylbenzene- sulfonate-type ion exchangers. It should be noted that sulfonate, although NapEBS is believed to be a far better model 1 OWL- for the exchanger than a 1-! inorganic electrolyte, —1 diffusion of a cat:on in the model-compound solution h much faster than in the exchanger. Further, the model-compound and the polystyrenesulfonate cunres do not seem to be approaching one another. The diffusion of HTO in the modd*cornpound (NapEBS) solution is compared with the diffusion of 8 H2 * 0 in a Dowex-50-type ion exchanger in Fig. 6.23. Although the hydrogen form of the resin is used for the comparison, a comparison with the sodium form of the resin should give nearly identical results, because H* and Na* k>rr. are known from experiment to have nearly identical effects on the mobility of H20. The Ft 603. ofHTO DHMNQNA- of Ha "O fa a Dowtx-SO-Type k» data in Fig. 6.23 show a semiquantitative agreement between the mobility of H20 in the model compound and in the cross-linked ion exchanger at concentrations common to the two sets of data. Further, the model- compound curve seems to extrapolate into the resin curve. Thus it seems that the model compound, NapEBS, is a better model for the ion exchanger whei! diffusion of neutral species is compared rather than diffusion of ions. This observation suggests that the of N»* few V; F«f. 6.21. Ti principal difference between an con exchange resin and Electrolyte Systems. its "model compound" is in the nstture of the distri bution of counter ions around a moving ion. ORKL-m. 70-9290 T i In addition to diffusion measurements in 3.3 m NapEBS, diffusion measurements in ion exchangers of the Dowex SO type will be made in the near future. The latter measurements will serv? two purposes: (1) it is n 1.2 desirable to check the literature values of £?H2O > cross-linked polystyrenesulfonate to establish whether the differe'.ices between the ion exchanger and the •e 0.3 model-compound data are real or due to experimental error in the former data, and (2) the available data with $ ion exchangers are not suitable for quantitative com RESIN iZn Form) parisons of DNt*/D/ (i * uther species) between 0 exchanger and model-compound solutions. The ion exchc."v»e resin measurements planned will provide data -0.4 suitabSe for this purpose. J L J L J. J_ -0.0 12 3 4 5 6 7 8 Fif. 6.22. Tracer DifYasioA Coefficient* of Zn* for Varkras 'Visiting scientist from the Department of Chemistry, Uni Electrolyte Systems. versity of Tennessee, KnoxnBe. 103 MASS TRANSFER IN ION EXCHANGE TUBES Equation (1) was tested further under conditions of F. Nelson large adsorbabSity and of negligible desurption of kms, in which case F. the fraction of tracer adsorbed, is equal 1 In a pteviou) annual report a generalized expression Then torm/(Vo) for the limiting current obtainable from oxidation- reduction reactions in poious and tubular electrodes as F~ 1 - expl-5.43(5//iir)?/JJ . (3) a function of the parameters of the system (reactant concentration, volume flow rate, diffusion coefficient The solid curve in Fig. 6.25 describes this equation, and of the reactant species, and capillary length) and valid the points in the figure are the results of experiments for both low and high flow rates was derived (£q. (2) of carried out similarly to those described above at three ref. I). Good ag.-?ement between theory and experi different flow velocities and for several segments (/) of mental limiting currents of redox reactions m tubular the tubular exchanger. The agreement of the data with platinum and graphite electrodes was demonstrated the theoretical curve is excellent over the entire range of flow rates, including the transition region between rate control by surface reaction and by convective diffusion. aunt.- owe. tt-assa This equation has now been modified to express the T ' 1—» I 'Ml 1 efficiency of adsorption of ion-, in tubular adsorbents such as ion exchanger tub s: S THEORETICAL a SLOPE 2/3- 'a. ~»So {1 ~ txpl-SAXH'u,)2'3)}. (1) M where i^ is the mass transport diffusion current 3 (moles/sec), u9 is the solution flow rate (cm /sec), c© is the concentration of diffusing species (moles/cm3), JQ is S 5- / the diffusion coefficient (cm2/sec), and / is the length ° J* of the tube (cm). The equation applies to conditions where the "back reaction'' is negligible. > *cr Two tesft of Eq. (I) were undertaken in experiments \ measuring mass transport in km exchange tubes by £ 2I 1 1 1 « 1 11 u radiochemical techniques. First,at sufficiently high flow f 2 4 6 8 10 15 rate Eq. (1) reduces to Item) Fig. 624. AdxxpfcM of Tact Na* m a Ttfaate Cstfoa iw*5.43c^^/^?/3/2/3. (2) Fviiifrr. AMF C-6C, uL « Confirmation of the dependence of the mass transport rate on the two-thirds power of the tube length at high flow rate was demonstrated by passing measured volumes of 10~3 M HC1 containing tracer "Na* through tubes lined with a cation exchange membrane (American Machine and Foundry C-60 membrane, H* form, 0.54 cm in diameter and 10 cm long) at a linear flow rate of 0.87 cm/sec (0.20 cm3/sec) for 25 n»n. Under these conditions desorption of adsorbed tr«c*r was negligible. At the end of each experiment the cation exchanger was cut into sections 1 or 2 cm long and analyzed for "Na activity, which is proportional to i . A log-log plot (Fig. 6.24) of the "Na activity m Fig. 6.25. Adtotptfam of Na* in a Cttioa Exchange Tnbe. summed over consecutive membrane sections vs the Trace Na* in 10~3 M HCI; membrane AMF C-60, H+ form, total length of the assayed sections shows a linear thickness 0.3 mm; tube length 1 to 10 cm, diameter 0.54 cm. relationship with slope ca. %, as expected from Eq. (2). Symbols correspond to experiments at different flow velocities, 104 In the case of very small loading of the exchanger, chemical in^cgy, the ca^ny diameter at constant that B, small F, Fq. (3) reduces to volume flow r»te has no effect on the limiting current m the laminar flow regime. F«5.43(ifr/^0-2/3, (4) One consequence of this model is that the adsorption c*er a relatively large number of layers may be which is stilt applicable at both high and low flow rates. expressed by: The log-log plot of F vs the dmentionless parameter {ujil) of Fig. 6.25 shows that in the limit of small F, cm/c9*(ct/c0f. (I) the data do indeed fall upon a straight line of proper slope as predicted by Eq. (4). where c0,ct, and «.„ are the concentrations of trace ion in the inflowing solution, m the effluent from one layer of beads, and from n layers of beads respectively. 1 K. A. Kms el at. Ckem. Dh. Aim. /Voar. RtpL May 20. To test the model, the rate of adsorption of ions at /967.0RNL-4164,p.86. tracer concentration in shallow beds of cation exchange resins has been measured as a function of solution flow rate over a wide range of linear vdocities. Solutions >9 MASS TRANSFER IN SHALLOW ION containing a radioactive tracer, *Cd", of high spe EXCHANGE BEDS cific activity were used so that loading of the small beds would be minimal. To assure that desorption of «ne Fred Nelson adsorbed tracer was negligible, the supporting electro lyte concentration was kept low (10~3 M HCD. The The previously considered electrochemical aspects of 2 beds had a cross-sectional area of 0.5 cm and were oxidation-reduction reactions in porous, screen, and prepared from spherical cation exchange resins tubular electrodes1 *' have been applied successfully to (Amberlite 1R-I20 or Dowex SO) of uniform size (20 or mass transfer in ion exchange tubes.3 A logical exten 35 mesh). Bed heights varied from a single monolayer sion -*' these studies is mass transfer m ion exchange of beads to as many as 20 layers. A few measurements beds. were also made with beds containing nonunifornvsized Consider an ion exchange column consisting of layers beads, 20 to 35 mesh and 35 to 75 mesh. of km exchange beads, each layer in close-pad < J array x Figure 6.26 shews the change in mass tiansfer current but the layers randomly stacked. In each la er the i (i.e., the amosm of ,0'Cd* adsorbed per second) solution may be pictured as passing through the iiscrete m with volume flow rate u for various numbers of iayers openings or "channels** between the individual beads. f Flow through tacit channel is considered to be laminar OMn. bw> «*-Mor* (except at very high flow rates), but considerable mixing between layers would be expected because, ideally, the exiting stream for each channel in one layer would not flow smoothly into a channel in the next layer below, but rather would impinge en ion exchange beads. This is assumed to result in complete mixing of the solution between layers. It should be noted tiiat the ion exchange process considered here is not an equilib rium one but concerns adsorption from a floy/ing solution, with the exchanger acting as an infinite sink for ions; therefore, the back reaction (desorption) is negligible. This mode) is similar to the "capillary model" applied earlier3 to porous electrodes, which were considered to be a labyrinth of capillary tubes. The difference here is I 1 • ••.••••! • "•'"' i •••••"' t • • • *"f • " that each layer of beads consists of an "array of 0O« 01 10 to 100 MOO capillary tubes" through which the flow is laminar, but FLOW RATE (ml/min) complete mixing of solution occurs between arrays. The 3 Fig. 6.26. AdMMptkm of Trace Cd* • 10~ AT HC1 in shape of the channel between the beads is, to a frst Shallow Beds of Cation Exchange Ren* .« a Fanctioa of Flow approximaiion, not important, for fn the electro R*te. Ambeditc IR-12C, 20 mesh, 0.5 en2 bed area. 10S of Ambe&te IR-120 ion exchangf beads. The dashed the empty column: A is the crost-sectionai area of the &e » the figure repttsents im for ICO? sdsorp&s. s COMirrw* (viTi )r. «iu A' » (nc mniaW uf channcb per situation which is reached experimentally only at very layer of beads. H?nce. slow How rale. At faster flow rates :he efficiency of adsorption decreases, and M sufficiently high flow rate MrKil}*UAKN£Q. the value of im should change *ith the cube root of i#r. as indicated in Eq. (2) of the preceding contribution.' and the product Nl is the only unknown. The !?»»*> that is. a log-log plot of im vs ur should in the limit nituds and constancy of Nl over the range of experi become a straight line of slope '^. as already has been mental flow rates is a test of 'he reasonableness of the shu*m for tubular, pt vous, and v:ree« etecliooes' •* and model. The result'* are summarized in Table 6.3. tubular cation exchangers.* This is seen to b? approxi mately the case in Fig. 6.26 for shallow beds of an ion Although the values of Nl are not constant but show a exchanger over a range of intermediate flow rates. grssua; inct-sase with iacreasiMg flow rate, agreement of A test of the validity of Eq. (I) is shown in Fig. 6.27. the data with the capilary model is considered satis* factory, SMV~ drifts in the value of A? could result from a which log (cjr0) for '••Cd* in 10° M HCI is plotted against the number of layers of beads (2f>mesh variations in channeling, wall effects, and bed packing Amberlite IR-120 cation exchange resin) for a range of from experiment to experiment. It appecis significant fast flow rates. The linearity of the plot is in accord that the magnitude of the drift is less for the 35-mesh withEq.(l). than the 20-mesh resin beds, presumably because wall The correspondence of these experimental results ei'.ects become relatively less important with finer with the theoretical relationship previously derived (Eq. resins in columns of fixed cross-sectional area. (3) of the preceding contribution9 and the solid curve A further test of the reasonableness of the model can in Fig. 6.25 J can also be tested. Tftts is poasMe since be made by comparing values of// computed from Nl each slope in Fig. 6.27 is equal to log (cfa) at the t (assuming / equal to the diameter of the beads) with given flow rate. Since F • I - (c /e©) is the fraction of t values of N estimated from geometrical considerations. tracer ions in solution that has been removed by Thus from Nl values of Table 6.3, N is found to range adsorption on the km exchanger, one can calculate F from 144 to 204 and from 358 to 482 (per square experimentally and, through Fig. 6.2S, find the corre centimeter) foi 20- and 35-mesh resin beds, respec sponding theoretical value of « !(£l). The volume flow 3 w tively, in the flow-rate region 0.25 to 2.0 cm /sec. The rate per channel, u, h equal to UA/N, where U is the f number of openings (channels) per sphere is 2 for an linear flow rate (cnv'»:c), iiiat is. the fluid velocity in ideal hexagonal close-packed array of spheres in an infinite plane. From the measured number of beads (per cubic centimeter) in the beds and assuming isotropic owwL-owc.ea-—*7 distribution of the particles, the mean number of beads per layer may be computed. These values correspond to N * 136 and 376 channels/cm2 for 20- and 35-meth resin beds respectively. Considering that wall effects are ignored, the estimated values of .V agree well with those computed from Nl Finally, Eq. (4) of the preceding contribution3 predicts that zi sufficiently high flow rates, the ratio of the fractions of elements adsorbed from volution should vary with the % power of the diffusion coefficients of the tracers. Table 6.4 summarizes rapid-flow experi ments carried out with tracer Na* uid Cd3* in 10~3 M 5 10 19 2C HCI; after each experiment the beds were analyzed NUMBER OF LAYERS Of BEADS , n radiometrically for both Na4 and Cd*\ and the fraction 3 of each element adsorbed from the solution, F * I - Fig. 6.27. Admptioa of Trice Cd* ia 10" M IICI in (c /r ), wa* computed. The last column of Table 6.4 Shallow Beds of Cation Emkanf * Rcata as a Famtfcm of the ff 0 Nwnbet of Layen of Beodi. Amberifte IR-120, 20 mesh, 0.5 shows that the ratio FNJFCd is approximately equal tc 2 em bed area. (W*>Cd)2/3»a*«P«cted- 106 TaattcU. Teat of Xaj•an-Larar" Modal of Mass TaasfV m Saalnw teaExdmg t Bads A*«?t»B sf spacer Cd* s 10** J55 HC! a tisaSs* beds of AnUrS:* lR-120 .*»* 5 Scd» - 0.72 X I0" f n'/acc bedarea(/4)*0.5cin2 J (/(cn/aSL) «,(cm /«c) -taR(c,/r0) F uji&& A7(cm) X 10s 4.0 2.0 0.00393 0.0090 14.7 18.9 2.0 1.0 0.00574 0.0131 8.40 16.5 1.0 0J 0.00640 0.0191 4.75 14.6 fc5 0.25 0.01247 0.274 2.82 12.7 IS-Me* Rasas 4.0 2.0 0.0**85 0.0111 10.7 26.0 2.0 1.0 0.0C730 0.0167 5.80 24.0 1.0 0.5 0.0106 0.0229 3.10 21.3 0.5 0.25 0.0157 0.0355 1.85 19.3 *Diraeiuiosd;ss parameter from Fig. 6.25 concspoMtiaf to the fetedvalue s off. TaMtftA Adt«rt>tfn ORM.-OWG. 70-«722 OMUL 0WGu7O-52*7 i.Of T -T i i niri » r TUT" T T T""T I • KIIJ Oo«ei 50X0.2:5 0.9 A Doaei SO-X0.5 ••3S c Cowi 50-X1 ] • SE Scthodei C-50 0-8 » 0o*e.- 1 - X 0.25 A Do«ei 1- X0.5 -V • QAE Sephodex A- 50 0-7 \ ° - » . a 06 Q5 *J 04 \ * 03(- "a \ 0-t; t\v MOLALITY OF NoCl 0.1 Rg. 6J8. Bed Vobaae of Soaw LowCra«4JBked Exchanfe ROM • Nad Sotctioas (25°CX. -I I l i n rl I aoi 0.1 1.0 to KX) woo OftNL-(WG. 70-4723 I i i urn i iiiim, i i i mill i IIIIIIIJ 1 i 11 ini| 300 Fig. 6.30. ComlatkM Data for © 0o««* 50-X0.25 SE Seofcxto C-50 Ion Exchange Resins in NaCt (25°C). ® Ocwex 50-XOi £200}- s 6.30, which satisfactorily correlates the swelling data for seven different cation and anion exchange resins. s Furthermore, the simplified treatment predicts that = 100 Q/C* should be ~0.5 at 2mNlCI/C£ = 1.5, which is o seen to be approximately the case from rig. 6.30. tel O For resins of high water content, th; ratio CJJ/C* is approximately equal to the ratio of the bed volume of K>,- 5 K) 10*J 10" ' 10" 10^ resin in NaCl solution to that hi water. Hence Fig. 6.30 MOLALITY OF NoCl should also bo useful for estimating relative bed volume Ft*, 6.29. Bed Vohune of Some LowCioaa-Liated Cation changes of highly swoDen resins in NaCl solutions when Exchange Ream n Nad Soirioat (25°C). the water-swollen volume is known. between the resin and the solution phases of the osmotic coefficients and of the activity coefficients of !K. A. Kreus, A. J. Shor, and J. S. Johnson, Jr., Destination the electrolyte are unity), the equation can U reduced 2, 243 (1967V 2 to an expression relating C%!C* and the quantity S. B. Sachs. W. H. Baldwin, and J. .. Johnson, Desotimtion 2m /C5, where C% is the capacity of the swollen 6,215(1969). NaCI 3Pharmacia Fine Chemicals, Uppsala, Sweden The prefixes resin in water (in moles of sites per kilogram of H 0 in 2 SE- and QAE- designate die sulfonate and quaternary Tim IK the resin) and C* is its capacity in NaCl solution of resins respectively. Correspondingly, the suffixes C- and A- refer concentration "tNaC). This relationship v, shown in Fig. to these cation and «nk>r tsins. 108 HYPERFILTRATION WITH DYNAMICALLY polyvalent courtenons, are usually easy lo form on a FORMED MEMBRANES wide variety of supports and have interesting rejections and high fluxes.8 psiucularly if formed at high circula 2 W. H. Baldwin J. R. Love tion velocity. An example is given in Fig. 6.31; since M. S. Bautista1 R. H. Mayer' 1 rejection* are presented as R0bs, obtained by compar J.Csurnv A. K. Mehta ison of feed and product concentrations, they underrate 2 2 J. A. Dahlheimer W. R. Mixon trie salt-filtering capability of the membranes. At such 3 4 L. Dresner J. W. Myers high fluxes, salt buildup at the feed-membrane interface 1 J.M.Ganzer D. C. Michelson affects results substantially. From concentration polar Neva Harrison H.O.Phillips ization eory9 we estimate the rejection R, based on J. R. Hart4 A. J. Shor4 6 the ** ence in concentration between the effluent C.E.Higgins Warren Sisson and that computed for the feed-membrane imerfac;-, to J. S. Johnson D. G. Thomas2 be 81%, compared with Robi = 57% for the poiit in 5 K. A. Kraus C.G.West Fig. 6.31 for the 0.45-fi support at 140 min ;~1^00 C. G. Westmoreland gpd/ft2). With hydrous oxide membranes, however, best salt rejections are usually found at high anion Hyperfiluation stidies under the Water Research exchange capacities, which usually occur at acidities Program continued to emphasize development of higher than those of most natural waters. Hydrous dynamically fanned membranes for desalination, sup- oxide anion exchangers also tend to be particularly pCi-ted by the Office of Saline Water, and for processing prone to poisoning by sulfate 2nd other polyvalent of effluents from conventional primary and secondary couii tenons. treatment of municipal sewage, supported by the We have found that some of the advantages of Federai Water Quality Administration, both sponsors hydrous oxide and polyacrylate membranes can be being agencies o<" the US. Department of the Interior. combined by forming a hydrous oxide sublayer,expos Numerous additives, porous supports, and procedures ing it at acidic pH to a feed containing polyacrylic acid, have been tested during the year. Theoretical studies and then adding base to bring feed pH into the neutral were resumed, particularly in the areas of transport range. Table 65 illustrates a typical membrane forma through membranes of mullicomponent salt solutions tion. A hydrous Zr(fV) oxide membrane, formed from and of concentration polarization with multicomponent a colloidal dispersion, filtered out 62% of salt from a solutions. Because this work is 10 be reported in detail 0.05 M NaCl solution. At pH 6, rejection of the Zr(!V) to the appropriate agencies, we shall confine this membrane dropped, since ion exchange capacity is account to a brief description of dual-layer hydrous lower under this condition. Rejection remained low on oxide-polyacrylic acid (PAA) membranes, in some ways the most interesting development during the year. 0RNL-0WG. 70-2669* In recent years we have tended to stress membranes K» T -T r o o of organic polyetectroiytes, since the pH of their ao _aas* Tai.^» 6-5. Formation of Hydrous Zr(IV) effect of Mg2* has appeared to be more rapidly OxMe-Poh/acrylaie Membrane reversibl'. MI some experiments. 0.05 M NaCl. 1000 psig. 37 fps. 0.45-M Of mo:e practical importance is the performance of Acropor AN support on tube the membrane with feed solutions of compositions 2 typical of natural wattrs, containing usually sulfate, Additive pH Robs(%) Flr.xigpd/ft ) magnesium, anc calcium in addition to sodium and 0.001 M hydrous Zr(IV) oxide 3.1 62 630 chloride ions. Figure 6.33 summarizes tests of mem None 6.0 32 690 branes on supports of two different pore sizes carried 20 ppm PAA 5.6 23 700 out about two weeks later in th* same tun in A'hich the 20 ppm PAA 2.7 53 370 results in Fig. 6.32 and Table 6.6 were obtained. Sonic 20 ppm PAA 5.6 82 210 of the tests were at twice and three times the usuai compositions, to simulate the effect of conce ntrating feeds as product is removed. Rejections, based on teal addition of neutralized polyacrylic acid. However, on anion (by-passage of samples through a colurai of adding HC1 to pH 2.7 and then NaOH to bring the pH chloria>form anion exchanger and determination of back to 5.6, rejection rose to 82%. chloride in the effluent), scatter between 85 and 95% It is not necessary to introduce the polyacrylate in for brackish waters and were surprisingly high even at the salt form, but only to exoose the hydrous oxide seawater concentrations. Figure 6.33 also includes sublayer to polyacrylic acid under acid conditions, values for a simple polyacrylate membrane (half-shaded preferably pVI below 4. Apparently some of the small noints) taken from Table IV of ref. 7. It can be seen fraction oi carboxyls ionized at acidic pH become attached to the anion exchange sites of the hydrous oxide, and the attachment is net broken on adding base 0RNL-0WG.70-4993A 100 T T unless high pH values [~pH 11 for hydrous ZrfTV) oxide] are reached. On raising pH the attached poly acrylic acid is converted to the salt form, and rejection increases with increasing cation exchange capacity. At high alkalinity, membrane .ejection may be deceased O \.2fL Acropor AN by loosening of the polvelectrolyte from the hydrous A 0.05A Mdiiiipore oxide, but it is usually restored by a cycle through acidic pH. O30 _ The effect of pH on rejection of NaCl is shown in Fig. _025 £ 6.32. The results are qualitatively similar to those given in Fig. 3 of ref 7 for a simple polyacrylate membrane. Rejections are a few percent higher for the dual-layer membrane, and the difference is greater than indicated by direct comparison, since Fig. 6.32 gives rejections as R and Fig. 3 of ref. 7, as R. The increase in rejection Fig. 6J2. Effect of pH oa Hypctflteatioa rtopwlk* of ob5 Potyaciytate Membiaae Dyaanucaly Fomed oa a Hydras with increasing pH to pH ~8 is consistent with Z«flV) Oxide Sublayer. COSAf NaCl; 1000 pug; 35ft/sec. acid-base titration of PAA: full neutralization is ap proached at about this pH. Fluxes are higher for the dual-layer than for the simple membrane. TaKe 6J6. Hyperinflation of Na2S04 and MgC12 by Hydrous Table 6.6 lists a sequence of rejections, including ZrflV) (hode-PAA Membrane* values for a salt with a polyvalent coion (Na S0 )and 2 4 pH = 7.P = 1000 psig, velocity = 35 fps. 0.05-fl Mifltport a polyvalent counterion (MgCl2). The rejections are in Flux L the order expected of a cation exchange membrane — Feed (%) 2 obs (gpd/ft ) highest for Na2S04, intermediate for NaCl, and lowest for MgCl2. The rejection of MgCl2 (64%) is consider O.OJAfNaCl 82 73 J ably higher than with a simple polyacrylate membrane, 0.025 AfNa2S04 98 72 2 <40% in Fig. 3 of ref. 7. Exposure to Mg * caused a 0.025 AfMfCI2 64 8.8 drastic decrease in flux, and much of the decrease 0.05 M NaCl 90 28 persisted after return to an NaG feed ir. «his case. The 110 0**!.-C>*5. 7?-.«99«9 with the latter cype of membrane were reported last year."' The feed was effuent from primary treatment, -Q • C „ ? HW O 5 B S to which 50J ppm NaC! was continuously added to a S = ^ £ a •= allow testing at higher dissolved solids than the rela 3 M I r applications. Rejections are p obably adequate for most MgC!2. Foss reservoir: 0.005 SI MgS04. 0.005 M CaS04, purposes. Perhaps the main difficulty (besides the 0.0014 Hi NaCl, 0.0026 M NaHC03. Dalpra farm: 0.008 M nece^ity for development of a suitable support mod NaHCO^. 0.G19 M Na2S04, 0.003 V MgS04. 0.003 M CaCl2, ule) which must be resolved before practical application 0.00004 M I eC!3. 0.00002 M MnC!2. Seauater: 0.47 .V NaCl, to sewage treatments is the high circulation velocities. 0.03 M MgS04.0.04 M MgCi2.0.002 M NaHC03. Fast feed flows ieem necessary to maintain high 1 xChem Div. Ann. Progr. Rept. May 20. 1969, 0RNL-4437, production rates *ilh both these types of »nembranes, p. 78. as well as for homogenized Sephadcx CM C25, a dextran-based carboxyla'e ion exchanger marketed for POLYMER STUDIES g»' filtration, anothei promising candidate for sewage treatment. Neva Harrison C. E. Higgi.is In summary, dual-layf hydrous oxide-polyacrylate J.Csurny W.H. Baldwin membranes usuaiiy have higher fluxes and somewhat Polymer Degradation by Shear higher rejections than simple polyacrylat? membranes. With compositions typical of natural waters, salt filtra Alexander and Fox1 have demonstrated the decease tion is much more efficient with the dual-layer type. 1: in the viscosity of polyniethacrylic acid by ultrasonics may weil be that hydrous oxides from corrosion and by highspeed stirring in a Waring blender (rated products have contributed to the performance of PAA 20,000 rpm). They interpret this decrease in viscosity membranes we have studied earlier. In our corrosion- to be a reflexion of the decrease in molecular weight. resistant loop, we have had difficulty forming simple We have confirmed this decrease in viscosity by polyacrylate membranes on 0.45-// supports. In seven stirring polyethylene oxide (WSR-205,5 g/Iiter) at high tests the best values of Robs obtained for 0.05 M NaCl speed in a Waring blender for 5 min; the intrinsic sc?»*ered between 25 and 60%. Only when Fe(IH) was viscosity of the solution was decreased by a factor of 2. introduced and an acid cycle was carried out were high If reductions of molecular weight are truly produced rejections consistently attained. by mechanical action, significant effects rray be ob Hydrous Sn(IV) oxide, as well as oxides ef Fe(IH) served in the hyper filtration process using dynamic and ZrfJV), has served successfully as a sublayer. In membranes where one circulates a solution of a some recent tests, hydrous ZrfJV) oxide premixed with polymer to form the membrane.2 Further, such d.r.iinu- excess polyacrylic acid appears to form membranes tion of molecular weight may result during polymer having properties rimilar to the uual-layer type. Two- preparation, since one often stirs polymers with sol step formation may therefore not be necessary. vents in a blender during purification. Preparation of Porystyrenesulfonate with Low 'Massachusetts Institute of Technology School of Chenrcal Degrees of Cross-Linking Engineering Practice. R. H. Mayer. Director, and M. S. Bautista, Assistant Director, of the Oak RkJfe Station. Polyelectrolytes with lew degrees of cross-Unking 2 Reactor Division. were desired for testing as dynamic membranes in 2 3Neutron Physics Division. hyperfiltration. Two methods were used wherein Reactor Chemistr, Divis'on- cross-linking was obtained by sulfone formation during Director's Division. the su?donation step, and a third method where a small Chemica! Technology Division. quantity of divinyibenzene was copolymerized with styrene to form the cross-linked polyhydrocarbon 7S. B. Sachs. W. H. Baldwin, and J. S. Johnson, Desalination 6.215(1969). which probably was further cross-linked during the 8 A. J. Shor. K. A. Kraus. W. T. Smith. Jr.. and J. S. Johnson, sulfonation step. Jr.,/. Pkys. Chem. 72, 2200 (1968). Reaction of polystyrene (moL wt 2 X !0S) with 9T K. Sherwood. P. L. T. Brian, R. E. Fisher, and L. Dresner. concentrated sulfuric acid (5 ml per gram of poly Ind. Etg. Chem. Fundamentals 4, 113 (1965). styrene) at 150°C for 5 hr yielded a gel containing 0.14 1 °CompOMtk>ns approximated from values given in Office of g of solid per g*am of gel and analyzing 4.4 miili- Saline Water Research and Development Report 134 and equivalents of acid per gran of dry polymer. Reaction personal communication from H. E. Podall. Natural seawater with chlcrosulfonic acid in CC14 produced a gel of used in test without hydrous oxide sublayer. Coalinga: 0.0028 0.O27 g of solid per gram of gel aiid 5.7 milliequivalents M NaHC03, 0.0096 M Ne}S04. 0.0018 M CaCl2, 0.0020 M of acid per gram of dry polymer. The product from 112 suJfonation of poly(styrene-ccKiivinylbenzene) with flow tangentially past a filtering surface under hydro- chlorcsulfonic acid contained 0.04 g of solid per gram dynamic conditions that prevent buildup of filter cake. of gel ard 4.2 miUiequivalents of H* per gram of dry An experimental system has been designed and con polymer. structed to evaluate cross-flow filtration for converting primary sewage effluent into potable water. Concur Equilibria in the System: Pob/(Hydroxypropyl rently we have begun construction of a mobile test loop Acrylate-co-Tetraethylenr Glycol Dimetruicrylate), in "POLYWATER," RAMAN AND 1 P. Alexander and M. Fox, /. PolymerScL 12,533 {1954). INFRARED SPECTRA 2J. N. Bain! el al., Chem. Div. Ann. Progr. Rept. May 20, 1969. ORNL-44?7, pp. 711-84. M.A. Bredig: 3C. E. Hggins and V>. H. Baldwin, Chem. Div. Ann. Progr Rept May 20,1968. ORNIM306, p. 71. Following the papers by Deryagin et al. ou 'anoma lous water," the report last June by Uppinco't et ai* Table 6.7. Eqaftbratioc* of Pcty(Hydroxypropyt on infrared and Rama.i spectra was the first to create Acetate-oTetraethytene Glycol Dinethacfylate) really intense and widespread interest among both the with Aqueous Electrolytes general public and the scientific community.! was then Exchange Capacity prompted to attempt bolstering, by a careful scrutiny Electrolyte (milliequrvalent per Swelling* of the spectroscopic evidence, the \«ry strong skepti gr; m of dry polymer) cism which I shared with ethers at this Laboratory in regard to the existence of i new form of liquid water. LiOH 10 Suggestions that because o its zlicged high-tempersiure NaOH.CsOH 9 stability "polywater" might find practical applications, 7 (CH3)4NOH including some in nuclear reactor technology, appeared Na2C03 3 to be attended by the spending of considerable research N*,HP04 09 effort throughout the country. This seemed to call for NaHC03 0.9 an earnest attempt at quick refutation. Sodhun acetate 0.8 My efforts were directed toward a demonstration that Cupric acetate 1.1 •he spectra, reportedly unique, could in fact be inter preted in terms of impurities or of simple well-known a 0.1 M electrolyte solution, nine days at room temperature. chemical entities, the presence of which vas suggested ^Volume of gel in 0.1 M electrolyte by the experimental conditions. volume in distilled water APPLICATION OF CROSS-FLOW FILTRATION The Raman Spectrum TO POLLUTION CONTROL PROBLEMS' H.A.Mahlman JC.A.Kraus A search through the Raman spectra of many W. G. Sisson1 J. Csurny compounds, especially those suspect .is contaminants, H.O.Phillips yielded no satisfactory fit. What may be taken a> the one exception was the spectrum of the SiF^2- ion.3 Its 1 Cross-flow filtration is a separations process in which strongest band, vx * 654 ± 5 cm" ,greatly resembles in solid suspensions or colloidal solutions under pressure relative intensity and width the strong band of "poly- 113 wat< r" centered at 644 or 630 cm"1, depending on cm"1 appear, both of which were essentially absent in which of two spectra reported2 is taken for compari spectrum I of Lippincott et al.2 (Fig. 6.35). These son. The discrepancy of 10 or 24 cm"1 is uncomfort absorptions represent considerable amounts of normal able but, in fact, hardly grea:er than that between the liquid water; consequently, the strong absorption band two spectra reported or greater than the naif width of near 1600 cm-1 must be assigned principally to the the band, if the "conventional methods" of cleaning H—O—H bending mode of normal liquid water rather glass reportedly used2 included hydrofluoric acid (cf. than to a new species, "polywater." 2 1 aiso Deryagin et al.), the presence of SiF6 ", perhaps in Both the distinc: peak at 1455 cm" , ignored by the 4 1 the form of solid Na2 SiF6, could be understood. Of the authors, and the veaker one a? 1665 cm" , on the 2 1 only other two, much weaker, Raman bands of SiF6 ", shoulder of the strongest band at 1600 cm" , were -1 one (p2 * 471 ±5 cm ) might be compared with the absent in the original "polywater" spectrum I. The Miiuiany ntar udnu m ful vm appealing in puiv- auuiuuu yji nit pcaiv ai ITJJ tin icuu.cu nic wate:." Identification of the second band (vs ^401 ± resolution of the "polywater" bands. The peak at 1665 5 cm"1) is impaired by the termination of the cm-1 was interpreted4 as the H-O-H bending mode of "pofywater' spectrum at 400 cm"1 ?nd the steeply normal liquid water and referred to as "1645." In the rising background. [Like the band at 1050 cm"1, background spectrum this H-O-H vibration is seen at ascribed by Lippincott et at. «o the quartz capillary but 1615 cm"1. Therefore, the 1665-cm"1 peak in the most likely due to the aigon laser lines 19,448 and spectrum of the sample cannot be the same species. 19,435 cm"1 (Ai« = 1044 and 1057), tnat background is Apparently a discrepancy of 50 cm-1 was sirrply definitely not attributable to fused quartz, because a ignored. I much prefer the assignment of both the strong band at 800 cm-1, very characteristic of fused 1665- and 1455-cm"1 absorptions to the rather dis quartz, was not observed.] tinctly separate two branches of the H-O-H bending 1 A strong point in support of "polywater'* has been vibration (yQ = 1595 cm" ) in water vapor which was jn?de of the absence of Rantn frequencies in the region evidently in imbalance within the double-beam, spec between 3000 and 4000 cm"' for the O-H stretch trometer used.4 [The small quantity of water vapor characteristic of normal liquid water.2 From experience thus indicated to have been present in the sample beam in our laboratory with laser-excited Raman spectra of may perhaps have arisen throughout the scanning minute quantities of water in narrow capillaries, it period from the sample as it warmed up in the strong would not be surprising if in Lippincott'i measurements infrared radiation. A similar though much lesser im part of the sample had distilled quickly out of the range balance in water vapor appears in the background of the intense exciting beam, .eavmg a residue contain spectrum, in addition to the liquid water bands around 2_ -1 ing the SiF6 ion behind. 3300 and 1600 cm , the presence of liquid water in A very weak, very narrow band at 3420 cm-1 was the background spectrum being unexplained. It evap ascribed by Lippincott el al. "to traces of residual orated during ihe scan from 4000 to 400 cm"1 (no water." This conclusion most astonish anyone familiar liquid water absorption band between 950 and 650 with the very broad Ramm band of water, having a cm"1). The presence of water vapor is indicated by the width many times that of the band at 3420 cm _1. undulation, small but distinctly visible, in the H-O-H It seems that at least a provisional identification of bending region, on both sides of the corresponding the r»« ticular single Raman spectrum published thus far band for liquid water, appearing at 1615 cm'1.] 2 Superimpositior. of the water vapor spectrum upon the for "polywater" as that of the SiF6 " ion has been achieved. absorption band of (normal) liquid water may explain why the 1600-cm"1 band in the "poly water" spectrum is somewhat stronger than expected in comparison with The Infrared Absorption Spectrum the O-H stretch band around 3300 cm"1. The only two infrared spectia in the characteristic Most significant is the observation that the second range between 4000 and 500 cm"1 reported thus far by strongest absorption band, centered around 1380 cm"1, the proponents2*4 of "polywater" differ considerably previously ascribed4 to unresolved "polywater" vibra from each other by the following features (Fig. 6.35). tions at 1410 and 1360 cm"1, perfectly fits the In spectrum II, more recently reported by Page, stronges* peak, at 1390 cm"1, which one obtains for Jakobsen, and Lippincott,4 which we consider first, aqueous carbonate solutions (Fig. 6.35). two strong, broad absorption regions from 3600 to Other peaks in spectrum II, weak ones at 1168 and 2900 cm"1 (the O-H stretch region) and 95'. to 650 1040 cm-1 ai:d a strong one at 11 "0 cm"1, appeared 114 similarly in spectrum I. They correspond tc the important absorption, near 3300 cm"1, for the O-H strongest absorptions for silicate and sulfate respec stretch, was reported to be absent. However, two tively. 1 prepared highly viscous solutions of sodium alternate interpretations come to mind, which I find as oxide and sulfate in water glass (sodium polysilicate). difficult flatly tc dismiss as to accept. One is similar to Spectra obt/aned between Irtran 2 (zinc sulfide) plates that given to spectrum i! but involves the icluctant from minute samples exposed briefly to the carbon assumption of an awkward experimental procedure dioxide of the air were characteristic of carbonate, leading to the presence of one, ant1 the absence of the silicate, sulfate, and water and closely resembled spec other, band of normal liquid water. The other, quite tram II of "polywater" (Fig. 6.35). different, interpretation, but also entailing only com The significance of these results was enhanced by mon chemical species, seems not less tenuous. I failed in refractive index measurements on such mixtures. I trying with sufficient assurance to verify postulates obtained values up to 1.46—1.48, similar to those about unusual experimental conditions that could have reported for "polywater."s affected the measurements. One is frustrated by the The interpretation of spectrum I (ref. 2), obtained uncommon paucity of experimental detail available in with diamond platelets, presents greater difficidty, the paper2 or from other sources. mainly for the following reason: the band near 1600 We may be left with a mystery as far as spectrum I is cm-1 cannot readily be assigned to the H-O—H concerned. At the same time we seem to be able to bending mode cf normal liquid water because its other ascribe the later spectrum II of Page, Jakobsen, and OKNL-0WG. 70-5986 WAVE NUMBER, cm*' 4000 3000 2000 WOO 160O 1400 1200 10CO 800 600 100, H20 1 vapor blank! 80 o 2 60 < (D vapor liquid Ci 40 Z SPECTRUM I (1969) _ o S 20 O 1 , I I i 1 1 1 - I I • I I 25 6 7 8 9 K) 12 15 20 background 2000 1800 1600 1400 1200 1000 800 600 15 20 Fig. 635. Comparison of Polywater Infrared Spectra 1 (ref. 2) and II (ref. 4> with Spectra of Mixtores of Carbonate, intfate, and Water. (A) Water glass + Na^COn, aq; (B) water glass • NajC03, aq + N^SO,, aq; (Q water glass + NajO • H20 * CC»2 (air). 115 Lippincoit4 to a mixture of the simple species carbon was devoted to experiments on the formation of the ate, sulfate, silicate, norma) liquid water, and water material and on measurement of a fev. of its properties; vapor rather tLan as unlikely a chemical entity as "a independently, M. A. Bredig3 undertook a itudy of the new liquid form of water."6 infrared spectroscopic experiments.2 (Note added in proof: Results of a most recent paper 1 was able to duplicate the principal results of by W. D. Bascom et al.1 may suggest that much of the Deryagin and his school on the formation of anomalous 1600-cm-1 band of both spectra I and H might be water, in particular the random nature of its occur assigned to solid potassium ^/carbonate rather than rence, the growth and disappearance as a function of normal water. KHC03 would also improve the fit in the the partial pi jssure of water, and the formation on flat region 3000 to 2000 cm-1 of spectrum 11. One surfaces as well as in capillaries. All of these observa contradiction is the predominance of sodium over tions coulu readily be explained as the condensation of potassium in polywater analyses,6 solid sodium bicar water on minute amounts of soluble impurities, specks bonate absorbing most strongly near 1300 cm-1 rather of dust, inclusions in the glass, or local residues of some 1 than 1400 cm" . Another is the existence, in KHC03, cleaning agent. of othe, bands of medium intensity near 1000 and 830 There lomained the problem of accounting for the cm"1, which are weak or nonexistent in the polywater supposedly anomalous properties reported for the spectra. The spectrum shown in Fig. 7 of ref. 7 does not material. A careful reading of the original papers fully satisfy comparison with polywater on account of showed that some of the properties could be explained the reversal in ielative intensities of the 1600 and 1400 as being simply those of electrolyte solutions of cm-1 bands and an overemphasis on the silicate band.) believable concentrations. These included freezing and melting behavior,4 thermal expansion,4 and vapor pressuie lowering.5 The viscosity measurements6 (ca. Thanks for valuable assistance and helpful discussions are 15 times the viscosity of water) were obviously dis due to many ORNL staff members, too numerous to list here. 2 torted by the large surface forces resulting from E. R. Lippincott, R. R. Stromberg, W. H. Grant, and G. L. nonuniform wetting of the capillary. The high density7 Cessac, Science 164,1482(1969). 3 3G. M. Begun 2nd A. C. Rutenberg. Inorg. Chem. 6, 2212 (1.4 g/cm ) could conceivably be that of a salt solution, (1967). particularly since the method of measurement (density 4T. F. Page, Jr., R. J. Jakobsen, and E. R. Lippincott, Science gradient column) allowed extraction of water during 168,51(1970). the measurement. The high refractive index8 was harder SG. A. CasteDion, D. G. Grabar, J. Hesson, and H. Burkhard, to reconcile with the impurity hypothesis, since there Science 167,867(1970). was not an obvious mechanism for concentrating the 6 After completion of the work described here, the papers by solution as there was in the density measurement. D. R. Rousseau and S. P. S. Porto, Science 167, 1715 (1970) Bredig3 observed that rather high solute concentrations and by S. L. Kurtin, C. A. Mead, W. A. MueDer, B. C. Kurtin, and E. D. Wolf, Science 167,1722 (1970) appeared with strong were required to match the refractive index if the evidence against the existence o*" a new liquid form of water. impurities were sodium carbonate and silicate. 7W. D Bascom. 2. J. Brooks, and B. N. Worthington HI, NRL Deryagin reported a high thermal stability,5 basing Report 7115 (Apr. 21, 1970). this on an experiment in which anomalous water was distilled from one end of a capillary to another through an intermediate zone maintained at high temperatures. ON THE EXISTENCE OF SO-CALLED To explain this on the basis of an impurity requires "ANOMALOUS WATER" either that a new portion of impurity be present in the E. H. Taylor far end of the capillary, or that the required impurity be transported in the vapor or by spray. Both these For about two years there has been widespread seem unlikely, but there was so little detail given for the interest in claims for the existence of a new form of original experiment that it seems preferable to discount liquid water, called "anomalous water" or "polywater" this experiment rather than to accept the idea of by various groups of proponents.1,2 I found the another form of liquid water. experimental and theoretical bases for these claims so Although most of the experimental results (including unconvincing, and the degree of acceptance of them so the spectra, described by M. A. Bredig3) can be surprising, that I repeated some of Deryagin's experi explained reasonably well by a simple hypothesis of ments and spent some time trying to explain the various impurities, there are some quantitative difficulties, and phenomena on more prosaic grounds. Most of the effort it would be desirable to be able to refute the existence 116 of anomalous water on more general grounds. One basis 8B. V. Deryagin, Z. M. Zorin, and N. V. Chureev, Dokl. Akad for such rejection is the widely supported observation Nauk SSSR 182,811 (1968). that anomalous water grows for only a limited time. It 9B. V. Deryajr.v B. V. Zheieznyi, N. N. Zakhavaeva. 0. A. appears as a droplet in a capillary, becomes a slug which Kiseleva, A. I. Konovalov, D. S. Lychnikov, Ya. I. Rabinovich, M. V. Talaev, and N. V. Churaev, DokL Akad. Nauk SSSR 189, grows in length for a time, and then ceases to grow. 1282(19e>9). Since the formation h attributed to catalysis, the 10G. A. Castellion, D. G. Grabar, J. Hession, and H. stoppage is attributed to poisoning, but it has not been Burkhard, Science 167,865 (1970). realized that this leads to a contradiction with other observations. Briefly, the contradiction is demonstrated by noting that the poisoning must be complete when MOLTEN SALTS AND RELATED the surface is covered by a monolayer and by calculat NONAQUEOUS SYSTEMS ing from that the maximum fraction of anomalous water that could be formed. (The bulk of the slug must be ordinary water condensed on the layer of anomalous HEAT CONTENT OF ALKALI METAL water.) / simpi? calculation shows this fraction to be FLUOROBORATES1 co. 3 X 10~3 n/D, »vhe;e n is the number of sheets of A. S. Dworkin M. A. Bredig closely bound H20 un«ts in the supposed polymer (anomalous water) and D is the capillary diameter in We have completed our high-temperature heat con microns. Since n is unlikely to be as large as 10 and D is T tent measurement of N aBF4, KBF4, RbBF4, and typically 30, the fraction expected is around 10'3. This CsBF4. The equations which represent our results for is much less than the claims of various observers which HT ~ /r*298 (cal/mole) are giver, in Table 6.8. Table 6.9 include the following values of the fraction of anoma summarizes the heats and entropies of melting and lous component derived from the stated property: transition. vapor pressure lowering,5 0.07; volume change on KBF4, RbBF4, and CsBF4 all undergo a solid-state freezing,9 0.02 to 0.6; refractive index,10 0.2 to 1.0; transition from the BaS04-type orthorhombic structure 2 2 4 molecular spectra, almost no ordinary H20. to the high-temperature cubic structure. " NaBF4, on Because of this contradiction, one must reject either the other hand, exists as the orthorhombic (pseudo- 5 the quoted measurement, the simple argument based on tetragonal) CaS04 type of structure at room tempera standard ideas from kinetics, or the existence of a new ture and in a noncubic form above the transition liquid form of water. Rejecting the measurements temperature.4'6 This latter structure has recently been would be tantamount to rejecting anomalous water, reported6 to be monoclinic with four molecules per since its existence is inferred from such data. Since the unit cell. However, a lowering of the symmetry at simple impurity hypothesis (with allowance for experi higher temperature without a lowering of the number mental uncertainties) is sufficient to explain the obser of molecules per unit cell is quite unlikely. The vations, it seems unwise to abandon well-tried concepts structure was derived from a powder pattern, and the in favor of so wild a hypothesis as the existence of authors state that their assignment is not necessarily anomalous water. correct or unique. We oelieve that this inconsistency may be avoided by showing that the x-ray spacings (Table 2, ref. 6) are compatible with the assumption of *B. V. Deryagin,Discussions Faraday Soc. 42, 109 (1966). 2 a mechanicJ mixture of the crthcrhombic low- E. R. Lippincott, R. R. Strombetg, W. H. Giant, and G. L. Cessac, Science 164, 1482 (1969). temperature phase with a high-temperature phase of 3M. A. Bird«, Ton/water,' Raman and Infmed Spectra," hexagonal, rather than monoclinic, structure. These preceding contribution, this report. data (Fig. 6.36) give c/a - 1.55, which may be 4 B. V. Deryagin, I. G. Ershova, B. V. Zhdeznyi, and N. V. compared with the high-temperature form of CaS04, Churaev,Dokl. Akad. Nauk SSSR 170,876-79 (1966). also shown7 to be hexagonal rather than cubic, with c/a *B. V. Deryagin, N. V. Churaev, N. N. Fedyakin, M. V. = 1.54, that is, slightly distorted from the ideal Tabev, and I. G. Ershova, Izv. Akad. Nauk SSSR, Ser. Khan., "close-packed" symmetry, c/a - 1.63, as in wurtzite, No. 10,2178(1967). ZnS. 6B. V. Deryagin, N. N. Fedyakin, and M. V. Tsdaev, Dokl Although the entropies of fusion of NaBF and KBF Akad. Nauk SSSR 167,376 (1966). 4 4 7B. V. DfTyagin, D. S. Lychnikov, K. M. Merzhanov, Ya. I. are similar (Table 6.9), the entropy of transition of Rabinovir a, and N. V. Churaev, Dokl Akad. NauV SSSR 181, KBF4 is much larger than that of NaBF4 (5.93 to 3.13 823 (1968). u). This may be explained qualitatively on the basis 117 Table 6.8. Equation Coefficients for Enthalpy Data for Equation: 3 _I H, //298 (cal/mole) =u + bT + cT + J7~ Average Temperature Compound a b c d Percent Error Rcnge(°K> X 103 X 10~* X 104 NaBF4 -3.820 3.148 3.703 -12.17 0.3 298-516 -9.785 36.48 0.1 516-679 -8.605 39.52 0.1 679-750 KBF4 -6.325 15.62 1.943 -1.737 0.2 298-556 -7.800 5,J5 0.2 556-843 n t -7,710 39.94 V. 1 843-900 RbBF4 -7.430 1.697 +°.677 0.2 29K-S18 -7.897 34.-,4 0.1 518-855 -7.985 39.92 0.1 855-1000 CsBF4 -7.614 17.6?. 2.009 + 1/.01 0.2 298-443 -8.673 34. i 5 0.1 443-828 -8.390 39.36 0.1 828-1000 Table 6.9. Heats and Entropies of Melting and TrszsttkK: of Alakli Metal Fhioroborates *"tr (°K) (kcal/mole) (eu/mole) A (kcal/mole) (eu/mole) (eu/mole) NaBF4 679 3.25 4.78 516 1.61 3.1 7.9 KBF4 843 4.30 5.10 556 3.30 5.9 11.0 RbBF4 855 4.68 5.5 518 2.86 5.5 11.0 CsBF4 828 4.58 5.5 443 1.94 4.4 9.9 of the differing structures of both the low- and to the decrease in lattice energy with increasing size of high-temperature solids, which in turn are due to the the cation, which also facilitates the rotation or large difference in the size of the cations. The NaBF4 libration of the fluoroborateion . The large decrease in structure is more disordered below the tra'.isition, which enthalpy as compared with the entropy cf transition if. reflected by the fact that at 500°K Sr - S2 9g is more also explains the relatively low temperature of transi ihan 1 eu larger for NaBF4 rr.an for KBF4. In tion found for CsBF4. addition, the high-temperature cubic structure of KBF4 most probably is more compatible with anionic rota tional or librational disorder than is the structure of 1 This work also has .been reported in the MSR Program Semiann. Progr. Rep\ Feb. 28.1970. NaBF4 of lower symmetry. 2 KBF , RbBF , and CsBF are isodimorphous and M. J. R. Claik and H. Lynton, Can. J. Chem. 47, 2579 4 4 4 (1969). therefore can be considered as a series separate from 3 D. J. Huettnerer al., J. Chem. Phys. 48.1739 (1968). NaBF . Table 6.9 shows that although the enthalpies 4 *C. Finbak and O. Hassel, Z. Physik. Chem. 32B, 433 (1936). and temperatures of melting are similar there is a 5 G. Brunton, Acta Cryst. B24,1703 (1968). decrease in temperature, entropy, and enthalpy of 6 C. W F. T. Putorius, J. C. A. Boeyens, and J. B. Cm*. High transition of 21, 25, and 41%, respectively, with Temperatures-High Pressures 1,41 (1969). increasing cation size in this series. The particularly 7M. A. Bredig, Chem. Div. Ann. Progr. Rept. May 20 i 968. large relative change in the enthalpy may be attributed ORNL-4306,p. 129. 118 ORNL-OWG. 70-5401 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 T T CaS04 HEXAGONAL O 1230 «C 11.4 212 obs. Fifrfce, cote. M.A.B. I M !0 10.1 10.2 ll.O 10.3 20.2 21.1 30.2 NaBF4 ° (HEXAGONAL) 238°? ® cole. (M.A.8.) 11.4 21.2 1 i II i 10 1.01 10.2 11.0 10.3 20.2 21.1 30.2 NaBF4 ° "311°C"? * r G) Cor238-C!; V„43=|7 istorius et al. , i • i i j L i •Hi iL NoBF 4 i i U I 4 41 JU U ORTHORHOMBIC 2S8'C © lOO colc.(M.A3.) .312 313 221 _I_ JJ i I I i Hi 200 020 02' 112 220 3*0 (13 023 400 331 NoBF4 022 004 420 ORTHORHOMBIC © ROOM TEMP, cole. (Brunton) S3 ± -ALG& 11 'M 200002 1020) 02' 11? 220 340113 023 02223 331 CaSCL 022 420 4 ORTHORHOMBIC © ROOM TEMP. (N.B.S.) 221 223 112 202 1 I, | WW I (indices converted) in 200 020 021 220 310311130023 400 002 022 004 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 Fig, 6.36. Interpretation of High-Temperature X-Ray Powder Pattern of NaBF4 (ref. 6) as That of a Phase Mixture. Note correspondence of most reflections of pattern 3 (observed) with those of 2 and 4 (calculated). lsodimorphousCaS04 (Nos. I and 5) for comparison (ref. 7). THE SOLUBILITY OF THORIUM METAL This is of the same low order of magnitude as the 1 IN THORIUM TETRAFLUORIDE solubility in 3LiFThF4 and as the solubilities of La, Ce, and Nd in their respective trifluorides, which we A. S. Dworkin M. A. 3redig had measured earlier. Thermal-analysis measurements were made to deter The low solubility of thorium i "hF4 indicates that mine the eutectic temperature in the Th-ThF4 system the formation of a stable trivalent thorium fluoride in and, through combination with the entropy of fusion of ?ny appreciable concentration is unlikely. ThF4, the solubility of thorium in ThF4. The eutectic temperature was found to be only i to 2° lower than the melting ooint (1110°C) of ThF4, indicating a 'This work has also been irported in the MSR Program solubility of about 0.1 to 0.2 mote % thorium in ThF4. Semiantu Progr. Rept. Aug. 31,1 >69, ORNL-4449, p. 135. 119 THE SYSTEM YTTRIUM METAL-YTTRIUM the determination of thermodynamic properties, the TRICHLORIDE AT HIGH TEMPERATURES junction potential must be eliminated or its magnitude A. S. Dworkin M. A. Bredig R. J. Katt1 and stability established. An electrochemical cell As a result of our previous work, we have been able to correlate solubilities of alkali and alkaline-earth metals NiF/ fa CaF2 LiF-BeF Ni - in their own halides both at temperatures near the t frit single crystal melting points of the salts and at much higher consolute ! (Hq) pellet. temperatures above which the systems are completely miscible. For the lanthanide systems the solubility of reported previously1 yielded an initial voltage at 600 C the metals in their halides i?. known in most cases orly of 1.870 V, in fairly good agreement with the calcu at temperatures within a few hundred 4egrees of the lated value of 1.900 V.2'3 This potential remained melting point of the salt. We have extended these constant for a very short period, and then a slow measurements to much higher temperatures (~1550°C) downward drift commenced, terminating at the end of in an attempt to find a consolute temperature for at 12 hr in a fairly steady potential of 1.35 V. This result least one divalent salt-metal system. may be explained by (1) the eventual saturation by The Y-YCI3 system was chosen for studv because CaF2 («12 mole %) of the LiF-ReF2 melt within the vapor pressure studies reported in the Russian literature tantalum frit wnkh may (but not likely) give a gave a solubility at about 13S0°C of 35 mole % liquid function potential of 0.5 V; (2) a mixed potential yttrium, which is high enough to indicate the possible./ at the beryllium electrode due to impurities in the of complete miscibiity at all temperatures be'ow the melt;2 (3) the establishment of a redox potentiJ by a meliing point of yttrium (~1550°C). lower-valent species of beryllium produced by reaction Our measurements show the literature data to be of the metal and normal beryllium ions of the melt; or incorrect. At 1350°C we find the solubility of yttrium (4) a combination of any of the above phenomena. An examination of die CaF2 crystal shewed some solvation in /Cl3 to be only about 1S mole %. At the monotectic temperature of 1480°C, wc find that a large irascibility action of the melt. However. *he beryllium electrode gap exists frorr.abou i 22 to 96 molr ^ yttrium. We also had undergone extensive attack — much more than estimate the consolute temperature to be much higher would be expected from trace impurities. tIianI6G0°C. In the course of events, D. L. Manning of the From the above results and a careful study of the Analytical Chemistry Division and I became aware of literature, we conclude that there are in all probability our independent but similar approaches to a reference no lanthanide metal-halids systems with a consolute electrode for use in fluoride melts. The combining of temperature less than 1600°C, with the exception of our individual experiences evolved the Bronstein- the•; involving the large'y divalent europium and Manning reference electrode system (Fig. 637). The ytterbium metals. single-crystal LaF3 has sufficient conductance, supplied virtually 100% by the mobile F" ion, which permits the elimination of a liquid-solid junction potential if the Cak R;dge Associated Universities Summer Student Trainee melts at both ends of the crystal are essentially the from Williams College, Wifliamstown, Mass., Summer 1969. t 3 same. The saturaed NiF2 solution (10~ mole fraction) would hardly altei the slight solubility of LaF3 0*1 mole % by analogy to CeF 4) in the upper melt held A REf ERENCE ELECTRODE SYSTEM FOR 3 within the cup portion of the LaF3 crystal. The USE IN FLUORIDE MELTS single-crystal LaF3, on account of its low solubility, Harry R. Bronstein could make contact diiectly with the melt, but slight temperature gradients within thw melt could cause mass Nuclear fuel technology has focused interest on the transfer from the small crystal and thus limit its chemical and thermodynamic properties of fluoride lifetime. The fine-porosity nickel frit limits the area of melts. One of the best means of gaining such informa contact of the main bulk cf the melt with the crystal. tion directly is to determine the emf of electrochemical The Ni-Ni(II) couple in fluoride melts shows ceils incorporating the materials of interest. However, Nernstian reversibility and fairly large exchange cur the half-cell of interest must be coupled through some rents.5 With the expected elimination of junction junction to a reference electrode system; therefore, for potentials and with the free energy of formation of 120 3 2 crystalline NiF2 well established, the use of this phenomenon occurred. According to Hitch and Baes couple in the LiF-BeF2 (67-33 mole %) melt saturated high-purity materials obviated the poisoning of their with NiF2 as the electrode of constant potential shoal 1 beryllium electrodes. However, in the (resent circum provide a very reliable reference electrode for use in stances the bfryllfum electrodes if poisoned should not fluoride melts. have shown iuch severe attack. Analysis of the melt and The magnitude of the liquid-solid junction potential electrode materials before and after the experiments to be eliminated was found to be 50 mV by measuring showed the presence of insignificant quantities of the potential of the cell impurities, quantities very much below the levels necessary to cause such attack. In some experiments the fdte melts were pretreated with beryllium chips in order to (•)M|^; 150-50£ % (-) remove any impurities which could poison or attack the |frit|cryjtJNf; electrode, in ali cases the beryllium electrodes still underwent attack, and the potential were 0.5 V below It was also experimentally confirmed that the differ the calculated value. In order to gain some insigr * into ence in the potentials generated at the surfaces of the the phenomenon occurring a, the beryllium electrode, the beryllium electrode was made cathodic by pulsing a LaF3 crystal under identical conditions was quite small, 15 mV, and probably due to an asymmetry potential. current between it and the nickel container. Asa result Asymmetry potentials for the glass electrode commonly of this current pulse, the potential of the beryllium fall in the range 0 to ±10 mV.6 electrode vs the reference electrode was 1.900 V, in 0 agreement with the calculated value. However, this In tests of this electrode vs the Be !BeF2-LiF system, the expected voltage,2'3 1.900 V, was obtained. How potential would shortly decay to the value previously ever, after a short period of stability this potential measured. Apparently by plating L fresh surface of 2 would gradually decay to a value approximately 0.5 V beryllium upon the electrode, the Be/Be * potential below the initial voltage. This voltage would then could be maintained. An anodic current had no effect 2 remain constant for the duration of the experiment. on restoring the electrode to the Be/Be * potential. The beryllium electrodes when removed from the melts Formation of a subvalent species through an attack showed catastrophic attack. In separate experiments on the electrode according to the reaction Be + BeF2 -»• where highest-purity materials were used the same 2BeF would explain the lower potential in terms of a redox couple Be*/Be2+ and the effect of cathodic and OftrtL-OWG. 70-887 anodic current upon the electrode. However, the work of Hitch and Baes2 seemingly eliminates this mech anism. Another system investigated which showed similar behavior was the Zr/ZrF4 couple in the melt LiF-BeF2, Lovite ZrF4 (5.0 mole %). Here again the initial potential of Ni Plate the cell, 1.620 V, was in good agreement with the 7 Boron N'tride calculated value (1.590 V), but after a short period of time (10 min) the potential decayed to the value 1.000 V and remained thereafter at this potential for the duration of the experiment - several days. Examination of the zirconium electrode revealed ~2vere attack. Again one is tempted to invoke the formation of a subvalent L0F3 Single species of zirconium as an explanation. Wnat occurs at Crystal the metai electrodes bears further investigation. In spite of the special difficulties described here occurring at the beryllium and zirconium electrodes, it may be said that the somewhat new concept for a reference electrode for use in fluoride melts has been successfully tested and should prove quite versatile. ?'"• Fig. 6.37. Bronstein-Manning Refeience»Electrode System for H. R. Bronstein, Chem. Div. Ann. Progr. Rept. May 20, Use in Fluoride Melts. J969, ORNL-4437,p. 102. 121 2 B. F. Hitcn and C. F. Baes. Jr.. EMF S.Wv of LiF-BeFz The hea» capacity of K2TcCl<, exhibits a lamb Ja-type Solutions. ORNL-4? 7 (July 1968); Inorg. Chem. 8, 201 heat capacity anomaly with a maximum at 7.0 ± G.1°K (1969). indicative of a cooperative-type- transition. By compari 3 R. J. Heus and J. I. Egan, Z. Physik. Chem. (Frankfurt) son with data2 '3 on K ReCl , there is no doubt that 49(1-2), 38-43 (1966). 2 6 this anomaly represents the transition from an ordered *}. A. Fredricksen, L. O. Gilpatrick, and C. J. Barton, Solubility of Cerium Trifluoride in Molten Mixtures of LiF, antifenomagnetic state below 7.0°K to a disordered paramagnetic state above this temperature. This is the BeF2, and ThFA. ORNL-TM-2335 (January 1969). SH. W. Jenkins, G. Mamantov. and D. L. Meaning. J. first unequivocal evidence that complex halide salts of Electroanal. Chant. 19,385 (1968). technetium, K2TcX6, become antiferremignetic at low 6D. J. G. Ives ind G. J. Janz. Reference Electrodes, p. 255, temperatures. Academic, 1961. The Neel temperature r«f K^TcCl^, 7.0°K. is con 7 C. F. Baes, Jr„ Nuclear Metallurgy, vol. 15, AIME Sym 2 3 siderably lower than that of K2 ReCl*, 11.9°K. - This posium oi. Reprocessing Nudrar Fuels, pp. 615-44 (1969). order is to be expected bince it has been recognized for a long time that exchange interaction forces increase CALORIMETRY rapidly in going from first- to third-transition-series- element compounds, giving rise to low magnetic LOW-TEMPERA1URE HEAT CAPACITY OF moments for paramagnetic compounds of the third POTASSIUM HEXACHLOROTECHN£TAT£(IV) transition-series elements.8 It should be appreciated R. H. Busey R. B. Bevan, Jr. R. A. GUbert that both these compounds are magnetically dilute; that is, the magnetic ions [Re(IV) or TcflV)] are separated The interest in the chemical thermodynamic proper by a distance of many Angstrom units by diamagnetic ties of potassium hexachlorotechnetate(IV), K^TcCl*, chloride ions. Thus the superexchange forces giving rise as well as the TcCk2- ion in aqueous solution, stems to antiferromagnetism at these temperatures are re from the fact that the TcCig2- ion is the stable species markably large. of technetium in strong hydrochloric acid,1 and knowl The heat capacity observations also revealed that edge of its properties is basic to the thermodynamics of K2TcCl6 may exhibit thermal-history behavior similar 5 6 technetium. Similar in behavior to the corresponding to that observed in K2ReBr6* and K2ReI6. ' There rhenium compound, K2Tc€i6 is expected to become was a small spontaneous evolution of heat around antiferromagnetic at tow temperatures2 and exhibit a I45°K which was found to be associated with a heat heat capacity anomaly at the Neel temperature.3 capacity anomaly around 200°K. If the heat evolution Finally, we are very interested in determining if was avoided by cooling the sample to only I6 The preparation of the calorimetric sample was centered cubic structure, a0 - 9.82 A, at room described !ast year.7 We report at this time only temperature.9 The heat capacity results indicate no qualitative results of the heat capacity observations, crystal structure change at low temperatures. This 10 because we discovered at the conclusion of the measure behavior resembles that of K2PtCk and contrasts ments that the sample had undergone some kind of with that of K2ReCI6, which is cubic at room tempera 9 decomposition during the course of the measurements. ture, a0 = 9.82 A, but undergoes several structure This decomposition was evidenced by a pronounced modifications below room temperature.3 According ?o color change of the sample from yellow to green. An Brown,'' for face-centered cubic structures A2MX6 unused portion of the sample stored in a glass bottle (where A is an alkali metal cation and MX6 is an within a desiccator also exhibited the same color octahedral anion), if the ratio of the radius of the change, a fact which shows that the decomposition was cation A to the radius of the cavity of X atoms in which not the result of cooling ihe sample to low tempera it resides is equal to or greater than 0.98, the compound tures. The tadioactivity of the "Tc is not responsible will remain cubic at low temperatures. Using this for the decomposition by radiolysis, because we have a empirical rule, the cell parameter, and our observation small sample of K2TcCI6 prepared several years ago that J^TcCI* remains cubic, it may be estimated that 2 which shows (colorwisc) no evidence whatever of the Tc-CI bond distance in the TcCI6 " ion in the decomposition. crystal is 2.39 ± 0.04 A. This result may be compared 122 with 2.36 ± 0.02 A for the average Tc-CI distance in represent the enthalpies of orthorhonbic PbF2 at TcCU'' (distorted octahedral coordination), and 2.35 temperature T and at the ice point, 2?3.15°K, respec A in the Tc^Cl*3- ion.15 The Re-CI bond length in tively. When the furnace temperature finally exceeded 14 K2ReC\is237A. the transition temperature, the enthalpy measurements gave (//£ - H°73) where //£ is the enthalpy of cubic ! R. H. Busey, Chem. Da. Ann. Progr. RepL June 20, 1959, PbF2 at temperature 7, and the enthalpy values fell on ORNL-2782,p.l3. a higher curve. In this manner the transition tempera 2R. H. Busey and E. Sonder,/. Chet.i. Phys. 36,93 (1%2). ture was established to be between 582° and 584°K. 3R. H. Busey, H. H. Dearnun, and R. 5. Sevan, Jr.. J. fhys. and was taken to be S83 ± 1°K. The enthalpy Chem, 66,82(1962). difference, |(/i? - H°-3) - (//? - H°n3)), where T is 4 R. H. Busey, R. B. Sevan, Jr., and R. A. Gibert,/. Phys. now the transiiion temperature, was observed to be 145 Chem. 69,3471 (1965). cal/mole. 5R. B. Sevan, Jr., R. A. Gflbert, and R. H. Busey, Chem, Piw. Ann. h-ogr. RepL May 20, J 966, ORNL-3994, p. 107. The only additional data required to obtain tl** 6R. B. Sevan, Jr., R. A. Gflbert, and R. H. Busey, Che/n. Diw. enthalpy of transition at the transition temperature Ann. Prop. RepL May 20, 1967, ORNL-4164, p. 102. from that at 25°C is ((#£,, - /jf73) - (//f98 - 7 R. B, Bran, Jr.. and R. 'I. Busey, Chem, Dh. Ann. Progr. H%13)] - 12 cal/mole, obtained from enthalpy meas RepL May 20, JJ69. ORNL-M37, p. il5. urements on the two modifications. The enthalpy of s J. H. Van Vleck, Theory of Electric and Maspetc Suscepti- transition at 583°K is then 373 ± 9 cal/mole, and the bilities," Oxford Univenity Press, Oxford, 1932. entropy of transition is 0.64 ± 0.02 cal deg~f mole"1. 9 J. Daiykl, N.S. Gffl, R. S. Nyho»m, and R. D. Peacock, J. The en^hsipy data on the o:thorhombic PbF2 ob Chem. Soc. (London) 1958,4012. tained during the course of the transition-temperature ,0L. V. Coulter, K. S. Pitzer, and W. M. Latimer, /. Am. measurement discussed aoovt were found to be in Chem, Soc 62, 2845 (1940). disagreement by approximate1*/ 2.5% from earlier meas U LD. Brown,Can. J. Chem, 42,3758 (1964). urements.2 A thorough exsrijn^fior? 2nd check of I2 M. Elder and B. R. P*?»foM »-*-£ C*«i 5, 1157 {I50«). various possible sources of error have revealed that the I3 F. A. Cotton and C. E. Coffee, /. Am, Chem, Soc 81, 7 enthalpy of the Nichrome V capsules varied from (1959). capsule to capsule, although the capsules had been 14B. Aminoff, Z. Am/. 94,246 (1936). prepared from the same rod. Earlier results3 in this Laboratory using Nichrome V capsules revealed no such errors, but measurements at the National Bureau of ENTHALPIES OF FUSION AND TRANSITION Standaids showed that Nichrome V capsules made from OF LEAD FLUORIDE adjacent sections of the same rod could have enthalpies 4 C. W. Linsey1 R. A. Gilbert R. H. Busey differing by approximately 1.5%. Additional measure ments on the lead halides are being made using The orthorhcmbic-to-cubic transition in PbF2 is platinum—10% rhodium capsules to obtain corrections highly irreversible, and the enthalpy of transition to be applied to the original data. cannot be determined directly by drop calorimetry. The Additional measurements on the enthalpy of fusion enthalpy of transition at 25°C (240 ± 9 cal/mole), of PbF2 lead to a final result of 3.52 kcal/mole and determined by solution calorimetry as the difference in 1103°K for the melting point. The low entropy of the enthalpy of solution of the two modifications in 1 fusion, 3.19 cal deg"1 mole"1, reflects the result of the M Fe(N03)3, was reported previously.2 The additional large configurational entropy (3.6 cal deg"1 mole"1) data required to determine the enthalpy of transition a* which develops from the order-disorder transition2 the transition temperature, A//tran$, have now been below the melting point. The sum of these two determined. entropies, ~6.8 cal deg"1 mole"1, which might be The transition tiinpt ature was determined from considered as the "normal" entropy of fusion (i.e., in enthalpy measurements by drop calormetry on a sample the absence of the order-disorder transition), compares of orthorhombic PbF2. The furnace temperature was favorably with the entropies of fusion of PbCl2 and -1 -1 2 increased only 1 to 2° between enthalpy determina PbBr2, 6.81 and 6.10 cal deg mole respectively. tions. Only the cubic-to-orthorhombic transition is extremely sluggish; the reverse transition is apparently 'Oak Ridge Graduate Fellow from North Texas State rapid. Below the transition temperature the enthalpy University, Denton, under appointment with Oak Ridge Asso measurements gave (H% - H°73), where H% andH$73 ciated Universities. 123 2C. W. Limey, R. A. Gilbert, and k. H. Busey. Chem. Dh: kcal/moie, which is superior to previous measr-sements. Ann. Prugr. Repi.. Hey 20, 7969. ORNL-4437. p. 111. This new re*ult. together with a recent enthalpy of 3R. A.GUbert./. Phys. Chem. 67.1143 (1%3). solution determination,* gives L revised result for the *T. B. Douglas and J. L. Derer. J. Res. NaiL Bur. Std 54, 15 enthalpy of formation of the perrhenate ion, (1966). Trie enthalpy of formation of K:ReBr6 determined from 'he enthalpy of hydrolysis is A//^ [K ReBr (c)] = FREE ENERGY AND ENTHALPY OF FORMATION 2 6 -248.8 kcal/mole it 25°C. This :esult is based upon a OFK2ReBr6 4 revised Afff[Re02 2H20(c), freshiy ppt] = -238J R. H. Busey E. D. Sprague1 R. B. Bevan, Jr. kcal/mole which incorporates the above new enthalpy oi formation of Re04~(aq). Other enthalpies of fonrn- The availability of high-purity K2KeBr6 usea in **v«« sww«*«a*.v» IVI ivavtivti \ i ; «iiu *vi tuv iv?i)tvilj vtviv low-temperature he«t capacity studies2 prompted the taken from the revised National Bureau of Standards measurements reported here for the determination by 7 2 7 Bulletin 500. At 25°C the entropy of formation * is solution calorimetry of the enthalpy of formation of 1 1 —39.6 cal deg" mole" , and the free energy of the compound. These measurements complete the formation is My = Af£ - T AS^ = -236.9 kcal/mole. extermination of the thermodynamic properties of K2ReB?6. The enthalpy of hydrolysis of K2 ReBr6 in alkaline 'Temporary employee. Summer 1967. solution at 25°C is given in Table 6.10. The calorimetric 2R. H. Busey. . K Bevan. Jr.. and R. A. Gilbert. /. Phys. procedure, including the pro cautions to exclude oxygen Chem. 69,3471 (1% from the solution, have been described.3 The reaction is 3R. H. Busey, £. D. Sprague. and R. B. Bevan, Jr.. J. Phys. assumed to be Chem. 73. 1039(1969). *R. H. Busey. K. H. Gayer. R. A. Gilbert, and R. B. Bevan. Jr.,/. Phys. Chen. 70, 2609 (1966). K2ReBr6(c) + 40rT S + E. G. King. D. W. Richardson, and R. V. Miazek, U.S. = Re022H20(c)+2K + 6Br", (I) Bureau of Mines. Rept. of Investigation No. 7323 (November 1969) 4 6 similar to that in the hydrolysis of K2ReG6. The J. C. Ahluwalia and J. W. Cobble. / Am. Chem Soc. 86, standard enthalpy of the reaction at infinite dilution is 5377(1964). -64.0 ± 0.2 kcal/mole. 7D. D. Wagman st al. "Selected Values of Chemical Thermo There has recently been a new determination of the dynamic Properties," Afar/- Bur. Std Tech. Notes No. 270-3 and 270-4 (January 1968). A#J Tabic 6.10. Enthalpy of Hydrolysis of ELECTROCHEMISTRY K2ReBr6 at 2SS.15°K Sample Weight |OH 1 -A// KINETICS OF THE CHARGE AND DISCHARGE OF (g) (30 (kcaJ.'mole) THE FILM ON SUPERPASSIVE IRON 28 0.2550 0.100 64.33 G.H.Cartledge 29 1.0073 0.400 65.10 1 30 0.5055 0.103 64.25 The last annual report presented measurements of 31 0.5022 0.300 64.66 the rate of charge and discharge of the fiim on iron 32 0.5011 0.0521 63.97 between two fixed potentials above the passivation 33 0.4998 0.397 64.54 potential in an inhibiting solution of potassium per- 34 0.5011 0.203 64.42 35 0.5009 0.395 64.86 technetate. It was shown that the rates are described by 2 36 0.5002 0.347 64.87 an equation derived on the prior assumption that the 37 0.4105 0.0509 63.86 superpassive state arises when a number of electron 38 0.5019 0.148 64.34 holes are formed in the fully oxidized (Fe(III)] film. In 39 0.3683 0.0595 64.15 the steady state, an equivalent number of protons will A//° = -64.0 ± have been transferred to the electrolyte. When the 0.2 kcal/moic potential is then suddenly lowered, the difference in the 124 mobility or electrons and protons causes a transient Tc • 4H20 - Tc(( HjU + 4H* + 4e", potential difference to be set up which lowers the activation energy for the rate-determining return of from which the free energy of formation of Tc(OH)4 protons to the film. may be calculated directly. Figure 6J8 shows a series During the past year the study was extended to other of measurements of this couple over a wide range of inhibiting electrolytes, the mofybdate ion being studied acidities. The calculated free energy, -199.7 kc«i/moie, extensively. The earlier results were fully confirmed, is in good agreement with the value, -202 kcal/mole, and the rate constants were quite similar, in spite of derived from a determination of the heat of comfcu?tion considerable differences in the thickness of the fuzz. of technetium to perteduuc acid' and the reversible The results mean that "passive iron" does not owe its potential of the Tc(IV-VII) couple.1 -2 passivity merely to the presence of a film containing Several other couple potentials were observed, and it Fe(II!) compounds, but rather to the unique properties was possible to identify them as including the new acquired b' the passrating interface when the film is compounds TcOH, Tc(OH)2, Tc(OH):», and Tc304 as supercharged either ekctrolytically or by vigorous components of surface films. The identification was chemical electron acceptors. The detailed interpretation based on an empirical relation found to exist when the has been given in a recent publication.3 free energy of formation, per equivalent, of oxides of a given metal in different valence states is plotted against the valence. The agreement between observed halts or 'G. H. Caitledge. Chen Da. Arm. Prop. Rept. May 20. 1969, ORNL-4437. p. 87. inflections in potential-time curves v»ith potentials 2G. H. Cartledge, Corrosion 24, 223 (1968). calculated from the approximated free energies was 3G. H. Cartkdge, Chimia 23,450 (1969). 'mambiguojs and provided data io' calculating fre; energies of formation for all the oxides. Certain features of the experiments indicate the probable need to consider the influence of the beta radiation of tech THE ELECTROCHEMISTRY OF TECHNETIUM netium and cf the radiolytic products in the electrolyte. G.K. Cartledge The corrosion potential of technetium in 1JVH2704 is approximately 20 mV noble to the reversible po Initiation of a study of the electrochemical properties tential of a hydrogen electrode in the same solution. of irai alloyed with 0.1 wt % technetium disclosed the After a film of TcOH has been formed, the electrode need for an investigation of the anodic behavior of remains essentially passive, the anodic current density elementary technetium itself. Anodic polarization of remaining in the order of 10"6 A/cm2 until the the alloy was shown to be attended by a large increase potential is raised by about 500 mV, when oxidation of in the concentration of technetium in the surface, and the film to Tc04" sets in. The study is continuing. this had a very considerable effect on the overvoitage of the alloy in both anodic and cathodic polarization. The study on elementary technetium embraced anodic polarization in variou* acid media, chiefly 1 N H2S04, in an atmosphere of helium. Other measure o sjifS points) ments were made on technetium, platinum, or gold substrates which had been coated with a film of 2 0- \^ hydrous oxide by cathodic reduction of a per- technetate. Such electrodes were found to give a <-100- ^N. number of reproducible potentials in acidic media and over a sufficient range of pH values as to leave no doubt that they correspond to definite couples between the a- -200 - ^-^59.16 mv / pH g Couple: Tc • 4HJ0 -»Tc(0H) «-4H* •• 4«*S. element and one of its hydroxides or between two such 4 2 V? * 0.296 ± 0.0O6V ^N^ compounds containing the element in different valence H fc-300- ^v ui ^ states. _i ui The study is incomplete, but certain conclusions are possible. Whan technetium is coated under suitable conditions, the electrode gives a potential for the Fig. 6.38. Electron Potential of the Tc-Tc(OI!>4 Couple as a couple Function of pH. Potentials arc referred to scv. 125 *J. w. Ccb^k. W T. Smith. Jr.. and G. t. Boyd. 7. -4m. responding to the dissolution reaction rises to a CAem. Sac. 75.5777 < 1953). maximum (im) at the "critical potential" (t'm) and 2G. H. CartKdge and W. T. Smith. Jr.. J. Phys. Chem. 59. then decreases as the metal is transformed trom the 1111(1955). active to the passive state. As is shown by curve D, an increase in pH is accompanied by a decrease in im and a ELECTROCHEMICAL BEHAVIOR OF TITANIUM displacement ot t'm toward more negative values. In *n 1 earlier report it was shown that d leg im/dEm and E. J. Kelly dEmJd pH are essentially constant, from which it follows that d log i /d jsH mist abe be consist. Tins report describes the effects of chloride, iodide, m Although various authors have verified one or more of and hydrogen ions and of the hydrogen evolution 2 reaction on polarization curves for the dissolution of these functional relationships. the values assigned to zone-refined titanium in H--saturated acidic sulfate the constants have been characterized by a lack of media The experiments represent part of a continuing agreement and even internal inconsistencies, that is, program which has as its goal the determination of the violations of the requirement that mechanisms of dissolution of titanium in the active and active-passive transition states and of the related phe d log ijd pH = (d log ijd£my(d£jd pH). nomena of corrosion inhibition and pitting corrosion. In Fig. 639 curves A and D illustrate the effect of pH on the anodic polarization curve?. At the corrosion The existence of such simple functional relationships greatly restricts mechanisms proposed for titanium potential tc (cf. curve A), titanium undergoes spon taneous active-state dissolution. As the potential is dissolution. However, in order to further limit the ma*!e increasingly positive, the anodic current cor- mechanistic possibilities, precise values of the de rivatives are required, and this has necessitated taking into account the effect of the hydrogen evolution ORNL-DWG. 70-5513 reaction on the measured values of im and Em. In Fig. K>00 T 1 1 : 639 the cathodic polarization curve (curve E) exhibits CURVE A ; I N ^S0 4 a Tafel region with a slope of - 120 mV/decade. The B; \N HgSC.O.IilfKJ . cathodic Tafel line (curve G), which corresponds to the C ; \ N H S0 , 0.1 AfKCi - 2 4 hydrogen evolution reaction, must be extrapolated into 0,E; CL5VNo2SOa, pH * 2.34 the anodic potential region and added to curve D in order to obtain curve F, which corresponds to just the titanium dissolution reaction. As a consequence of this correction, it is seen that the correct value for im (curve F) is somewhat greater than the apparent value given by curve D, and, similarly, the true value of Em is more negative than the apparent value. As the pH decreases, the correction for ihe effect of the hydrogen evolution reaction diminishes, and for curve A i! is negligible. In Fig. 6.40 curve I shows that log im is a linear function of Em, and curve II shows that log im is a linear function of pH. From curves I and II one obtains , d\o%iJdEm =( /2)-(F/2303/?r) and d\ogim/dpH = -%. -0.3 -0.4 -0.5 -0.6 -07 -0 8 -0.9 -1.0 POTENTIAL (volts) vs S.C.E. It follows that Fig. 6.39. Effects of pH, Chloride Ions, and Iodide Ions on 4 the Polarization Characteristics of Titanium at 30°C. dEJd pH = -( /3)(2.303/?77F). 126 lehutdy irsigeifkant. In the case of active iron, the 0PNL-DWG.7O-55I4 surface is occupied almost completely by adsorbed POTENTIAL (*©Hs) $s S.CE. water molecules only * which are dapped by the -a6 -0.7 -0.8 adsorbed inhibitor. In die case of titanium, the results *# T T T T obtained in this investigation suggest the existence of a surface occupied not by water molecules but rather by adsorbed surface intermediates such as TtO and T.O-OH. The inability of iodide ions or chloride ions to displace these adsorbed species could account for the 400 results described above. *E J. Kef>. Chem. Dir. Aim. Progr. Rrpt Mtjr 20. 1969. OR VL-M37.«. S9. 2 e N. T/Thorns and k. Nob*. J Ekctrochem. Soc. 116.174* (1969). o 3&. E. Header and G. H. Carttofee. / Ekctruchem. Soc. 108. (UPPER SCALE) 732(1961). (LOWER SCALE) 4 £€ «0 E J. Keiy, / EUctrochem. Soc. 115.1111 (1968). u •: o CHRONOTOTimnOMETRY AND VOLTAMMETRY OF THE Afc-AgO ELECTRODE IN BLOWING STREAMS - EXPERIMENTAL' R. E. Meyer P. M. Lantz M.C.Banta2 F.A.Posey In previous reports3'4 we described a chronopotentio- PH metric technique for the analyse of solutions contain Fig. 6.40. Variation of im E #Ci I) pH ing chloride ion. This work has been extended to at30°C include chronopotentiometric and voltsmmetric analy ses of the chloride ion in flowing streams by use of a channel electrode. A schematic diagram of a channel The nature of these constants is of prime diagnostic electrode is shown in Fig. 6.41. Flow of solution is significance in the elucidation of the mechanism of assumed to take place along the x direction. The titanium dissolution. electrode length in the x direction is denoted by / (cm), The presence of chloride or iodide ions at concentra and the width of the working surface of the electrode is tions of 10"3 and I0~2 M had no discernible effect on w (cm). The dimensions of the channel which de the anodic polarization curves of titanium in 1 N termine the flow pattern are the width C, respectively, in Fig. 6.39. As measured at in, the reduction amounts to approximately 8% for I~ and 10% for d~. No effect on Em is observed. The significance of these results derives from the fact that for other metals which undergo active-state dissolution in 1 N H2S04 (e.g., Fe and Co), the iodide ion is a powerful inhibitor of the dissolution reaction. In the case of iron, for example, the adsorption of iodide from 1 NH2S04 solutions containing even lower concentrations of iodide than those employed in this work is sufficient to lower the anodic polarization curve by several orders of Fig, 6.41. Typical Experimental Configuration for Electro- magnitude.3 The effect of Br" is less, and that of CI" is analyfls in Flowing Solution. 127 and the distance from the entrance of the channel to CPftt-DVG. 70-t3!8* the leading edge of the electrode /.. • I T Two modes of operation were investigated in this work. In the voltammetric mode we were primarily interested (I) in the rdaticr. between the limiting current which results from oxidation of a silver elec trode in the presence of chloride ions and the param eters which determine flow rate, and (2) in applying these results to the analysis of solutions containing low concentrations of chloride ion (<10~3 M\. For analysis of solutions containing higher concentrations of chlo ride ion, we investigated the chronopotentiometric mode of ooersiion * 0.2 0.4 0.6 1.0 2.0 4.0 6X) 1QO In terms of voii'me (Tow rate and the parameters of tLECTROOE LfMGTH fcra) Fig. 6.41. the limiting current is given by5-* I = l.461z»,FC (-j {-*) . (1) Fqg. 6.43. Unating Carat as a Fuwcwon of Ekcvo* L 0 Leaf* at Various Flow Rales. 2J> X 10~3 M NaCl, ©U5 M KHO3, +0.300 V TJ ace. Flow rates: cam A, 0.189 cm3/sec; 3 3 where IL is the limiting current due to convective ewe B. 0.485 cm /sec; and cunre C, 0.7J7 cm /sec Slope of diffusion (A), z is ion charge, F is the Faraday constant stnadit fines ^ 0 **. (cowombs/'equivatent), C© is bulk reactant concentra tion (moles/cm3), D is the diffu ton coefficient 2 OUH'.-OWG. 70-1319 (cm /sec), and Ur is the volume flew me (enr/sec). Several cells were constructed which had the geometry of Fig. 6.41, and a number of experiments were carried out to see if the limiting current conformed to th* predictions of £q. (IK Experimentally observed rela tions between limiting current and flow rate, electrode length, and bulk concentration of chloride ions are shown in Figs. 6.42-6.44. These results show that Eq. (1) holds to - high degree of accuracy. In Fig. 6.43 a blank current is first subtracted from the polarization ORNL-OWG. 70-13«7 4.0 i—»—r ?7 5*10 -L_-l__l l_ -L -I I- • 0.25 +0.30 + 0.35 ELECTRODE POTENTIAL vs S.C.E. (V) Fig. 6.44. Limiting Cunent as a Function of NaCl Concen tration. 0.25 M KNO3, 0.5 X 1.5 cm electrode, volume flow rate = 0.189 em'/sec; (A) 10"3 M NaCl, (B) 5 X 10"4 M NaCl, (O 2 X 10"* M NaCl, (D) 10"* M NaCl, (E) blank. -0.3 -0.6 -0.4 -0.2 0.0 0.2 0.4 curves to get the horizontal lines which correspond to 3 LOGARITHM OF FLOW RATE (cm /sec) the limiting currents. These results demonstrate that Fig. 6.42. Limiting Current as a Function of Volume Flow successful analyses may be carried out by tee of this 4 Rate. 0.5 X 1.5 cm electrode, 5 X 1C M NaCl, 0.25 M KN03, technique, since limiting currents are directly propor +0.300 V vs see. tional to the bulk concentration of chloride ions. 128 VoJtammetric measurements were found to be useful ORNL-DWG. 70-1321 for chloride analysis in the concentration 'ange 1 X T—r T—i—i—r T T—r 3 10~* to 5 x 10" M C\- (approximately 4 t0 200 ^ ppm). c 2C0 in the chronopotentiometric mode of operation, the 3 effect of increasing the solution flow rate is to increase >. w the transition time and to broaden or retard the O transition of the potential from the Ag-AgCl electrode reaction to the next available reaction. This broadening effect is shown in Fig. 6.4S, where chrcno- 150 potentiograms for various flow rates are shown for a 3 UJ solution of 5.63 X 10~ M NaCl. Little change in the io- initial sections of the curves is noted, but in the final o_ section the siope of the rising portion decreases o considerably. It is quite difficult to det'. .-mine the 2 100 u. I— transition time by conventional graphical techniques, «J UJ but with a derivative technique transition times may be _l determined with considerable precision. Ti.e potential UJ derivative vs time curves for these chronopotentiograms £ 50 are shown in Fig. 6.46. As expected, the derivative I- peaks broaden, but the transition time, that is, the | maximum point, may be determined with reasonable or UJ o UJ ORHL-CmC. 70-I320 j i i_ _L • ' » i 200 -L 5 10 15 Vertical Bars Denote TIME (sec) Transit-in Time Fig. 6.46. Effect of Flow Rate on Derivatives of Chrono- potenbogranu. 5.63 X 10>- 3* M NaCl, 0.25 M KNO3,0JS X 1.5 cm electrode, / = 0.518 mA; (A) 0.0 cm31sec, (B) 0.162 150 cm3/sec, (O 0.273 cm3/sec, (0) 0.392 cm3/sec, (£) 0.565 cm /sec. > E precision. It was found that the transition time ob < 100 - tained with a channel el^cUode is a reproducible Z function of the flow rate and is also a reproducible UJ t— function of the usual parameters, current density and O a. reactant concentration. By use of appropriate calibra a: o> tion piocedures, precise chronopotentiometric analyses (±0.5%) may be carried out with a channel electrode over the concentration range 3 X 10"4 to 10_1 M CI" (approximately 10 to 3500 ppm). Research jointly sponsored by the Office of Saline Water. U.S. Department of the Interior, and by the U.S. Atomic 5 10 15 Energy Commission under contract with Union Carbide Corpo TIME (sec) ration. Fig, 6.45. bffect of How Rate on Chronopotentiograms. department of Chemistry, Sam Houston State University, 3 Huntsville, Tex. 5.63 X 10~ M NaCl, 0.25 M KN03, 0.5 X 1.5 cm electrode,/ » 0.518 mA; (4) 0.0 cm3/sec, (B) 0.162 cm3/sec, (O 0.273 3R. E. Meyer el al. Chem. Div. Ann. Progr. Pept. May 20, cm3/sec, (D) 0.3? 2 cm3/sec, {E) 0.565 cm3/sec. /967.0RNH164.P. 87. 129 R. E. Me>er et ni. Chem. Dir. Ann. Progr. Rept. May 20. a new cell was designed, constructed, and tested. In 1968. ORNL-»306. p. 113. addition a new instrument was designed and built for V. G. Levich. Physicochemical Hydrodynamics, p. 112. use with the cell.5 Prentice-Hall. EnglewoodC lift's. N.J.. 1962. Chronopotentiometric analysis of the chloride icn is 1-. A. Posey and R. V. Meyer. 'X'hronopotent iometry and based upon accurate determination of the time required Voltammetry of the Ag-AgCl E lee trod? in Flowing Streams. II. Theoretical." submitted to the Journal of Electroanalytical to deplete the boundary layer (transition time? when an Chemistry. anodic current is applied to a silver electrode in the presence of chloride ion. Accurate analysis requires precise control of the applied current density and the CHRONOPOTENTIOMETRY AND geometry of the cell. In addition, electrodes should be VOLTA*?METRY OF THE Ag-AgCl ELECTRODE 1 easiiy replaceable, and the entire cell should be easy to IN FLOWING STREAMS - THEORETICAL disassemble and clean. These requirements are met by F, A.Posey R. E. Meyer rhe ceil shown in Fig. 6.47. The main body of the cell is machined from a cylinder of Lucite. The a«ea of the Solutions to the equation of convective diffusion electrode is precisely defined by pressing the silver disk were obtained for chronopotentiometry and voltam- against the machined flat surface of the Lucite. The metry of an electrode located in a channel where the vertical sides of the cell at the electrode edges shield the electrode process involves formation of a solid phase. The relations derived for voltammetry permit computa 1 tion ot ieaciant concentration from experimental polar 0HNL-0WG.7O-5* * ization curves, polarization resistances, or limiting currents with a knowledge of solution flow rate, applied current, electrode and channel dimensions, and other parameters. An approximate net hod of solution of the equation of convective diffusion, b?sed upon a :>E m<=i Nernstian diffusion layer approximation, was used to obtain a useful expression for the effect of flow rate and other pertinent variables on transition times for chronopotentiometry in flowing streams. The theoretical relations proved to be useful in the interpretation of vottammetric and chrono- potentiometric measurements on the Ag-AgCl channel 1 i electrode, which has application to rapid chloride 1 1 1 analysis in flowing streams. Two manuscripts on experi 1 mental and theoretical aspects of the Ag-AgCl channel 1 electrode have been submitted for publication to the 1 Journal of Electroanalytical Chemistry. *•>•-• J Research jointly sponsored by the Office of Saline Water. VS. Department of the Interior, and by the U.S. Atomic _i Energy Commission under contract with Union Carbide Corpo G ration. H INSTRUMENT AND CELL DEVELOPMENT FOR RAPID CHRONOPOTENTIOMETRIC ANALYSIS OF CHLORIDE ION1 <=C R. E. Meyer Fig. 6.47. Chloride Test Ceil Assembly. (A) Teflon support A rapid method of chronopotentiometric analysis of (B) Lucite reservoir; (Q stainless steel electrode support; (O; 2-4 epoxy-coated stirrer; (£f) epoxy-coated Ag-AgCl reference elec chloride ion has been described previously. Because trode; (F) silver polarizing electrode; (G) silver disk; (//) practical jpplication of an analytical method depends stainless jice! washer; (/) reference electrode connector; (/) on the availability of convenient and reliable apparatus, polarizing electrode connector; (K) test electrode connector. 130 electrode in order to prevent interference by horizontal An instruction manual has been written tor both the components of mass transport of the reactant at the instrument and the cells. This apparatus has been used edges. Total volume of the cell is about 15 cm3 „ but as and tested for several months, resulting in a consider little as 5 or 6 cm3 is sufficient for analysis. able increase in precision of measurement and con The electronic instrument designed fo: use with this venience of operation. cell incorporates three basic functions »n one instru ment. Three integrated-circuit miniature operational amplifiers (Fairchild UA741C) are used. One of the amplifiers is used to control the current to a preset value and will maintain a constant current regardless of 1 Research jointly sponsored by the Office of Saline Water. changes in cell impedance. The magnitude of the U.S. Department of the Interior, and by the VS. Ator.ac current is determined by settings on a digital po Energy Commission under contract with Union Carbide Corpo tentiometer and a range switch. The other amplifiers are ration. used for measurement of the electrode potential and 2R. E. Meyer et aL. Chem. Div. Ann. Progr. Rept. May 20. the time derivative of the electrode potential, fhe time 1967. ORNL-4164, p. 87. 3 derivative is used for precise determination of the R. E. Meyer et aL. Chem. Div. Ann. Progr. Rept. May 20, 1968. ORNL-4306, p. 113. transition time 4 A switch converts the control circuit 4R. E. Meyer, F. A. Fosey, and P. M. Lantz, J. Electroanal. to a potentiostat for operation of the test electrode at Chem. 19,99(1968). constant potential. This instrument may be used as a The invaluable advice and assistance of J. L. Loworn. generalized electrochemical instrument designed for Instrumentation and Controls Division, is gratefully acknowl easy portability and low cost (less than $500). edged. 7. Chemical Physics NEUTRON AND X-RAY DIFFRACTION Vole 7.1. Comparison of Observed and Calculated Lattice Parameters, Atomic Coordinates, interatomic Distances, and Lattice Energies for MgCI , CaCl , SKX, and BaCI INTERf RETATION OF THE STRUCTURES 2 2 2 OF SOME ALKALINE EARTH CHLORIDES IN TERMS OF INTERION1C FORCES wo!>crveu Calcinated Difference W. R. Busing Lattice Parameters (A) and Atomic Coordinates An earlier report1 presented some of the reasons for MgCU establishing a model to interpret crystal structures in a 3.596 3.587 -0.009 terms of interionic and intermolecular forces and c 17.590 17.502 -0.088 a descrbed a computer program which can adjust the Clr 0.273 a CaCI2 parameters of such a model on the basis of experi a 6.24 6.310 0.070 mentally observed crystal struct^?* These calculations b 6.43 6.310 -0.120 have now been improved to include as observations c 4.20 4.261 0.061 thermochemical information on lattice energies, to allow CIJC 0.275 0.304 0.029 for the weighting of observations according to their y 0.325 0.304 -0.021 SrCI estimated errors, and to permit information about 2 a 6.977 7.004 0.027 several substances to be used in adjusting common BaCl parameters of the model. The form of the interatomic 2 a 9.415 9.353 -0.062 repulsion potential has been revised so that the expres b 7.878 7.969 0.091 sion for the lattice energy is c 4.731 4.831 0.100 Bax 0.118 0.108 -0.010 y 0.250 0.248 0.002 A A r QiQ/ op,- i + j- if Cl(l)x 0.431 0.422 -0.009 + (£, + £/)exp w-kZL V 0.356 0.357 0001 i I u Bi + Bj CU2)x 0.829 0.839 0.010 V 0.473 0.486 0.013 : Here r/;- is the distance between two ions, Qt is the ionc charge, and Df is a coefficient in the van der Waals term. Interatomic Distances (A) The repulsion term is in the form suggested by Gilbert,2 Mg-Cl a 2.32 a in which Ais a radius and B is a hardness parameter. i ( Ca-Cl 2.7G 2.72 0.02 The present study, which is described in more detail 2.76 2.76 O.CO elsewhere,3 considers four related substances with Sr-CI 3.02 3.03 0.01 different structure types: MgCl , a CdCI -type layer 2 2 Ba-CI(l) 3.06 3.06 0.00 structure; CaCl2, a distorted rutile arrangement; SrCI2. 3.07 3.09 0.02 the fluorite structure; and BaCI2, the orthorhombic 3.14 3.13 -0.01 Ba-CI(2) 3.24 3.14 -0.10 PbCI2 structure. Values of the Qfs, Dfs, and Bfs were established on a theoretical basis. Parameters A, for the 3.26 3.25 -0.01 3.56 3.74 five kinco of ions and one factor multiplying the van 0.18 der Waals contributioi s were adjusted for a least- Lattice Energies (kcal/mok) squares fit to the 17 observed structural parameters and MgCI2 -602.8 -601.6 1.2 -538.2 the four lattice energies. The resulting model was then CaCI2 -537.3 0.9 SrCl tested by adjusting the structural parameters of each 2 514.0 517.6 3.6 BaCI -489.3 substance to minimize the calculated energy W. Table 2 489.0 0.3 7.1 shows a CDmparison of observed and calculated "Not yet observed. 131 132 lattice parameters, coordinates, interatomic distances, to second-rank symmetric polar tensors2 or are limited and lattice energies. In general the agreement is good, to one orientation of the site point group.1 showing that the mode! is a lcasonable first approxima A comprehensive tabulation for second-, third-, and tion. Fo: CaC.t, however, this model predicts the fourth-rank symmetric polar tensors used in the tetragonal rutile structure rather than the orthorhombic cumulant-expansion structure-factor equation3 and for distortion which is observed. second-rank general axial tensors used in rigid-body It is now fairly clear that the modei must be analysis4 has now been derived for all possible settings elaborated to allow for the polarization of the ions due of the special t jsitions in the crystallographic space to the presence of their neighbors. Earlier attempts1 to groups- This tabulation, which covers all subgroups of include deformable ions failed to produce stable struc point groups m3m and 6/mmm including conjugate tures because the form of the restoring force allowed subgroups, will appear as part of a chapter5 on the dipole moments to increase indefinitely. New thermal-motion analysis in a forthcoming volume of attempts using an exponential restoring force seem to The International Tables for X-Ray Crystallography. be more successful, and there are indications that this A computer program using the FORMAC (Ft// CaCl2. written to evaluate algebraically the appropriate tensor In an attempt to explain the four different structural transformation equations1 and to sum the tensors arrangements found for these compounds, further resulting from all the different transformations of a calculations were made assuming each of the three given subgroup.2 The groups of transformations were alternative structure types for each substance. The formed from generator elements',7 by the group- values found previously were used for the parameters of multiplication-table method. The restrictions among the the energy expression, and each hypothetical structure tensor coefficients for a given site symmetry were was adjusted to minimum energy. For CaCl2 and SrCl2 found by inspection of the algebraic form of the iensor the results of they; calculations were satisfactory in that sums and were recorded in a notation which could be all of the alternative arrangements were less stable than verified algebraically by another FORMAC program. those observed. On the other hand, the calculations There are 98 subgroups of point group m3m and 54 imply that both the rutile and fluorite structures for subgroups of bfmmm (inclv-Mrg conjugate sets). For ar| tne BaCl2 d rutile structure for MgG2 would be more the contravariant components of the tensors men stable than the observed structures. This is a further tioned, a total of 230 different tensor-component indication that the model is not yet complete. restrictions were found. In addition, the restrictions for The worK is continuing, and efforts are being made to all covariant components and certain mixed covariant - include polarization effects as mentioned above. The contravariant combinations were derived for the hexag result of adding van der Waals terms in r~8 and r~10 onal axis system, in which covariant and contravariant will also be examined. components have different symmetry restrictions. !W. R. Busing, Chem. Div. Ann. Progr. Rept. hay 20, 1968, ORNL-4306.p. 139. !R. R. Bins, Symmetry and Magnetism, North-Holland. 2T. L. Gilbert, J. Chem. Phys. 49,264G (i968). Amsterdam, 1964. 3W. R. Busing, Trans. Am. Cryst. Assoc. 6 (1970), to be *W. J. A. M. Peierse and J. H. Palm, Acta Cryst. 20, 147 published. (1966). 3C. K. Johnson,/*eta Cryst. A25,187 (1969). 4 SITE SYMMETRY RESTRICTIONS ON THERMAL- V. Schomaker and K. N. Truebiood, Acta Cryst. B24, 63 (1968). MOTION TENSOR COEFFICIENTS C. K. Johnson and H. A. Levy, "Thermal Motion Analysis C. K. Johnson Using Bragg Diffraction D2t*" in International Tables for XRay Crystallography, Suppl. to Vols II, III (eds. W. A. Hamilton and When an atom (or molecule) in a crystal is situated on J A. Ibers), Kynoch Press, Birmingham (in press). a site of special symmetry of the unit cell of the crystal, 6R. Tobey. J. Baker, R. Crews, P. Marks, and K. Victor. the C\ mponents of any tensor representing a property PL/I FORMAC Interpreter User's Reference Manual. iBM Con tributed Program Library No. 360D-033 004, Ha%:horne, of the ;>tom for molecule) are restricted according to N.Y., 19*7. 1 the point symmetry of the site. The existing tabula S. C. Miller and W. I-. Love, Tablet of Irreducible R 'presen tions for these restrictions are inadequate for modern tations of Space Groups and Co-Representations of Magnetic thermal-motion studies because they are either limited Space Groups, Pruets Press, Boulder, 1967. 133 A NEW STRUCTURE-FACTOR EQUATION FOR p/k, where the matrix l|p/A|| = p is the inverse of the ANALYZING SKEWNESS AND KURTOS1S IN matrix a. The singly contracted polynomials are THERMAL-MOTION DENSITY FUNCTIONS 3G™(t) = «2 5V" (2) C. K. Johnson The Gaussian probability density function is used and widely to approxmite the thermal motion of atoms in crystals. Skewne.s and kurtosis, the deviations of odd and even symmetry from the Gaussian density function, can provide valuable characterizations for anharmonic wiiere the components s! of the vector s are given by vibration effects. The cuinulant-expansion structure- factor equation12 has been used successfully for the /*! determination of skewness in thermal-mo lion density s'= £ 0 K=l functions. The skewness coefficient tensor in the curnuiant expansion adds ten parametcis per atom to and ihe scalar Q is the nine parameters per atom normally de;ermined in a crystal sti ucture refinement. The kurtosis coefficient tensor in the cumulant expansion has not been used e=E*",- because it introduces an additional 15 parameter: per 7=1 atom. A new model with fewer parameters clearly is needed. The structure-factor equation described here The density functions obtained by Fourier transforma utilizes the properties of contracted multidimensional tion of Eq. (1) are basically power-series expansions Hermite polynomials to obtain a reduced set of about the Gaussian thermal-motion density functions; skewness and kurtosis parameters which are orthogonal however, they are rather cumbersome expressions to the usual atonic position and temperature-factor (because of the parameter a) and are not shown here. parameters. The orthogonalizaiion scalar a is an empirical param eter serving as an approximation for the first- and The structure-factor equation incorporating the con second-order correction terms7 which are omitted from tracted Hermite polynomials is Eq. (1) because of their functional redundancy with the normal first- and second-order terms containing the F(t)= £ At)exp(/Jx//){expf-f toikt^ parameters x and a. The scalar a is adjusted to minimize / k atoms \/=i / I V /.*=! / interactions between xf and c-. and between oi and d:k (/, k = 1,2,3) which arise in a least-squares refinement. f ,c w When a = 0.5, the factor enclosed by the braces in Eq. ioJB, - " (1) becomes a three-term tensor series of biorthog- tn— l onal4,7 Hermite functions (i.e., parabolic cylinder 8 d m functions ); however, the experimentally derived values *k t mn*G »(t) , (1) m,n=\ for a which minimize the above interactions have been found to be in the range 0.2 to 0.4. The parameter a where f{i) is the atomic scattering factor and t = 2nh, allows the character of the Fourier-transformed series9 with h the vector of Miller indices. The nine normal in direct space to change from a power-series expansion coefficients xf and aotk (/', k = 1, 2. 3:/ < k) are the about the Gaussian when a = 1 to a Ciam-Charlier parameters for the mean position vector x and the differential expansion6,10 when a -*• 0. If the atom dispersion matrix oca. of the Gaussian density func displays significant skewness or kurtosis. a can be tion for an atom. The ten new parameter* ure the adjusted as an ordinary least-squar parameter; alterna "orthogonalization scalar" a, the "contracted skewness tively, a may be adjusted empirically to minimize the vector" Ik.-ll = c, and the -ymmetric "contracted correlation coefficients tor the above interactions, in kurtosis matrix" !|d^|| = d. The polynomial tensors general, a single overall value for u will work reasonably with components 3Gm(i) and *Gm"(t) are derived by «'«*!!; r.v/*ever. the least-squares program written for contracting3 the third- and fourth-order G Hermiic these studies provides an a parameter for each atom. polynomial tensors4-* with components 3C'*;"(t) and In practice, the three skewness coefficients Cj (j = 1, *Gikmn{\), with respect to the tep^,r with components 2, 3) account for about half the total improvement in 134 the agreement factor R that can be realized when the and full ten-parameter skewness tensor is used. The skew ka ness vector w = oe (in crystal coordinates) is along the 4 2 » V« • direction of maximum asymmetry of the density function and may be compared with the downward- These omitted terms incorporate H Hermite polynomials rather than G Hermite polynomials in order to ensure orthogonality pointing shaft of a beach umbrella. between different-order terms. The G and H Hcrmite polyno The singly contracted kurtosis tensor with com mials are biorthogonal relathc to the weighting function ponents d.k has six unique elements. The three scalars / 1 3 \ k \k and the three vectors v^ in the matrix equation f " «Kt) "C^i -°m(t) »Hfii ^(t) dt give the principal axes of leptokurtosis (positive X's) and platykurtosis (negative X's) in the density function. is nonzero oniy if m = n and the sequence of tensor indices cr ..X^, is the same as or a permutation cf the sequence ft ..$ . The matrix p is the inverse of a, and the vectors v^, t t n 8N. N. Lebedev, Special Functions and Their Applications, which are not necessarily orthogonal, are resolved along chap. 1C, Prentice-Hall, Englewood Cliffs, NJ., 1965. the crystal axes. 1! N. Ja. Vilenkin. Special Functions and the Theory ofG'oup An example of a "kurtose" thermal-motion density Representations, 565 pp., Am. Math. Soc., Providence, R.I., function is that for the xenon atom in the square planar 1968. 12 I0 molecule XeF4. The xenon atom in the crystal M. G. Kendall and A. Stuart. The Advanced Theory of cannot display skewness because it is on a center of Statistics, vol. 1, Griffin, London, 1963. symmetry; however, kurtosis is allowed, and four of the 1 !The adjective "kurtose," from the noun kurtosis. is coined six coefficients d:k have magnitudes from 1.3 to 1.6 to complement the adjective skew in describing aberrations of times their standard errors as determined by the the Gaussian density function. method of least squares. The principal axes oi kurtosis I2J. H. Bums, P. A. Agron, and H. A. Levy, p. 211 in calculated with Eq. (4) indicate that the density normal Noble-Gas Compounds, ed. by H. H. Hyman, University of Chicago Press, Chicago, 1963. to the plane of the XeF molecule is leptokurtic m.i 4 l3C. K. Johnson, Chen Div. Ann. Progr. Rept. May 20, that the in-plane density is platykurtic. This pattern of 1969, ORNL^»437, p. 122. kurtosis suggests that certain modes of internal mo lecular vibration are enharmonic. The fluorine atoms A PRELIMINARY STUDY OF THE USE OF are relatively free of kurtosis, but they do have POSITION-SENSING DETECTORS IN X-RAY appreciable skewness which is reasonably consistent AND NEUTRON DIFFRACTION STUDIES with that calculated for rigid-body libration.13 H.A.Levy R.D.Ellison A study of the use of position-seusing neutron and 'C. K. Johnson, Acta Cryst. A25,1S7 (1969). x-ray detectors in single-crystal diffraction experiments 2 C. K. Johnson, chap. 9 in Thermal Neutron Diffraction, ed. was begun. Our preliminary results apply to both of the by B. T. M. Willis, Oxford University Press, London, 1970. detection systems being developed by members of the *H. Grad, Phys. Fluids 6, 147 (1963); see Appendix, p. 178. Instrumentation and Controls Division: the system Erdelyi (ed.), Bateman Manuscript Project, Higher Trans cendental Functions, vol. II, pp. 264 ff., McGraw-Hill. New using image-intensification and television techniques 1 York. 1953. designed by J. B. Davidson and the position-sensing 5P. A. Tortrat, "Les Fonctions Orthogonales D'Hermite a proportional-countei technique of M. K. Kopp and C. J. 2 Plusieurs Variables et Relations Dlncertttude De Heisenberg," Borkowski. Because of its potential for use in neutron Theses, Universite de Paris. 1953. diffraction investigations where only a relatively low P. I. Kuznetscv, R. L. Siiaionovich. and V. I. Tikhonov, neutron flux is available, experimental evaluation of the Theory of Probability Appl (USSR) English Transl. 5, 80 former will be undertaken first. (1960). Best use of these detectors may be had in recording The redundant first and second-order correction terms omitted from the series enclosed by brackets in Eq. (1) are the diffraction patterns of crystals with large unit-cell dimensions where many diffraction peaks occur simul 3 i 2 of '//yo taneously. We have written .? computer program to calculate the position and size at the detector of each 135 diffiacted beam for the case of a crystal rotating about 2C. J. Borkowski and M. K. Kopp. Rev. ScL tnstr. 39, 1515 a single axis. A search is made for spatial overlap of • 1968). reflections that occur simultaneously. The method used was to generate the indices of reflections of interest and to calculate the rotation A LEAST-SQUARES METHOD FOR THE ABSOLUTE required to orient ihe crystal for a reflection and the SCALING AND NORMALIZING OF OBSERVED coordinates of tha* refleciion on the face of the STRUCTURE FACTORS1 detector. The spread of the reflection on the detector H. A. Levy W. E. Thiessen2 G. M. Brown was calculated as the sum of the effects due to the divergence of the incident beam, its wavelength varia The usual single-crystal diffraction experiment pro tion, the size of the crystal, and, for the neutron ca?e, vides, for the various reflections h recorded, values of the correlation of wavelength variation with incident the observed structure-factor square U^fli)!2 which are beam direction. The rarge of crystal rotation required correctly scaled relative to each other (apart from to integrate over the reflection was calculated from an minor experimental errors) but not absolutely scaled. assumed mosaicity of the crystal, the beam divergence, Generally methods of solution for the crystal structure the wavelength spread, and the correlation. The list of require at least zn approximation to absolute scaling at reflections was put in the order of appearance as the the beginning, and structure determination is facilitated crystal rotates: the disappearance of each reflection was if an estimate of an over-all temperature factor for all also entered into the list. As each reflection was entered the atoms in the crystal can be made as well. Knowl into the ordered list, the detector coordinates of its edge of both the absolute scale and the temperature boundaries were compared with these of reflections factor is essential for the calculation of the normalized that had begun but not yet ended. Simultaneous structure factors required in the powerful direct reflections that were separated by less than the semi- methods of solution which have been applied so dimension of the one that required the largest detector successfully in recent years.3 It is important that the area were considered to overlap. best possible estimates be made for the scale and For the x-ray case, the calculation was performed temperature factors so that the normalized structure subject to the following experimental conditions: beam factors calculated from the observations will represent divergence of 0.27° vertical and 0.07° horizontal zs faithfully as possible the normalized structure (approximately those currently used with our single- factors, E(h), defined in the theory of direct methods:4 crystal diffractometer): a hypothetical monoclinic crystal 0.5 mm along each edge and with unit-cell parameters of a = 30 A, b = 35 A, c = 40 A, cos 0 = -0.087 and a mosaic angular spread of 0.5°: a detector placed 212 mm from the crystal: and Cu Ka radiation. in which k is the reciprocal of the factor required to put The area of the detector was kept relatively small (25 X the observations on an absolute scale and p is the 250 mm), as was the total crystal rotation (5°), to known mean value of E2 for a particular subset of reduce computing time. Results of this calculation were reflections: p is always unity for general reflections in encouraging: as many as 67 simultaneous reflections primitive space groups but may take en higher integral may be expected to appear with no overlaps in the values in centered cells or for zones or rows specially range of Bragg angles covered. A total of 99 reflections affected by a symmetry element.5 The sum of squares is expected during 5° of crystal rotation: the rotation of the atomic scattering factors (including thermal required to cover one equatorial reflection is as much as attenuation), s> , is assumed to be factorable: 0.78°. If each reflection were measured separately using the same angular velocity of crystal rotation, the time required for measuring all 99 reflections would be 99 X sz = I /J(W) Tfi) = t J?(W) W = MM) 7Th) • 0.78/5 = 14.7 times that required using the position- /= l i<••-1 sensing detector. Larger advantage factors would be expected for crystals with larger unit cells. Here o2 is the sum of squares of the scattering factors of all /V atoms in the unit cell at rest, and T represents !J. B. Davidson, abstract VIII-7. Collected Ab«'ract.< of the an over-all temperature-factor function which may take Eighth International Congress of Crystallography. Acta Cryst. various forms. In the Wilson plot method,6 which is A25.partS3.p.S66(1969). widely used to calculate normalized structure factors, T 136 is assumed to have the Gaussian form exp(-#|h|2/2). Anisotropy in the thermal attenuation of intensities was Averages of F^/po2 over small 'anges of |h| are noted during data collection. calculated, and their natural logarithms are plotted Normalized structure factors calculated using the against |h|2; the straight line best fitting the points is isotropic function T(h) = exp(—B\h\2f2) in the least- assumed to have a slope of -fl/2 and an intercept at In squares method were quite different from those calcu k. The A'-curve method7 is similar but does not assume lated from a Wilson plot using seven intervals of |h| but a Gaussian temperature factor; the averages are plotted were practically identical to those calculated with 25 directly vs |h|, and the value of Tat any |h| is estimated intervals. Changing the for-n of the temperature factor from a smooth curve drawn through the points. to Although these methods do not readily lend them selves to anisotropic forms of 7Xh), Maslen8 has 7Th) = expi-Vtfh) described an addition to the normal Wilson plot process involving a second series of plots against six products of led to a dramatic change in the magnitudes off. In this the Miller indices. This method has a fault in common equation h is the coiumn matrix o. reflection indices with the Wilson plot itself: the results are affected, and h is its transpose. The matrix 0 is the usual 3X3 sometimes strongiy, by the choice of intervals foi the matrix of anisotropic thermal parameters. It is apparent averaging process. from Table 7.2 that agreement between the experi We have developed an alternative way employing the mental values of E and those calculated from the solved 2 structure for reflections with large E values is consider method of least squares for fitting the |F0(h)| to the mean values of the Wilson distribution. The function ably improved; the value of 2 2 5= E wh[|F„(h)| - kp a2(|h|) 71(h)] tf/r = z||£o!-|£cl|/zi£cl h is 0.120 for the isotropic model and 0.078 for the is minimized by adjusting k and the parameters implicit anisotropic. The values for the 106 reflections having in 7Xh). The weights are given by Ec > 2.00 are Riso - 0.108 and Ranii0 = 0.086. The quality of the correction for anisotropy can be judged 2 2 wh = [var (F*0) + (kpa2 Tf var (E )] "» , by comparison of the average value of E vs Miller indices in Figs. 7.1 and 7.2. The drift observed with the vhere var (F£) is the experimental variance and var (E2) is the variance of the theoretical distribution: 2 var(£ )=! -a4/a\ Table 7 .2. Comparison of die 13 Laigest Normalized Structure Factors for the Steroid-fsocyanide Addition Compound9 for the acentric distribution, and Q0H50O3N2, Derived 'rom the Observations Using an Isotropic Fomi of the Temperature Factor, an Anisotropic Form of the Temperature Factor, 2 var(f ) = 2-3a4/ai and Calculated from the Solved Structure 6 £ for the centric distribution, where h k I *iso anuo ^calc 0 26 0 3.42 3.38 3.71 10 9 0 3.95 3.53 3.50 o* « £ # C4oH5o03N2 (spacegroupP2,2,2, ;Z = 4, 4267 inde pendent reflections measured using Cu A*a radiation). This reflection severely affected by extinction. 137 ORNL-DWG- TO-5705 1.5 2.6 -I J. Karle. 'The Phase Problem in Structure Analysis." pp. 131 222 in Advances in Chemical Physics. I. Prigogine and S. • • A. Rice. eds.. Interscience. New York. 1969. D. Rogers. "Statistical Properties of Reciprocal Space." 2 chap. 15 in Computing Methods in Crystallography. J. S. • 7 i o J. Karle and I. L. Karle. "Phase Determination for Centro- symmetric Crystals by Probability Methods." chap. 17 in 1 muscle tissue, through increased efficiency of protein A preliminary account of this work was given at the American Crystallography Association Wintei Meeting. March utilization. This anabolic activity was first observed in 1 5. 1970. held at Tulane University. New Orleans. La. testosterone, HI, the natural male hormone, which 'National institutes of Health Special Postdoctoral Fell.;-*. cannot itself be used as an anabolic agent because of its Y Karlc and I. L. Karle. ,4c/<7 Cryst. 21. 849 (1966). undesirable side effects (development of masculine 138 ORNL-OWG. 70-5713 above the 0.75 probability level from the 2, relation 7 ,Vl7 ship are given in Table 7.3. The key to the solution of the structure lay in relating 0o.~2"6.o, 08,71,0. a°d #a.3 8,o- These pfores, plus the four arbitrarily assigned, were sufficient to relate the entire set of 312 reflections having E > 1.8, A basic OAc contradiction is immediately obvious: all three of these phases are predicted to have the value it by Si, but the more powerful 22 relationship, on which the tangent formula8 is based, predicts that the sun: of these phases should be zero since their indices add to zero. The tangent formula approach outlined in an accom panying report9 was applied by assuming in turn that each one of the 2t indications was incorrect. The three resulting phase sets had values of the inconsistency index9 Q of 0.32, 0.37, and 0.41 respectively. An E iz map based on the most consistent set revealed the positions of 39 of the nonhydrogen atoms among the Fig. 7 J. (I aad II) Structures Proposed3 for the 2:1 Addition Products of Isocyanides with 0,0- Unsaturated Ketones; Oil) the 45 highest peaks, and the steroid skeleton was im Structure of Testosterone; (IV) the Correct Structure of the 2:1 mediately recognizable from a stereo plot of these 45 Addact. peak positions produced in the program ORTEP.1 ° A Fourier synthesis based on all reflections im mediately revealed the remaining "heavy" atoms. All of the hydrogen atoms were subsequently discovered in secondary sex characteristics, etc.). The changes in difference Fourier maps, and full-matrix least-squares structure from testosterone to methenolone (the change refinement with anisotropic "heavy" atoms and iso in position of the double bond and introduction of a tropic hydrogen atoms brought the final R(F) value to methyl group) have the effect of reducing the side 0.045. effects while maintaining the desired anabolic activity.5 it is worth noting that the crucial 2j relationship Whatever the structure of the isocyanide addition would not have been available without the Cu K0 data, product, it seemed likely that one or more new since the reflection 8,38,0 is outside the limits of the carbon-carbon bonds hV. been formed in that part of the molecule in which structural changes produce changes in biological activity. Table 7.3. Initial Phase Assignments (0 ) and Final Crystals of the methenolone adduct are orthorhombic { [space group ^2,2,2,, a = 12.9791(4) A, b = Phase Values ($A in the Solution of the Structure of die 2:1 Adduct via the Tangent Formula 33.526(13) A, c = 7.885(9) A, Z = 4]. A sample of irregular shape with no dimension less than 0.2 mm or h k / E 0, 0/ greater than 0.5 mm was mounted on the Oak Ridge To Specify Origin and Enantiomorph computer-controlled x-ray diffractometer. Intensity 10 9 0 3.50 0 0 measurements were carried out with Cu Ka radiation 7 0 10 3.15 n jr 3 from 20 = 60 to 20 = 161.5° by the 26 scan technique 09 16 0 3.10 */2 it H and ai smaller scattering angles by an w scan technique. 5 0 2.88 ir/2 nil In addition the accessible Cu K0 reflections outside the From E j limit given above were surveyed, and integrated inten 0 26 0 3.33 n 0 sity measurements were performed on 185 of the 8 12 0 2.79 IT IT strongest of these. The usual processing of the data 08 38 0 2.64 u It included an absorption correction. 4 4 f 2.51 0 It I It The observed intensities were reduced to normalized 0 34 2.17 n 4 6 12 0 2.09 0 0 structure factors, E, by a new least-squares technique. 0 36 4 2.02 w 0 The phases assigned arbitrarily to define the origin and 018 0 2 1.97 w It enantiomorph7 and those phases which were indicated ORNL-DWG '0-2068 Fig. 7.4. Stereoscopic View of the 2:1 Adduct Between 2,6-Dimethytphenylisocyanide and Methenolone Acetate. The ellipsoids describe the volume within which the probability of finding the atomic center is 0.5. diffractometer with Cu Ka radiation. This experience ORNL-DWG. 70-5714 recalls the similar ease of solution of the structure of sedoheptulosan hydrate described in an earlier report1' which also employed Cu K$ data. The structure actually determined for the meth enolone adduct (IV) differs from the proposed struc ture in that addition of the isocyanide moieties has taken place at the carbon-carbon double bond rather than at the carbonyl group, as previously postulated. Whether modification of the addition product will produce biologically active compounds remains to be Fig. 7.5. A Schematic Representation of the Cyclobutane seen. In any case, knowledge of the correct structure Ring in the 2:1 Adduct Viewed Edge On. will enable organic chemists to plan further reactions intelligently. A stereoscopic drawing of the molecule (omitting hydrogen atoms for clarity) is given in Fig. 7.4. Although detailed analysis of the molecular geometry is 2. The cyclobutane ring is, as expected, puckered; the not yet complete, two structural features of interest are angle between the (approximate) planes of the apparent: C-C=N groups is 14°. In addition, the imino groups I. The 2,6-dimethylpheny! groups attached to the imino nitrogens cannot achieve coplanarity with the C imino groups for steric reasons. The angles between are not strictly planar; the nitrogen atoms are forced their planes and those of the imino groups (87 and away from each other, presumably by dipole-dipole 73°) bespeak conjugation with the nitrogen lone interactions. This effect is illustrated schematically pairs. in Fig. 7.5. 140 A preliminary account of this work was given at the and II (Fig. 7.6), respectively, by Ohta, Sakai, and American Crystallographk Association Winter Meeting, March Hirose.3 The chemical evidence adduced by these 1-5,1970, held at Tulane University, New Orleans, La. workers does not establish the stereochemistry at the 2 National Institutes of Health Special Postdoctoral Fellow. centers indicated by wavy lines in Fig. 7.6, nor does it 3 B. Zeeh, Tetrahedron Letters. 1%9(2), 113. rule out alternate structures of type III (Fig. 7.7). In 4 H.-J. Kibbc, Angew. Chem. 80, 389 (196%); Angew. Chem. order for a rational synthetic scheme for these natural Intern. Ed. /, 389 (1968); T. Saegusa, N. Takaishi, and H. Fujii, Tetrahedron 24, 3795 (1968). products to be devised, an experiment distinguishing G. K. Suchowsky and K. Junkmann, "Recent Findings in among these structural possibilities was necessary. Anabolic Steroids," pp. 155-59 in Hormonal Steroids; Bio Degradation work on the cubebenes is complicated at chemistry, Pharmacology, and Therapeutics, vol 2 of the the outset by the difficulty of separating the a and 0 Proceedings of the First Internationa; Congress on Hormonal isomers. Ozonolysis of the hydrocarbon mixture fol Steroids, L. Martin and A. Pecile, eds., Academic, New York, lowed by treatment with hydrogen peroxide gives, after 1965. separation of the acidic products derived from a-cube- "H. A. Levy, W. E. Thiessen, and G. M. Brown, "A Least-Squares Method for the Absolute Scaling and Normalizing bene, the norketone IV (Fig. 7.6) derived from 0-cube- of Observed Structure Factors," preceding contribution, this bene. This crystalline ketone can be reconverted in report. good yield to 0-cubebene by reaction with triphenyl- 7 J. Karle and H. Hauptmann, Acta Cryst. ?, 635 (1956). phosphinemethylene, demonstrating that no rearrange 4 8J. Karle and I. L. Karle, Acta Cryst. 21, 349 (1966). ment has occurred in the ozonolysis. Crystal structure 9W. E. Thiessen, "Structure and Stereochemistry of <*- and analysis of this nor-0-cubebone was therefore under- 0-Cubebene from the Crystal Structure of Nor-0-cubebone," following contribution, this report 1 "Program ORTEP, written by C. K. Johnson, ABC Docu ment No. ORNL-3794, Revised (June I9fi5). 0RNL-0WG. 70-5702 llG. M. Brown and W. E. Thiessen, Chem. Div. Ann. Progr. Rept May 20,1969, ORNL-4437, p. 129. CH3 H STRUCTURE AND STEREOCHEMISTRY OF a- AND 0CUBEBENE FROM THE CRYSTAL STRUCTURE 1 OF NOR^CUBEBONE H CH(CH3)2 W.E. Thiessen2 m or- and 0-Cubebene, isomeric hydrocarbons from the oil of Piper cubeba L., have been assigned structures I Fig. 7.7. An Alternative Structure for oCubebene. ORNL-DWG. 69-8216B H H CHCCr^ CH3 H CH3 H CH(CH3)Z «5>jhP-CHg m,p. 58.5-59.5° H C 1 2 I'fmix 1715 cm" H " CH(CH,)2 X™, 209nm («*2210) n Fig. 7.6. Structural Relationships Between a- and 0-Cubebene and Nor-0-cubebone. 141 taken to ascertain the structures of the natural products and, as a bonus, to determine the accurate molecular k geometry' of a conjugated cyclopropyl ketone system. The spectral characteristics of nor-0-cubebone given in Of tne eight sets of phases produced in this way. the Fig. 7.6 indicate some degree of electronic interaction four in which £364 had been origiiiatiy set to a cardinal between the three-membered ring and the carbonyl point (0, n, or ± rt-2) had values of the inconsistency group. index Preliminary Weissenberg photographs displayed sys tematic absences and symmetry uniquely consistent e^E^h-'Ai/E ifhi. > with the orthorhombic space group / 2|2l2l. The h >> tendency of the crystalline ketone t. sublime at an where appreciable rate at room temperature was first noted at this stage. Consequently, after a sphere approximately 0.35 mm in diameter was selected from several which fh-c^+^'VEiJVk-ki. k had been ground from single crystals, it was coated with a thin film of white glue prior to mounting on the of 0.32 to 0.33. The otier four had Q greater than Picker automatic diffractometer. A least-squares fit of 037. angle data from 14 reflections (T = 24°; Cu Ka Only one of the four of the most self-consistent phase radiation, X = i.54051 A) yielded the following cell sets is in complete agreement with the E, predi:ticns dimensions: a = 8.4800(16) A, b = 23.5020(54) A,c = listed in Table 7.4. An E map was accordingly calcu 63138(10) A. lated from this set. Of the six strongest peaks in this Intensity data for 1598 reflections accessible with Cu map, five made up a very plausible arrangement Ka radiation below 20 - 160° were measured with the consisting of the expected cyclopropane ring with two diffractometer in automatic mode by the 20-0 scan more atoms connected to one apex at reasonable technique. The intensities of standard reflections de distances and angles. Fourier methods, using the Sim- 8 creased steadily with time, shewing that the attempt to Wool fson weighting scheme, and refinement of phases 9 prevent sublimation was not entirely successful. This by the method of Karle led to chemically reasonable loss of intensity was nearly linear, the final standard positions for 12 atoms but also produced obviously measurement showing 58% of the initial intensity. A spurious peaks. No placement of the remaining atoms dec?y correction employing linear interpolation be from chemical reasoning or from analyst of the tween successive standards was applied along with Patterson map was found which led to even approxi Lorentz and polarization corrections. No absorption mate agreement of observed and calculated structure correction was attempted in view of the uncertainty of factors. shape of the crystal as it evaporated. Phase determination of the 193 reflections with FR > The observed structure factors were put on an 1.47 was therefore attempted, allowing 0364 to take absolute scale and corrected by an average isotropic values from 0 to 19ny20 in increments of w/20. These temperature factor by use of a Wilson plot program to sets converged in 18 to 30 cycles; and of the three most 5 nearly self-consistent sets, two were very similar and give normalized structure factors £*h. Four zonal reflections of proper parity6 were chosen from among had the predicted values for those phases known from v those with the largest values o. £h for arbitrary phase assignments to define origin and enantiomorph (Table Table 7.4. l.titial Values of Phases Assigned to Reflections 7.4). In addition, one genera! reflection (364) was with Large Normalized Structure Amplitudes allowed to take on initial values from 0 to 7^/4 in steps of ;r/4 in order to begin the phase determination tor the To Specify Orudn _ 125 reflections with £h > 1.62 by the tangent JC / u FromZ,: formula,7 and Enantiomorph: h k I E 0 h k I E tan $h = A IB , 1 29 0 3.41 nil 0 18 0 2.60 0 where 0 9 2 2.90 »/2 0 28 0 2.30 it 0 19 1 1.96 ff/2 0 o 6 2.30 n 10 11 0 2.13 0 2 28 0 1.74 0 ^=E^k£h-klsin(*k+^h-k)' 142 £,, but the arbitrary starting value for tf, 2t,o had been The conjugation in the cyclopropyl ketone mciety changed frcr.i rtl2 to -n/2. An E map calculated from inferred from spectral observations is strikingly verified the slightly more nearly self-consistent of these twc sets in the geometry of the molecule: revealed positions for 14 of the 15 nonhydrogen atoms among the 21 strongest peaks. One of the methyl 1. The length of the bond connecting the cyclopropane carbons of the isopropyl group was missing but was ring io the carbonyl carbon atom, C(7)-C(8), is revealed by a subsequent Fourier synthesis based on all 1.469 A, as short as the corresponding bond in a,0-unsaturated ketones and much shorter than the reflections. Full-matrix least-squares refinement of 3 2 these atom positions, together with isotropic and then typical sp -sp bond, C(8)-C(9), 1.511 A, on the anisotropic temperature factors, reduced R{F) to 0.11. other side of the carbonyl. A difference Fourier map showed peaks corresponding 2. The two bonds of die three-membered ring involved to calculated positions for all 22 hydrogen atoms. :n conjugation, C(l)-C(7) and C(6)-C(7), are ap Further refinement (keeping hydrogen atoms isotropic) preciably longer than C(l)-C(6), which is not reduced R(F) to 0.053 and showed clearly that the involved. strongest reflections suffered from extinction. An iso 3. The five-membered ring is, of course, not planar but tropic extinction correction was applied; the value of puckered; that is, C(9) is out of the plane of the the extinction parameter was treated as a variable in the other atoms, so as to avoid eclipsing of the hydrogen 10 refinement. The final R(F) for 1496 reflections is atoms connected to C(9) and C(10). The direction 0.044. of the puckering is puzzling at first glance - the Comparison of the final structure with the partial distance between the hydrogen pointing forward false structure found earlier revealed that the carbon from C(9) and the hydrogen on C(6) is 2.40 A, fully atoms (numbered 1, 6, and 7 in Fig. 7.8) of the 0.1 A shorter than any intermolecular hydrogen- three-membered ring, all of which have approximately hydrogen contact in the structure, whereas if C(9) the same y coordinates, are reflected through a point in had puckered the other way, no apparent disruption the false structure to give another grouping having of the packing (Fig. 7.9) would have resulted. nearly the same set of interatomic vectors. The rest of the false structure is ttV.r* made up of correct inter Figure 7.9 is a Newman projection looking down the atomic vectors springing from the incorrect positions. C(7)-C(8) bond. Of the two possible puckering direc The final structure given in Fig. 7.8 corroborates the tions depicted, the one actually observed (upper left) gross structure of Ohta, Sakai, and Hirose and reveals tends toward a situation in which the carbonyl bisects the unknown stereochemistry. The absolute configura the three-membered ring, whereas the alternative (upper tion indicated is correct, since it has been shown3 that right) tends away from this geometry. Electron diffrac treatment of a-cubebene with dry HC1 in ether yields tion studies of cyclopropanecarboxaldehyde,1 * cyclo (-)-cadinene hydrochloride, the absolute configuration propyl methyl ketone, and cyclopropanecarboxylic acid of which is known. chloride13 show that the favored conformations are «WL-0»-. S9-694* Fig. 7.8. Stereoscopic View of the Nur-0-cubebone. Bond lengths are uncorrected for thermal motion and have standard errors of <*out 0.004 A 143 ORNL-OWG. 69-8214 °A correction procedure based on the theory of W. H. Zachariasen, Acta Cryst. 23. 558 (1967), has been inserted into the least-squares program ORI-'LS by A. Vos and C. K. Johnson. 11L. S. BarteU rnd J. P. GuUlory. J. Chem. Pfiys. 43, 647 >-7 (1965). 12L. S. BarteU. J. P. Gufllory, and A. T. Parks./. Phys. Chem. 69,3043(1965). O H A SINGLE-CRYSTAL NEUTRON DIFFRACTION STUDY OF UREA-PHOSPHORIC ACID E. C. Kostansek1 W. R. Busing In a previous neutron diffraction study Worsham and Busing2 showed that the compound formed from urea and nitric acid is a salt, uronium nitrate, in which the acid hydrogen ion is attached to the urea oxygen atom Fig. 7.9. (Top) Newman Projections Showing the Two and forms a moderately strong hydrogen bond to the Possible Conformations of the Five-Menibeted Ring; (Bottom) nitrate ion. An x-ray study of the one-to-one compound The Favored Conformations of Cyciopropai.ecarboxaldehyde, of urea and phosphoric acid which was reported by Methyl Cydopropyt Ketone, *nd Cydopropanecarboxyfk Acid Sundera-Rao, Turley, and Pepinsky3 showed a very Chloride. short 0...0 distance between the two moieties, which implied that the acid proton may be shared equally between them. The neutron diffraction study which we those depicted in the bottom of Fig. 7.9. Evidently the report here confirms that the hydrogen ion is essentially H—H contact costs less energy than is gained by centered in a strong hydrogen bond, so that the increased orbital overlap. substance is intermediate between a salt and an addition compound. The urea-phosphoric acid compound is orthorhombic, 3 1A preliminary account of this work was published in the Pbca, with lattice parameters a = 17.68 A, b = 7.48 A, Abstracts of the Eighth International Congress of Crystal c = 9.06 A and eight formula units per cell. Single lography, Stony Brook, New York, August 1969. See Acta crystals were grown from aqueous solution, and the Cryst. A25, abstract X1II-52, p. S144 (1969). intensities of 2079 reflections from a 69.3-mg sample 2 National Institutes of Health Special PostdoctorrJ Feilow. were measured using the Oak Ridge automatic neutron 3 Y. Ohta, T. Sakai, and Y. Hirose, Tetrahedron Letters 1966, diffractometer.4 The observations were corrected for 6365. absorption5 and converted to structure factors in the 4 These experiments were carried out by W. G. Dauben and R. 6 Shavitz, to whom I am obliged for the crystals used in this usual '.vay. A tnree-dimensional Fourier synthesis using investigation. signs calculated from the x-ray structure revealed the 5Program FAME, written by R. Dewar and A. Stone, positions of all seven hydrogen atoms. The atomic University of Chicago. coordinates and anisotropic temperature factor coef 6J. Kirie and H. Hauptman, Acta Cryst. 9,635 (1956). ficients were adjusted by the method of least squares. It 7J. Karle and I. L. Karle,/tela Cryst. 21, 849 (1966). Tangent was immediately apparent that the data showed the formula refinement was carried out using program PHASEM, effects of severe extinction, and an isotropic extinction written by M. G. B. Drew, Lawrence Radiation Laboratory, correction7 was included in the refinement. Even this University of California, Berkeley. did not solve the problem completely, and eventually 8 G. A. Sim, "Aspects of the Heavy-Atom Method," pancr 24 64 reflections, the strongest of which was observed with in Computing Methods end die Phase Problem in X-Ray Crystal Analysis, R. Pepinsky, J. M. Robertson and J. C. Speakman, eds., an intensity only 4.9% of that calculated, were omitted frergamon, Oxford, 1961. See also M. M. Woolfson, Acta Cryst. from the refinement. The agreement factor R(F*) is 9,804(1956). now 0.108, but these results are not considered to be 9 J. Karle, Acta Cryst. B24,182 (1968). final. The atomic coordinates are as follows: 144 Oilier distances of interest are: p 0.3109 0.2783 0.3094 C-0(5) 1.284 A 0(1) 0.3389 0.09*U 0.3617 C-S(l) i.330 A 0(2) 0.2775 0.3842 0.4352 C-NC) 1.332 A P-O(l) 1.565 A CH3) 0.2469 0.2509 0.1928 0(4) 0.3795 0.3664 0.2378 p-ou> 1.VJ5 A '..iol A 0(5) 0.4471 0.6339 0.3109 P 0(3) 1.5 26 A N(l) 0.5078 0.7834 0.4911 P Cut) N(2) 0.3965 0.6359 0.5426 Distai-cCi in the urea group are intermediate between, C 0.4499 0.6833 0.4466 those found in urea8 and those in uronjum nitiate,2 a 0.4087 H(l) 0.5047 0.2821 fact which is consistent with ihe resonance theory 0.2977 H(2) 0.0098 0.3937 2 H(3) 0.2610 0.1986 C.0952 discussed by Worsham and Busing. H(4) 0.5497 0.8067 0.4220 In the phosphoric acid group, 0(2), which makes the H(5) 0.5121 0.8210 0.5953 shorlest bond to phosphorus, has no hydrogen atom of H(6) 0.3987 0.6777 0.6481 its own but is the acceptor of three hydrogen bonds. H(7) ft ccc* U.JUOO 0.3517 Each of the atoms 0(1) and 0(3), which form the longest bonds to phosphorus, has its own hydrogen Figure 7.10 is a Stereoscopic view of one formula unit atom but accepts no hydrogen bond. Intermediate and its surroundings. Each of the seven hydrogen atoms between these extremes is 0(4), which shares its acid is involved in a hydrogen bond with the following hydrogen atom and is the acceptor for one other distances and angles: hydrogen bond. X-H-.0 X-H(A) H_0(A) Aagteat H(deg) *Oak Ridge Associated Universities Sunaner Student Trainee from Hiram College, Hiram, Ohio, Summer 1969. 0(5)JI(1)^0(4) 1.21 1.22 169 2 Od)-H(2)_0(2) 0.99 1.67 174 J. E. Worsham V. and W. R. Busing. Acta Cryst. 825, 572 0(3)-H(3)_0(2) 1.00 1.60 177 (1969). N(l)-H(4)_0(4) 0.99 1.96 171 3K. V. G. Sundera-Rao, J. W. Turlcy, and R. Pepinsky, Acta N(l)-H(5)_0(5) 0.99 2.29 145 Cryst. 10,435(1957). N(2)-H(6)_0(5) 1.01 2.21 148 4W. R. Busing, H. G. Smith, S. W. Peterson, and H. A. Levy, N(2)-H(7)_0(2) 1.00 2.00 168 /. Phys. (Paris) 25,495 (1964). SW. R. Busing and H. A. Levy, Acta Cryst. 10,180 (1957j. The acid hydrogen, H(l), is shared nearly equally 6G. M. Brown and H. A. Levy, J. Phys. (Paris) 25, 469 between 0(5) of urea and 0(4) of phosphoric acid, and (1964). the difference between this compound and uronium 7W. H. Zachariasen, Acta Cryst. 23,558 (1967). nitrate can be related to the fact that phosphoric acid is 3 J. E. Worsham, Jr., H. A. Levy, and S. W. Peterson, Acta weaker than nitric acid. Cryst. 10,319(1957). Fig. 7.10. Stereoscopic View of Oae Fonmla Uak of Ure«-Pfco«pfcooc Acid Showing die Hydropm Boads to NMghfcoriag Atom. 145 CRYSTAL STRUCTURE OF TRItp-BIPHENYLYU- prism and mounted. From preliminary x-ray precession AMIN1UM PERCHLORATE photographs, the space group w»s established as/*2i/c, 1 ami approximate unit-cell parameters *vere established. G. M. Brown G. R. Freeman Precise values for the cell parameters were obtained by The tr uiicmiiy udid IOI yw^j mucfsciiucui lcucvuuio wcic recorded with the automatic diffractometer and Cu/Cot 1 radiation to the limit 161.5° in 20. The crystal specimen was measured accurately to obtain the neces sary data for making absorption corrections1' and for free-radical ions are isoelectronic with the corre- computing derivatives to be used later m applying sponding uncharged triarylmethyl radicals and are corrections for extinct' "ae value of the absorption expected to be similar in structure to the latter more coefficient used was 10.&8 cm-1; the absorption familiar radicals and also to the triarylcarbonium ions correction factors on the observed intensity values and carbanions. There exist in all these species similar ranged from 1.25 to 1.41. The raw intensity data and possibilities for delocalization of the unshared electron corresponding standard errors were converted in the or of charge around the aromatic ring systems. No data usual preliminary processing to s set of observed are available for the carbanions, but the results of 3 7 structure-factor squares FVs, wiih standard errors diffraction studies ' suggest that, in general, triaryl o(f£)'s. The normalized structure factors12 E were also methyl radicals and carbonium ions have essentially computed. plane trigonal arrangements of C-C bonds at the central carbon atoms, which correspond in position to The solution for the structure was obtained through the nitrogen atom in the aminiurn cation. X-ray use of Long's computer program13 for direct sign analyses oil tri(p-fluorophenyl)amine and tri(/>-iodo- determination by the S&yre14 equation. Ail of the 42 phenyl)amine described in last year's annual report8 atoms of carbon, nitrogen, oxygen, and chlorine in the suggest that even the triarylamines in general have plane asymmetric unit were identifiable with peaks in the £ or nearly plane arrangements of the valence bonds at map1 s computed with the "best" sign combination for nitrogen. The study described here was undertaken to the 730 £"s of magnitude >1.50. After some prelim confirm the expectation that triarylaminium radical inary cycles of 'east-squares refinement, starting co cations have a simflar geometry for the nitrogen ordinates for the hydrogen atoms were computed valences. according to chemical-structural considerations, and The particular compound tri(/M)iphenylyl)aminium both the coordinates and the thermal parameters of the perchlorate was chosen for analysis because of its hydrogen atoms were adjusted thereafter. In the final known stability in the solid state.1 This compound was refinement cycles, coordinates and anisotropic thermal also mought to be of interest because of the possibility parameters were adjusted for all atoms, and for each of of observing varying effects of crystal environment on the five atoms of the perchlorate ion the ten extra the twist from coptanarity of the two rings in the parameters of die three-cumulant model16 were also biphenylyl group. It is known (see the convenient adjusted. Corrections for mild extinction were applied tabulation of Suzuki9) that the twist angle varies widely according to the method of Zachariasen17 in the among various biphenyl compounds, depending upon least-squares calculations; the extreme correction on the what substituents are present on the rings and on the calculated structure factor squares f^'s was about 0.85. environment of the biphenyl system. Final values of the usual measures of goodness of fit* * A crystal specimen with minimum and maximum are: R{F) * 0.051, R(F* ) = 0.050, RW(F* ) = 0.087, o, _ I CC diameters 2DO!«» 0.25 zr.d 0.5C rrjr. ?.is cut from • — 1 .->->. 146 The shapes of the radical-cation and oi the perchlo- As may be seen from Table 7.5, no carbon atom is rate ion are shown in the stereoscopic drawings of Figs. displaced from the best plane of its own ring by more 7.11 and 7.12, in which the atoms are represented by than 0.009 A, an amount which is hardly to be regarded their 50% probability ellipsoids.19 The geometry of the as significant. On the other hand, generally for all six ions is described more precisely by the numerical data rings the atoms directly attached to the rings ar° in Tables 7.5-7.7 and in Fig. 7.13. Table 7.5 specifies displaced somewhat more, probably indicating effects the deviations of various atoms from the exact plane of packing in the crystal. (7) of the triangle of carbon atoms about the central nitrogen atom and from the best least-squares planes (1, From the data in Table 7.5 for plane T it is clear that J', 2, 2', 3, J") through the atoms of the individual the configuration described by the nitrogen atom and six-membered rings. Table 7.6 gives valence angles in the three sets of axial atoms of the biphenyiyi groups is the cation and the interplane angles in the cation which approximately but not exactly plane. The distance of are of most interest Figure 7.13 shows all bond lengths the nitrogen atom from plane T is 0.014 A, about ten m the cation, and Table 7.7 gr-es bono lengths and times the standard error of position of the atom along angles in the perchloric ion. the perpendicular to the plane. This may be a signift- OfmL-sma. -c-i53 Ffc.7. *i Drawng of At Trifji biyht •jtyfliwiaiiiw Cxoom, S«owwg 50% Prohabifty for AB Atoms. ORNL-0WG. 70-55«9 0(4) P(2) 0(3) Prj. 7.f2 «*—«?~ggh *>n^is§ i! &s RMMIK MM m i ny> ttfrntrnf tyt Ffcfdtfonte, Showing *e 50% ^wiNMWy 147 cant displacement in the formal mathematical »ense, the carbon triangle T ard the rings /, 2. and 3 would all but it is clear that the geometry of the nitrogen valences be coplanar. These angles have the values 43.5. 45.3. is essentially plane trigonal, as expected. The small and 26.5°. respectively, all within the range of values displacement of the N atom corresponds to a bending found for the corresponding twists in various tri- of each C-N bond from the exactly plane configuration phenylanunes.* triphenylmethyls.5-4 and triphenyl- by only 0.6°. carbonium ions.5-7 The interplane angles T-l. T-2. and T-3 are essentially The interplane angles /-/', 2-2', and 3-3', which have twist angles around die C-N bonds from the hypo the values 36.4. 14.5. and 23.0°. respectively, specify thetical configuration (physically impossible) in which the twist angles about the central bonds of the three 2P \ I L/.< tf Fm. 7.13. Drawing of die Trite hmktmytynmmmjum Cat*"*, SK!-*25 ASC-Czsd.»»•C* - ^vacnmara ror crrecu of Ttcmal Motion). The standard errors of the bond lengths range from about 0.002 A fc? bonds at the center of tne km to aboot 0.0C2 A fu bend* ncs? fe r-anj^-— 148 Table 7.5. Disuses of Varions Atouu from Exact tlaae T Through the Tluee Cfebon Atoms Attached to tie Nitrogen Atom and from the Least-Sqeares Best Planes Through the Six-Membered Rings The atom numbering scheme is given in fig. 7.13. where ring /' is designated IP. and so forth Distance Distance (A) from Ring Plane - Atom from Plane Atom T(A) / /' 2 y 3 / X 10~3 X 10~3 X 10 3 x 10 ~3 X 10~3 x 10~3 •A 10-3 #"•/» \ N -14 *.»»» -4 3 1 3 -6 7 C(4,l> 8 C(2) 5 -8 -8 4 6 -3 •t ca.i'i 26 C(3> -1 6 9 — i 1 _2 C(4,l') 110 C(4) -3 1 _2 4 -8 3 r C<4,2) 24 C(5) 4 —«/ -7 3 8 1 CO.?) 56 C(6) -1 4 8 -6 -1 -6 C(4^) 81 Q4.3) _! N« -45 -23 -18 C(1.3') -11 C 'Atom* attached to the six-membered rings for which the best plur? were calculated. Table 7*. V; 7.7. See text i I caption of Table ?J for deftuticas of The atom nambcrs refer to Fig. 7.12. The standard The standard errors cf me vakace errors of the uncorrected bond lengths an* ranee 0.1 to 0.2°. and angles are about 0.002 A and 0.2°. gkcatNidogui Anatfeg) Paraneters from Two- Intermode Bond or Qi.D-N-aij> Cfl.D-N-QU) «l>N-aiJ) Cmubat Refinement rhstaaces (A) 117.1 12Z0 120.9 Angle .r . aid Angles (drg) Uncorrected Corrected •les at Carbon)Moaatfeg ) Aagk Bjmeuyhll BipbeayHi2 Bipfceayty13 0-0(1) 1434 1472 1.453 CI-0(2) 1.417 1.471 1.431 Q6)-Ol)-C(2) 120.3 119.9 118.7 CI-0C3) 1.425 1.469 1.447 Ql)-C(2)^C<3) 119.6 119.9 120.4 Cl-0<4) C(2)-C(3)-C(4) 120.9 121.7 121.6 1.422 1.472 1.446 C(3)-C(4)-C<5) 118.2 117.1 117.3 C(4)-C(5)-a6) 121.7 121.9 122.0 119.4 119.5 120.0 Q5)-a6)-ai) 0(l)-a-0(2> 109.2 109.6 108.7 d^-cfri-cd") 118.7 117.3 118.2 0(l)-CI-0(3) 108.9 108.5 108.6 C(l')-C(2')-C(3') 120.4 120.9 120.3 110.0 109.5 110.1 C(2')-Q3')-C(4') 120.2 120J 120.5 oci)-a-o(4) C(3')-C(4')-C(5') 120.0 119.7 119-5 0(2)-Cl-0(3) 109.5 109.3 110.5 C(4')-C(5')-C(6') 120.3 120.1 1208 0(2)-Cl-fJC4) 109.4 109.7 109.5 C(5')-C(6')-C significant difference is probably related to the fact that distances.1 * which should be better approximations to the ring 3 is twisted about 20° less than / or 2 from the the actual mean Ci-0 separations than the uncorrected plane T. i he lesser twist should make bond N-C( 1,3) distances obtained from a .refinement with the usual stronger and shorter than the other two, since the two-curnulant model. The corresponding valence-angle ir-orbital overlap integral is proportional to the cosine e5lii.^2*<^ defined by the intermode vectors were also of the twist angle. It follows from the valence-shell computed. However, the way to obtain the most electron-pair repulsion theory of directed valency20 reliable description of the perchlorate ion is to make that the C-N-C angle opposite C(l,3) should be the corrections on the bond lengths and angles through a smallest of the three C-N-C angles, as is observed. rigid body analysis.22 For this purpose we used the Unfortunately, the significance of thi* correlation is program of C. K. Johnson23 and the coordinates and diminished somewhat by the fact that the expectation anisotropic thermal parameters from the last refinement of a similar correlation of twists about the three cycle before the three-cumulant model was introduced. inter-ring bonds of the biphenylyl groups with the Tabk 7.7 shows the corresponding uncorrected and lengths ef these bends is net fulfilled. The bond which corrected bond lengths and angles, along with the appears shortest, C(43)-C( 1,3'). has the intermediate intermode distances and angles calculated from the twist. parameters of »iie three-cumulant model. The agree It is of some significance that we were aNe to refine ment among the four Ci-O distances corrected by the successfully the anisotropic thermal parameters of the rigid-body calculation is extraordinarily goo*, especially 27 hydrogen atoms, since this has rarely been done for so in view of the large corrections, 0.0i8 to 0.054 A. hydrogen atoms in x-ray analyses untj recently. Last The rms amplitudes associated with the three principal year a similar successful refinement for the hydrogen axes of Mbration of the ion are 12.9,9.8, and 7.7°. atoms in tri(/>-fluorophenyl)amine* was reported. These The average corrected Cl-0 bond length of 1.471 A successes attest to the quality of our data. Although no is in fair agreement with averages of similarly corrected detaied analysis of the thermal parameters has been values that have been reported previously: 1.464 A in attempted, it is dear from the ellipsoids depicted in Fig. nitronkun perchlorate,24 1.464 A in monocline hydro- 7.11 that generally they are physically sensMe. ruum perchlorate at -80CC^S 1.452 A in ortho- The apparent C-H bond lengths show the systematic rhombic hydronium perchlorate at room tempera error of shortening usually observed in x-ray analysis ture.26'27 In these other cases the individual bond for chemical bonds involving hydrogen atoms. This length values differ among themselves by from 0.026 to shortening is attributed to the shifting of the ccntroids 0.034 A. of the hydrogen electron clouds from the proton We thank Professor Robert I. Walter of the University positions as a result of chemical bonakig.21 In ihe of Illinois at Chicago Circle for suggesting this work and present cox the mean apparent C-H bond length is for supplying crystals of the subject compound. 0.970 A, and the rms deviation is 0.028. Thv minimum and maximum lengths are 0.904 and 1.030 A respec tively. The ar.tual C—H intemuckar distance is knovn 'Oak Ridge Graduate Feflow from North Texas State to be about 1.08 A in aromatic compounds. Unrversny. Denton, under appointment with Oak Ridge As- The determination of the detailed structure of the :"octated Unirrrnties. 2 perchlorate ion in this work is one of the few R. 1. Walter./ Am. Chrtn. Soc. Ttm5999 (1955). determinations of even moderate precision ever re 3P. Amfersei:. Acta Chem Scand. 19,622 (1965). ported for this ion, and it may be the best one. 4P Andersen and B. Klewr. Acta Chem. Scand 21. 2599 Perchlorate ions are quite often found to be in a (1967). disordered arrangement, which makes it impossftle to 5P. Andersen and B. Kiewe. Acta Chem. Scand. 19, 791 determine their atomic parameters precisely. In the (1965). 6 present case the ions are in an ordered arrangement, A H. Gomes de Mesquita. C. H MacGfflaviy. and K Erics. ActaCryst. 18.437 M965). though the oxygen atoms are characterized by rather 7L. L. Koh. Dissertation Absfr. 25, 3860 (1965). large rmr. vibrational amplitudes (up to 0.46 A in %Chem. Dir. Ann. Prow. Rept May 20. 1969. ORNL-4437. p. magnitude). It was these large amplitudes which sug 125. gested the use of the three-cumutant refinement for the *H. Suzuki. Electronic Absorption Spectra and Geometry of atoms of the perchlorate ion. This retirement aiiow? d ^.T^s.'^i".TTi^rcisn, AcsSftMiv. r«i» IVIK, ITO». us to reach the best agreement betweer f£'s and F? 's 10W. R. Busing et aL. The Oak kidge Computer-Controlled and also allowed calculation of *hs Intercede C\ O X-R*r Di/jfractometer. ORNL4I43 (1968). 150 1 !D. J. Wehe. W. R. Busing, and H. A. Levy, A FORTRAN distances in the proposed structure indicate that van der Program for Calculating Single-Crystal Absorption Corrections. Waals forces may be responsible for the increase in the ORNL-TM-229 (1962). stability of this compound over liiat observed in the gas 12 H. Hauptman and J. Karle. Solution of the Phase Problem, phr.se. A study at low temperature is required for I. The Centrosymmetric Crystal. Am. Cryst- Assoc. Monograph No. 3, 1953. further elucidation of the details of the structure, which 13R. E. Long. Ph _D. dissertation. University of California at are marked by large thermal motion of fluorine atoms Los Angeles. 1965. at 8°C. 14D. Ssyre. Acta Cryst. 5,60 {1952). 1 sl. L. Karle and J. Krie.Acta Cryst. 16, 969 (1963). *H. A. Levy and P. A. Agron. J. Am Chem Soc. 85. 214 C. K. Jchsson. "Genrratueu Treatments fur Thermai < 1963): S. Siegd and E. Gebert. J. Am Chem Soc. 85, 240 Motion.** chap. 9 in Thermit \eutron Diffraction. B. T. M. (1963). Wilis, ed., Oxford. 1970. 17*V. H. Zachariasen. Acta Cryst. A24, 212 (1968). 1 'Definitions: R{F) and RiF2) are defined by NEUTRON AND X-RAY DIFFRACTION STUDIES OF XENON HEXAFLUORIDE S||F*|-S*|FJIJ/I|FJ|. H. A. Levy P. A. Agron with x = 1 and 2 respectively: Single-crystal diffraction data were collected on the automated ORNL instruments for two phases1 of 2 2 xenon hexifhioride. X-ray data for both the inonodmic ^=[S^S fJ) /tn-p)]«/2. and cubic phases2 were taken at 20°C. In addition, where p is the Bwnber of parameters fitted to the n observa neutron data were obtained on the cubic phase of XeF* D 2 tions. The factor 5 is the factor scahng the vanes If*J to the at 3 and -11 C. The observation has been made by vahKslF L several investigators that both phases can apparently be ,9C K Johnson. OR TEP: A FORTRAN Tkemmi^mjpsoid held unchanged for long periods at room temperature Plot Program for Crystai-Sirveture Imatrmtkms, ORNL-3794 but that the monoclifuc crystals are disrupted on revised (1965). cooisrg to to I0°C. The elucidation of the nature of 2°R. LGOespie./. Chem. Educ 40, 295 (1963). the stablity of these phases awaits a complete solution ZIR. F. Stewart. E. R. Davidson, and W. T Simpson, J. of the two »rmctures. Chem. Phys. 42. 3175 (1965). Recently a structure was proposed3 for the cubic -2V. Scaomaker and K. N Truebtood. Acta Cryst. 124,63 phase of XeF* based on single-crystal x-ray diffraction (1968). data obtained at -80°C. According to this proposal 23C. K. Johnson. "The Effect of Thermal Motion oa both tetramers and hexaroers of xenens bridged by Interatomic Distances and Angles,"* m CrystaBographic Com fluorine atoms occur. Since neutron diffraction is much puting, F. R. Ahmed, ed.. Monskgaard. Copenhagen, m press. 24 more favorable, in this instance, for establishing the M. R. TrutCT, D. W. J. Crukksfaanfc. and G. A. Jeffrey. Actm CrysL 13,855, I960). positions of the fluorine atoms, the proposed model 2 5C E. Nordman. Acta Cryst. 15.18 (1962). was tested with the reduced neutron data obtained at 26M.R.Tniter.,4cia Cry**- 14,318(1961). -11°C. The discrepancy index, 27F. S. Lee and G. B. Carpenter. J. Phys. Chem. 63, 279 (1959). R(F) « Z\\F0\ - \Fcl\/Z\F0\ = 0.20, based on 11 atoms and 79 parameters indicates that the X-RAY DIFFRACTION STUDY OF proposed model is not adequate. Since the cubic phase KRYPTON MFLUORIDE appears to be stable at low temperatures, a neutron P. A. Agron H. A. Levy diffraction study with reduced thermal motion is called for to establish the fluoiine positions. The unit cell dimensions a - 4.60 A and c - 5.83 A G. R. Jones has also proposed4 a possible structure for krypton difiuoride at 8°C were determined by x-ray for the monoclinic XeF* based on the tetrameric diffraction using precession photography. The most species present in the cubic phase. This model has b«en probable «nace •?**•••« is PA-Jrrjr.v*. The poking of She appiicu io a set of nenrrrm {f»»» *!»d 2g2!*T 2 fcUT^J IC linear molecules In the crystal differs from that re give an inadequate fit. The discrepancy index based on ported for XeF2.' Intermolecular krypton-iraorirte 27 atoms and 107 parameters gives R(f) = 0.25. 151 P. A. Agron. C. K. Johnson, and H. A. Levy. Inorg. SucL The scattering of x rays fr >m a solution of trimethyl- Chen Utters 1. 145 (1965). amine in water having the same composition as the These 69-6955 60 - TOTAL COHERENT INTENSITY i 50 a — MtoBiid Soon Anqie Scattering b InterpoiaJed c ••• Meosuwd Ux^e Angle ScoRering « 40»- x: o f 30h a s S 1 i 20 «_ 10 6 8 10 14 — *.(«./X)»»Q [XI—* «§. 7.14. Total Scattmd I ofn>i for Uqaid Tiwailhjtwww Dccawrdnle at 5 C A stoichiometric not «f station 8.9ft note % tncnettrytenine and 91.02 mole % water n viwalrttd at representativeo f the whole tototkm The wnol-tssle raftering watraeasared to valoes of* >O01 A"'. 152 interactions of y nitrogen atoms and (1 y) oxygen atoms with 4f nearest neighbor atoms, y being the mole f taction of irimeihylamine and F < ! ihe fractional occupancy oi the assumed tetrahedral net work. Let the broad maximum around 45 A corre spond to a similar distribution of 12F average aton»s ! 2 centered at r, = r0(8/3) ' characteristic of a tetra- hedra! network. Let higher neighbor interactions and ill intermolecular interactions involving hydrogen atoms and methyl groups be described by uniform distribu tions. Without further specification of the detailed nature of this assumed tetrahedral network of oxygen and nitrogen atoms, we can calculate an intensity function for this very simple model of the tnnwthy!- i \M amine solution. Using Eq. 5 of ref. 4 and adjusting by >L_i • i • «56 least squares the occupancy factor F and the rms — r;I,— variations in the first- and second-neighbor distances, a value of F = 0.95 was found to give the best agreement Hg. 7.1S. X4tqr with the experimental curve for the solution. The a«l liqpat Ti correlation function calculated for ths model is shown The rdcalitrd cane for the bdovr 2E23 Aad ei the dotted curve of Fig. 7.15, and agreement with lfordisiaMXsr>2^A. the experimental curve is surprisingly good. The calcu lated curve for distances r < 2.5 A is model inde pendent, the parameters des<"~i>ing the intrarnoieculax 7 between water and trirrrthyiarnine molecules extended interactions being taken from gas diffraction results. '* to larger distances (as might be the case if the molecules The average coordination number of oxygen (nitrogen) formed large dusters held together by hydrogen bonds, atoms in the solution, 3.8, is thus smaller than the value or if regions containing qualitatively different local of 4.4 found for pure water. It should also be noted arrangements or "phases" were present), the intensity that a similar mode? for water gives rather poor 6 function (Fig. 7.141 should exhibit interference maxima agreement with the x-ray data. ana this leads to the in the region of small scattering angles, that is, below conclusion that the first coordination sphere of an the first major diffraction peak at ^1.7 A'1. The average molecu^ is more complex in pure water than in observed lack of interference in the small-angle region ihe trimethylamine solution. precludes any significant varir\on from unity of the Our analysis of the diffraction pattern for the correlation function not included in the curves of Fig. trimethylamine solution supports the idea thst the 7.15. hydrogen bonds between water molecules form an The maximum at 2.S4 A in the correlation function extensive three-dimensional network in which the ni f of pur« water represents6 "-4.4 0—0 interactions per trogen atoms o the amine participate through the average water molecule, indicating predominantly tetra- formation of N—H-O hydrogen bonds. The detailed hedral coordination. The location of the maximum near features of such a network would of course be short 4.5 A, when compared with the nearest-neighbor lived, and the local and instantaneous environment of distance, is a strong indication that the average devia individual molecules is distorted fiom the average tion from ideal tetrahedral coordination in both pure tetrahedral geometry. These small but continuous devia water and the solution must be quite small. In the tions from the average result in the loss of all positional solution, however, the irimethylamine molecules are correlation a few molecular radii away from any expected to interact strongly with water through the starting point, characteristic of a liquid. formation of N-H-0 hydrogen bonds,as is known to Intensity and radial distribution functions calculated be the case in the crystalline hydrate;3 these interac tor two specific different models for the trimethyl- tions must therefore contribute significantly to the amine solution give equally good qusniiiauvc agree gsximutn at 2.85 A. Let us assume that this peak can ment with the x-ray data.9 One model assumes that the be represented by a Gaussian distribution of distances tetrahedral network is similar to the ice I structure (ice centered at rrt - 2.85 A and characteristic of the i model) with none of the cavities occupied by 153 "interstitial" water molecules and 95^ of th^ network INFRARED ASu kAMAN SPECTROSCOPY positions being randomly occupied by oxygen *nd nitrogen atoms. The second model assumes that the ?hort-rangc order in the solution is. OP the average, SPECTROPHOTOMETRY OF SOLUTIONS OVER similar to that found for the solid hydrate, ail the large WIDE RANGES OF TEMPERATURE cavities characteristic of this striKiure* being randomly AND PRESSURE occupied by trimethylamine and water molecules- W.C.Waggener A. J. Weinberger These two different structural models have the same R. \V. Stoughton density, and the calculated distance spectra differ significantly only at relatively large separations, where Our efforts to understand the condensed states of all positional correlation in the liquid solution has simple molecules more nearly completely through disappeared. studies of their near-infrared spectra as a function of The fact that two modeb based on qualitatively temperature jnd r»rec«jr* have continued- different crystal structures describe the average short- Preliminary results comparing parameters of the four range order in the liquid trirnethylamine solution bands observed in the spectrum of orthobaric fcqirid equally well, illustrates that the three-dimensional H:S in the region 1.1 to 1.2 u with those of its cogener. configuration of molecules in a liquid cannot be H:0. in the region between 0.£ and 1.6 u were deduced uniquely from one-dimensional diffraction published.' Th? H:S spectrum differs from that of data. However, it has been shown4 that a dsthrate R.O in that the bands of the former are narrower, are model is incompatible with diffraction zneasurements in general less intense, and broaden with incrcasmg on pure eraser (and hence is unsatisfactory for dilute temperature and decreasing density from the freezing solutions): it does not afford a continuous transition point. This broadening, which must arise from kinetic from dilute to concentrated solutions of trimethyl- processes connected with weak intermolecular associa anine in water. The ice I model, on the other hand, is tion, is similar to that which we have observed in pure in excellent agreement with the x-ray data on pure Lorentzian bands in liquid C0> .2 except that the band water.10 and it describes quantitatively the radial broadening and shifting for the same range of reduced 1 3 distribution in other aqueous solutions. '"' While this temperature are in orthobaric liquid C02 8 times model cannot be proved to be unique, it seems to smaller, indicative of still weaker inlet-molecular forces. provide a more satisfactory description of the short- In view of the unexpected highly Gaussian distri range order found in water and n.any aqueous systems. bution functions required for a least-squares fit of the 1.6-p vibrational-band cluster of liquid H2S. we con cluded that H bonding, while much weaker in liquid H:S than in HjO. stit! is a controlling factor in the 'Crystallography Labor*!->ry. InKernty of Pittsburgh. Pitts band profile. Consequently, we have turned to a study burgh. Pa. 15213. of the liquid haloforms.3 in which H bonding is known Metals and Ceramics DivrTon. to he extremely weak. Harmonic and combination 3D. Panke.y. Chem. Pays. 48, 2990 (1968). bands involving the C-H stretch (y,) with the C-H 4 G. A. Jeffrey and R. K. McMuHan. Progr. Inorg. Chem. 8.43 bending mode {vA) are relatively intense compared with 11967). the other vibrations present and ate more susceptible to 3 A. H. Narten. X-Ray Diffraction Data on Liquid Water in the band analysis than the summation bands in n-hexane Temperature Range 4 - 2#fC. ORNL-4578 (1970). and cydohexane which we have already measured. We 6A. H Narten and H. A. Levy. Sconce 165.447 (1969). are measuring the 3f, band of CHBr3 and CHC13 near 7S. Shibata and L. S. Bartetl./. Chem. Phys. 42. I i47 (1965). 8675 cm"' and both the 2v2 + 2J»4 and the 3vt bands *B. Beagiey and T. G. Hewitt. Trans. Faraday Soc. 64. 2561 centered i. . 8589 and 8793 cm ', respectively, in the (1968). dilute gas. To date we have measured CHBr3 at 19°, *C. Folzer. R. W. Hendrkk*. and A. H. Narten. to be CHC1 at 19 and -63° (fp),and CHF at 19, -48, and submitted to the Journal of Physical Chemistry. 3 3 ,0 -63°. It is apparent for these halolorms that (I )aii the A. H. Narten. M. D. Danford. and H. A. Levy. Discussions Farsdcy Soc. 42.97(i%7>. bands exhibit a distinct asymmetry. (2) the CHF. band 11 A. H. Nanen. J. Chem Phys. 49. 1962 (1968). intensities are on the order of one-tenth of those for 12 A. H. Narten and S. Lmder.h urn./ Chem Phys. 51. 1108 CHC13 and CHBr3. and (3) changes in density of CHF* (1969). have an opposu* effect upon the band width and 13 A. H. Narten,/ Phys. Chem. 74. 765 (1970). position than obscived for CHC13. 154 Values of 1.11 and 1.79 for the asymmetry index, Thus these haloform spectra are more complex than defined as the ratio of integrated intensities above and we expected, and the spectra of liquid CHF3 are below vmiX, were obtained for the 3P% bands of CHBr3 qualitatively different from liquid CHC13 and CHBr3. and CHC13, respectively, at 19°C. Overlap of the 2»», + For CHCI3 the changes in the position and width of the 2"4 and 3?i bands in the liquid CHF3 spectra (Fig. 3f, band with temperature are small and negative. 7.16) prevents estimate of their asymmetries, although However, for liquid CHF3 vmMX{3»i) increases 32 Newness is apparent in the bands both at 19 and cm"1 between room rrn^rature and -63°, and its -46°C. estimated half bandwidth increases from 70 to 116 -1 The asymmetry in the two spectra of gaseous CHF3 cm (also see Fig. 7.16). This very large increase in (Fig. 7.16) and the asymmetry observed in the spectra bandwidth with increasing density and decreasing tem of the liquid haloforms suggest that some form of perature suggests association in the liquid, and we are quantized rotstion or libration may persist in the liquid particularly interested in measuring the CHF3 bands to rtale. At 48° (5 atm) the envelopes of the single P. Q, the freezing point (-155°C). and R rotational branches of each band are dearly We expect to complete measurements of the liquid resolved. In each case the central Q branch is very sharp halofonns from their respective freezing points to their (~650 liters mole"' cm"1) and incompletely resolved, critical points or to the point of thermal instability. An and the R branch is much more intense than the attempt will then be made to correlate the respective corresponding P branch. The asymmetry index for the spectra with the size and polarizability of the attached integrated intensity of each band is sbou' 1.5. At 19° Br, O, and F. (40 atm), which is near the critical temperature (33°C), For several years we have been concerned with the the profile of the gas-phase spectrum is clearly ap measurement and interpretation of the spectra of pure proaching that of the orthcbaik liquid. The Q rota liquids. Our equipment, however, was intended pri tional branch of each band lias broadened and become marily for solution spectrophotometry, and we have less intense. The P and R branches are no longer established some limits of applicability of nitric, sul resolved but appear as slight inflections and humps on furic, and perchloric acids as aqueous solvents up to the low- and high-energy series of the bands respectively. 250° .* This year we plan to make an exploratory study IV asymmetry indices have increased to 1.8 (2i>i + of species present in the aqueous chromate-di~hromate 2*4) and 2.0 (3P,). system as a function of temperature from 25 to 2S0°C. The equilibria involved apparently have not been studied as a function of temperature, and almost certainly not above 100°C. Our study should provide ORNL-DWG. 70-52C2 fundamental equilibrium and rate data fot chromium T r 1 r 1 ' 1 species which are extremely important oxidizing agents and corrosion inhibitors in the chemical processing industry. We believe that our initial studies of the chromate-dichromate system in dilute acids will lead to other extremely important and profitable studies in volving the oxidation states and hydrolytic behavior of chromium, iron, 2nd other members of the first ttansition series. Our original Ca~y model 14 spectrophotometer was replaced with an updated model 14 with a Datex digital system This instrument, specially built for us, has optimized performance in the wavelength range (0.25 to 3 0 M) most useful for studies of liquids and solutions W4VENUM6CR (cm') in cells with sapphire windows. It can be operated with the infrared source beam reversed to eliminate the Ffc. 7.t6. Spsctn of OrAobaric Liq«id and Gateow CHF3 at several watts of sample heating and permit operation at 19 and 48°C. Taken with a Caiy model 14 spectrophotometer lower sample temperatures. Furthermore, it s possible provided wfc« a 0 to 0.2 abtorbance nuuje. Sample ceil, 2.54 cm to measure photosensitive samples. vs reference eel, 0.25 cm (CCI4,25°). Ease tint tor correction of liquid and fas measurements obtained with CCI4 and vacuum, We found it impractical to adapt the available rapectivdy, in sample cdL machine-language programs for conversion of digital 155 information on punched tape to processed data stored INFRARED AND RAMAN SPECTRAL STUDIES x on magnetic tape. Therefore computer progra.ns ON "O-ENRICHED POLYCRYSTALUNE KN03 written in convenient FORTRAN IV language were developed which were suited to our particular n<*eds for M.H.Brooker' G.E.Boyd processing the digital data output from the new Isotonic substitution (e.g.. ,80, ISN, etc.) in mo spectrophotometer and for computing and plotting lecular ions in crystalline solids can facilitate -he spectral parameters. The method of W. R. Busing interpretation of vibrational spectroscopic measure (Chemistry Division) was used to transcribe from paper ments made after radiolytic decomposition by energetic to magnetic tape. Spectral scan information (identifi ionizing radiations.2 Infrared and Raman studies have cation, wavelength, filter, absorbance, and slit width) been performed with poly crystalline samples of 51.7% is processed and stored on duplicate library magnetic 18 0-enriched KN03 by techniques described previ tapes with provisions for editing the tape to remove ously. Band frequencies and assignments from these both machine and human errors from a given data set. rtvasurerrsents for the four possible isotopicaOy dif From these, calculations, tabulations, and graphs of 8 l4 ,8 _ ferent species (N"G3~, N'*fV 0\ N 0 02 , publishable quality can be generated. Punched tape ,8 N 03~) are listed *.i Table 7.8. These frequencies are generated during the day can now be processed, stored, in excellent agreement with infrared studies of l80- and plotted overnight. substituted nitrate in KBr pellets.3 The four intense Raman bands associated with the totally symmetric stretching vibration appeir to have identical molar 1W. C. Waggener. A. J. Weinberger, and ?.. W. Stoughfon, /. extinction coefficients ano can be used quantitatively Phys. Chem. 73,3518(1%9). to determine ' *0 isotope constitution4 (Fig. 7.27). 3 W. C. Waggener, A. J. Weinberger, and R. W. Stoughton, J. s Substitution of either one or two ' O atoms on the Phys. Chem 71,4320(1%?}. 3 nitrate ion lowers the symmetry from the D point W. C. Waggener, A. J. Weinberger, and R. W. Stoughton, ifl Ckem. Div. Aim. Progr. Rept. May 20. 1969. ORNL-M37. p. group to C2r. The vy (£* ca. 1350 cm"') and P4 (£* ca. 1 107. 710 cm' ) modes split into an Ax and .. B2 mode 4W. C. Waggener, A. J. Weinberger, and R. W. Stoughton, (TaNe 7.8, Fig. 7.18). The separatioc between these 1 AppL Spectry. 22,545 (1968). two components is about 15 cm" in the p3 region and Table 7.8. V ibfaoonal Frequencies and Aasgnments for Bands ObservediaSI.7S ia OEMkaed KN03 at Room Temperature" D^f, Symmetry C2r Symmetry Frequency (cm-1) Frequency (era "') ,8 Assiznmtat ,*. .. 1 ! ,8 l8 Asflgnment N *o3" N o3- N *02 0 N'*O 02 Raman Infrared Raman Infrared Raman Infrared Raman Infnred 716 715 777 776 (£*) »4 706 705 694 693 699 698 686 685 5, J 826 819* 828 816* (A j> *2 824* P, m7 846c 1051 1051.0 991 991 (/4'i)v, 1031 1031 1011 1011 At p( 1048c 1049.9* 988* 1028*" 1008* 1383d 1363d (£*) ) !353* 1383d 1331* 1363d d d •345 1324* (Atf[p) 1338* 1371 1346* 1377 1360 1339* dp*] 'Alignments are based on a free-ion approximation. A more complete analysis of the spectrum of solid KNO* H found from factor group .^presentation; see. for instance, M. H. Brooker and D. E. Irish. Cm. J. Chem. 48. 1198 (1970), *Curve resolved from band envelope. ^ands are I 156 POMl-DOS 70-55M 80, and 50 cm*1 respectively. The relatively large N^O^- frequency shifts in the bands at an 120 and 80 cm*' NVO" on substitution of the heavier ' *0 atom would indicate that these bands are essentially Ubratmnal modes of the nitrate km, whle the 2-cm"1 shift in the band at cm. 50 cm"' would be consistent with this band being due to a translatory motion of the nitrate ioa. NC,0- M\ 'Vnttiag meatuf: National Research Coaadi of Ci fortdoctoialFelow. 1969-70. aK. H. Brooke? and G. E. Boyd. ~ft«*o»ywi of'i » PblytryitiBiar KNO$.** a coatribatioa in S^ Infrared and Raman spectra of the cubic crystals GafNG,),. ScflvOjfc. Ba 1 (MATR) techniques were useful for obtaining spectra of 6 cm' in the » region. A weak shoulder on the A the strongly absorbingr, region at c§. 1380 cm"'. low-frequency side of each of the ?, Raman com ponents may be assigned to a band due to correlation field splitting. This would indicate ;hat the smaB mass change on substitution of * *0 for * *0 is not sufficient 'Exploded abetfact of paper scaedmfad lo appear ml Clm to decouple the vibration* of t«eighboring nitrate ions in Mrs S3 (Aafwt 1.1970). the crystal. s Vieitlng tbeaffct: National fttanrca COMC4 of Caaoaa In nonennched KNO,, lattice frequencies occur at PortooctoralFeaow. |v*9-70. 126 (weak), 85 (intense), and 52 (medium) cm"'. In sDcparbmai of Cbtmhuy. Uairaifcy of Waterloo. Wau^oo. 51.7% "Oenriched KNO,. the frequencies arc 120. Ontario. Canada. 157 ORNLOWG 69-13280 2.0 C Tf' 1 1 SLIT 5.0cm' SLIT 0.4O Cn." SLiT 5.0 cm*'SL'T 0.50 enrf SLIT IxlO3-/* 2*K)\/s 5xK)2 c/s 5xl02c/s 5x102c/s 1 »1 . I t N to .y a i i i. i J L_J L 1 I , I , , • , t 1640 133)1450 1400 1350 1060 1050 -V 824 820 816 740 720 -< cm Fig. 7.19. ofSKNO,), crated «tt»4ttoAaajo»ioa TRANSVERSE OPTICAL FREQUENCIES FROM CORRELATION FIELD COUPLING OF MULTVLE ATTENUATED TOTAL REFLECTANCE NONDECENERATE MTRATE VHRATONS' INFRARED SPECTROSCOPY1 M.H.Btooker* K.H.Brooker* Laser Raman spectra have keen recorded for several • MC oc muiuptc attenuated total reflec ionic nitrates at relatively high resolution. Band raulti- tance (MATR) spectroscopy have been found useful for pfcity in the out-of-pjane defomtation vibration in its obtaining infrared spectra of strongly absorbing first crwr.oiw* and in the symmetric stretching regions samples. No dispersing medium is reoi*?ed; h«te* was observed at.*! has been discussed according to the spectra can He gbiaiftcd tree from interfering bands selection rules for the appropriate factor group repre contributed by organic mulling ois and free from sentation (Table 7.9). Correlation field splittings are poariMe ion exchange effects common to alkali haBde considered to be the result of dipokvdipole interactions pressed pellets. Tbeorettcatty, for infrared reflection and are inversely proportional to the third power of the spectra each absorption band should give rise to :wo distance between molecules. The magnitude of the components: (I) a transverse optical. TO. and (2) a correlation field splitting (Table 7.10) may be related to longitudinal optical, LO. mode. We haw found that both the distance between and the relative orientations infrared peak frequencies determined with solid samples of the neighboring NO," kms. The magnitude of thf by MATR methods are the same as those obtained from correlation field splitting is essentially independent of transmission spectra. Contributions from LO modes do not appear to contribute significantly to the MATR band intensity. Since the vibrational modes in the first overtone region of the out-of-p!ane vibrations have identical 'Expanded abstract of a paper to bt pwbtohed in / Chtm. symmetry ioecses and similar frequency, Fermi reso fkft. nance interaction is possible. Evidence exists for some 3yWtint •cienifci; National Re*earca Coundl of Canada mixing of the etgenfunctions; however, the observations Postdoctoral Ftflow. 1969-70. are not fully consistent with Fermi resonance. 158 Table 7.9. Vwottoaal Fsffiaiifi fee Bandstkmn* bam the Huaaigi anHI F«idi". .fi»-sicsfcaSSi^*•* *i 1 2»l Ramaa Infrared Raman Infrared RW LtiOa 1071 (1.0) UL la. 838 1676(0.016) NaHOj 1068(1.0) i*. La. 836 1673(0.012) KN03-KI50°O 1056(1.0) loss- La. 836* 1672(0.011) KKOj-ti (25°0 1048 (0.04) f 828* 829* 1653(0.003) 826 (0.0005) 828 1051 (0.%) 105I| 1051.0 \S46 849 "*1664 (G.002) -1675 (0.0025) 1686(0.003) RbNOa 1053(0.08) 1053^ *3o(<0.0001) 836 1674 (0.019) 1057 (0.92) 1057/ CsNOj 1047 (0.10| 1047^ 833 <<0.0001) 834 1668 (0.02) 1051(030) 1051^ A1NO3 1043 (0.15) 302 1605(0.005) 1045 (0.85) 1046 809(0.003) '.614 (0.006) TWO, 1039(0.10) 819 1639 (O.OOT) 1043(0.90) 1042 821 (0.002) 1643 (0.009) CatNOjh 1066(0.3) 813 1628(0.006) 1069(0.7) 819 (0.001) 1633 (0.004) SifNOsh 1054(0 J) 814 1630(0.005) 1056 (0.8) 1055 820(0.001) 1635 (0.004) BatNOsh 817 1634(0.006) 1048(1.0) 1047 820(0.001, 1638 (0.004) fbCNOjh 1044(0.2) 807 1614 (0X105) 1046(0.8) 1045 811(0.002) 1618 (0.004) *Raman ianmitari relative to the total PX inteasity taken as unity are given ia parentheses. "Unless othcwbe stated, infrared Tabes are the powder vanes reported by M. H. Brooker and D. E. Iris*. Cm. J. Chem. 48.1198 (1970); M. H. Brookex. D. E. Irish, and G. E. Boyd. /. Chem. Phyt. S3 (1970); abo "Ionic Intenctkws in Crystals: Infrared aad Raman Spectra of Powdered CafNOjh, Sr(N03)3, Ba(N03)2, and PbtNOs^."' a preceding contribution in this Section, tins report. **2»1 modes are Raman active and infrared forbidden for afl centrosymmetric crystals, and Raman and infrared active for noncentrosy mmetric crystals. ^Oriented scngfe-crysa! values obtained from A. A. Shultin and S. V. Karpov. J. Phys. Chem. Solids 30,1981 (1969); 29,475 (1968). 'Oriented single-crystal values; M. H. Brookcr and D. E. Irish, unpublished work. -'Obtained from notvcfy«t*Htn* amnU A*r**nt*A c~ 22 .*^S; p~tc. !»««• >jm.u« WTIC i«wroe6 under bjgn-resolution conditions on a P£. 521 grating infrared instrument. 159 TaMeT.10. Ftoaerfies of Ionic Metal Nitrate Crystals" Closest Magnitude of Molecules NO3" ^.Hatire N-N Space Correlation Field Site N0 " Distance 1 3 Splitting (cm' ) GFOQP Primitive Symmetry Orientation in Unit CeB CeH(A) "7 2*2 »i LINO, Z>5«r*3C 2 03 ParaDd out-of-ptane. 3.70 0 0 0 copbnar 4.69 NaNOs DljRlC 2 03 Parald o«t-of-ptane. 4.07 0 0 0 copbnar 5.07 KNO34 £>5^3C 2 03 Parallel out-of-piane. 4.48 0 0 0 copbnar 5.42 KNO3-II D^-Pnrm 4 c, Stacked 3.22 20 33 3 RbN03* Cf«, 3 C, Parallel out-of-pane 4.85 0 0 4 CSNO3* Ci^3, 3 c, Parallel out-of-plane 5.20 0 0 4 AgNOa D^Pco. 8 Off-center, tited stack 3.85 7 9 2 TINO3 D^-Atme 8 or 1 4.05 2 4 4 C\y*bn2x 4 Shghuy routed from perpendicular J Ca(K03h 7*ft3 4 c3 Mutually perpendicular 4.35 6 5 3 SrtNoy)2 T%?* 4 «-3 Mutually p~rpcadkular 4.50 6 5 2 fb(NOj>2 lj« 4 MutuaCy perpendicular 4.55 4 4 2 c3 BafNOsh 7jA3 4 MutuaBy perpendicalar 4.70 4 4 0 c3 "Stable room-temperature phases except for KNO3J, which is stable above 130 C. *RbN03 and &NO3 hare been treated on the assumption that the space groups are identical Distances based on the pseudocubk unit ceSs. 1 Expanded abstract of a paper to be published in / Chan. The crystal structure of MoF4 has not been de Phys. (1970). termined, so an interpretation of the Raman spectrum 2Visi!'iig scientist; National Research Council of Canada of this material cannot be given at this time. However, Postdoctoral Fellow. 1969-70. in the likelihood that the unit cell contains MoF4 tetrahedra, we can propose a tentative assignment of the major features of the spectrum shown in Fig. 7. >0. The strong band at 722 cm* is a totally symmetric RAMAN SPECTRUM OF CRYSTALLINE MoF< crystal component of »», (A,), and one of the weaker bands at 746, 710, and 690 cm*1 may be a second John B. Bates 1 component of vx (the 746 cm" is a likely candidate Tne Raman spectrum of crysvalline MoF4 has not for the second vx component). Two of the three weakrr been reported previously. A sample of this material was bands observed in this region are likely to be crys'al supplied in the form of a yellowish-tan solid contained components of the v3 (F2) asymmetric stretching in the bottom of an evacuated quartz reaction flask.1 mode. The Raman spectrum shown in Fig. 7.20 was measured The degenerate bending modes v2 (E) and P4 (F2) are on a Jarrell-Ash model 25-300 spectrophotometer using giving rist to the low-frequency components observed both a helium-neon laser (Spectra-Physics 125-A, X = at 280, 251, and 211 cm'1 and to a low-frequency 6328 A) and an argon ion laser (Spectra-Physics 141, X shoulder on the 251-cnT1 band observed at about 220 = 4880 A) source to excite the spectra. cm"1 (Fig. 7.20). The hands observed at 176 and 142 160 ORNL-0WG. 70-4717 (b) (c) 722 em" 690 c«r 746 c» en 2 Ul -L -L_ 900 800 700 600 500 400 300 200 100 FREQUENCY (cm'') Ffc.7.20. M0F4 at 298°E. 1 cm* nay be due to external lattice phonons of the 298°K was obtained from a sample of crystalline MoFs MoF4 lattice, since these frequencies have about the sublimed onto the walls of a quartz reaction flask. This magnitudes expected for Ubrational motions of the sample was produced in one of the steps in the process M0F4 tetrahedra. leading »o the synthesis of M0F3.1 By measuring the Although the above assignment of the Raman spec Raman spectrum of MoFs in the reaction vessel, it was trum of crystalline MoF4 is only tentative, the reported not necessary to interrupt the synthesis of MoF3 at this spectrum can be used to identify MoF4 in samples of stage. unknown composition. Since our measurements were A second sample2 -3 of polycrystaliine M0F5 sealed in made on samples of M0F4 contained in a thick-walled a i]uartz tube having an optical flat at one end was quartz reaction flask, it should be possible to follow the reaction leading to the formation of M0F4 (and to other fluorides of molybdenum) by continuously meas ORML-OWG. 70-«l66 uring the Raman spectrum of the products formed 1 r 1 | i during the course of the reaction. 1 1 i 1 MoF, J 1 i » *1 : 1 : 'Samples of M0F4 were supplied by C. F. Weaver and H. A. Friedman of the Reactor Chemistry Division. z RAMAN SPECTRUM OF POLYCRYSTALUNE MoFs John B. Bates The Raman spectra of polycrystalline samples of _1_ _L X _L _L MoF were measured at 298°K (Fig. 7.21) and at about 800 700 600 500 400 300 200 $ FREQUENCY (cm*') 100°K (Fig. 7.22) using the 4880-A line of an a.-gon laser as the exciting source. The spectrum measured at Fig. 7.21. Raman Spectrum of Crystaffae MoF5 at 296*K. 151 ;«•*•.-3-aG -C-«TK The spectral activity and qualitative intensity predic tions derived from the purely group theoretical analysis of the vibrational spectrum of crystalline MoFs are in Siit * 2c*r" TS*00*K good agreement with the experimental data (this work and ref. 6). The present analysis provides an alternative to the discussion by Beattie et aL~ in which the ta« vibrational spectra of crystalline NbF5 and TaF5, which are isostructural with crystalline MoFs. were inter ,' ^-,. /\^J^\J VKX preted on the basis of a normal coordinate analysis of I i i ; • • . : . j the tetrameric Mo F "super" molecule. The pre 800 700 €00 500 400 30C 2O0 «00 4 20 FREQUENCY (w'l dicted intensities for the optical modes of crystalline M0F5 which would follow from this latter analysis do Faj. 7.22. Raana Spctti— of CijilJaai MoF at Aboat s not appear to agree with the observed intensities (this JOtfK. work and ref. 6). secured to the brass tai section of a Raman cold cell.4 C. F. Wearer aad H. A. Fnedmaa, MSR nupmtt Sonant. Raman spectra of this sample *ere measured with the Pmr. RepL Aug. 31.1969, ORNL-4449. pp. 114-15. taJ-section temperature at 77°K. Although a direct 2Tte «araple of M0F5 was Badcy applied by G. U. Bcaaa. measurement was not possible, die temperature at the 3A. C Rateabeig, Chem. Da. An*. fra&. RepL May 20, sample was estimated to be no lower than 100°K. 1969. ORNL-4437, pp. 46-47. The Raman spectra of crystalline MoFs w?re Inter * J. B. Bases, "M^Ople-^ii^ili^CoM Cd for a Laae*Excitod preted on the basis of die crystal structure data of Edwards et of..5 in which it was found that the four Sectioa, tab icport SA. J. Edwanh. R. D. Peacock, aad R. W. H. San*,/. Chem. moh/bdenum atoms in die primitive unit ceC (C2k) occupy two sets of nonequivalent sites. From the Sac. 19*2,4486. irreducMe representation for the 69 optical modes of *T. J. Qadfctie. C. T. RatdaTe, aid D. W. A. Sharp./. Or-m. Soc A 1949,2351. theMoF iaitice given by $ 7I. R. Beattie K. M. S. Liuajtf m, G. A. Oa, aad a J. ReraoUs./. Chem. Soc A 19*9,95?. r°P(C^) - 19,4, • l7Bg+ \SAU + 18a„ , it would appear that die 36 Raman-active modes would POLARIZED RAMAN SMTTRA OF give rise to a complex Raman spectrum of crystalline SINGLE-CRYSTAL Na#F4 MoF«. John B. Bates Comparison of the observed crystalline spectra with tht Raman spectrum of liquid MoF$* suggested an Measurements of *he polarized Raman spectra of interpretation of the infrared6 and Raman spectra7 of oriented single crystals of organic o inorganic com crystalline MoF5 based on two correlation schemes pounds allow one to determi^ rl»» symmetry type of which map the Difl point group of MoF5 through the each Raman-active crystal vibration and to study the C2 and C, (nonequivalent) site groups onto the C2A contribution from each dement of the polarizabflity point group Bomorphous to the crystatiographic C'IJ, tensor to the observed scattering. The additional infor factor group. According to this interpretation each mation gained from polarized spectra of single crystals nondegenerate 03/, molecular mode of MoF$ will give compared with that obtained from spectroscopic meas rise to two Raman-active Ag modes (components) in urements made on the corresponding poiycrystattine the crystal, vhe intensity of each crystal component materials is analogous to the gain in information from being comparable with the intensity exhibited by the x-ray diffraction experiments with single crystals rather corresponding molecular mode in the spectrum of the than with the corresponding crystalline powder, liquid. Each doubly degenerate 03A molecular mode of although the difference is not as great in the spectro MoF5 could exhibit four components in the Raman scopic case. spectrum of the crystal, but. in the absence of strong The polarized Raman spectra of an oriented singb correlation field coupling, it is likely that only two crystal of sodium tetrafluoroborate were measured in component: for each of the degenerate modes would be the internal mode region at 298 and 77*K, The faces of 1 observed. a single crystal of NaBF4 (orthorhombic). which had 162 been oriented by x-ray diffraction, were polished A second single crystal of NaBF4 was mounted with parafld to the (100), (01G), a«d (001) crystaDographic the (100) face held against the brass block of a Raman planes; the ceti edge* had lengths of 5. 2, and 2 mm cold eel4 and with the b axis parallel to uV horizontal parallel to the crystaBographsc b. a, ana c axes plane. Using liquid nitrogen as the cootam. the po respectively. larized Raman spectra of NaBF4 were .-..easured as Polarized Raman spectra were measured using a described above. The scattered tight in 'Jus case was JarreaVAsh 25-300 spectrophotometer equipped with a collected b> a 100-mm-focal-kngth came* !emstopped Spectra-Physics model 141 argon ion laser. The room- down to/72.8. temperature measurements were made on the singSe At room temperature, NaBF4 belongs to the ortho- crystal mounted at the end of a goniometer and placed rhombic system.5 ** The space group was determined to at the focus of the incident laser bam. The polarization be D\l (Cmcm)y and the primitive unit cell contains 5 of the incident radiation (4880 A) was controlled by a two BF«~ ions located on C,r sites. -* Based on the half-wave plate inserted before the condensing lens, and known unit-cell structure, the irreducible representation the tiobnzatkm of thi scattered light was determined for the 18 optically active internal modes arising from by a sheet of Polaroid mm placed before the entrance vibrations of the BF4~ «ons n given by slit of the monochroatttor. A 25-mm-focaUength camera lens was used to collect and coBimate the n* 7.H. forN*BF4 Site Factor Gnwp, Cwup, r. '** x* • Y2 • z2 be (2z2 -x2 -y3.x2 - y2) b fry, xz. yz) t c The b axis is unique in the NsBF4 stractvie, so n»t x 'c.ys.mdz'b in determinfaif the symmetry oi vector or tensor components in the i>: * peep. 163 sibie foe the observed spectrum.7 Thus. c{ab)a indicates ORNL-OWG. 70-5510 that the incident radiation is directed parallel tc the c axis and polarized parallel to the a axis and that the scattered Sght is collected parallel to the a axis and analyzed paraOd to the b axis. ORNL-0W6. 70-5509 1 ! 1 SINGLE CRYSTAL NoBF. T = 298*K 563 !534 765 !|530 366 c(ob)a 1343 i! k bcooo 11 i : i i Jl T 800 600 400 200 1 ' ! 1 FREQUENCY (cm" ) fig. ?J4. MMM Ram Soocto of SJo*»Oy«al N*tF4 o(bb)c ' r z TaMt7.ll. Fwauoacioi wart Mripwiatifaw tf»Marto< Ul RwawS»Kt»«fSi^t of tfcnt ci oactfOMAMioike b(cc)o From the polarization measurements described above, an unambiguous assignment can be made for the Raman-active correlation field components of the vmra- JV 1 A4 lional modes of the BF4" ion. Tbe crystal structure d*na for NaBF« supjesi that the er plane is nearly isotropic: 800 600 400 200 this is rtflecied m the small spUtiing observed between the Bi and B% components of the F modes (Table FREQUENCY (cm*) n t t 7.12). Abo because the NaBF4 crystal is nearly F%.7JJ. Sooctm of Sfciilt'Crysfst NaBF« optically uniaxial (pseudoieirafonal or pseudocubk). dtpotar^atkm of the incident and scattered radiation 164 may occur along one of the crystal iXc*, winch would Special techniques were developed by the ORNL result in the appearance of residual (Le., theo. Mically Glass Shop to seal one end of these tubes so that the forbidden) components in the Raman spectrum for inner and outer surfaces were essentially flat, parallel, certain orientations. Indeed, as can be seen in Figs. 7.23 and optically transparent. Each tube, after filing with and 7.24, residual components do appear in several of the required amount of lk,uki, was sealed (by fusion) the notarized spectra. However, additional factors such under vacuum, and the extra length was removed. Final as smaB errors in crystal alignment or crystal imperfec lengths of the sealed tubes ranged from 1.5 to 2 in. tion (mosaic spread) can also be responsible for the For the measurements at elevated temperatures, the appearance of residual components. tubes were inserted vertically into the center of a high-temperature furnace described elsewhere.1 The The Raman spectra of NaBF4 at 77°K (Fig. 7.24) were nearly identical to the room-temperature spectra, 4880-A laser beam entered the flat end of each tube indicating that no phase change occurs at this tempera and passed through its entire length. The scattered light, ture. Only slight frequency shifts from the room- either from the liquid, vapor, or supercritical fluid, was temperaUre measurements were observed, and no collected at 90° from the incident beam through a additions! Statures appeared ic the spectra. quartz window in the furnace. CoOection and focusing of the Raman scattered radiation was accomplished by the same optical arrangement as described in ref. 1. 'Crystals of Na*F woe Mnfly supplied by L. O.Gifcntrick, 4 The Raman bands of water of greatest interest in this Reactor Ckenustry Dmpoo, 3 study are those from approximately 3200 to 3700 S. P. S. Porto, J. A.Gk*dinam, aodT.C. Dame*. Pays- Re*. 1 147,60S (1966). cm' . The spectra of the liquid in this wavelength 3 region at temperatures from 25 to 373° are presented in 3. B. Bates, 0. at. HKMMS. A. Bandy, and E. R. Lippiacott, Sftecirodtiiu. Acta. to bv pvbtithed. Fig. 7.25. The most noticeable features are the rapid 1 4 J. R. Baits. ^«Mpte~*4**ptiag CotdCcI fot a Laser-Excited decrease in the intensity of the 3250-cm' shoulder Raman Sptctmpko*om#x OMNL-MGL 70-59OS /\ A > * 25*C nee ; \ 1 75 or. Slrt •' 9.0 cm'Slit ' \ 4 5xt0 c/s . 2xK>Vs \ 1 1 \ J 1 I l_ _• !_ 4200 3800 3400 3000 2600 3800 3400 3000 2600 A 2I6*C 302*C 373 "C H H 7.3cm Slit 8.0cm Sl!t 8.5 cm1 Slit 4 1xlCJ*c/s 5x» c/$ 2x103c/s / V J 1 I I _1_ J L J L J L 4000 3600 320C 2800 3800 3400 3000 3800 3400 3000 cm'1 Faj.7.25. Spectra of liquid Water at Saturation Vapor Pressure to 373 C. ORNL-DWG. 70-5506 3700 1 T SUPERCRITICAL FLUID (0-«gcm~3) nitrate was observed and compared with similar effects 3600 in aqueous nitrate solutions. A single broad band ca. 115 cm'1 was attributed to an external lattice-like vibra 'i tion. The vibrational spectrum of molten sodium nitrate 3500- is consistent with a semiordered array of ions in which the N03" ions occupy sites of low symmetry. Local order in the melt may resemble the arrangement of ions found in a particular crystal structure, but the Raman 3400J 200 300 400 500 600 spectrum does not present sufficient information to TEMPERATURE (*C) justify the complete factor group representation pro posed by other workers.3 '4 ¥'%. 7.26. Frequency of die Band Maximum for liquid and Gascons Water at a Function of Temperature. 1 Expanded abstract of paper in Chem. Phys. Letters 5, 357 (1970). RAMAN SPECTRUM OF MOLTEN NaN0 ' 3 2Visiting scientist; National Research Council of Canada M. H. Brooker2 Arvin S. Quist G. E. Boyd Postdoctoral FcBow, 1969-70. 3K. Williamson, P. Li, and J. P. Devlin, /. Chem. Phys. 48, The Raman spectrum of molten sodium nitrate has 3891 (1968). been recorded (Table 7.13). Lifting of the degeneracies 4D. W. James and W. H. Leong, /. Chem. Phys. 51, 640 of the i>i (£") and vA (£*) modes in molten sodium •i969). 166 Table 7.1 J. VmatiOMl (at,1)©/MrttenNaNOj Raman, 1 affiled, Raman, Ref. 3 Rrf.4. r-336°C 315°C 360°C 310 lUdpt-SOccT1) -125 140 170 719 dp 718 722 dp 732 dp 828, ~20 on"1) S25 833 1033 1057 P( 17 cm"') 1063 10S5P 1047 13*5 F» Mem"1 > 1345 1398 1398 dp 1390 1420 dp (90 cm'1) 1430 1656ti 17 cm'1) •dp, depolarized line: P. polarized line Bsadwidth at half height pven m parenthesei. VibratiofMl frtqaeniz* iitowed no ngntficant lem- peraftire-dependent variations. RAMAN SPECTRA OF SOLID AND MOLTEN A typical Raman spectrum for molten Lh BeF4 at 533° •er\ ANDLtiBeF. is shown in Fig. 7,27. The Raman spectrum of solid BeF was measured Arvm S. Quist John b. Bates G. t. Boyd 3 from room temperature to its melting point (555°) with the equipment described. For these studies a hand- The solvent for ftssic *nd fer. '*. materials in the picked piece of BeF2 glass approximately 5 ram in motteivstJt brecdt-r reactor wiH profebry be a mixture height and roughly triangular in cross section was of LiF and BeFa with a BeF2 I.iF ratio somewhat less contained in a sealed quartz tube (8 mm a.d., 6 mm than the composition LijBeF*. However, a melt with Id.) having a quartz window fused to one end. The the composition LijBeF* is a possible choice for use as spectrum of BeFj glass at 25s is presented in Fig. 7.28. a flush salt and/or as a coolant for future molten-salt The maximum of the most intense band appeared to be reactors. Therefore it if of some importance in esteb- near 280 cm'1. Weaker component* were observed at Ushinf a basic ut^derstanding of these high-temperature approximately 205. 395, and 440 cm"'. The spectrum systems to attempt in measure the v&ratsonai spectra did not change significantly until devitrification oc of the beryiliuro-fiuonne complexes which may exist in curred at temperatures near 230°. After devitrification, molten LiF-BeF, mixtures, not only t« pin informa the observable R*man spectrum contained only a angle tion on She species that nuy be present, but also to peak, which was centered near 345 cm'1. Only this characterize the bands caused by beryHninvfluorine single band was observed as the temperature was imeracttom so that these can be identified m systems increased to the melting point of BeF2. The Raman coniatfcing other complex ions (such as frssion product spectrum of molten BeF} has not yet been measured. fluorides) dissolved in this solvent. It is clear from the observations tlius far reported that Raman spectra of molten LiJBeF4 have been the present information regardm*. the vibrational obtained to 640*C. The met? was contained in window- spectra of molten LijBeF< and 40!id BeF2 is far from less nickel ceDs of the type described elsewhere for complete. Definite conclusions regarding the structure these measurements.1 Sample Rumination was per of beryllium fluoride melts (based only on spectro formed with the 4£80>A fine U a Spectra Physics model scopic evidence) therefore cannot be made at this time. Ml argon km laser. The furnace and optical system also However, comparison of the Raman spectrum of 3 s have been described and were used in conjunction molten Li2BeF4 with that of molten NaBF4 suggests w*th a Jarrel-Ash model 25-300 Raman spejtrometer. the following provisional interpretation of the Lij BeF4 167 ORNL-CWG. 70-9696 U2B«F4(1) 533'C aocm-'s^ 5 * K)2 c/s / Vy***^ 1000 900 800 70C 600 500 400 300 200 cm' Ffc.7.27. SfflCtIMB ©f MOHM UI**4 X 533 _, , center estonated to occur at about 240 cm'1. This band also can be assigned to a bending mode. Z5*C 9LO OK-' S«t If the above assjs>itnent of the band observed at SSO SitO3 c/i cm"' to the symmetric beryUium-fluorine stretching mode is correct, then it can be argued that, although / beryllium may be teuahedraOy coordinated in molten LijBeF4, each fluorine atom is bicoordinated with two beryllium atoms. By using the ratio of the boron* / fluorine and beryllium-fluorine force constants as calcu lated from the vibrational frequencies observed for ^ diatomic boron-fluorine and beryflhinvfluorine4 and L - assuming this ratio holds for the tetrahedral species, 600 500 400 300 200 «00 a 1 cm BF4~ and 3eF4 ~, a value of 670 cm' was computed for the totally symmetric stretching mode of BeF4*~ 1 Fig. 7.28. Spec tram of BeF2 Gtaa at 25°C based on the value of 779 cm" observed for vx (A t) in 3 molten NaBF4. This computed frequency for vx (A t) 2 of free BeF4 ~ ion is probably 10% too low, but the result indicates that the band observed at SSO cm"1 in spectrum, assuming tetrahedral coordination of beryl molten Li?BeF4 is far below what we expected for the 2 lium in the melt: The strong band observed at -550 fi mode of free BeF4 ~ ions. The lower observed cm'1 is the totally symmetric stretching mode. The frequency, however, can be explained by allowing broad, weak band centered at about 800 cm"' is an bkoordination of the fluorine atoms: sharing fluorine asymmetric stretching mode, and the band at 390 cm'1 atoms between two beryllium atoms would weaken the is asfigned to a bending mode. A change in tuz slope of beryllium-fluorine bond and hence result in a lowering the background scattering between 170 and 300 cm"1 of the frequencies of the beryllium-iiuonr.e stretciung (Fig. 7,27) indicates the presence of a weak band with a modes. Thus although the spectroscopic studies (and, 168 consequently, the theoretical interpretation) are not spectroscopy has led to successful measurement of the complete and definite conclusions cannot be made at Raman spectrum of molten NaBF4 to 556*C. this time, our results indicate thai an important feature Although Raman scattering measutements with poly- 1 cf a mode! for molten Li2B*F4 wi8 utcluue tetra- crystalline NaBF4 have been publisheJ, ;he recent hedral coordination of the beryllium atoms and Inco avaiablity of Raman spectrometers designed for use ordination of the fluorineatoms . with stable, intense laser light sources has made it possible to obtain a spectrum of the solid material which reveals much more detail than was previously 'A. S. Qvirt, "A Windowlest Cd for Laaer Ranaw Spectros observed. A spectrum of potycrystalline NaBF .2 con copy of Molten Fluorides," another contritwstiea is ths 4 Section, Utii report. tained in a melting-point glass capillary near 25°, is 3 A. S. Qukt, MA Furnace for Molten-Sail Raman Spectros presented in Fig. 7.29. The sample was illuminated with copy to Mf/t," another contribution in that Section, tin 4S*0-A light from a Spectra Physics model 141 argon ion laser; the scattered light was collected and col- ' A. S. Quift, J. B.Batei,s*dG.E. Boyd, HRamaa Spectra of limaied by a 2S-n«n-focal-lesgth/?Q.9S earners lens and Moiten NaBF4 fo SS6X," roBowinff contribution, tins report. focused onto the entrance slit of a Jarrell-Ash model 4G. Hcnberg, Spectra ofDittomk Mokrules, Van Nottraod. 25-300 Raman spectrometer by a 270-mm-focaMength Near York, 1950. achromatic lens. For the measurements on liquid NaBF4, the melt was contained in nickel windowless cells of the type 9 RAMAN SPECTRA OF MOLTEN M-SF4 TO SS6°C described previously. The resistance-heated furnace Arvin S. Quist John B. Bates G. E. Boyd and the optics for collecting the Raman-scattered light have also been described.4 Data were collected from a Possible use of molten NaF-NaBF4 .fixtures as a few degrees above the melting pohu (406°) to 556°, at low-melting, low-cost coolant for a molten-salt breeder which point surface-tension forces were no longer able reactor ha> Jed to an interest in obtaining an under to contain the melt within the cell. A typical Raman standing of the properties of this system. The charac spectrum of molten NaBF4 is presented in Fig. 7.30. teristic vibrational spectrum of the BF4" ion in these The frequencies of the bands observed in the Raman melts has not been obtained until now, primarily spectrum of molten NaBF4 at 437*C and in the Raman because these molten salts rapidly attack the usual spectrum of potycrystalline NaBF4 at 2S°C are col optical window materials. However, the recent develop lected in Table 7.14. The tetrahedral BF4" ion has four ment of a windowless cefl for use in molten-salt Raman normal modes of vibration, all of which are Raman 0RNL-DW0. 70-5521 T 1 NoeF4 3.0 cm"' Slit 5 HO3 c/s ^M **••*« *Mn.^A Vn^^miaa»ta«h M _JJL 1200 1100 1000 900 800 700 600 500 400 300 200 -i cmk Fig. 7.29. Raman £oectram of ForycryarafJae NaBF4 at 25°C. 169 ORNL-0*0 70-S522 1 T 437 »C aO cm' Siit 2 i I03 c/s ± _i_ X J_ _L 1300 1200 1100 \000 900 POO 700 600 500 400 300 200 100 cm'1 Ffe.7.30. Spectra of MoMea NilF4 at 437°C. TaMe7.l4. Baa* Obaanied m tf i Rin u Spectm of Mottea temperature is characteristic of a difference tone. It NaBF4 at 437°C and Potyci) 4alJaeNaBF 4at25°t may also be due, however, to an impurity in the- melt. The v (£) and p (F ) bending modes of BF " were Frequency (cm'1) 2 4 2 4 Assignment observed at 362 and 535 cm-1, respectively, in the (7 Symmetry) Melt(437°Q FdyaystaOine (25°Q d spectrum of the melt at 437°C (Table 7.14). These modes were observed to split into two components each 1090l 1075 in the spectrum of polycrystalline NaBF (Table 7.14). 1056 J "3 (*S) 4 The crystal structure of NaBF belongs to the & \ 779 786 »|Mi) 4 % space group5 with two BF ~ ions located on C sites hi 720 »j-i»2« impurity (?) 4 29 554 \ the primitive cell. Thus the BF4" vibrations give rise to 535 533/ *4 (^2) the following Raman-active components in the bttke: 3691 Ax+Ag,E^> Ag + Btg, and F2-+Ag + B2g + B3g. We 362 "2 (£) 343/ can expect to observe, then, two components for the v2 (£> mode and three components for the v4 (F2) mode. As discussed above, two components were observed for each of these modes in the Raman spectrum of active. The totally symmetric stretching mode, vx (A t), polycrystalline NaBF4; the third component for i»4 was observed at 786 cm*' in the polycrystalline solid (F2) was either too weak to be observed under the (25°C) and at 779 cm'1 in the spectrum of the melt at present experimental conditions or it was accidentally 437°C. As the temperature of the meit increases, the v\ coincident with one of the other two observed com peak appears to shift slightly to lower frequencies, ponents. occurring at 775 cm-1 at 556°C. However, a weak band The V3 (F2) asymmetric stretching mode of BF4~ appears on the low-frequency side of vx in the ivielt appeared in the Raman spectrum of the melt as a broad, spectrum, and its apparent increase in intensity with weak band centered at about 1075 cm"1 (Fig. 7.30). In increase in temperature could be responsible for the the spectrum of the polycrystalline solid, two com 1 apparent shift in the band maximum of vx. This weak ponents were observed for i>3 at 1090 and 1056 cm" . band, which occurs, at about 720 cm'1 in the spectrum As discussed above for the v4 (F2) mode, the third of the melt at 437°C (Table 7.14), may be due to v3 - Raman-active component of v3 is either too weak to be v2 since an increase in the intensity with increasing observed under the present experimental conditions or 170 the frequency is accidentally coincident with one of the the suitability of the polymeric model in describing the observed frequencies of thr. other two components. vibrational spectrum of the Lt2 BeF4 melt. Both the number of frequencies and intensiti** of the The theory and methods used in calculating the tends observed in the Raman spectrum oi molten optically active vibrations of the BeIIF2ll+2 polymer NaBF« (Fig. 730 and Table 7.14) are entirely con (where n is assumed to be infinitely large) have been 3 sistent with a tetrahedral structure for the BF4~ ion in described elsewhere. The lattice (polymer) potential the melt. This result is particularly important in view of function is approximated by a modified valence force the spectroscopic measurements of the beryllium fluo field in which the diagonal elements of the matrix are ride-containing melts described elsewhere in this re the force constants for the internal coordinates, and the port,4 because it establishes trends for spectral behavior off-diagonal elements are the interaction constants whenever the dominant S£«cie$ in a melt is a free between pairs of internal coordinates. Figure 7.31 letrahedral fluoride-containing anion. shows a segment of the Be^Fj^j polymer with the primitive unit cell (primitive repeating unit for the 1 J. Coubeui aarf W. cues, £ Aitarg. AUgtm. Chem. 268,221 polymer) indicated by the dashed outline. The lattice (1952). has DJh symmetry; theie are two beryllium atoms and 2Sttpp&cd by L. O. Gflpatrick of the Reactor Chemistry four fluorine atoms in the unit cell (Fig. 7.31), and the Division. irreducible representation for the 15 optical modes of 3A. S. Quirt, "A Wmdowfcss Cel for User Raman Spectros the lattice is given by copy of Molten Fluorides," another contribution in this Section, this report. 4A. S. Oust, UA Furnace for Molten-Salt Raman Spectros + copy to 800°C," another contribution in mis Section, urn * 2*1,, 2*2« • 2B3U . report. 5G. BrantonMcts OysL B24,1703 (1968). The frequencies for the optically active vibrations of 6 A. S. Qoist, J. B. Pates, and C. E. Boyd, "Raman Spectra of the BeRF2n+2 polymer are obtained from the eigen Solid and Molten BeF2 and LijBeF4,** preceding contribution, values X, of KJOP/^P - X£l« 0, where E is the identity this report. matrix and where 6°P and F°V are given by DYNAMICS OF A POLYMER MODEL FOR MOLTEN *n Lh BeF : SOME PRELIMINARY RESULTS <#"! «,-'*?*» 4 1=1 John B. Bates and The importance of polymeric structures for inter l l preting the thermodynamic properties of BeF2 melts /TOP = V /H s V V z 4> has recendy been discussed by C. F. Baes, Jr.1 The uv id uv Li Li **uvw *Mw polymeric models considered in this work were based 1=0 /=G uvw on 'etrahedrally coordinated beryllium atoms which are In these equations, £°P is the optically active/? matrix bridged through bicoordinated fluorine atoms to pro and is defined by duce a large number of anionic BeaFft species. Fn particular, assuming that beryllium remains fully foar- coordinated in the melt, it was concluded in ref. 1 that W°Z< f=o the BenF2n+2 chain structures involving shared letra hedral edges were especially important in meits of high beF? content such as LiF-BeFj. 0RNL-DWG. 70-5698 In view of the foregoing hypothesis and the "tirrent "1 investigations of the Raman spectra of Li2BeF4 melts, we have calculated the vibrational spectrum of the F-. XiX Be F +2 polymer assuming the chain length n to be „-F-« R 2R • ^Be J Be F sufficiently large that the effects of end groups can be \.V ^ F neglected. The initial calculations were intended to test F the assignments proposed for the observed Raman ._J spectrum of molten Li BeF 3 and, conversely, to test 2 4 Fit. 7 Jl. Polymer Mode) for Molten Li2BeF4. 171 in which the Bti are the B matrix elements relating the symmetric F-H-F" ion as compared with the free 3 Cartesian displacement coordinates e, for masses mi to H-F value. ) In addition, as the concentration of BeFj the internal displacement coordinates, S., by the increases, the effects due to fluorine bicoordination equation should become mon* apparent in the Raman spectrum of molten LiF-BeF2. St=L E*rW' '-l."3». 1=0 1=1 *C. F. Baes, Jr.,/. Solid State Chem. !, 159 (1970). 2 A. S. Quist, J. B. Bates, and G. E. Boyd, "Raman Spectra of t where n is the number of atoms per primitive cell and Solid and Molten BeF2 and Li2BeF4,* another contribution in the sum over / includes ill primitive cells containing this Section, this report. 3 atoms involved in defining the internal coordinate S In J. B. B^tes, £. R. Lippincott, Y. Mftawa, and R. J. Jakobsen, r /. Chem. Phys. 52,3731 (1970). computing the optically active force-constant matrix, f°P, ^ is a one-dimensional array containing valence and interaction constants for the /th cell, and Zl is the constraint matrix for the /th cell.3 A FURNACE FOR MOLTEN-SALT RAMAN The results of the calculation are given in Table 7.1S. SPECTROSCOPY TO 800°C Only the calculated frequencies corresponding to those Arvin S. Quist bands observed in the Raman spectrum of molten Lij BeF4 are given, along with force constants obtained A vacuum-tight furnace was designed and constructed from a least-squares fit of the observed and calculated for use in measuring the Raman spectra of molten salts frequencies. The good agreement between the observed to 800°C. This furnace was intended for use in the cell and calculated frequencies for the three modes given in compartment of a JarreD-Ash model 25-300 laser Table 7.IS suggests that the assignment of the Raman Raman spectrometer (Jarrell-Ash Company, Waltham, spectrum given in another contribution to this report2 Massachusetts), but it could also be easily adapted for is at least tenable on the basis of a polymeric model for use with other laser Raman systems. molten Li^BeF^ The low value of the beryllium- The basic features of this furnace are the same as have fluorine stretching force constant and the relatively been described earlier for use in absorption spectro- large stretch-stretch interaction constant (for beryl- photometric studies of molten fluoride salts.1'3 Major hum-fluorine bonds joined to a common beryllium modifications to these previously described furnaces atom) were expected in view of the bicoordinated include (1) changing the position of one of the two side fluorine atoms. (For comparison, the value of the windows to the top of the furnace to permit entry of hydrogen-fluorine force constant is about 80% lower in the laser beam, (2) use of cartridge heaters (Watlow, Saint Louis, Missouri) in place of platinum-wire heaters, and (3) use of a bellows assembly to connect the side window to the main body o.r the furnace. The main Table 7.15. Calculated Frequencies and Force Constants features of the present high-temperature furnace as for Three Optical Modes of the BenF2A+2 Polymer, sembly are shown in Fig. 7.32. and Comparison with Experimental Results Twelve %-in.-diam cartridge heaters are arranged Frequency (cm _1) symmetrically in U-shaped grooves rrlWcd in the cylin 2 Assignment drical nickel furnace body. Three 2 in.-long heaters are Obsenred Calculated positioned under the viewing port in the side of the 800 800 Asymmetric Be-F stretch nickel body; the other nine cartridge heaters are each 550 550 Symmetric Be-F stretch 3*4 in. long. Maximum output of the 12 120-V heaters 390 390 FBeF bend is 2100 W. The control Chromel-Alumel thermocouple, connected to a proportional temperature regulator, is Force Constants positioned in a hole drilled in the nickel furnace body Fg^f 2.10mdyn/A in the side opposite to the viewing port at a point ^Be-F Be-F ®'^ mdyn/A(interaction of bonds approximately % in. equidistant from two heaters. joined to a common Be atom) The molten salt whose Raman spectrum is to be H g^ 0.54 mdyii-A/rad2 (bend between! F' NF bridging F atoms) measured is held in its container in a cylindrical silver block which fits inside the nickel furnace body. An 172 light-collection system is the aperture stop of the side window of the furnace, which is approximately f/23. The entire furnace assembly is supported on a positioning table by three adjustable vertical pins. The p3sitioning table is adjustable in the horizontal plane by two micrometer screws at 90° to each other. This arrangement permits accurate placement of the simple in the laser beam. The complete unit, furnace and positioning table, can be moved easily into and out of tfie sample compartment of the Jarrdl-Ash Raman spectrometer. The Raman spectra of molten nitrates, ftuoroJx sates, and fluorides bwe been measured at temperatures to 8u0° with this furnace. With nitrates « quartz contain ment cell open to the atmosphere of the furnace interior was used; the interior was either evacuated or contained helium. Molten fluoroborates and fluorides were contained in windovdess cell;, which are described in the following contribution to this report. 1 J. P. Young and J. C. White, Ami. Chan. 31,1892 (1959). 3 J. P. Young, AnaL Chem. Dif. Ann. Pngr. Rept No*. 15, /965,ORNL-3S37,p.26. 3 J. P. Young, Inorg. Gum. 6,1486 (1967). A WINDOWLESS CELL FOR LASER RAMAN SPECTROSCOPY OF MOLTEN FLUORIDES ArvinS. Quist Ffe. 132. Schematic Groat Section at Furnace. (1) Window flange, (2) V'iton window pad, (3) quartz window, (4) O-ring, A windowless or captive-liquid cell has been designed, (5) cooling water channels, (6) nickel bellows, (7) beater damps, (8) cartridge heaters, (9) water jacket, (10) fibrous fabricated, and utilized to measure the Raman spectra insulation, (11) heater-connector assembly, (12) metal-sheathed of molten fluorides to temperatures of 800°C. This cell thermocouples, (13) mckd furnace body, (14) cylindrical suVsr was built for the furnace described earlier1 and is to be sample-holder block, (15) sample positioning screw. used specifically for laser Raman spectroscopy. Its design is based on the general principles successfully employed for several years in the construction of cells adjustment screw at the bottom of the sample holder to measure the visible and ultraviolet absorption spectra cavity allows freedom in the initial positioning of the of fluoride melts.3 No window materials are necessary; sample holder. A Chromel-Ahimel thermocouple lo the melt is retained in trie cell by surface tension. cated in the interior of the silver block at the same A schematic diagram showing dimensions of the height as the molten, salt is used to determine the windovdesa. ceils for Raman studies on molten fluorides temperature of the melt. is given in Fig. 7.33. These cells are usually constructed The laser beam enters tfc furnace through the top from pure nickei or from oxygen-free copper, since window and is brought to a focus in the molten salt at these materials are satisfactory container materials for the center of the viewing port. The Raman-scattered the melts of interest to us. However, they could be light is collected and collimated by a compound f/2 constructed from a variety of other materials for use 100-mm-focal-length lens positioned adjacent to the with other molten-salt systems. side window. A 270-mm-focal-length achromatic lens Prior to use, the cells are degrcased by conventional focuses the collimated light on the entrance slit of an techniques, and the surface oxides are removed by //8.7 double monochromator. The limiting factor in the heating in a hydrogen atmosphere. Filling of the cells 173 with solid fluorides is carried out in an inert-atmosphere advantage of the desirable optical features of a quartz glove box. About 0.3 to 0.4 g of salt is required to fill cell while avoiding the difficulties which arise when V the cell to a lew! about J4 to % in. above the top of molten fluorides come into contact with quartz. The the slot. The filed cdls are heated in an evacuated sample b completely enclosed in an inert atmosphere, quartz tube to melt the fluoride and to fill the lower thus presenting no problems in subsequent experl* portion of the cell completely. This procedure removes mental manipulations. The containment feature is of most of the trapped air and allows fluoride in excess of particular importance when working with toxic beryl- that which can be held in the cell by surface tension to hunt-containing melts. escane through the slot. The remaining volume of the Raman spectral measurements or. *ht molten salt are melt usually does not escape from the cell during made by placing the seated quatU tube containing the subsequent experimental measurements. windowless cell into the central portion, ordinarily a The cell is transferred, after cooling, to a 6-mm-iD, removable silver block, of the resistance-heated furnace 8-mm-OD quartz tube which ha* a V|«-in-thick opti described tariier.1 This quartz tube is held in a vertical cally fist quartz disk (used to one end. The open end of pociicn, with the laser beam entering through the the metal cell is placed nearest the optical flat The optical flat A 19-m.-focaHecgth lens is used to bring quartz tube is sealed by fusion under reduced pressure, the beam Jo a focus at the vertical center of the slot of thereby safely containing the windowless cell holding the windowless cell. Although entry of the laser beam the fluoride salt in a convenient-sized tube for Raman into the molten salt through its concave meniscus spectral measurements. Tins arrangement for containing causes sortie divergence, beam defbeusing usuaDy is not molten fluorides for laser Raman spectroscopy takes significant Most of the incident light passes through the molten salt in such a manner as to give an adequate amount of Raman-scattered hght through the slot in the 70-57DO windowless ceD. The scattered light is colected at the side port of the furnace by a compound/72 iOO-mm- focaMength camera lens. The coBimated tight is focused on the entrance slit of a double monochromator by a 270-mm-focal4ength achromatic lens. The anal width of the slot (0.03125 m.) for the exit of the Raman-acattered light from the windowless eel is not a limiting fector in determining the amount of fight which subsequently enters the monochromator. The ft—2."—«i focused laser beam, with a diameter of less than 0.0004 *^32 • in., can be considered to be a point source of scattered light. Ordinarily the point of focus of the laser beam will occur in the cross-sectional center of the window less cell; however, even if the point of focus falls at the 32 rear of the moften-salt-contaimng cavity, the dftaace from scattered-light source to slot would be only 0.125 'i" in. Consequently, the maximum /value of the window- 32 te» cell would be 0.03125/0.125, or 0.25. This is a much smaller value than the focal ratio of the furnace aperture, approximately/72 J. Therefore, in the present 5» experimental system, the width of the opening in the /K S \ windowless cell does not limit the amount of scattered light which * transmitted to the double mono Ti chromator. 4 The height of the slot (0.250 in. or 6.3 mm) also is not of major importance in limiting the amount of light jj reaching the spectrometer. The collecting and cofli- mating lenses give an overall magnification of approxi Fi§. 733. Wiadowtai CM for ham Rama Spectroscopy of mately 3 for optimum light-gathering capacity. Conse Molten Fhwride*. quently, the magnified image of the slot usually 174 completely fiBs the 204iinvhjgh entrance slit of the TO-MW monochromator* Windowkai ccOs of the above design have been used Sinumt succestfutty to obtain tfce Raman spectra of molten VACUUM POUT (»*•*»! fluorides, fluoroborates, and ftuoronrcooatest o tem O^ • " TMCWMOCOunC w£*OS peratures of 800*. Representative spectra so obtained are given in other contributions to this Section of this annual report. *A. 3. QMM, "A r«m for WoiteB-Sata Kama Spectre* copy to WfC~ BHcidun coatribmtoa,ftus itport. *J. P. V iiULTaTU^AMPUNG COLD CELL FOR A LASER- EXCfTEORAIUNSrSCTROfHOTOilETER John B. Bates An inexptmive sample eel for a laser-excited Rao&n SIDE YIC1 (A) spectrophotometer was dwigried for measurements to Hf. 734. SdMOMtfcSMfe Vtowofaw COM CM. 77*K (liquid nitrogen) for use wit* a variety of samples JndwKng single crystals, powdered solids contained ic which extend outward on either side of the lower edge Pyrex or quartz capflhries, porycrystaflinc deposits of of the surface to provide support for large single organic liquids or gases, and liquids which can be crystals or liquid cells. Single crystals are mounted on contained in quartz or Pyrex tubes. the surface of the Mock by covering one face of the A schematic side view of the cell is shown in Fig. crystal with a thin layer of sflicone grease and pressing 734. The outer part of the cell is constructed 'som this face of the crystal against the block, for measuring Pyrex, with flat Pyrex windows sealed directly tc the the Raman spectra of condensed gases, liquids, or cefl body for entrance of the incident laser bean, «nd matrix-isolated species, fhe attachment shown in Fig. exit of the scattered light. At the top of the ceo *etr 734c is used to form a deposit of the material on the the 45/50 standard-taper ground-glass joint, a vactrom cold surface of the sample Mock («3). A sample bulb port (three-way stopcock) is joined to the left side of containing the vaporized material a attached to the ball the cell (facing the exit window) and a 12/30 standard- socket, and the vapor is directed onto the Mock taper ground-glass joint containing thermocouple leads through the flared end of the glass tube (cl). The cold is joined to the right side of the cell (Fig. 734a). finger is then rotated 180° to place the sample in the The inner section of the cryostat is a Pyrex cold laser beam. finger which termi ater in a brass sample block joined The temperature near a given sample is measured by a io the cold finger through a Kovar seal. A huge portion thermocouple attached to the sample block by means of the sample block («2) is hollowed out to provide for of a set screw (AI). In some cases, as with single maximum cooling. The sample block is constructed so crystals, the thermocouple can be attached directly to that opposite faces may provide differing sampling the sample. The scattered light from a sample is arrangements. The front face cf the block, shown in collected and coUimated using a 100-iran-focai-length Fig. 7.34b, is used for materials (principally powders) //2.0 Angenieux s3 camera lens. The cold cell has a contained in quartz or Pyrex capillaries (maximum clear aperture of about //0.8, so that it is not the outside diameter about 2 mm). A capillary is secured to limiting stop of the system. the surface of the horizontal groove with a thin layer of Typical low-temperature Raman spectra which can be sflicone grease. A vertical groove at the center of the obtained with this cold cell are presented in other face (Fig. 7.34b) allow* the laser beam entering through contributions to this Section of this annual report.1 the bottom window of the cell to be focused near the center of the capillary. 'See, for example, J. B. Bates, "Raman Spectrum of The flat surface on the opposite face of the sample Poh/crystalMne M0F5," another contribution to this Section, block (a 3) has two small brass posu (2 mm square) this report 175 MICROWAVE AND RADIO-FREQUENCY Here, too, a very much higher radical concentration was SPECTROSCOPY produced by the addition of H,0,. Measurements were made both in H,0 and DjO solution*. In a solution having I Jb Hi sodium citrate and 0.6 M H;0* at 3S*C, PARAMAGNETIC RESONANCE STUDIES the g value is 2J00325. There b a 20-304* coupling OP LIQUIDS DURING PHOTOLYSIS from the CH proton, a 0.27-G coupling from an Ralph Livingston Henry Zddes exchangeable proton, which is assigned 10 the OH Jurgen K. Dchnmnn1 proton, a 0SS-C coupling assigned to one of the two CHj protons in the y position, and a* 0.11-G coupling An electron paramagnetic resonance (epr) spectrum assigned to the other CHj proton. The noneqmvrJenct has bee4 studied during the photoiysts of aqueous of these two 7 protons it not surprising, as the coupling solutions of citric acid at room tempenture. Three f«Hi) proton (as well as a 0 protoa) is known to radicals were identified. One is (HO,CCH,),COH, depend upon the steric arrangement of the molecule. fenced from excited citric schJ by s^iuiiti off ihc Hyperime splittings from ' *C in natural abundance central carboxyl group. In a 3.6 A/ solution a* 3I*C the have been studied for several short-lived radicals during C valu* is 2X10314 and there is a 14.52-G hyperfme photolysis in liquids. A strong spectrum of CHjCOO" iptii if»f for four equivalent methylene protons and a was made by photoryiing an aqueous solution con- ; 04? ; spatting for the hydroxyl proton. By addition laming acetate ion and HaO,. WHh a signal aver CM strong mineral acid the hydroxy! proton splitting was ager. »»C coupUngi o{3109 and 13AS G were found reduced to aero. This etTect is caused by aod solution which aiso contained H20*. Photolysis of for CHJCOCHJNOJ " strong enough to see **C tines rijOj gave the reactive OH radical, which quickly without signal averaging was obtained' by photoryznis abstracted a methylene hydrogen of citric acid. With a basic aqueous solution containing acetone and potas the higher radical concentration it was possible to sium nitrite. A single ' 3C coupling of 11.05 G was resolve further hyperfine structure. Measurements were found and assigned to the carbonyl carbon. The acetoin made both in HjO and D20 solutions. A coupling of radical, CHsCOHCOCH,, was studied using the signal 032 G was found for an exchangeable proton and t> averager. The radical was prepared4 by photolysis of assigned to the hydroxyl proton. A coupling of 0.30 G solutions containing 1 or 2% diacetyl in isopropyl was found for two equally coupled protons and is alcohol. In strongly acid solution there is rapid ex assigned to the methylene hydrogens in the position y change4 between tautomeric forms, which causes the to the unnaired electron. two central carbons as well as the two outer carbons to Photolysis of aqueous sodium citrate solutions gave 3 fccont equivalent. A singje l3C coupling of 5.12 G very weak epr spectrum. Only one radical, was found for the rapidly exchanging radical *r>d is "OjCCH2C(OHXCOa")CHC0j", was identified. This attributed to the two central carbons. This radical was radical, like its triply protonated derivative in citric acid also investigated in the absence of acid, where negligible solution, was most likely formed by hydrogen atom exchange occurs. Without exchange all carbons are abstraction (from citrate ion) by a reactive radical. inequivalent. Lines due to ,3C were seen, and or»<; 176 soiifiitig of 7,8 C was evaluated. A provisional coupling PARAMAGNETIC RESONANCE STUDY OF of 10J8 G for another carbon was foand. GAWA-IRRADIATED SINGLE CRYSTALS OF Studies of aqueous solutions of tartaric acid during KHCO, AND KDCO, photolysis wart continued. A radical, all of whose R. W. Hotrnberg eae)ti nyptrtme lines were in emission rather than absotption, had been found and identified5 as An electron paramagiietk resonance (epr) study of H0OCCH(0H)CH(0H). A second radical had been the radicals formed when single crystals of KKCO, and identified' as HOOCCHCHO, and it was postubted that KDCO, are gamma irradiated has been undertaken. the first radical was converted to the second by an Earlier workers' have observed the radicals C02 ~ and aod-catatyaed pinacoMike reananfement similar to that CO, when KHCO, was irradiated at room temperature. found4 for a similar radical produced by removal of a We have not detected C03" when the crystals were hydrogen atom from ethylene glycol. It was believed irradiated at 77°K. TV radical CO,' is formed at the that emission was seen because the radical had some low temperature, but its formation represents only a how been produced with more molecules in the upper nanor fraction of the radiation damage as seen by C|X. electron spin state than in the lower and because the Two new radkats were seen predominantly. One is very fcainrapnaent to form the second radical occurred probably CO,*". Its spectrum in KHCO, consists of a rapidly enough to prevent thermal relaxation processes rng|e broad, slightly anisotropic line which iaturates at from producing the higher equilibrium populati?** of relatively low microwave power. In KDCO, additional the lower electron spin state. Additional observations structure was resolved, presumably arising from weak have now been made in which the pH of the solutions ii^'perfine interactions with several nearby potassium has been varied. This WJS done to change the (add nuclei. The other radical has been tentatively identified catalysed) rate of conversion of HOOCCH(OH)CH(OH) a* (HCO,)j". Such & radical might be formed from the to HOOCCHCHO. When the pH was increased by dimeric pairs of bicarbonate ions in the crystal by loss reducing the concentration of tartaric acid, the emission of an electron. It would thus be analogous Jo the V spectrum was progressively converted to an absorption centers seen in alkali haftde crystals. Its spectrum in spectrum, but at a different rate for the different KHCO, is characterized by a small 1-2-1 hyperfme hyperfme lines. The hither-field hyperfme lines became splitting from two equally coupled protons. absorption lines more quickly. This indicates that they When the crystals were warmed to room temperature, have a shorter thermal relaxation time. As was ex both of these radicals disappeared and CO," grew in. pected, it wav found that when Use spectrum from When crystals of KHCO, which had previously been HOOCCH(OH)CH(OH) was changed to an absorption irradiated and warmed to room temperature were spfcU&s by dilution, it could be converted back to an reirradiated and observed at 77°K, several !np!et-state entsaion spectrum by the addition of strong mineral radicals were seen. These radicals were not detected on Kid. When the pH was lowered the concentration of first irradiation, even when comparable total irradiation HOOCCHCHO increased greatly. This is consistent with doses were given. An analysis of their g and D tensors the more rapid transformation of 1I00CCH(0H)CH(0H) suggests that they are C03"£03" radical pairs. Pre to HOOCCHCHO. sumably the initial radiation forms defect centers which allow C03" radicals to be stably trapped in adjacent sites in the crystal lattice. *G. W. Huntry, A. Honfield, J. R. Morton, and D. H. 'On leave from lnstnut fttr Physflcalische Chemie der Frefcn Whitttn, MoL Phys. 5,589 (1962). Uiitersttat Berlin, Germany. *H. Zddes and R LKingaon, /. Chem. Phys. 45, 1946 (1966). ELECTRON SPECTROSCOPY 3H. Zddes and R. Livingston, J. Am. Chen Sac. 90,4540 (1968). USE OF SOFT X RAYS IN CHEMICAL 4 H. Zeldes and R. Livingston, J. Chem. Phys. 47, 1465 ANALYSIS (1967). SR. Livingston and H. Zetdes, Chem. Dh. Ann. Prop. Rept. T. A. Carlson L. D. Hulett' May 20.1969. ORNL-4437, p. 115. *R. Livingston and H. Zelde*, /. Am. Chem, Soc. 88, 4353 The construction and use of our high-resolution (1966). electron spectrometer has been discussed previously.3 177 In our initial work we used an electron gun for of the motivations cf the study was to determine promoting Auger lines and a gas discharge tube to whether an dectrcn-spectroscopic method could be obtain the narrow helium resonance line for studying used to evaluate the behavior of arsenic in herbicides molecular orbitais. This work is continuing, and, in when exposed to soil. A defoliant containing cacodyiic addition, we are now using an x-ray source for acid, (CHj^AsOOH, was added io soil, which was measuring the inner-shell binding energies of atoms by allowed to stand for a week. The arsenic could be means of the photoelectric effect. observed easily sr.d appeared as a sir^e peak, which The importance of determining the binding energies indicated a single oxidation state. The principal point in the inner shells of atoms as a function of chemical here is that electron spectroscopy offers a good environment has been amply illustrated by Siegbahn opportunity to study what happens to arsenic in various and others.3 The valence shell acts as an outdde environments in situ. potential to the inner shells of an atom. Changes in the In Fig. 736 is shown a plot of the chemical shift of electron density of the valence shell are reflected by bromine in different oxidation states. These da»n are shifts in the binding energies of the inner shells. To compared with those taken for other harides. The measure accurately the binding energy of an inner compounds compared are the alkali metal salts of the atomic shell is to offer a threefold analysis: (1) halides, halites, halates, and perhalates. The solid brie qualitative, each dement is characterized by the binding represents calculations lised on Hartree-Fock wave energies of its atomic shell; (2) quantitative, the relative functions for the free ions analogous to the nominal intensity of the photoelectron is proportional to the oxidation states. These calculations, of course, highly amount of the different dements present; and (3) exaggerate the chemical effect (electrons are not interpretive, in the sense that it yields an evaluation of brought to infinity as suggested by oxidation number). die dcctron density surrounding the atom, or in crude However, by normalizing the calculations at one point, terms its oxidation state. the value for the perchlorate km, the calculations do We have utilized these capabilities in the following explain qualitatively the data for all the halides, application: (i) studies of chemical shifts of the namely, a continuous rise in binding energy as one goes different dements in tKNA and its components, (2) measurements of chemical shifts of arsenic in various oxidation states, (3) studies of chemical shifts in bromine in KBr, KBr03, and KBr04. Item l has been previously discussed in part.4 Here we shall briefly present the data on items 2 and 3. Figure 735 shows a plot of the binding energy (eV) of the 3d shell for a series of arsenic-containing compounds as a function of the "calculated charge** on the arsenic. The "calculated charge" is a value obtained by a method suggested by Siegbahn3 using elec tronegativity differences between arsenic and its neigh boring atoms. A monotonic function is obtained. One 0«NL-0W6T0-369 •2 »3 *4 As 0 2 5 # OXIDATION STATE r s ___. _^*^ ? pSOIL "SAMPLES ^ 1— 4'i°-V- Fig, 7.36, Chemkai SUfts in the Inner-Shell Wooing Energies — 4 »- . of Halogens. £ (-l) arc binding energies taken front data on u. g 3 ~~(CH3)2 As —OH the halides, oxidation state = - i; £g(n) arc the binding energies I /»?s, i taken from the halites (n = +3), halites (n * +i), and peihzlate* < 2 (* = +7). Data on NaCl, NaCIO, NaOOj, and NaCO,. shown —--- 1 i i by o, are from ref. 3; data on KBr, KB1O3, and KB1O4, shown Fig. 737. Chamber foi /Ligalar EMstribvtioa Stadia Used with Electroa Spectrometer. To the teft is the flange which connects to spectrometer. At a 60° angle from the flange is a gas-discharge tube. Diameter of chamber is IS cm. ORNL-CWG. 7D-54I< ~r ' i • i T i • i • i ' i ' I i hv* 21.22 eV x £•188 x I ' » ' <—• •••••!• • » » ' 1 -i1 I1 1I iI I •I iI •I I •I I • I• I• 1• )I _J- I I I I I I II •I I .I I ••••••• I • I • I• * f 40 60 80 100 120 140 160 180 0 20 40 60 80 100 120 140 160 180 0 20 40 60 80 100 120 140 160 180 ANGLE (degrees) ANGLE (degrees) ANGLE (degrees) ' I ' I ' I ' I ' I ' I ' I 1.23 Xe 5P1/2 hv<16.8*eV \^ Qt > I • I • 1 • I, • I . i • I i I • I I • 1 i i • I • i i I i I i I i I i 1 I • ji _ • Ji_ • _'i_ • J_i • i—i i• iI • iI • iI •. 0 20 40 60 80 100 120 140 160 180 0 20 40 60 80 100 120 140 160 180 0 20 40 60 80 100 120 140 160 180 ANGLE (degrees) ANGLE (degrees) ANGLE (Cegrees) Fig. 7.38. Angular Dw*nbation of Photoefectrons Ejected from the Outermost Orbital of Ar, Kr, and Xe. 0 is defined in Eq. (1). The solid line is the best fit given by Eq. (1\ The dotted line corresponds to calculations from ref. 4. 180 measure the angular dependence of the vibrational W. McGowan, D. A. Vroom, and A. R. Comeaux, J. Chem. structure arising from photoionization may prove to be Phys 51,562611969) another important probe into the nature of molecular 5i. T. Manson and J. W. Cooper, submitted to the Phvseccl orbitals. Review. 5J. C. TuUy, R. S. Berry, and B. J. Dalton,Phys. Rev. 176,95 (1968). 6 1 Guest student from the University of Tennessee, Knoxville. B. Schneider and R. S. Berry, P/ry* Rev. 182,141 (1969). 7 2 P. W. Turner. A. D. Baker, C. Baker, and C. R. Brundle, High D. W. Turner and D. P. May,/. Chem. Phys. 45,471 (1966). Resolution Molecular Photoelectron Spectroscopy, Wiley, in preparation. 3 J. Berkowitz and H. Ehrhardt,7%>* .etters 21,531 (1966); MASS SPECTROMETRY AND RELATED J. A. R. Samson. Proc. Roy. Sue. (London) (to be published); J. TECHNIQUES 0RNL-0W3. 70-5409 CHARACTERIZATION OF VOLATILE AND T—' i—•—r ' 1 1 1 1 1 NONVOLATILE SOLIDS OBTAINED I.Ot- FROM THE GAS-PHASE RADIOLYSIS OF PENTABORANE 9' -2 0.81- >- i- 3 v. James W. Pinson P. S. Rudolph z Russell Baldock z 111 >0.4 - Cobalt-60 gamma-ray radiolysis at room temperature 0 ' f.75- of pentaborane-9 (raol. wt 63) in the gas phase 0.2- g produced both volatile and nonvolatile polymeric ; ^*w~ solids. At the completion o~ each radiolysis run, all I 1 L J i I i_ ! J_ 0 20 40 60 80 HJO 120 140 160 ISO solid products were deposited on a 1 .quid-nitrogen- ANGLE (deyees) coded surface. No solid derx ;its on tie glass surface v/ere evident during the radiolysis process. A solid, Fig. 7.39. Aagabr EKrtritatHM of Fhotdectioas Ejected fees: Hi. Transitions are to the v = 2 vibrational level in H2* volatile at room temperature, was separated by standard (which is the most probable transition). The 0 is that calculated vacuum techniques and identified by its physical in ref. 5. properties and its infrared spectrum 2s decaborane-16. C9?:'.-0W3. 70-5407 FIRST iONiZ&TiON POTENTIAL Sr.COND I0N12ATI0N POTENTIAL 0.10 \ ' r "1 * 1 s<»!- -j {" RATIO OF VIBRATIONAL STATES J- • I . I 0 20 43 60 30 100 120 140 160 IflO 0 20 40 60 BC 100 120 140 160 180 ANGLE (degrees) ANGI E (degrees) 0 20 40 6C 80 100 120 140 160 180 C 20 40 60 80 ICO 120 140 inO ISC- AUGLE (degrees) ANGLE (degrws) Fig. 7.40. Angular Distributions of Photoetectrom Ejected from N2. The bottom iwo graphs shcx S» dstri&iiiicn for the fwo ic-ut-bound orbitals. The sottd lines are the best fit using Eq. (1). The dotted line is from theory, ref, 6. The upper two graphs show the relative intensities for transitions to the different vibrational states. 181 This identification was substantiated by differential MOLECULAR BEAM STUDIES thermal analysts (DTA). Nonvolatile solids were sepa rated into a benzene-soluble fraction and an acetone- CROSSED-MOLECULAR-BEAM STUDIES 4 soluble fraction. Thermal-probe mass-spectral analysis CF BIMOLECULAR ASSOCIATION AND of the acetone-soluble fraction, which constituted UNIMOLECULAR DECOMPOSITION r app oximaUly 80% of the solids, revealed three main REACTIONS groups whose major peaks were at m/e values of 101, 115, and 132. Mass-spectral analysis of the benzene- R. E. Minturn Sheldon Datz soluble fraction revealed group* at 125, 180,231,285, Our studies of the association reactions and "sticky ^nd 320. Infrared and DTA analyses indicated five collisions" between amines and BF3 reported pre distinct types of polymers in this fraction. Infrared 5 2 viously * were terminated because we were once again analysis showed R-H apex bonds present in the unable to detect the vibrationaily excited intermediate aceiune-soi'Voie fraction of the nonvolatile soiid indi complex we expected to find. Even following apparatus cating nonmolecclar-type dimeric 'fragments." This modifications that made our detection system some ten bonding was absent in the bcnzene-soluWe fraction of times more sensitive, a signal indicating the existence of die nonvolatile solid and in the B h\ volatile 10 6 a long-lived complex could not be extracted from the fraction. DTA data arc in agreement with this interpre 2 noise background. The anomaly noted in the distri- tation. Additional mass-spectral, infrared, DTA, b»tion of BF molecules elastically scattered by NH thermogravimetric analysis, ana rate studies are being 3 3 was rernoved however, when this experiment was correlated to a previously proposed mechanism.s 4 repeated after the modifications indicated above. The reasons for our repeated failure to observe the predicted excited product molecules from these re 1 Research sponsored jointly with the Ur.^ersity of Southern actions are still not clear, but since many other types of Mississippi, Hattiesburg. interesting reactions do exist which may be more 2 Presented at the 159th National Meeting, American Chemi cal Society, Houston, Tex., Feb. 26, 19 TO. amenable to exploitation by crossed-beam technique?, 3Oak Ridfce Associated Universities Research Participant from we do not plan to pursue the experiment further. the University of Southmi Mississippi, Hattiesburg, summers 1968 and 1969 1R. E. Minturn and S. Date, Chan. Div. Ann. Progr. Rept. Perfoimed by W. T Rainey. Jr.. Analytic*! Chemistry May 20.1968, ORNL-4306, p. 170. Dhrisk-n. 2R. E. Mintum and S. Date, Chent Div. Ann. Progr. Rept 5S. W. Pinson and T. J. Klingen, Gamma-Ray Radiolysis of May 20,1969, ORNL-4437, p. 138. Pentaborane-9 Vapor, abstract PHYS-173, 156th National Meeting, American Chemical Society, Atlantic Chy, NJ..Sept. 8-13 1968. CROSSED-MOLECULAR-BEAM STUDIES OF REACTIONS OF ATOMIC DEUTERIUM WITri HALOGEN MOLECULES George E. Moore Sheldon Datz Robert M. Statnick1 T.ffi TWO-STAGE MASS SPECTROMETER Product DI molecules from the reaction of D atoms Russell Baldock with CH3I were not detected with the general-purpose The two-stage mass spectrometer is being operated in crossed-molecular-beam apparatus, in spite of the im support of the superheavy-elenient program of the provements in signal detection previously described2 Chemistry Division, currently using extracts from care and the elimination of the if interference from the fully selected samples of mica.' Preliminary analyses signal by use of an improved linear amplifier. This result have been made to establish separation procedures, suggests that the yield of product molecules in this sample sizes, and the circumvention of interferences by reaction is too small for detection in our system; impurities. consequently, the reaction of deuterium atoms with a more highly halogenated molecule (such as CBr4 ) might be more suitable for study, since then, at least 1R. V. Gentry, J. W. Boyle, and Russell Baldock. "Studies of intuitively, the probability of collisions of proper steric Pleochroic Haloes," a contribution to Chap. 2, this report. orientation for reaction would be increased.3 182 An investigation of the reaction of thermal deutenem the deuterium atom beam; although the surface re atoms with CBr4 molecules has beer, undertaken. In action still can take place, modulated DBr can result initial experiments the deuterium-atom main beam was only from the gas-phase reaction. IF iulated at 100 Hz, and modulated product DBr was detected using differential pulse counting at m/e = 83. However, a ver> large part of the product DBr was US. Atomic Energy Commission Postdoctoral Fellow under produced not in the gas-phase reaction but in an appointment with Oak Ridge Associated Universities. interaction of modulated gas-phase deuterium atoms 2G. E. Moore, S. Datz, and R. M. Statnick, Ciern Div. Ann. with solid CBr4 (mp 90°), probably at slit edges in the Progr. Rept. May 20, 196C, ORNL-4437, p. 141. scattering or detector chambers. In current experiments 3Chemical intuition may be unreliable. See, for example, P. the cross beam of CBr4 mole ;ules is modulated, but not R. Brooks. J. Chen Phys. 50,5031 (1969). Publications NUCLEAR CHEMISTRY G. Chilosi,1 G. D. O'Kelley, and E. Fichler, 'TheDecay of 8.8-mii 49Ca to Levels in 49Sc,"Nucl. Phys. A136, 649(1969). 5. H. Hamilton,2 F. E. Coffman,2 A. V. Ramayya,2 and N. R. Johnson, "Decay of 74 As," Nucl. Phys. A132, D. G. Sarantites,3 N. R. Johnson, and H. W. Boyd,4 "Levels in *x °Cd Populated in the Decay of 69-min : * °*In," Nucl. Phys. A138,115 (1969). K. S. Toth,s R. L. Hahn, M. F. Roche,5 and D. S. Brenner,6 "New Erbium isotope, l ssEx"Phys. Rev. 183, 1004(1909). K. S. Toth,5 R. L. IIuh:%C. E. Bemis, Jr.,T. H. Handley,7 and M. F. Roche,5 "Search for *72Hf Alpha Sway," J. Inorz. Nucl. Chem. 32,1051 (1970). R. A. Kuebbing,8 "Measurements of Transition Probabilities in Some Middleweight Nuclei," PhD. thesis, Case Western Reserve Univrrsity, Cleveland, Ohio, January 1970. R.L.Hahn, M.F.Roche,5 and K. S. Toth,5 "Alpha Decay of 221\j;'Phys. Rev. 182, 1329(1969). F. Plasil,9 R. L. Ferguson, and H. W. Schmir*,9 "Neutron Emission in the Fission of 2,3Ai," pp. 505-17 in Physics and Chemistry of Fission (P.oc. Second IAEA Symposium, Vienna, Austria, July-August 1969), IAEA, Vienna, 1969. L. H. Niece,10,:' D. E. Troutner,10 and R. L. Ferguson. "Independent Yields of 95Zn from Thermal-Neutron Fission ol 2 3 5 U and 2 3 3U,"Phys. Rev.C\,3\2{\970). J. D. Hastings,1012 D. E. Troutner,10 and R. L. Ferguson, "Fractional Cumulative Yields of ,03Mo, '05Mo, and ' 06Mo from Thwimal-Neutron Induced Fission of 23 s!J," Radiochim. Acta 11,51(1969). N. G. Runnalls,10'13 D. E. Troutner,10 and R. L. Ferguson, "Charge Distribution in Fission: Fractional Cumulative Fission Yields of' 43Ba from Thermal-Neutron-Induced Fission of 23 5 U," Phys. Rev. 179,1188(1969). J. F. Emery,7 J. E. Strain,7 G. D. O'Kelley, and W. S. Lyon,7 "Non-Destructive Neutron Activation Analysis of the Allende Meteorite," Radiochem. RadioanaL Letters 1, 137(1969). 1 Visiting scientist 1964-65; present address: INFN and Istituto di Fisica Superiors. Universiti di Napoli, I taly. 2Physks Department, Vanderbilt University, Nashville, Tenn. 3Chemistry Departr»*-nt, Washington University, St LOWS, MO. 4Oak Ridge /»>«xia ted Universities Research Participant from West Georgia College, CarroMton. s Electronuclear Division. 6Chemistr> Department, Clark University, Worcester, Mass. 7Analytical Chemistry Division. 8Oak Ridge Graduate FeBow under appointment with Oak Ridge Associated Universities. 'Physics Division. l0University of Missouri, Columbia. 1 f Present address: Abbott Laboratories, Chicago, IU. 12 Present address: Mound Laboratory, Miamisburg, Ohio. 13Presem address: Stout State University, Menomonie, Wis. 183 184 G. D. O'Keiley, J. S. Eldridge,7 E. Schonfeld,14 and P. R. Bell,14-15 "Elemental Compositions and Ages of Lunar Samples by Non-Destructive Gamma-Ray Spectrometry," Science 167, 580 (1970). Lunar Sample Preliminary Examination Team (including P. R. Bell,14,15 J. S. Eldridge,7 and G. D. O'Kelley), "Preliminary Examination of Lunar Samples from Apollo 11," Science 16*,) 211 (1%9). Lunar Sample Preliminary Examination Tsam (including P. R. Sell,14'15 J. S. Eldridge,7 and G. D. O'Kelley), Lunar Sample Information Catalog - Apollo II, Science and Applications Directorate, NASA Manned Spacecraft Center, Aug. 31,1969. Lunar Sample Preliminary Examination Team (including P. R. Cell,14'1 s J. S. Eldridge,7 and G. D. O'Kelley), Apollo 11 - Preliminary Science Report, NASA SP-214 (1969). G. D. O'Kelley, J. S. Eldridge,7 E. Schonfeld,14 and P. R. Bell,'4'15 "Primordial Radionuclide Abundances, Solar-Proton and Co«mic-Ray Effects, and Ages of Apollo 11 Lunar Samples by Non-Destructive Gamma-Ray Spectrometry," Geochim. Camochim. Acta, Suppl. 12.1407 (1970). Lunar Sample Preliminary Examination Team (including P. R. B-U.14,!5 J. S. Eldridge,7 V. A. McKay,16 G. D. O'Kelley, and R. T. Roseberry16), "Preliminary Examination of Lunar Samples from Apollo 12," Science 167, 1325(1970). Lunar Sample Preliminary Examination Team (including P. R. Bell,14,! 5 J. S. Eldridge,7 V. A. McKay,16 G. D. O'Kelley, and R. T. Roseberry16), Lunar Sample Information Catalog - Apollo 12, Science and Applications Directorate, NASA Manned Spacecraft Center, Report MSC-01512, Jan. 12,1970. CHEMISTRY AND PHYSICS OF TRANSURANIUM ELEMENTS R. J. Silva, R. L. Hahn, M. L. Maliory, C. E. Bemis, P. F. Dv .ner, 0. L. Keller, J. R. Stokely,7 and K. S. Toth,s "Nuclear Chemistry with the Oak Ridge Isochronous Cyclotron," Proc. Intern. Conf. on the Use of Cyclotrons in Chemistry, Metallurgy and Biology, Oxford, England. 3ept. 22-23,1969. J. Halperin, C. E. Bemis, Jr., R. E. Druschel, and J. R. Stokely,7 "The Thermal Neutron Cross Section and Resonance Integral of 2 5 2Cf," Nud. Sci. Eng. 37,228 (1969). E. T. Chulick,3'17 P. L. Reeder,2 E. Eichler, and C. E. Bemis, Jr., "Redetermination of Delayed Neutrons from 2 5 2Cf," Rauiochim. Acta % 2,'. o4 (1969). O. L. Keller, Jr., J. L. Burnett, T. A. Carlson, and C. W. Nestor, Jr.,18 "Predicted Properties of the Superheavy Elements. I. Elements 113 and 114, Eka-Thallium and Eka-Lead,"./. Phys. Chem. 74, 1127(1970). L. J. Nugent, P. G. Laubereau,19 G. K. Werner,9 and K. L. Vander Sluis,9 "Electron-Transfer Absorption in Some Actinide(IH) and Lanthanide(IU) Tricyclopentadienides and the Standard IMII Cation Oxidation Potentials," Proc. 8th Rare-Earth Research Conference, Reno, Nevada, Apr. 19-22,1970. M. 0. Workman20 and J. H. Burns, ''Studies on the 'Isomeric' Forms of Some 0-Diketone Complexes of Europium(IlI) ana Neodymium(IIi)," Inorg. Chem. 8, 1542(1969). J. H. Burns and M. D. Danford, "The Crystal Structure of Cesium Tetrakis(hexafhioroacety!acetonato)europate and -ai 'cate. Isomorphism with the Yttrate;' Inorg. Chem. 8,1780(1969). P. G. Laubereau19 and J. H. Burns, "Tricyclopentadienyl-curium," Inorg Nucl. Chem. Letters 6, 59 (1970). 4NASA Manned Spacecraft Centei, Houston, Tex. 5 Now of the Director's Division. * Instrumentation and Controls Division. 7Pre,ient address: Texas A & M University, College Station. 'Mathematics Division. Visiting scientist from the Federal Republic of Germany, Bonn. ;0Department of Chemistry, University of Virginia, Charlottesville. 185 P. G. Laubereau19 and J. H. Burns, "Microchemical Preparation of Tricyclopentadienyl Compounds of Berkeiium. Californium, and Some Lanthanide Elements," Inorg. Chenu 9,1091 (1970). ISOTOPE CHEMISTRY D. A. Lee, "Extraction of Lithium Values," VS. Pat. 5,479,147 (Nov. 18,1969). L. L. Brown and J. S. Drury, "Nitrogen Isotope Effects in the Reduction of Nitrate, Nitrite, and Hydroxylamine to Ammonia. II. The MgO and CuS04 Systems,"/. Chem, Phys. 51,3771 (1969). A. C. Rutenberg and J. S. Drury, "Chemical Fractionation oi Uranium Isotopes," J. Inorg. Nucl. Chenu 31, 2289 (19*9). G. M. Begun and R. N. Comp'on,21 "Threshold Electron-Impact Excitation and Negative-Ion Formation in XeF6 and XeF4,"/. Chem. Phys. 51, 2367(1969). RADIATION CHEMISTRY 22 C. J. Hochanadel, J. A. Ghormley, and P. J. Ogren, "Pulse Radiolysis of NO: Production of N02 and N203 and the Production and Relaxation of Vibrational^ Excited NO," /. Chem. Phys. 50,3075 (1969). J. W. Boyle, J. A. Ghormley, C. J. Hochan&ael, and J. F. Riley,23 "Production of Hydrated Electrons by Flash Photolysis of Liquid Water with Light in the First Continuum," /. Phys. Chem. 73, 2886 (1969). C. J. Hochanadel (book review), Radiation Chemistry, vols. I and II, Advan. Chem. Ser. No. 81 (1968), in Nucl. ScLEng. 36,460(1969). G. E. Boyd and Q. V. Larson, "Chemistry of Iodine-128 and Iodine-130 Recoils in Neutron-Irradiated Crystalline K103 and Ki04,"/. Am. Chem, Soc. 91,4639 (1969). G. E. Boyd and L. C. Brown,24 "Investigations on the Thermal and Radiolytic Decomposition of Anhydrous Crystalline KCI02," ' Phys. Chem. 74,1691 (1970). L. C. Brown24 and G. E. Boyd, "Microanalytical Method for Determination of Perbiomate Ion in the Presence of Macro-Amounts of Other Bromine Anions," Anal Chem. 42,291 (1970). ORGANIC CHEMISTRY C. J. Collins and C. E. Harding,25'26 "Ratio of the Rates of Solvent Attack and 3,2-Hydride Shift in the Norbornyl Cation,"/. Am. Chem. Soc. 91,7194(1969). H. Kwart,27 E. N. Givens,28 and C. J. Collins, "The Acetolysis of 3-Phenyl-2-butyIsulfoxonium Ions,"/. Am. Chem. Soc. 91, 5532(1969). C. J. Collins, "Protonated Cyciopropanes," Ckem. Rev. 69, 543 (1969). C. E. Harding,2 5'26 'The Solvolyses of Carbon-14-Labeled 2< A3-Cyclopentenyl)ethyl Tosylates," Ph.D. thesis, University of Tennessee, Knoxville, August 1969. 2' Health Physics Division. "Department of Chemistry, Maiyvilte College, MaryviUe, Tenn. 23Present address: Lockheed Palo Alto Research Laboratory, Palo Alto, Calif. 24 Now of the Isotopes Division. 25Oak Ridge Graduate Fellow from the University of Tennessee, Knoxvflle, under appointment with Oak Ridge Associated Universities. 26Present address: University of Tubingen, Tubingen, West Germany. "Department of Chemistry, Univroity of Delaware, Newark. 28Oak Ridge Graduate Fellow from the University of DeSawaie, Newark, under appointment with Oak Ridge Associated Universities. Itt C. J. Collins, M. D. Eckart,"*2' and V. F. Raaen, "Anion Control of Stereoselectivity During Dearrunations," J. Am. Chem. Soc. 92,1787 (1970). C. J. Collins and B. M. Benjamin, "Concerted, Backside Displacement and Exo:Endo Stereospecifkity on Dcamination of Substituted Norbornylamines,**/. Am. Chem. Soc. 92,3182 (1970). B. M. Benjamin and C. J. Collins, "Wagner-Meerwein Rearrangements of Substituted Classical Norbomyl Cations,"/. Am. Chem. Soc. 92,3183 (1970). PHYSICAL CHEMISTRY Y. C. Wu,30 R. M. Rush, and G. Icatchard,3" "Osmotic and Activity Coefficients for Binary Mixtures of Sodium Chloride, Sodium Sulfate, Magnesium Sulfate, and Magnesium Chloride in Water at 25°. II. Isopiestic and Electromotive Force Measurements on the Two Systems Without Common Ions,"32 /. Phys. Chem. 73, 2047,4434 (1969). to. U. Lietzke and R. W. Stoughton, "Electromotive Force Studies in Aqueous Solutions at Elevated Temperatures. XI. The Thermodynamic Properties of HCl-LiCl Solutions,"/. Tenn. Acad. Set 44,66 (1969). M. H. Lietzke and R. W. Stoughton, "Electromotive Force Studies in Aqueous Solutions at Elevated Temperatures. XII. The Thermodynamic Properties of HCl-CsCl-BaCl2 Mixtures,"/. Inorg. Nucl Chem. 31, 3481 (1969). R. 1. Beshinske33 and M. H. Lietzke, "Monte Carlo Calculation of Some Thermodynamic Properties of Steam Using a Dipole-Quadrupole Potential," /. Chem. Phys. SI, 2278 (1969). H. B. Hupf,34 "The Thermodynamic Properties of Aqueous Hydrochloric Acid-Cesium Chloride—Barium Chloride Mixtures,** PhD. thesis, University of Tennessee, Knoxville, June 1969. F. Vadov, "The Apparent Molal Volumes of the Lithium and Sodium Halides. Critical-Type Transitions in Aqueous Solution,**/. Phys. Chem. 73,3745 (1969). S. Lindenbaum, L. Leifer,35 G. E. Boyd, and J. W. Chase,36 "Variation of Osmotic Coefficients of Aqueous Solutions of Tetra-rt-alkylamnionium Halides at 25 and 65°C,"/. Phys. Chem. 74,761 (1970). S. Lindenbaum, "Heats of Dilution at 25° of Aqueous Solutions of the Bolaform Electrolyte [Bu^N^CHj),- NBu3JX2,"/. Phys. Chem. 73,4334(1969). G. E. Boyd, Thmnal Effects in Ion Exchange Reactions with Organic Exchangers: Enthalpy and Heat Capacity Changes,** Proc. Intern. Conf. on Ion Exchange in the Process Industries, Society of Chemical Industry, London (1970). G. E. Boyd and J. Schubert,37 'The First Use of Organic and Inorganic Ion Exchangers for Separating Plutonium from Uranium and the Fission Products,** Progress in Nuclear Energy, Series III, vol. 4, pp. 319-44, Pergamon, London, 1969. "Present address: Tennessee Eastman Cap., Kingsport, Tenn. 30Piesent address: National Bureau of Standards, Washington, D.C. 3'Consultant; Ptoiessor of Physical Chemistry, Emeritus, Massachusetts Institute of Technology, Cambridge. "Research jointly sponsored by the Office of Saline Water, VS. Department of the Interior, and the VS. Atomic Energy Commission under contract with Union Carbide Corp. and under Contract No. AT-(30-l>-905 with the Massachusetts Institute of Technology. "Department of Chemist:y, St, John's University, Jamaica, N.Y.; present address: RCA Research Laboratories, Princeton, N J. 34Isotopes Division; present address: The Medical School, University of Miami, Miami, FU. 35Michigan Technological University, Houghton. 36 Xerox Corporation Research Laboratories, Rochester, N.Y. "University of Pittsburgh, Pittsburgh, Pa. 187 S. B. Sachs.38 W. H. Baldwin, and J. S. Johnson. "Hyperfiltration Studies XVI: Salt Filtration by Dynamically Formed and Cast Poly C. J. Barton,42 M. A. Bredig, L. 0. Gilpatrick.4 2 and Judy A. Fredericksen,44 "Solubility o Cerium Trifluoride in Molten Mixtures of Lithium, Beryllium, and Thorium Fluorides," Inorg. Chem. 9,307 (1970). M. A. Bredig, 'The Experimental Ev: Icnce for 'Complex Ions' in Some Molten Salt Mixtures," book chapter in Molten Salts: Characterization and Analysis, ed. by Gleb Mamantov, Marcel Dekker, New York-London, 1969. G. H. Cartiedge, ''Kinetics of Charge and Discharge of the Film on Superpassive Iron," Chimia (Aarau) 23,450 (1969). CHEMICAL PHYSICS J. E. Worsham, Jr.,45 and W. R. Busing, "The Crystal Structure of Uranium Nitrate (Urea Nitrate) by Neutron Diffraction," Acta Cryst. B25,572 (1969). G. M. Brown, "The Crystal and Molecular Structure of 6-Mercaptopurine Monohydrate. A Second, Independent X-Ray Diffraction Determination " Acta Cryst. B25,1338 (1969). G. R. Freeman,8 "The Crystal and Molecular Structures of Tri-(p-fluorophenyl)-amine and Tri-(p-iodophenyI)- amine," PhD. dissertation, North Texas State University, Denton, January 1970. A. H. Narten and H. A. Levy, "Observed Diffraction Pattern and Proposed Models of Liquid Water," Science 165,447(1969). A. H. Narten and H. A. Levy, "Structure of Water," Science 167,1520 (1970). A. H. Narten and S. Lindenbaum, "Diffraction Pattern and Structure of the System Tetra-n-butylammonium Fluoride-Water at 25°C,"/ Chem. Phys. 51,1108(1969). A. H. Narten. "Diffraction nattern and Structure of Aqueous Ammonium Halide Solutions,"/. Phys. Chem. 74, 765(1970). W. C. Waggener, A. J. Weinberger, and R. W. Stoughton, "The Near-Infrared Spectrum of Liquid Hydrogen Sulfide,' I Phys. Chem. 73,3518(1969). 46 M. H. Brooker A. S. Quist, and G. E. Boyd, "Raman Spectrum of Molten NaN03," Chem. Phys. Letters 5, 357(1970). Visiting scientist from the Weizmann Institute of Science, Rehovoth, Israel; present address: Gulf General Atomic, San Diego, Calif. 39Research sponsored jointly by the Office of Saline Water, U.S. Department of the Interior, and the U.S. Atomic Energy Commission under contract with Union Carbide Corp. 40Director*s Division. 4' Present address: Technical Center, Union Carbide Corp., South Charleston. W.Va. 42 Reactor Chemistry Division. 43Based on work sponsored by the Office of Saline Water, U.S. Department of the Interior. 44Oak Ridge Associated Universities Research Participant from St. Cloud State College, St. Cloud, Minn. 4SChemistry Department, University of Richmond, Richmond, Va. 4 Postdoctoral Research Fellow from the National Research Council of Canada. 188 R. W. Hcimberg, "ESR Study of HCO in Single Crystals of Formic Acid at 77°K, J. Chan. Phys. 51. 3255 (1969). Z. Luz,47 A. Reuveni,47 R. W. Hofanberg, and B. L. Silver,4* "ESR of' 70 T. A. Carlson, C. W. Nestor. Jr.,1 * F. B. Malik,5' and T. C. Tucker,1 • "Calculations of K, L, M, and N Binding Energies and K X-Rays for Elements from Z = 96-120," NucL Phys. A135,57 (1969). M. 0. Krause,52 F. A. Stevie,53 L. J. Lewis,5 * T. A. Carlson, and W. E. Moddeman,55 "Multiple Excitation of Neon by Photon and Electron Impact," Phys. Letters 31 A, 81 (1970). T. A. Carlson, W. E. Moddeman,5 5 and M. O. Krause,53 "Electron ShakeOff in Neon and Argon as a Function of Energy of the Impact Electron," Phys. Rev. A 1,1406(1970). T. A. Carlson, W. E. Moddeman,5 5 B. P. Puflen,25 •** and M. O. Krause,52 "Identification of High Energy Lines in the AM/, Auger Spectrum of N2," Chem. Phys, Letters 5f 390(1970). B. P. Pullen,2 5 *5* "The Construction and Use of a High Resolution Photodectron Spectrometer," PhD. thesis, University of Tennessee, KnoxvOlc, February 1970; ORNL-TM-2794 (February 1970). F. Schmidt-Bleek,57 G. Ostrom,57 and S. Datz, "Hot' Atomic Halogen Beams from Sputtering of Stiver HaUdes,"/?ev. Set Instr. 40,1351 (1969). 47The Weizmann Institute of Science, Rehovoth, Israel. 48Techmon, Haifa, IsaeL 49SoM State Division. 50Metab and Ceramics Division. 1 Physics Department, Indiana University, BkKHrangton. "Thermonuclear Division. 53USA£C FeBow in Health Physics from Vanderbflt University, NashvMe, Tenn. 54Su.nmer student from Morehouse College, Atlanta, Ga. S5Graduate student from the University of Tennessee, Knoxvile. 56Present address: Department of Physical Science, Southeastern Louisiana State College, Hammond. "Department of Chemistry, Purdue University, Lafayette, Ind.; present address: Department of Chemistry, University of Tennessee, Knoxvile. Papers Presented at Scientific and Technical Meetings NUCLEAR CHEMISTRY F. E. Coffman,*' J. H. Hamilton,1 A. V. Ramayya,1 and N. R. Johnson, "Zero Spin for the 1482.6-keV Level in 74Ge from 7-7(0)," International Conference on Properties of Nuclear States, Montreal, Canada, Aug. 25-30,1969. L. L. Riedinger,*2'3 E. Eichler, V. Fuglsong,4 G. Hagemann* and B. Herskind4 "Coulomb Excitation of iS4Gd and "6Er," International Conference on Nuclear Reactions Induced by Heavy Ions, Heidelberg, Germany, July 15-18,1969. K. S. Toth,*5 R. L. Hahn, M. A. Ijaz,6 and W. M. Sample,6 "New Isotopes: 's *Er,'56Yb, and '57Yb," 1970 Spring Meeting, American Physical Society, Washington, D.C., Apr. 27-30, 1970; Butt. Am. Phys. Soc. 15, 645 (1970). R. G. Lanier,*7 •» R. A. Meyer,» J. B. Ball.5 N. R. Johnson, G. D. O'KeUey, and R. K. Sheline,10 "Levels in i61Tb Excited by the (3 He//) Reaction," 1970 Spring Meeting, American Physcal Society, Washington, D.C., Apr. 27-30, l970;BuBAm, Phys. Soc. 15,552 (1970). J. H. Hamilton,*1 P. E. Little,1 A. /. Ramayya,1 and N. R. Johnson, "M\ Admixtures ii. the 2+{fi) -+ 2* Transition in ' 78Hf," 1970 Spring Meeting, American Physical Society, Washington, D.C, Apr. 27-30,1970; Butt. Am. Phys. Soc. 15,524(1970). P. E. Little,*1 J. H. Hanuiton,1 A. V. Ramayya,1 and N. R. Johnson, "Decay of 178Ta,M 36th Meeting, Southeastern Section, American Physical Society, University of Florida, Gainesville, Nov. 6—8, 1969; Butt. Am. Phys. Soc. 15,179(1970). N. R. Johnson, "Applications of Quantitative Gamma-Gamma Coincidence Measurements," International Conference on Radioactivity in Nuclear Spectroscopy, Vanderbilt University, Nashville, Term., Aug. 11-15, 1969 (invited). J. H. Hamilton,*' N. R. Johnson, L. L. Riedinger,2'3 D. J. McMillan,1 A. F. Kluck,2 and L. C. Whitlock,1 "Systematics of Kit — 0" and 1 ~ Octupole Bands in Transitional Nuclei," International Conference on Properties of Nucleai States, Montreal, Canada, Aug. 25-30,1969. R. L. Ferguson, Franz Plasil,11 G. D. Alam,12 and H. W. Schmitt,*11 "Fragment Energy Correlation Measurements in the Fission of Spontaneously Fissioning Isomers," 1970 Spring Meeting, American Physical Society, Washington, D.C., Apr. 27-30,1970; AtflL Am. Phys. Soc. 15,648 (1970). •Speaker. 1 Physics Department, Vanderbflt University, Nashviiie, Term. 2Oak Ridge Graduate Felov. from Vandcrbilt University, Nashvik, Term., under appointment with Oak Ridge Associated Universities. 3Prese-ii address: Physics Department, University of Notre Dame, Notre Dame, Ind. 4 Niels Bohr '"tfitute, University of Copenhagen, Copenhagen, Denmark. Etectronucleai Division. 6Physk$ Department, Virginia Polytechnic Institute, Blacksburg. 7U.S. Atomic Energy Commission Postdoctoral Fellow under appointment with Oak Ridge Associated Universities. ^Present address: Lawrence Radiation Laboratory, Livermore, Canf. 9 Lawrence Radiation Laboratory, Livermore, Calif. I "Florida State University, Tallahassee. II Physics Division. 12Guest Scientis* fror.. PINSTECH. P.O. Nilore, Rawalpindi, Pakistan. 189 190 G. D. Alan,*12 R. L. Ferguson, Franz Plasfl,11 H. Roesler,13 and H. W. Schmitt,11 "Fragment Energy Correlation Measurements for Neutron Induced Fission of 234U ss a Function of Neutron Energy," 1970 Spring Meeting, Aurcrican Physical Society, Washington, D.C., Apr. 27-30, \910,BulL Am. Phys. Soc. IS, 648 (1970). G. D. O'KeOey,* J. S. Eldridge,14 E. SchonfeM,1 s and P. R. BeD,1 s>1 * "ElemenUl Compositions and Ages of Lunar Samples by Non-Destructive Gamma-Ray SpectroniCtry " Apollo 11 Lunar Science Conference, Houston, Tex., Jan. 5-8,1970. G. D. O'KeBey, "Preliminary Gamma-Ray Spectrometry Results on Apollo 12 Samples," Apollo 11 Lunar Science Conference, Houston, Tex., Jan. 5-8, 1970. G. D. O'Kebey, "Preliminary Examination of Lunar Samples from Apollo 11," Tennessee Academy of Science, Seventy-Ninth Meeting, Sewanee,Tenn.,Nov. 21-22,1969. G. D. OTCefley,* J. S. Eldridge,14 E. Schonfdd,15 and P. R. Befl,151* "Comparative Radionuclide Concentrations of Apollo 11 and Apollo 12 Samples by Non-Destructive Gamma-Ray Spectrometry,'' American Geophysical Union, Fifty-First Annual Meeting, Washington, D.C., Apr. 20-24,1970. CHEMISTRY AND PHYSICS OF TRANSURANIUM ELEMENTS C. E. Bonis, Jr., "Nuclear Structure Studies in the Transuranium Region at ORNL," 158th National Meeting, American Chemical Society, New York, Sept 7-12,1969; abstract NUCL-78 (invited). R. J. Suva, R. L. Hahn,* O. L. Keller, K. S. Tom,5 M. L. MaDory, M. F. Roche,5 C. E. Bemis, and P. F. Dittner, "Nuclear Chemistry Kith Heavy Ions at ORNI," 158 th National Meeting, American Chemical Society, New York, Sept. 7-12,1969; abstract NUCL-46 (invited). R. J. Suva, R. L. Hahn, M. L. Mattory,* C. E. Bemis, P. F. Dittner, O. L. Kefler, J. R. Stokery,14 and K. S. Toth,5 "Nuclear Chemistry with the Oak Ridge Isochronous Cyclotron," International Conference on the Use of Cyclotrons in Chemistry, Metallurgy, and Biology, Oxford, England, Sept. 22-23,1969. O. L. Keller, Jr., "Actinide and Transactinide Elements Production and Research at Oak Ridge," Robert A. Welch Foundation Conferences on Chemical Research. XIII. The Transurzur^m Elements - The Mendeleev Centennial, Houston, Tex., Nov. 17-19,1969. M. R. Schmorak,17 C. E. Bemis, Jr.,* and M. J. Zender,1 * "Levels in 24°Pu Populated in the Decay of 240mNp and in the Alpha Decay of 244Cm," International Conference on Radioactivity in Nudear Spectroscopy: Nuclear Techniques and Applications, Vanderbflt University, Nashville, Term., Aug. 11—15,1969. M. R. Srhmorak,*17 C. E. Bemis, Jr., M. Zcnder,18 F. Coffman,1 A. Ramayya,1 and J. H. Hamilton,1 "A Two-Phonon Octupole Vibrational Band in 240Pu," 1970 Spring Meeting, American Physical Society, Washington, D.C., Apr. 27-30, l970;ButL Am. Fhys. Soc. 15,547 (1970). R. E. Dmschel,* J. Halperin, and C. E. Bemis, Jr., "Half Lives of 2 s 3Cf and 2 53 Es," 21st Southeastern Regional Meeting, American Chemical Society, Richmond, Va., Nov. 5-8,1969; abstract No. 42. L. J. Nugent, P. G. Laubereau,*1 * G. K. Werner,1' and K. L. Vander Shiis,1 f "Electron-Transfer Absorption in Some Actinide(III) and Lanthanide(III) Tricyclopentadienides and the Standard II-FII Cation Oxidation Potentials," 8th Rare-Earth Research Conference, Reno, Nev., Apr. 19-22,1970. Guest scientist from Techrasche Hochschule, Munich, Geimany. 14Analytical Chemistry Division. 15NASA Manned Spacecraft Center, Houston, Tex. 16Ncw of the Director's Division. 17Nncleai Data Group. 18Oak Ridge Associated Universities Research Participant from Fresno State College. Fresno, Calif. 19 Visiting scientist from *he Federal Republic of Germany, Bonn. 191 L. J. Nugent, M. W. Swagel,20 and F. M. Johnson,20 "Laser-Induced Single- and Double-Photon Excitation and Dissociation in Gaseous Nitrous Oxide" (by abstract only), 36th Meeting. Southeasterr. Section, American Physical Society, University of Florida, Gainesville, Nov. f. -8,1969, BuH Am. Phys. Soc. 15,164(1970). 2 J. H. Bums* and J. R. Peterson, ' "On the Structures of AmCl3 and CfCl3 and the Ionic Radii ci Aconide Elements," American Crystallographic Association, Winter Meeting, New Orleans, La., Mar. 1-5,1970. C. E. Bemis, Jr., "Performance and Operating Experience with the Oak Ridge National Laboratory ISO-cm Sector Separator," Third American Electromagnetic Isotope Separator Symposium, Brookhavt National Labora tory, Upton, N.Y., Sept. 16-17,1969 (invited). ISOTOPE CHEMISTRY G. M. Begun, "Simple Modification of the Cary Model-Si Raman Spectrophotometer to Permit Use of Laser Light Sources," International Conference on Raman Spectroscopy, Carieton University, Ottawa, Canada, Aug. 4—7, 196*;. RADIATION CHEMISTRY 32 R. W. Matthews,* H. A. Mahbnan, and T. J. Sworski, "Kinetic EvHencc for a Primary Yield of N03 Radicals in the Radiorysis of Aqueous Nitric Acid Solutions," XXII International Congress of Pure and Applied Chemistry, Sydney, Australia, Aug. 20-27,1969. G. E. Boyd, "Recoi and Radiation Chemistry of the Crystalline Alcali-Metal Habtes and Perhalates," International Symposium on Chemical Effects of Nuclear Transformations, Cambridge, England, Jury 1-3, 1969 (invited). PHYSICAL CHEMISTRY G. Scatehard,*23 R. M. Rush, and J. S. Johnson, 'The Excess Free Energy and Related Properties of Electrolyte Solutions,'' symposium on Structures of Water and Aqueous Solutions in honor of T. F. Young, University of Chicago, Chicago, ID., June 16-18,1969 (invited). R. M. Rush and J. S. Johnson,* "Isopiestk Studies on Mixed Perchlorate Solutions," Symposium on Electrolyte Solutions, Middle Atlantic Regional Meeting, American Chemical Society, Newark, Dei, Apr. 1-3,1970 (invited). G. E. Boyd, Thermal Effects in Ion Exchange Reactions with Organic Exchangers: Enthalpy and Heat Capacity Changes," Internatioril Conference on Ion Exchange in the Process Industries, Society of Chemical Industry, Lond,.,, England, July 16-18,1969 (invited). G. E. Boyd, "Volume Changes in Ion Exchange Reactions," Gordon Research Conference on Ion Exchanp*, Meriden,NJl., Aug. 18-22,1969(invn\-d). K. Bunzl*24 and G. E. Boyd, "Donnan Equilibrium in Ion Exchangers," Second Symposium on Ion Exchange, Hungarian Chemical Society, Balatonszeplak, Hungary, Sept. 10-14,1969 (invited). F Nelson, "Some Observations on Mass Transport in Ion Exchange Columns," Gordon Research Conference on Ion Exchange, Meriden, NJi., Aug. 18-22,1969 (invited). 22 Xerox CorpJEOS Division. Research sporuored by Edgewood Arsenal, VS. Army. 21 Department of Chemistry, University of Tennessee, Knoxvilli. 22 Visiting scientist from the Australian Atomic Energy Commission Research Establishment, Lucas Heights, New South Wales. 2 Consultant; Professor of Physical Chemistry, tmeritu*, Massachusetts Institute of Technology, Cambridge. 24Visiting scientist from Gesc'bctuft f. Strahlenforschung MBH, Munich, Germany. 192 R. A. Gilbert, R. H. Busey, C. W. Linsey,25*2* and R. B. Escue,*27 "Calorimetric Melting Points and Heats of Fusion for Lead Halides," 158th National Meeting, American Chemical Society, New York, Sept. 7-12, 1969; abstract INOR-30. R. H. Busey,* C. W. Linsey,25'2* and R. B. Escue,27 "High Temperature Enthalpies of Lead Halides," 24th Annual Calorimetiy Conference, Portsmouth, Nil., Oct. 14-16,1969. F. A. Posey, "Corrosion Processes in Restricted Geometries," Advanced Short Course in Aqueous Corrosion, Ohio State University, Cohimbus, Oct. 29,1969 (invited). CHEMICAL PHYSICS W. R. Busing, "Least-Squares Refinement of Lattice and Orientation Parameters for Use ir Automatic Diffractomeiry," international Summer School on CrysUllographk Computing, International Union . f Crystal lography Commission on CrystaUographic Computing, Carleton University, Ottawa, Canada, Aug. 4-12, 1969 (invited). V. \. Agroa and W. R. Busing,* MA Neutron Diffraction Study of Magnesium Chloride Hexahydrate,** Eighth General Assembly and International Congress, International Union of Crystallography, Buffalo, Stony Brook, and Upton, NX, and Washington, D.C.y Aug. 7-24,1969. W. R. Busing, "An Interpretation of the Structures of Alkaline Earth Chlorides in Terms of Interionic Forces," American CrystaDographk: Association Winter Meeting. Tulane University, New Orleam, La., Mar. 1 - S, 1970. C. K. Johnson, "Introduction to Thermal-Motion Analysis," "The Effect of Thermal Motion on Interatomic Distances and Angles," "Higher Order Statistical Models for Thermal Motion,** and "Drawing Crystal Structures by Computer," International Summer School on CrystaUographic Computing, International Union of Crystallography Commission on Crystaflographic Computing, Carleton University, Ottawa, Canada, Aug. 4—12,1969 (imr.ted). C. K. Johnson, "Kinematics of Molecular Motion in Crystals,** Eighth General Assembly and Irternational Congress, International Union of Crystallography. Buffalo. Stony Brook, and Upton, N.Y., and Washington, D.C., Aug. 7-24, !969 (invited). C. K. Johnson, "Series Expansion Models for Thermal Motion," American C.ystallographic Association Winter Meeting, Tulane University, Ne*v Orleans, La., Mar. 1-5,1970. G. M. Brown, "Nsutron Diffraction in the Studv of Carbohydrates,** Gordon Research Conference on the Chemistry of Carbohydrates, Tilton School, THton, N.H., June 9-13,196S (invited). G. M. Brown* and R. Chidambaram,28 "A Model for Torsional Oscillators in Least-Squa.es Refinement,** Eighth General Assembly and International Congres, International Union of Crystallography, Buffalo, Stony Brook, and Upton, N.Y., and Washington, D.C., Aug. 7-24,1969 (invited). G. R. Freeman,*25'29 H. A. Levy, and G. M. Brown, "Crystal and Molecular Structures of Tra>- fhiorophenyl)amine and Tri(/Modophenyl)amine,** Eighth General Assembly and International Congress, Inter national Union of Crystallography, Buffalo, Stony Brook, and Upton, N.Y., and Washington, D.C., Aug. 7-24,1969. G. M. Brown* and W. E. Tluessen," "The Crystal Structure of Sedoheptulosan Monohydrate," Eighth General Assembly and International Congress, International Union of Crystallography, Buffalo, Stony Brook, and Upton, N.Y., and Washington, D.C., Aug. 7-24,1969. "Oak Ridge Graduate Feflow from North Texas State University, Denton, under appointment with Oak Ridge Associated uunremues. 2*Present address: Ertporia Colege, Emporia, Kan. 27Chenu*try Department, North Texas State University, Denton. "Visiting scientist 1964-65 fromBhabha Atomic Research Centre, Trombay, Bombay-74, India. 29fresent address: University of Alabama in Birmingham, University of Alabama Medical Center, Birmingham. 30NatJonal Institute of Health Special Postdoctoral FeBow. 193 H. A. Levy.* W. E. Thiessen, and G. M. Brown, "A Least-Square; Method for Converting Observed Intensities to Normalized Structure Factors," American Crystallcgraphic Association Winter Meeting. Tulane University. New Orleans, La., Mar. 1-5,1970. W. E. Thiessen,30 "Structure and Stereochemistry of a- and 0-Cubebene from u> Crystal Strucrare of Nor-0- cubebone," Eighth General Assembly and International Congress, International Union of Crystallography, Buffalo, Stony Brook, and Upton, N.Y., and Washington, D.C., Aug. 7-24,1969. W. E. Thiessen,30 "The Addition Product of an Isocyanide with a Steroidal a./RJnsaturated Ketone: Structure Determination," American Crystallographic Association Winter Meeting, Tulane University, New Orleans, La., Mar. 1-5,1970. A. H. Narten* and H. A. Levy, "Observed Diffraction Pattern and Proposed Models of Liquid Water," Eighth General Assembly and International Congress, International Union of Crystallography, Buffalo, Stony Brook, and Upton, N.Y., and Washington, D.C., Aug. 7-24,1969 (invited). 31 C. Foker* and A. H. Narten, "X-Ray Dirraction Pattern and Structure of Molten (CH3)3N10.13 H20 at 5°C," Eighth General Assembly and International Congress, International Union of Crystallography, Buffalo, Stony Brook, and Upton, N.Y., and Washington, D.C., Aug. 7-24,1969. A. H. Narten, "Diffraction Pattern and Correlation Functions of Liquid Gallium," Gordon Research Conference on the Chemistry and Physics of Liquids, Hokkrness, Nil., Aug. 11-15,1969. A. H. Narten, "Diffraction Pattern and Structure of Aqut Halide Solutions," 158th National Meeting, American Chemical Society, New York, Sept. 7-12,1969; abstract ?h /S-227. Ralph Livingston, "Paramagnetic Resonance of Liquids During Photolysis," Southeastern Magnetic Resonance Conference, Huntsville, Ala., Sept. 25-26,1969 (invited). B. P. Puflen,*32'33 T. A. Carlson, W. E. Bull,21 and G. K. Schweitzer,21 "Photoefectron Spectroscopy of Fhiorinated D3h, Td, />_£, Oht and C3w Symmetry Group Compounds," 158th National Meeting, American Chemical Society, New York, Sept. 7-12,1969; abstract PHYS-176. W. E. Moddeman,34 B. P. Pullen,*32'33 T. A. Carlson, W. E. Bull,2' and G. K. Schweitzer,2 • "Photoetectron Spectroscopy of Group IV A Td and C3r Symmetry Group Compounds," 158th National Meeting, American Chemical Society, New York, Sept 7-12,1969;abstract PHYS-177. W. E. Moddeman,*34 T. A. Carlson, B. P. Pullen,32'33 and M. 0. Krause,35 "Auger Spectra of Simple Molecules," 158th National Meeting, American Chemical Society, New York, Sept. 7-12,1969; abstract PHYS-178. T. A. Carlson, B. P. Pullen,32'33 W. E. Moddeman,*34 M. 0. Krause,35 and F. W. Ward,3' "A High Resolution Electron Spectrometer for Photodectron and Auger Electron Studies," 158th National Meeting, American Chemical Society, New York, Sept. 7-12,1969; abstract PHYS-179. M. O. Krause,*3 $ F. A. Stevie,3 7 L. J. Lewis,38 T. A. Carlson, and W. E. Moddeman,34 "Multiple Ionization of Neon by Electron and Photon Impact," 22nd Conference on Gaseous Electronics, American Physical Society, Gatlinburg, Tenn., Oct. 29-31,1969. Crystallography Laboratory, University of Pittsburgh, Pittsburgh. Pa. 32Oak Ridge Graduate Felow from the University of Tennessee, Knoxvale. uno>r «*«pointt»eu? with Oak Ridge Associated Universities. 33 Present address: Department of Physical Science. Southeastern Louisiana State C'oMege, Hammond. 34Graduate student from the Univsrsiry of Tennessee. Knoxvflle. 3 $Thermonuclear Division. 3*Pbnt and Equipment Division. 37U«S. AEC Felow in Health Physics from Vanderbilt University, Nashvlk, Tenn. 3SSummer student from Morehouse Cofege. Atlanta. Ga. 194 T. A. Carbon, "Determination of Electron Structure in Molecules by Means of High Resolution Electron Spectroscopy,** 27th Annual Pittsburgh Diffraction Conference, Pittsburgh, Pa., Nov. 5-7,1969 (invited). B. P. PuBen,32'33 T. A. Carlson, G.K.Schweitzer,*21 and W. E. Bull,21 "High Resolution Electron Spectrometry for Study of Electronic Structure of Molecules,** 21st Southeastern Regional Meeting, American Chemical Society, Richmond, Va., Nov. 5-8,1969; abstract No. 32S. 32 33 2 21 B. P. Puhen, « T. A. Carlson, W. E. Bull, ' and G. K. Schweitzer,* "The Photoelectron Spectra of CH3C1 and CF3C1,** 21st Southeastern Regional Meeting, American Chemical Society, Richmond, Va., Nov. 5-8, 1969; abstract No. 326. T. A. Carlson, "Scope of High Resolution Electron Spectroscopy in Chemical Analysts,** Eastern Analytical Symposium, New York, Nov. 19-21,1969 (invited). L. D. Hulett*14 and T. A. Carlson, "The Analysis of Compounds of Biological Interest by Electron Spectroscopy,** Second Annual Symposium on Automated High Resolution Analysis in the Clinical Laboratory, Oak Ridge National Laboratory, Oak Ridge, Tenn., Mar. 12-13,1970. T. A. Carlson, "High Resolution Auger and Photoelectron Spectroscopy,** International Symposium on Photoelectron Spectroscopy, University of Tennessee, KnoxvOle, May 14-15,1970 (invited). J. W. Pinson*39 and P. S. Rudolph, "Characterization of Volatile and Nonvolatle Solids Obtained from the Gas Phase Radiolysis of Pentaborane-9," 159th National Meeting, American Chemical Society, Houston, Tex., Feb. 26, 1970; abstract PHYS-100. S. Datz, "Molecular Beam Experiments on Inelastic Scattering,** Gordon Research Conference on In'ermolecular Energy Transfer, Andover, Nil., June 16-20,1969. F. Schmidt-BIeek,*40 G. Ostrom,40 and S. Datz, "An Atomic Halogen Beam Source for the 0.1 to 10 eV Region," 5th International Hot Aiusr. Chemistry Symposium, Cambridge, England, July 3-5,1969. P. F. Diitnn* and S. Datz, "Inelastic Scattering of Afkali Atoms and Ions from Hydrogen Molecules,** V7th Intemr'ional Conference on the Physics of Electronic and Atomic Collisions, Cambridge, Mass., July 28-Aug. 2, 1969. S. Datz,* C. D. Moak,11 B. R. Appleton,41 M. T. Robinson,41 and O. S. Oen,41 "Energy Dependence of Channeled Ion cr%ergy Loss Spectra,**42 Conference on Atomic Collision Phenomena in Solids, Sussex,England, Sept. 7-12,1969. F. Schmidt-Bleek,*40 G. Ostrom,40 and S. Datz, "Hot Halogen Atoms from Sputtered T»:get$,' 21st Southeastern Regional Meeting, American Chemical Society, Richmond, Va., Nov. 5-8,1969; abstract No. 102. Oak Ridf? Associated Universities Research Particspant from the University of Southern Mississippi, Hattiesbuig. 40Depc/tmet.t of Chemistry, Punh.c University, Lafayette, Ind.; present address: Department of Cktorotry, University of Tennessee, Knoxvlle. 41 Solid State Division. 42CoRabontire with Sofd State Division. Lectures NUCLEAR CHEMISTRY E. Eichler, "Nuclear Chemistry Research at ORNL," Swedish Research Council Laboratory, Studsvik, Sweden, Mar. 10,1969. E. Eichler, "Nuclear Spectroscopy in the A = 90 Region," Instituut voor Kernfysisch Onderzoek, Amsterdam, Netherlands, May 21,1969. E. Eichler, "The Use of the (p,ny) Process in Nuclear Spectroscopy Studies," Istituto di Fiska Superiore di Firenze, Florence, Italy, Jury 21,1%9. E. Eichler, "Nuclear Spectroscopy," Istituto di Fiska Superiore dell Universita di Napoli, Italy, July 28,1969. N. R. Johnson, "Some Aspects of Vibrational Behavior in Deformed Nuclei," Seminar, Michigan State University, Lansing, Mar. 18,1970. G. D. O'Kelley, "Preliminary Examination of Lunar Samples from Apollo 11," Meeting of Directorr of Industrial Research, New York, Sept. 26, 1969; Analytical Group, East Tennessee Section, American Chemical Society, Oak Ridge, Tenn., Oct 24,1969; Department of Chemistry, University of Tennessee, KnoxviHe, Nov. 17,1969. G. D. O'Kelley, "The Origin and History of the Moon from Studies of Lunar Samples from Apollo 11 and Apollo 12," National Science Foundation In-Service Science Institute, KnoxvSle College, Knoxvirie,Tenn., Mar. 4, 1970; Department of Chemistry, Florida State University, Tallahassee, Mar. 13, 1970; Knoxville Science Club, Knoxv3lt,Tenn., Apr. 3,1970. G. D. O'Kelley, "Decay of Neutron-Deficient Nuclides of Mass 89," Department of Chemistry, Florida State University, Tallahassee, Mar. 12,1970. G. D. O'Kelley, "A New Look at the Moon: Analysis of Samples from Apollo 11 and Apollo 12," Western Carolinas Section, American Chemical Society, Brevard, N. C, May 5, 1970; Society of Sigma Xi, Vanderbflt University, Nashville, Term., May S, 1970; Savannah River Section, American Chemical Society, Augusta, Ga., May 8,1970. CHEMISTRY AND PHYSICS OF TRANSURANIUM ELEMENTS O. L. Keller, Jr., "Actinide and Transactinide Elements Production and Research «t Oak Ridge," North Carolina State University, Raleigh, Dec. 11,1969. R. J. Suva, The Transuranium Elements," Oak Ridge Associated Universities, Oak Ridge, Term., July and September 1969. R. J. Sirva, "One Atom at a Time Chemistry," Department of Chemistry Seminar, University of Tennessee, Knoxvflle,Feb.25,1970. P. F. Dinner, "Production and Detection of Transuranium Element*." Seydd-Woolley Visiting Lectureship, Georgia Institute of Technotofc., Atlanta, Jan. 19,1970. R. L. Hahn, "Beta Emission and Interactions," Symposium on Liquid Scintillation Counting, Oak Ridge Associated Universities, Oak Ridge, Taut., June 2-20,1969. R. L. Hahn, "Experiments at the Oak Ridge Isochronous Cyclotron," Summer Institute for College Science Teachers, Oak Ridge Associated Universities, Oak Ridge, Tenn., A<«. 8,1969. R. L. Hahn. "Experiments at the End of the Periodic Table," Physics Department Colloquium, University of Houston, Houston, Tex., Nov. 2C. 1969. 195 196 L. J. Nugent, ^Transuranium Element Production at ORNL and the Luminescence of CmfJH) in Various Liquid Media/* Physics Department Coloquium, Vanderbflt University, Nashville, Tenn., May 23,1969. L. J. Nugent, The Man Made Transuranium Elements and Some Recent Spectroscopic Studies of Their Chemical Compounds,** American Chemical Society Lecture, University of Louisville, Louisvflle, Ky., Jan. 29,1970. L. J. Nugent, "Intramolecular Energy Transfer and Sensitized Luminescence in Actinide(III) 0-Diketone Chelates," Chemistry Department Seminar, University of Louisvffle, Louisville, Ky., Jan. 29,1970. ORGANIC CHEMISTRY C. J. Collins, "Aufklarung von Reaktionsmechanismen in der orguiischen Chemie," Gesellschaft Deutscher Chemiker Ortsvergand Wuppertal/Hagen, Wuppertal-Elberfeld, May 21,1%9. C. J. Collins, "Erinnerungseffekts wahrend Desamurierungen,** University of Gottingen, Germany, June 2,1969; University of Munich, Germany, July 4,1969. C. J. Collins, "The Use of Isotopes in Organic Chemistry,** Birmingham Southern College, Birmingham, Ala., Nov. 7,1969;Southern Illinois University, Carbondale, Feb. 6,1970. C. J. Collins, "Memory Effects During Deaminations," University of Alabama, Tuscaloosa, Feb. 18, 1970; Unjversi'y of Oklahoma, Norman, Mar. 12, 1970; University of Wisconsin, Milwaukee, Apr. 6, 1970; Northeast Tennessee Section of the American Chemical Society, Emory and Henry College, Emory, Va., May 4,1970. PHYSICAL CHEMISTRY M. H. Uetzke, "Desalination and the Thermodynamics of Sea Water," Dupont Seminar, University of Tennessee, Knoxvile,Oct. 9,1969. R. J. Herdklorz,1 "The Thermodynamic Properties of Aqueous Hydrochloric Acid—Metal Chloride Mixtures at Elevated Temperatures," South Carolina Academy of Science, "olumbia, Apr. 24,1970. E. H. Taylor, "Anomalous Properties, Yes; Anomalous Water, No!** Seminar, Brookhaven National Laboratory, Upton, N.Y., Apr. 8,1970. F. A. Posey, "Crevice Corrosion and Pitting of Titanium and Its Alloys,** Seminar, Department of Metallurgical Engineering, Ohio State University, Columbus, Ohio, May 29,1969. CHEMICAL PHYSICS C. K. Johnson, "Mathematical Models for Analyzing Bragg Diffraction Data from Crystals with Non-Gaussian Thermal Motion," National Bureau of Standards, Washington, DC, Jan. 6,1970. C. K. Johnson, "On Extracting Information of Chemical Interest from Crystallographic Thermal-Motion Parameters,** Iowa State University, Ames, Apr. 30,1970. C. K. Johnson, "The Analysis of Skew and Kurtose Thermal-Motion Density Functions," Iowa State University, Ames, May 1,1970. W. £. Thiessen,1 "Applications of Diffraction Methods to Organic Structure Determinations,** University of Kansas, Lawrence, Feb. 13,1970;Clemson University, Ctemson, S.C., Sept. 17,1969. T. A. Carlson, "Determination of Electronic Structures in Molecules by Means of High Resolution Electron Spectroscopy,** Chemisuy Seminar, University of Minnesota, Minneapolis, Feb. 19,1970. !Oak Kidfr Gradual* Fdfew from mt Uuwuiity of T« '.. Ktoxvafe. andcr appointment with Oak Rides Asndatcd Umvositit*. xNaoonal I tstittttrs of Hofth Special Postdoctoral Fdow. 197 T. A. Carlson, "Electron Spectroscopy in Chemical Studies,** Chemical Physics Seminar, University of Tennessee, KnoxviBe, Apr. 18,1970. P. S. Rudolph, 'The Changing Techniques in Radiation Chemistry,** Seminar, Thomas More College, Covington, Ky.,Apr.20, i970. P. S. Rudolph, "The Mass Spectrometer as a Tool in Radiation Chemistry,** Physical Science Seminar, Department of Physics, Thomas More College, Covington, Ky., Apr. 20,1970. S. Datz, "Fast Heavy Ion Collision Physics,** Institute of Physics, University of Aarhus, Aarhus, Denmark, Aug. 27,1969. S. Datz, "Channeling: Motion of Energetic Particles in Solids,** Department of Physics, University of Georgia, Athens, Oct 31,1969. Supplementary Activities STAFF PROFESSIONAL AND EDUCATIONAL ACTIVITIES Russell BaWock Editorial Board, International Journal of Mass Spectrometry and Ion Physics, 1 %8-present G. E. Boyd Nominating Committee, Division of Nuclear Chemistry and Technology. American Chemical Society, 1970. Professional Awards Committee, Division of Nuclear Chemistry and Technology, American Chemi cal Society, 1970-1971. Session Chairman, Fifth Intemational Informal Hot-Atom Chemistiy Meeting, Cambridge, England, July 3-5,1969. Editorial Advisory Board, Radiochimica Acta, 1963-present. Honorary Editorial Board, Radiokhimua, Pergamon Press, Inc., 1961-present HILBusey Secretary-Treasurer, Calorimetry Conference, 1963-1969. Director, Calorimetry Conference, 1969-1971. W. R. Busing Vice-President, American CrysUllographic Association, 1970. Program Chairman, Winter Meeting, American Crystallographic Association, Tuiane University, New Orleans, La., Mar. 2-5,1970. Editor, Transactions of the American Crystallographic Association, Volume 6,1970. T. A. CarUon Lecturer in Physics, University of Tennessee, Oak Ridge Extension, October 1969-March 1970. C. J. Collins Professor of Chemistry, part time, University of Tennessee, Knoxville, January 1964-present S. Date Steering Committee, International Conference on the Physics of Electronic and Atomic Colli sions. International Union of Pure and Applied Physics, 1963-present. Program Committee, Division of Electron Physics, American Physical Society, 1969-1970. Co-chairman, Conference on Dynamic; of Molecular Collisions, Oak Ridge National Laboratory. 1969-1970. Editorial Advisory Board. Atomic Data, 1969-present. Chairman. Gordon Research Conference on Particle-Solid Intetactions, 1969-1970. ORNL Long Range Planning Group, December 1969-April 1970. Guest Professor, Institute of Physics, University of Aarhus. Aarhus, Denmark. April 13-June 12, 1970. R.L.Hahn Committee on Major Nuclear Facilities. Division of Nuclear Chemistry and Technology. American Chemical Society, 1970. Ad Hoc Committee on the Outside Use of the Supcr-HILAC. American Piysicai Society. 1970. O. L. Keller. Jr. USAEC Transphitonhim Program Committee. 1969-1972. Member. Nuclear Physics Survey Panel. National Academy of Sciences. 1969-1970. K. A. Kraus Editorial Boatd. Journal of Ckromatopapky. 1958-present. Editorial AdvHory Board. Journal of Inorganic and Sudear Chemistry. IS58 - prcsent. Editorial Board. DesaHmtkm. 1966 - pretent. M. H. Lieoke Professor of ChemHtiy. pan time. Univeniry of T«nne«e«. KnowHIe. January 1964 present. 198 199 Siegfried Lindenbaum Professor of Biomedical Sciences, part time. University of Tennessee-Oak Ridge Graduate School of Biomedical Sciences, October 1969-present. Ralph Livingston Professor of Chemistry, part time, University of Tennessee, KhoxviUe. January 1964-present. ORNL liaison officer for ORNL -University of Tennessee part-time teaching programs. 1968-presenL Member, Graduate Council, University of Tennessee, KnoxviDe, January 1970-present. Vice-chairman, Southeastern Magnetic Resonance Conference, Columbia, S.C., Oct. 1-2,1970. Co-chairman. ESR Symposium. Division of Physical Chemistry, American Chemical Society. Athens. Ga., Dec. 7-9,1970. Participant, Workshop for Faculties of Traditionally Negro Institutions, Oak Ridge, Tenn., Aug, 4-29,1969. Participant, Southern College University Union Workshop, September and November 1969. G. E. Moore Instructor in Chemistry, National Science Foundation In-Service Institute for Secondary School Science Teachers, Knoxville College, Knoxvflie. Tenc.. 1%7-present. G. D. O'Kelley Professor of Chemistry, part time, University of Tennessee. Knoxvfte, January 1964-present. Subcommittee on Kadiochemistry, National Academy of Sciences-National Research Council, 1962—present. Lupar Sample Preliminary Examination Team, an advisory committee to the NASA Manned Spacecraft Center, Houston, Tex., 1967-1970. Committee on Major Nuclear Facilities, Division of Nuclear Chemistry and Technology, American Chcnical Society, 1967-1969. Chairman-Elect, Division of Nuclear Chemistry and Technology, American Chemical Society. 1970. R. J. Random State Sponsor of the Collegiate Division, Tennessee Academy of Science, 1965-present Presiuent-Elect, Tennessee Academy of Science, 1970. R. W. Stoughton Editorial Advisory Board, JounJl of Inorganic and Nuclear Chemistry, 195 8-present. E.H. Taylor Board o* Directors, Institute of Catalysis. Participant. Workshop for Faculties of Traditionally Negro Institutions, Oak Ridge, Tenn., Aug. 4-29, 1969. Participant, Third Summer Conference on "Science for Clergymen," July 7-18,1969. FOREIGN MEETINGS AND ACTIVITIES Meeting and/or Activity Location Staff Members) Visiting Professor of Chemistry, Chemisches Institut der Tubingen, West Germany C. J. Coffins Untversitat Tubingen (September 1968-July 1969) Guest scientist, Nieh Bohr Institute (August 1968-August 1969) Copenhagen. Denmark E. Eichler International Conference on Nuclear Reactions Induced Heidelberg. Germany E.Ekhler by Heavy Ions. July 15-18.1969 International Conference on the Properties of Nuclear Montreal. Canada E.Ekhier States. Aug. 25-30.1969 International Symposium on Chemical Effects of Nuclear Cambridge. England G. E. Boyd Transformations. July 1-3.1969 Interratio* A Coaf*»e«e on Ion Exchange m the Process London. Engfaed a E. Boyd Industries. Society of Chemical iMosstry. July 16-18. 1969 Second Symposium on the Physics and Chenmtry of Vienna. Austria R L. Feiguja Fission. July 2*~Auf, I. 1969 International Conference on Raman Spectroscopy. Carteicn University. G M. Bmn An*. 4 ?. 1969 Orti*i.C 200 Meeting and/or Activity Location Staff Memben(s) International Summer School on Crystallographic Carieton University. W. R. Busing Computing, International Union of Crystallography Ottawa, Canada C. K. Johnson Commission on Crystallographic Computing, Aug. 4-12,1969 Ninth International Symposium on Free Radicals. Banff. Canada R. Livingston Aug. 24-29.1969 Conference on Atomic Collision Phenomena in Solids. Sussex. England S. Datz Sept. 7-12,1969 International Conference on the Use of Cyclotrons in Oxford. England M L Mallory Chemistry, Metallurgy, and Biology, Sept 22-23. 1969 COLLABORATIVE RESEARCH institution Colabontor(s) Subject Staff Members) University of Alabama D. A. Zatko Study of silver compounds by electron T. A. Carlson spectroscopy Andrews University M. C. Ketley Search for the 0* member of the two- N. R. Johnson J. R. Van Hise phonon vibrational state in ' Cd 2 Argonne National Laboratory A. M. Friedman Search for fission isomerism in ' Pu C. E. Bemis, Jr. ,0, Centre DTiude de L'Energie P. Fettweis Decay of Tc G. D. O'Kelley Nudeaire, Mot, Belgium David Lipscomb College J. W. Dawson An investgation of radioactive Tm N. R. Johnson R. J. Silva University of Delft, Netherlands B. van Nooijen Properties of radioactive 84Y and 86Y N. R. Johnson University of Delhi, India S. C. Pancholi Investigations of the decay properties N. R. Johnson of*4Yand59Fe Florida State University R. K. Sheline Levels in '6 'Xb excited by the (3He4) N. R. Johnson reaction and by the decay of 3.7-min I6i Gd Indiana University F. B. Malik Use of atomic wave functions' T. A. Carlson Institute of Nuclear Research, J. Konijn Properties of radioactive 84Y, N. R. Johnson Amsterdam, Netherlands Lawrence Radiation Laboratory, J. Harris Chemical separation of element 104 R. J. Silva Berkeley M. Nurmia K. Eskola A. Ghiorso Lawrence Radiation Laboratory, R. G. Lanier Search for the 0* member of the two- N. R. Johnson Livermore phonon vibrational state in Cd R. G. Lanier Levels in ! 6' Tb excited by the N. R. Johnson R. A. Meyer ( He4) reaction and by the decay G, D. O'Kelley of3.7-rninl6,Gd Maryville College P. J. Ogren Pulse radiolysis of nitric oxide C. J. Hochanadel J. A. Ghormley Massachusetts Institute of Tech Various teams Hyperfiltration with dynamically formed J. S. Johnson nology School of Chemical mtmbranes K. A. Kraus Engineering Practice, Oak Ridge Station li collaboration with the Physics Division. 201 Institution CoBabontoits) Subject Staff Met. ) Middle East Technical University, N. K. Aras Decay of l0,Tc G. D. O'Keiley Ankara, Turkey Level properties of the deformed nucleus N. R. Johnson 184W University of Missouri D. E. Troutner Independent fission yield studies R. I.. Ferguson University of Naples, Italy G. G. dittos: Decay of ,0lTc G. D. O'Keiley NASA Manned Spacecraft Center F Schonfeld Determination of primordial and G. D. O'Keiley cosmogenic radionuclide content of lunar materia! by gamma-ray spectrometry Purdue University R. C. Hagenauer Decay of neutron-deficient nuclides of G. D. O'Kclley mass 89 E. Eichler Savannah State College M. P. Menon Decayof86-sec'36I E. Eichler N. R. Johnson G. D. O'Keiley University of Southern Mississippi J. W. Pinson Study of solid polymers from the R. Baldock radiorysis of pentaborane-9 vapor P. S. Rudolph St. John's University R. J. Beshinske Monte Carlo calculations of the thermo dynamic properties of water M. H. Lietzke University of Tennessee F. K. Schmidt- Chemical accelerator sources Bieek S. Date W. E. Bull Use of electron spectroscopy for G. K. Schweitzer chemical analysis1 T. A. Carlson Vanderbilt University J. H. Hamilton Two-phonon octupoie states in 240P. u A. V. Ramayya C. E. Bemis, Jr. F. E. CofTman G. D. Benson Decay of ,92Au G. D. O'Keiley R. G. Albridge G. D. Benson Decay of '94 Au to levels in 194Pt G.D. O'Keiley A. V. Ranuyya R. G. Albridge J. H. Hamilton Systematics of the KM = 0~ and 1 octupoie N. R. Johnson A. V Ramayya bands in transitional nuclei A study of the properties of some vibra N. R. Johnson tional spherical nuclei Studies of the vibrational behavior of de N. R. Johnson formed nuclei Virginia Polytechnic Institute M. A. ijaz and Properties of rare-earth alpha emitters R. L. Hahn W. M. Sample Washington University D. G. Sarantites Levels in '' °Cd populated in the decay II0 N. R. Johnson of69-min *In West Georgia College H. W. Boyd Xerox Corp., Pasadena, Calif. M. W. Swagcl Laser-induced single- and double-photon L. J. Nugent F. M. Johnson excitation and dissociation in gaseous nitrous oxide 202 ANNUAL INFORMATION MEETING AND ADVISORY COMMITTEE The Annual Information Meeting of the Chemistry Division was held October 8,1969. Reports presented at the Meeting were: E. H. Taylor Introduction S. Datz Collision-Induced Vibrational Excitation and Dissociation of Molecular Hydrogen w**h Energetic Alkali Atoms T. A. Carlson The Use of High-Resolution Electron Spectroscopy in Chemical Analysis1 G. D. O'Kelley Determination of Radionuclides in Lunar Samples from Apollo 11 A. R. Jones Eneigy Transfer in the Radiolysis of Aliphatic Carbo.:ylic Acids T. J. Sworski Kiaetic Evidence for a Primary Yield of HS04 Radicals in the Radiolysis of Aqueous Sulfuric Acid Solutions R. Livingston Paramagnetic Resonance Studies of Liquids R. A. Gilbert The High-Temperature Enthalpies of the Lead Halides W. R. Busing Ir.terionic and Intermolecuiar Forces in Crvs'sIIiae Hydrates A.ftNarten Structure in Water and Aqueous Solutions N. R. Johnson Vibntiona! Properties of Nuclei R.J.Silva Heavy Actinides and Transactinides O. L. Keller Superheavy Elements of the Advisory Prof. Paul D. Bartktt (1966-1965) Department of Chemistry Harvard University Cambridge. Massachusetts 02138 Dr. Gerhart Friedlander, Chairman (1966-1%9) Department of Chemistry Brookhaven National Laboratory Upton, Long Island, New York 11973 Dr. Joseph J. Katz (1965-1969) Argonne National Laboratory 9700 South Cass Avenue Argonne, Illinois 60439 Prof. Harry H. Sister (1966-1969) Dean, College of Arts and Sciences University of Florida Gainesville, Florida 32601 VISITING SCIENTISTS Name Affiiatio* ORNLRcfeard Sponsor I. L. Atwood University of Alabama Transuranium Research Laboratory ORAU Faculty Research Participation Program ML C. Banta East Texas Baptist College Electrochemical Kinetic* Summer employee (faculty) LBlum UnW?:»ity of Puerto Rico Neutron and X-Ray Diffraction ORAU Faculty Research Participation Program ML H. Srookci University of Waterloo, Radiation and Hot-Atom Chemistry National Research Waterloo, Ontario of Inorganic Crystalline Solids Council of Canada R. Desiderato North Texas State University Neutron and X-Ray Diffraction ORAU Faculty Research Participation Program 203 Name AflHbtion ORNL Research Program Sponsor J. K. Dohrmann Freie Unrversitait Berlin, Microwave and Radio-Frequency Deutsche Institut fur Physilalische Spectroscopy Forschungsmeinschaft Chemie Leela Ganguly Louisiana State University Transuranium Research Laboratory Louisiana State University R. V. Gentry Columbia Union College Transunnium Research Laboratory Columbia Union College E. W Graham University of California Physical Chemistry UCLA at Los Angeles R. G. Lanier r STUDENTS GRADUATE Major Professor Name Staff Advisor Field of Research and/or Institution Sponsor J. A. Fahey J. R. Peterson, University L. J. Nugent Transuranium Research Labora- Oak Ridge Graduate of Tennessee tor" Fellowship Program L. Finkel J. A. Marinsky, State G. E. Boyd Independent fission yields of University of New York E.EichK ,0,Tc. ,04Tc.and,05Tc at Buffalo R. L. Ferguson from thermal-neutron induced fission of 23SU 204 Major Professor Nine Staff Advisor Field of Research and/or Institution G. R. Freeman Robert Deskkrato, Jr., H. A. Levy The Crystal and Molecular Oak Ridge Graduate North Texas State G. M. Brown Structures of Tri- versity of Tennessee aqueous HCl-Naa-MgCl2 Fellowship Program mixtures H. B. Hupf3 M. H. Lietzke, Uni ML H. Lietzke The Thermodynamic Properties ORNL versity of Tennessee of Aqueous HCI-CsCl-BaCl2 Mixtures (Pt«.D. thesis, June 1969) A. E. Jonas W. E. Bull and T. A. Carbon Photoelectron spectroscopy University of G. K. Schweitzer, of gaseous molecules1 Tennessee University of NASA Research Tennessee Grant N. KashJhira F. K. Sdunidt-Bleek, S. Datz Chemical accelerator sources University of Tennessee A.F. Kluk J. H. Hamilton, N. R. Johnson Vibrational behavior of deformed Oak Ridge Graduate Vandcrbilt University rare-earth nuclei Fellowship Program R. A. Kuebbing Case Western Reserve L. Eichkr Measurements of Transition Oak Ridge Graduate University J. K. Dkkens4 Probabilities in Some Middle Fellowship Program We«ht Nuclei (PtuD. thesis, January 1970) C.W. Linsey R. B. Escue, North R.fLBusey High-temperature enthalpies of Oak Ridge Graduate Texas Sute University R. A. Gilbert the leac h*ides - enthalpies Fellowship Program and entropies of fusion W. E. Moddeman W. E. Bull and G. K. T.A.Carbon Auger spectroscopy of University of Schweitzer, University gaseous molecules1 Tennessee NASA of Tennessee Research Grant G. L. Ostrom F. K. Schmidt-Bkek, S. Datz Sputtering studies Univcrsiiy uf Tennessee B. P. Pullen W. E. Bull and T. A. Carbon The Construction and Use of a Oak Ridge Graduate G. K. Schweitzer, High Resolution Photoelectron Fellowship Program University of Spectrometer (Ph.D. thesis, Tennessee February 1970)1 'M.Ed, candidate in the College of Education. Isotopes Division. 4Neutron Physics Division. 205 Name Major Professor Staff Advim Field of Research Spomrt and/or institution P. R. Reed F. K. Schmidt-Bleek, C. 1. Hochanade! Radiation chemistry AUA-ANL Pre- University of T. J. oworski of methane doctoral Fellowship Tennessee N.Singhal J. H. Hamilton, N. R. Johnson Vibrational properties Vanderbilt Vanderbilt University E. Eichler of even-even spherical University nuclei J. N. Stevenson J. R. Peterson, O. L. Keller, Jr. Transuranium Research University of Laboratory Temrcssee UNDERGRADUATE Name Institution ORNL Research Sponsor L L. Ansell Kansas State College Organic Chemistry ORAU Summer Student Trainee Program R. J. Boulware Haverford College isotope Chemistry Black Undergraduate Program K. H. Bowen University of Mississippi Molecular Beam ORAU Summer Student Trainee Program A. Elaine Cureton Knoxville College Water Research Program Black Undergraduate Program Linda L. Gainer Fisk University Chemistry of Aqueous Systems Black Undergraduate Program R. J. Katt Williams College Molten Salts ORAU Summer Student Trainee Program F. C. Kostansek Hiram College Neutron and X-Ray Diffraction ORAU Summer Student Trainee Program Ivy W. Nixon Tennessee State University ORNL Summer Secretary Omega N. Norton Knoxviile College Organic Chemistry Black Undergraduate Program J. G. Porterfieki University of Tennessee Chemistry of Aqueous Systems Cooperative Education Program Elizabeth E. Willis Westhampton College Chemistry of Aqueous Systems ORAU Summer Student Trainee Program