A STUDY OF THE ADDITION COMPOUNDS OF TITANIUM TETRABROMIDE AND TITANIUM TETRAIODIDE WITH 1,4-DIOXANE, TETRAHYDROFURAN, AND TETRAHYDRQPYRAN
DISSERTATION
Presented in Partial Fulfillment of tha Requirements for the Degree Doctor of Philosphy in the Graduate School of The Ohio State University
Robert Fredrick Rolsten, B.S.
The Ohio State University
1955
Approved by:
D r ACKNOWLEDGEMENTS
The author wishes to express appreciation to Dr. Harry H. Sisler for his continued personal interest and guidance throughout the course of the investigation. Appreciation is also extended to Dr. Edward D.
Loughran for his cooperation in the use of the infrared spectro photometer, to Dr. Preston M. Harris and Mr. Herbert W. Newkirk for contributing to the interpretation of the X-Ray data. The arrangement between Battelle Memorial Institute and the Graduate School of The
Ohio State University with regard to tuition is gratefully acknowledged.
I fully recognize the sacrifice my children have made in tolerating my necessary absence while attending school and which resulted in my failing of fatherly obligations. I sincerely hope the means has not destroyed the end.
ii TABLE OF CONTENTS
Page
ACKNOWLEDGEMENTS ...... ii
LIST OF ILLUSTRATIONS ...... iv
LIST OF TABIES ...... viii
I. INTRODUCTION ...... 1
II. HISTORICAL ...... 3
III. PREPARATION AND PURIFICATION OF REAGENTS ...... 25
IV. PREPARATION OF ADDITION COMPOUNDS ...... 34
V. X-RAY DIFFRACTION ANALYSIS ...... 55
VI. NEUTRALIZATION EQUIVALENT WEIGHT ...... 136
VII. INFRARED ANALYSIS ...... 184
VIII. CRYOSCOPIC STUDY ...... 208
IX. REACTIONS OF TJ.I4 WITH EPOXY COMPOUNDS ...... 219
X. X-RAY DIFFRACTION ANALYSIS ...... 232
XI. THEORETICAL DISCUSSION ...... 255
XU. SUMMARY ...... 266
XIII. SUGGESTED RESEARCH PROBLEMS...... 268
APPENDIX I ...... 269
APPENDIX II ...... 275
APPENDIX III ...... 278
APPENDIX IV ...... 280
AUTOBIOGRAPHY ...... V ...... 283
iii LIST OF ILLUSTRATIONS
Figure Page
1 Apparatus for Preparation of TiBr4 ...... 27
2 Reaction Flask for The Preparation of TiBr^,...... 29
3 Titanium Tetrabromide Storage Ampoules...... 30
4 Apparatus for Preparation of Addition Compounds...... 35
5 Purification of the Addition Compound, TiBr4 »C4Hg0 2 . ... 37
6 Photograph of TiBr4 and TiBr4 *C4 Hg0 2 ...... 40
7 Infrared Spectrogram of Tetra hydro fur an ...... 47
8 Infrared Spectrogram of Viscous Liquid As a Result of The Reaction of TiBr4 and Tetra hydro fur an...... 47
9 Infrared Spectrogram of TiBr4 *2Tetrahydrofuran'.in Nujol.. 49
10 Infrared Spectrogram of Water Insoluble Liquid...... 52
11 Infrared Spectrogram of Viscous Liquid After Passing Through a Column of Al2 0 3 »celite...... 53
12 Geometrical Features of the Debye-Scherrer Technique. ... 57
13 X-ray Spectrometer Data for Ti0 2 - 78
14 X-ray Diffraction Patterns of Ti02 (Anatase)...... 79
15 Determination of Lattice Constant, a0, for Ti02 (Anatase) 80
16 Determination of the Lattice Constant, a0, for TiBr4 . ... 90
17 X-ray Diffraction Pattern of TiBr4 ...... 91
18 X-ray Diffraction Pattern of TiBr4 *Dioxane, Iron Radiation...... 106
19 X-ray Diffraction Pattern of TiBr4 *Dioxane, Cobalt Radiation...... 106
iv LIST OF ILLUSTRATIONS (Continued)
Figure Page
20 X-ray Diffraction Pattern of TiBr4 *Dioxane, Copper Radiation...... 106
21 Determination of the Lattice Constant, a0, for TiBr4 *Dioxane...... 107
22 X-ray Diffraction Pattern of TiBr4 *2Tetrahydropyran. ... 118
23 Determination of the Lattice Constant, a0 , for TiBr4 *2Tetrahydropyran...... 119
24 Determination of the Lattice Constant a0 , for TiBr4 *Tetrahydrofuran (excess TiBr4 )...... 127
25 X-ray Diffraction Patterns of TiBr4 «2Tetrahydrofuran, Copper Radiation, Excess,TiBr4 ...... 128
26 X-ray Diffraction Patterns of TiBr4 *2Tetrahydrofuran, Copper Radiation, Excess Tetrahydrofuran...... 128
27 Determination of the Lattice Constant, aQ, for TiBr4 *2Tetrahydrofuran (excess THF)...... 134
28 Neutralization curve for TiBr4 (2.0283 grams)...... 152
29 Volume of NaOH versus A pH/0.1 ml.; sample: TiBr4(2.0283 grams)...... 154
30 Neutralization curve for T H 4 (2.1067 grams)...... 156
31 Neutralization Curve for TH 4 (1.6805 grams)...... 158
32 Neutralization Curve for Til4 (2.4927 grams)...... 160
33 Neutralization Curve for TiBr4 »Dioxane (0.4762 grams). 162
34 Neutralization Curve for TiBr4 *Dioxane (0.4102 grams). .. 164
35 Neutralization Curve for TiBr4 *2Tetrahydrofuran (2.3092 grams) Prepared from Excess TiBr4 ...... 166
36 Neutralization Curve for TiBr4 »2Tetrahydrofuran (1.3734 grams) prepared from Excess TiBr4 ...... 168
37 Neutralization Curve for TiBr^*2Tetrahydrofuran (0.1644 grams) prepared from Excess Tetrahydrofuran. ... 170
v LIST OF ILLUSTRATIONS (Continued)
Figure Page
38 Neutralization Curve for TiBr4 *2Tetrahydrofuran (0.2872 grams) Prepared from Excess Tetrahydrofuran 172
39 Neutralization Curve for TiBr4 *2Tetrahydropyran (0.3335 grams)...... 174
40 Neutralization Curve for TiBr4 *2Tetrahydropyran (0.3826 gram)...... 177
41 Neutralization Curve for TiBr4 *2Tetrahydropyran (0.9934 grams)...... 179
42 Neutralization Curve for TiBr4 *2Tetrahydropyran (0.6743 grams)...... 181
43 Neutralization Equivalent Weight Apparatus...... 182
44 Infrared Spectrogram of Tetrahydrofuran...... 187
45 Infrared Spectrogram of 1,4-Dioxane...... 188
46 Infrared Spectrogram of Tetrahydropyran; Cell Thickness, Plate to Plate...... 189
47 Modes of Vibration of the Imaginary CH£ Molecule...... 19U
48 Infrared Spectrogram of Nujol; Cell Thickness, Plate to Plate...... 194
49 Infrared Spectrogram of TiBr4 «Dioxane Mulled in Nujol; Cell Thickness, Plate to Plata...... 194
50 Infrared Spectrogram of TiBr4 *2Tetrahydropyran Mulled in Nujol; Cell Thickness, Plate to Plate...... 195
51 Infrared Spectrogram of TiBr^»2Tetrahydrofuran in Nujol.. 196
52 Freezing Point Cell...... 212
53 Typical Cooling Curve...... 214
54 Molality Versus Molecular Weight of Addition Compound. . 216
55 Apparatus for Preparation of Titanium Tetraiodide by Direct Synthesis...... 220
vi LIST OF ILLUSTRATIONS (Continued)
Figure Page
56 Apparatus for Preparation of Titanium Tetraiodide by Disproportionation of Titanium Triiodide...... 222
57 Purification of Til4 « ...... 223
58 Apparatus for Preparation of Tilg...... 226
59 Needles of Titanium Triiodide...... 228
6 u Infrared Spectrogram of the Til4 »Tetrahydrofuran oil. Cell thickness: Plate to Plate...... 231
61 Determination of the Lattice Constant, a0, for TH 4 . ... 241
62 X-ray Diffraction Patterns of Til4 ...... 242
63 X-ray Diffraction Patterns of Til4 , Iron Radiation. .... 242
64 X-ray Diffraction Patterns of Tilg, Copper Radiation. .. 253
65 X-ray Diffraction Patterns of Tilg, Iron Radiation. 253
66 Determination of Lattice Constant, a 0 for Tilg...... 254
67 Graphical Determination Sf/S^...... 274
68 Mole Fraction of ®r2(j£) -^Br4(j0 as a Function of Temperature (Pressure c 760 mm.). 277
vii LIST OF TABLES
Interplaner Spacings (ASTM) for T 3.O2 as Obtained From a G. E. Spectrometer...... 65
Interplaner Spacings for Ti02 as Obtained From a Philips X-ray Spectrometer...... 66
Measurement of Ti02 Film, Molybdenum Radiation...... 67
Measurement of Ti02 Film, Copper Radiation...... 68
Measurement of Ti02 Film, Copper Radiation...... 70
Measurement of Ti02 Film, Copper Radiation...... 71
Measurement of Ti02 Film, Iron Radiation...... 73
Measurement of Ti02 Film, Iron Radiation. .... 74
Calculation of Absorption Effects for Anatase (Ti02). ...76
Calculation of Absorption Effects for Anatase (Ti02) ao/co B 0.39779...... 77
Interplaner Spacings (ASTM) for TiBr4 ...... 84
Measurement of TiBr4 Film, Iron Radiation...... 85
Measurement of TiBr4 Film, Iron Radiation...... 86
Calculation of Absorption Effects for TiBr4 ...... 87
Calculation of Absorption Effects for TiBr4 « ...... 88
Calculation of Absorption Effects for TiBr4 , a 0s 11.292$. 89
Measurement of TiBr4 *Dioxane Film, Cobalt Radiation. ... 95
Measurement of TiBr4 »Dioxane Film, Copper Radiation. ... 97
Measurement of TiBr^Dioxane Film, Copper Radiation. ... 99
Measurement of TiBr4 *Dioxane Film, Iron Radiation......
Measurement of TiBr4 *Dioxane Film, Iron Radiation......
Determination of Lattice Constants for TiBr4 *Dioxane.
viii LIST OF TABLES (Continued;
Table Page
23 Determination of Lattice Constants for TiBr^'Dioxane a 0 - 18.446$, a 0 /c0 ■ 2.463...... 104
24 Measurement of TiBr4 *2Tetrahydropyran Film, Copper Radiation...... * 109
25 Measurement of TiBr4 »2Tetrahydropyran Film, Copper Radiat ion...... Ill
26 Measurement of TiBr4 *2Tetrahydropyran Film, Copper Radiation...... 113
27 Determination of Lattice Constants for TiBr4 *2Tetrahydropyran...... 115
28 Determination of Lattice Constants and Miller Indices for TiBr4 »2Tetrahydropyran...... 116
29 Measurement of TiBr4 »2Tetrahydrofuran Film, Copper Radiation...... 121
30 Measurement of TiBr4 »2Tetrahydrofuran Film, Copper Radiation...... 123
31 Determination of Lattice Constants for TiBr4 *2Tetrahydrof uran...... 125
32 Determination of Lattice Constants for TiBr4 »2Tetrahydrofuran...... 126
33 Measurement of TiBr4 *2Tetrahydrofuran Film, K«-alpha Radiation...... 129
34 Determination of Lattice Constants for TiBr4 *2Tetrahydrofuran...... 131
35 Determination of Lattice Constants for TiBr4 »2Tetrahydrofuran...... 132
36 Summary of Neutralization Equivalent Weight Data...... 150
37 TiBr4 (2.0283 grams)...... 151
38 TiBr4 (2.0283 grams)...... 153
39 Til4 (2.1067 grams )...... 155
ix LIST OF TABLES (Continued)
Table Page
40 Til4 (1.6805 grams)...... 157
41 Til4 (2.4927 grams)...... 159
42 TiBr4«Dioxane (0.4762 grans)...... 161
43 TiBr4 *Bioxane (0.4102 grams)...... 163
44 TiBr4 *2Tetrahydrofuran (2.3092 grams)...... 165
45 TiBr^^Tetrahydrofuran (1.3734 grams)...... 167
46 TiBr4 *2Tetrahydrof uran (0.1644 grams). 169
47 TiBr^*2Tetrahydrofuran (0.28 72 grams)...... 171
48 TiBr4 *2Tetrahydropyran (0.3335 grams)...... 173
49 TiBr4 »2Tetrahydropyran (0.3826 grams)...... 175
50 TiBr4 *2Tetrahydropyran (0.9934 grams)...... 178
51 TiBr4 «2Tetrahydropyran (0.6743 grams)...... 180
52 Absorption Bands for Tetrahydrofuran...... 199
53 Absorption Bands for Tetrahydropyran...... 200
54 Absorption Bands for 1,4-Dioxane. 201
55 Infrared Spectra of Epoxy Compounds...... 202
56 Infrared Spectra of Epoxy Compounds...... 203
57 Absorption Bands for TiBr^*Bioxane in Nujol...... 204
58 Absorption Bands for TiBr4 *2Tetrahydr ofur an in Nujol. .. 205
59 Absorption Bands for TiBr4 *2Tetrahydropyran in Nujol. .. 206
60 Summary of Cryoscopic Data...... 215
61 Interplaner Spacings for Til4 ...... 234
62 Measurement of Til4 Film, Copper Radiation...... 235
x LIST OF TABLES (Continued)
Table Page
63 Measurement of T H 4 Film, Copper Radiation; Til4 Prepared by Dis pro port ionati on of Tilg...... 236
64 Measurement of Til^, Iron Radiation...... 237
65 Measurement of Til4 Film, Cobalt Radiation...... 238
66 Measurement of Til4 Film, Cobalt Radiation...... 239
67 Determination of Absorption Effects for Til4 ...... 240
68 Measurement of Tilg Film, Copper Radiation...... 245
69 Measurement of Til3 Film, Iron Radiation...... 247
70 Measurement of Til3 Film, Iron Radiation...... 249
71 Determination of Lattice Constants and Miller Indices for Tilg...... 251
72 Determination of Lattice Constants and Miller Indices for Tilg...... 252
73 Mole Fraction of Brg end TiBr4 at Various Temperatures. . 276
xi A STUDY OF THE ADDITION COMPOUNDS OF TITANIUM TETRABROMIDE AND TITANIUM TETRAIODIDE WITH 1,4-DIOXANE, TETRAHYDROFURAN, AND TETRAHYDROPYRAN
I. INTRODUCTION
Pfeiffer’*" observed "that "the ability of tin tetrahalides to form addition compounds with Lewis bases decreased greatly with increasing 2 14 size of the halide. Sisler, et al. ' 1 have shown that, whereas tin
and titanium tetrachlorides readily form stable molecular addition
compounds in the solid state with various ethers, silicon and
germanium tetrachlorides do not exhibit this tendency. The formation
of tin tetrachloride addition compounds was interpreted as resulting
from Lewis acid-base reactions in which the metal atom expanded its
valence shell by accepting a pair of electrons from each of two
molecules of ether to form compounis of thegeneral type MCl^^RgO.
The failure of silicon and germanium tetrachlorides to form such
compounds was attributed to the size of the chlorine atom being such
as to cause four of these atoms to fill so completely the coordination
sphere of the silicon or germanium atom, as to prevent any reaction
with the ether. This is in line with the measurements^ of the
dipole moments of solutions of silicon, germanium and tin chlorides
^■Pfeiffer, P., Halperin, 0 ., Z anorg. Chem. _87, 335-52 (1914). ^Sislor _et _al., J. Am. Chem. Soc. 70, 3818-21 (1948). % i s l e r _et al., ibid., 70, 3821-4 71948). 4Sisler et al., ibid., 75, 2881-3 (1953). ^Lane, T. J,, McCusker, P. A., Curran, B. C., J. Am. Chem. Soc., _64, 2076-8 (1942). -1- -2-
in dioxane, whioh indicated that the extent of coordination increased with increasing atomic weight.
It was, therefore, decided to determine what would be the
effect, if any, on the tendency for titanium tetrahalides to react with ethers by changing the chlorine atoms with the larger bromine
or iodine atoms. II. HISTORICAL
The widespread use of metallic titanium was the requisite stimulus for the increased intensity and scope in the investigations of the chemistry and reactions of titanium. During the past ten years tho main objective has been to study or prepare compounds in order to obtain information that would be useful to the producers of pigment products, pure titanium metal or ultimately lead to new methods of metal production. Prior to this time, the main interest in titanium compounds was apparently academic. Thus, it seems imperative that the knowledge of the methods of preparation and proper ties of existing titanium compounds should be carefully reviewed.
Except for the reaction of titanium tetrabromide and titanium tetraiodide with Lewis bases it was not intended that the survey should be complete, but rather that enough of the field should be covered so that general trends could be considered which might lead to a better interpretation of the data.
Addition Compounds of TiBr/j..
Scagliarini and Tartarini® reported the formation of the brown crystalline compound TiBr2 (OCgHgCHO^iHBr when salicylaldehyde was added to a solution of TiBr4 in CHClg. With salicylic acid^, TiBr^_
Scagliarini, G., Tartarini, G., Atti. Accad. Lincei (6)_4, 318-24 (1926); Chem. Abs. J21, 739 (1927). ^Rosenheim, A., Schnabel, R., Bilecki, R., Bor. _48, 447-52 (1915). -3- -4-
dissolved in absolute ether yields hydrogen bromide and the compound
TiBr(0CgH4 CC>2H)g*HBr. Deep dark red, almost black crystals of o TiBr4 *2 C4 H^Q0 were prepared in an excess of diethyl ether at low temperatures. The addition compound is very sensitive to moisture.
9 10 Ruff, et al. ’ prepared the yellow crystalline compound,
TiBr4 »8NH3 by direct snythesis. Dry NH^ was passed over a very thin film of solid TiBr4 and the reaction controlled by the flow of gas and immersion of the reaction flask in a COg-alcohol bath. TiNBr 11 results upon further ammonolysis . Dry NHg gas bubbled into a solution of TiBr^. in diethyl ether will produce^ a deep brown amorphous substance which readily decomposes. In H2 S, TiBr4 f o r m s ^ the vermilion colored dithiohydrate, TiBr4 '2H2 S and the deeper colored monothiohydrate, T i B ^ ’H^S, as determined by thermal analysis.
TiBr4 in liquid SOg exhibits a wide region of incomplete miscibility^.
At temperatures above 29° there are two liquid phases in equilibrium with one another. Their critical solution temperature is 103,8°C. which corresponds to between 64.53 and 68.87 wt. percent TiBr^, The eutectic temperature could not be accurately determined since TiBr4 is not too soluble in liquid SO2 at low temperatures. The solid
15 0 crystalline phase in equilibrium with both solutions at 29.4 C. is
TiBr4 *£S0 2 . T i B ^ rapidly dissolves in PH^ to produce^-® deep red
®Oberhauser, F., Schormuller, J., Ber. 62, 1436-41 (1929). 9 Ruff, 0., Eisner, F . , Ber. 41, 2250-64~Tl908). lORuff, 0., Treidel, 0., t|Ber. _45, 1364-73 (1912 ). Oberhauser, P., Schormuller, J., Loc. Git. l^Rosenheim, A., Schutte, 0., 2 anorg. Chem. _26, 239-57 (1901). ISBiltz, W. Keunecke, E . , 2 anorg. Chem. 147, 171-87 (1925). •^Bond, P. A,, Crone, E. B., J. Am. Chem. Soc. _56, 2028-31 (1934). ■^Bond, P. A., Belton, W. E., J. Am. Chem. Soc. _67, 1691-3 (1945). iSHoltje, R . ( 3 anorg. Chem. 190, 241-56 (1930). -5-
aGicular crystals. The thermal analysis at 0°C. shows the existence
of the monophosphine, TiBr^'PHg, while at 15 atmospheres phosphine pressure the compound TiBr4 »2PH3 is formed. Raeder^ identified
TiBr^»2PBr3 and had evidence for the existence of but could not
identify TiBr’PBrg. TiBr^^PBrg forms red needle-like crystals and has lattice constants of a 48 13,84" 0,05A°; b ** 8,61" 0»05A° and c * 7.24" 0.05A° as determined by X-ray studies (Laue powder
diffraction patterns). Absolutely dry HCN reacts with TiBr4 to form the compound TiBr4 *2HCN, which is brick red. The color deepens at about 1 0 0 °C. and the compound decomposes at about 132°C. In moist
air it forms HBr, HCn and -the decomposition product is yellow.
TiBr4 *2BrCN is formed^ by direct reaction. The compound is brick
red, melts at 151-2°C. without decomposition, is very hygroscopic,
can be sublimed at reduced pressure and reacts with dry NHg gas to
produce NH4 B1’, and NH4 CN. A similar compound is formed with C1CN.
19 Scagliarini and Monti prepared the needle-like crystals of
2TiBr^»7C0H-|_2N4 »C2H 2 Cl2 by mixing an excess of hexamethylenetetramine
with a dilute solution of TiBr4 in ^as previously
cooled. A difference in concentration of the solvent or of the
organic base lead to the formation of different products. Obarhauser
and Schormuller^^ did not use ether solutions'in the preparation of
the above compounds because T i B ^ and ether gives the compound
TiBr4 *2 (C2Hg)2 0 . No further evidence of the latter compound was given.
■^Raeder, M. G., Kgl. Norske Videnskab. Selskabs. S Krifter Nr. 3, 1-118 (1929); Chem. Abs._25, 17 (1931). l^Oberhauser, P., Schormuller, J., Loc. Cit. •^Scagliarini, G., Monti, E., Atti Accad. Lincei (6 ) 4, 210-4 (1926)., Chem. Abs. jJl^ 213 (1927). ~ 200berhauser, P., Schormuller, J., Loc. Cit. -6~
Addition Compounds of Til4 ,
Biltz and Keunecke^l reported that Til^ is not soluble in and
did not react with liquid HgS. There is no compound^ formed between
solid or liquid Til4 and liquid PHg and there is no evidence of Til4
solubility in liquid PHg, There is a slight evolution of heat23 when
Til4 is mixed with PClg. The products of the reaction are ^iCl^ and
PI3 which were separated by distillation. Prom the abnormally high
boiling point elevation of TiCl4 , resulting from the addition of Til4»
it was observed^ -that at the boiling point, practically complete
substitution occurred according to the reaction:
3TiCl^ + Til^ <= 4TiClgI. Compounds of this type have not been
isolated. A dark brown product^® is formed whan Til^ is reduced with
metallic Mg in diethyl ether* There was no evidence of metallic Ti.
A solution of 'Pil4 in bromoform when added drop wise to
hexamethylenetetramine foms^® the yellow crystalline powder
TiI4 »4 CgH^2N4 *5CHBrg. jn an excess hexamethylenetetramine a red
gelatinous compound is formed.
Additions Compounds of TiCl4 .
Strahler^ prepared the yellow TiCl4 »8TJHg by adding dry gaseous
ammonia to a solution of ^iCl4 in ether. He also isolated a yellow
^B^ltz, W., Keunecka, E . f Loc. Cit. ^^Holtje, P., L q q „ Cjt, ^Karantassis ,"""^7, Ann. Chim. _8 , 71-119 (1927). ^Raeder, M. 6 ., Loc. Cit. ^^Rheinboldt, H., Schwenzer, K., J. prakt. Chem., 140, 273-90 (1934). ^Scagliarini, G., Brassi, E., ■Atti. accad. Lincei, (6 ) 2, 269-74 (1925); Chem. Abs. _20, 156 (1926). *" 27strahler, A., Ber. 38, 2626-9 (1905).. powder of composition TiCl^»6NHg by mixing NHg, TiCl^ and Hg in the vapor phase. The 6 -ammine which was warmod in the absence of air and
over CaCl2 became pure yellow in color. This is in contrast to the results of Rosenheim and Schutte2 8 Who prepared the yellow to reddish- brown amorphous powder Which analyzed TiCl^»6NHg while still moist with 27 ether. The 6 -ammine quickly hydrolyzes ' in air With the formation
of TiOg, ^ 3 an^ NH4 C1 . The ammine was reduced^ to metallic
titanium by metallic potassium or sodium. hrager prepared^
TiCl4 »4NHg by reaction of TiCl^ and at -30°C. Heating to 20°C.
produced.a yellow to yellowish-red solid. The distorted tetragonal
structure changed to cubic and the color changed to gray-green at
2 0 0 °C. On heating®9 , to 350-400°C. for 2-3 hours, the black to
black-violet TiNCl -was formed. Brager also determined the crystal
structure of TiCl^'dNHg. The addition compound and NH^Cl (internal
standard) were mixed in equal quantities and the constants for the unit
cell, a powder pattern. Gaseous fluorine nitrate, NOgF, bubbled through a op solution of Tici^ in Cci^ reacted with the evolution of heat to yield a yellow solid compound which is so unstable that it decomposes O Q in a vacuum desiccator. TiCl^*2N 0Cl or (NO)gTiClg was prepared by the addition of TiCl^ to a solution of NQC1 in 9 C1^. The compound _ It ZoRosenheim, A., Schutte, 0., Loc. Cit. 29Rose, H., Pogg. Ann. 16, 57-67 (1829). ^OBrager, A., Acta physiochim. U.R.S.S. _10, 887-902 (1939). 3lF0Wles, G. W. A., Pollard, F. H., J. Chem. Soc., 2588-93 (1953). 32Ruff, 0 ., Kwasnik, W., Angew, Chem. _48, 238-40 (1935). 33Rheinholdt, H., Wasserfuhr, R., Ber., 60, 732-7 (1927). was yellow and extremely sensitive to moisture. Hake3^ reported the crystals to be octahedral, yellow and iridescent. The solid is insoluble33 in liquid N0C1 and does not conduct electricity, A crystalline compound of the same composition was prepared by Weber33 by reacting TiCl^ with the vapor over aqua regia. Hampe37 mixed N02 and and obtained a solid product, 3TiCli|»4N0Cl, which Was QQ sublimed; it is to be pointed out that this compound is more probably TiCl4 »N0Cl. TiCl^*2N0Cl can be prepared3^ by bubbling N2 O4 through TiCl^ and heating the solid product which forms. The addition compound was purified by sublimation. Tetranitromethane, C(N02 )4 , or trichloronitromethane, CClgtNOg), mixed with TiCl^ and then heated also gives rise to an addition compound. TiCl4 and liquid H2S at -78.5°C. produces’^ the lemon yellow dithiohydrate TiCl^*2H2S which Was identified by thermal analysis. According to Ralston and Wilkinson^ a yellow crystalline solid whose composition is 2TiCl4 »H2S is formed at -7 7 °C. This compound is quite unstable and is almost almost explosive upon rapid heating. The reaction between f i C ^ and liquid H2S is very yigorous even at room temperature. At first a brown, solid substance is formed which dissolves in liquid HgS to form a red solution which has the odor characteristic of mercaptans. After a 3% a k e , A. Reihlen, H,, Lieb. Ann. 452, 47-66 (1927); Chem. Abs. 21, 1418 (1927). Burg, A. B., Campbell, G. W., J. Am. Chem. Soc., _70, 1964-5 (1948). 36Weber, R . , Pogg. Ann., 118, 471-9 (1863). 37Hampe, «., Ann., 126, 43-8 (1863). 38Dermer, 0. C., Fernelius, W t C., Z anorg. Chem. 221, 83-96 (1934). 3 ®Reihlen, H., A. Hake., Loc. Cit. ^^Biltz, W., Keunecke, E., Loc. Cit. ^Ralston, A. W., Wilkinson, J. A., J. Am. Chem. Soc. 50, 258-64 (1928). 9- few hours a layer of black needles of titanium ( + 3) chloride mixed with yellow sulfur is formed. Wolbling42 prepared the addition compound TiCl^'N^S^ by adding 5 grams of TiCl^ diluted With Cci^ to a boiling solution of 4 grams of N4 S4 in CCl^. The solution did not become turbid on further addition of TiCl^ in GCl^. The brownish red precipitate was washed with ^Cl^ in the absence of moist air and drisd in a vacuum disiccator. It had the composition of TiGl^'N^S^ as proven by analysis. Purification by means of recrystallization was not possible since no suitable solvent could be found. The compound, in contrast to N^S^, is not very explosive but burns upon ignition with a bluish flame leaving behind a white residue. On Warming to approximately 1 0 0 °C. the color deepens and the compound finally completely decomposes without melting. It reacts quite vigorously with HgO, KOH solution and HNO3 but reacts mildly with absolute alcohol or aqueous Hci, Bond and S-fcephens^ found in the system TiCl^-SOg a Wide region of incomplete miscibility of the two liquid phases. In a later investigation^ the solid 2TiCl/j.»S02 was found to be in equilibrium with both liquids at -31.4°C. The compound TiCl^/SOg was obtained^ as the result of the reaction AG between TiCl^ and chlorosulfonic acid. Lutschinsky prepared TiCi4 *2 S0 g as the result of the reaction between TiCl^ and SOg in the solvent CCI4 . This compound was also prepared from the reaction of Ti 02 and SO2 CI2 at 300-400°C. The product, a yellow crystalline solid which has a burning disagreeable odor and which decomposes organic ^Wolbling, H., Z. anorg. Chem., _57, 281-9 (1908). ^^Bond, D. A., and Stephens, W. R . , J. Am. Chem. Soc., _51, 2910-22 (1929). ^ B ond, P. A., and Belton, W. E., L o c . Cit. 4 ^Clausnitzer, N., Bar. _11, 2011-2-1 (1878). ^Lutschinsky, G. P., Z anorg. Chem. 226, 333-7 (1936). materials, can be sublimed With the evolution of light and simultaneous decomposition of TiCl^ and SO3 . The addition compound reacts with Water to form ClgTiCSllg.) and ^Cl. The compounds TiCl^.»2S03 and TiCl^'SSOg Were also prepared by Lutschinsky by reaction of TiCLj and SO3 dissolved in SO2CI2 . The yellow, solid 1:2 product is formed when the reaction mixture is composed of 6 moles of SO3 per mole of TiCl^ but the 1:3 product is formed when the 6 to 1 ratio of SO3 to TiCl^_ is exceeded. Liquid TiCl^. reacts with liquid SO3 to produce yellow TiCl^*2S03 with a large evolution of heat. Lutschinsky^ found liquid TiCl^ to be completely miscible in liquid SO2CI2 but identified the compounds T i C ^^SOgC^ in excess TiCl/j. and TiCl^/SC^C^ in excess S02 Cl2 by thermal analysis. The components, TiCl^ and SO2CI2 were obtained by distillation of TiCl4 *2S0 2 Cl2 . The compound TiCl^/SC^ is formed by the action of SOg on TiCl^»2S02Cl2 . The yellow compound, TiCl^*SCl^ was prepared48 by the drop-wise addition of sulfur and chlorine into a solution of TiCl/j. in SO2CI2 and by Rose48 from the conduction of gaseous chlorine over sulfur and titanium. Rose also prepared 2TiCl4 »SCl4 by the chlorination of Ti02 with CI2 and sulfur monochloride. Wise^ 8 precipitated the white crystalline compound, TiCl^^SeOClg, from a supersaturated solution of TiCl4 in SeOC^. Rose8’*- dissolved TiCl4 in PH3 at room temperature to produce a yellow solid. The reaction is quite exothermic. At room temperature a maximum of 1.90 moles of PH3 is taken up per mole of TiCl^ a-fc a PH3 pressure 4 ^Lutschinsky, G, P., J. Gen. Chem. (U.S.S.R.) _7, 207-11 (1937); Chem. Abs. _31, 4613 (1937). 4 8 0. Ruff., G. Fischer., Ber. _37, 4513-21 (1904). 48Rose, H . , Loc. Cit. 50Wise, C. H . , 1. Am. Chem. Soc., 45, 1233-7 (1923). ^■*-Rose, H., Loc. Cit. -11- of 15 atmospheres. The monophosphine complex, TiCl^/PHg is in equilibrium with TiCl^ at 0 °C., the equilibrium pressure being of approximately 5 mm. Hg. The complex TiCl^*2PHg can also be prepared and it is in equilibrium with the monophosphine complex at 0 °C, at an equilibrium pressure of 138 mm. Hg. H^ltje^ obtained crystals of this addition compound from sublimation. The compound TiCl^’PClg has been studied quite extensively. Bertrand88 found it to be a yellow solid which melts at 85.5°C; Raeder8^ studied the compound cryoscopically and ebullioscopically; Sj^rum88 found the crystals to be rhombohedral, although nearly octohedral with the lattice parameters + + to be, Z = 8 ; a - 12.61 0.050, b ^ 13.59" 0.05, c B 12.70" 0.05 5 and the ratio a:b:c equal to 0.930? 1: 0.937. TiCl^.pClg was prepared88 from the vapor of its components in a heated tube although wehrlin and Giraud87 prepared it.by heating to 150°C. an equi-molar mixture of TiCl^ and PClg in a sealed tube. It was also prepared88 by heating one mole of ^i 02 with three moles of FClg and evaporation of the POClg. Gervecka^ burned titanium phosphide in chlorine gas to produce the spongy yellow solid TiCl^PClg which was purified by sublimation. It reacts with methanol and ethanol to form TiCl(0R)g, HC1 and an alkyl chloride. Ruff and Ipsen68 prepared the yellow crystalline TiCl^^PQClg from a mixture of TiCl^ and excess PQClg. There is some controversy shrouding the compound TiCl^*POClg Fj2 H^ltje, R., Loc. Cit. 88Bertrand, A., Bull. Soc. Chim. (l),_33, 565-6 (1880). ^Raeder, M. G., Loc. Cit. 8 8 Sjrfrum, H., Norsks Vidensk Selsk. Forh. _17, 17-20 (1944); Chem. Abs. 40, 5974 (1946). “Sfeber, R . , Pogg. Ann. JL32, 452-6 (1867). Wehrlin, E., Giraud, E., Compt. Rend. _85, 288-90 (1877), 88Tuttschew, J., Ann. 141, 111-8 (1867). %ervecke, J., Lieb. Ann. 361, 79-88 (1908). 60Ruff, 0., Ispen, R . , Ber. 36, 1777-83 (1903). -12- which was formed56 as crystalline needles from the drop-wise addition of POClg to TiCl4 . Wahrlin and Giraud prepared the compound by heating in a sealed tube a mixture of 2 moles of PC15 per mole of TiOg. Ruff and Ipsen maintain that the so-called 1:1 compound is actually the 1:2 compound based on melting and boiling point data. Gutman61,62 used the characteristic dissociation of POCl^ to define acids and bases. Thus the solvated compound TiCl4 *2P0Clg whose solution is an electrical conductor, is postulated to be composed of the ions, N M 2POCI2 and TiClg" . No compound containing P0C14 in the solid 6 3 state is known. It is to be noted that TiCl^ and PClg do not react in the absence of air. In the presence of 02, PCI3 reacts to yield POClg which then reacts with TiCl4 . Phase studies show the formation of compounds with mole ratios corresponding to 1:1 and 1:2. X-ray analysis of TiCl^'POClg was identical to that obtained by S^rum55 for the compound thought to be TiCl4 *PCl3 . The compound TiCl^»2HCN was formod64,65 from its components cooled in a brine mixture. This compound is a lemon yellow solid which crystallizes in the rhombic octahedral habit. The gaseous compound decomposes^ with evolution of light to titanium nitride and perhaps carbon. A yellow crystalline solid of TiCl4 *ClCN is prepared66 by direct reaction of the components. It absorbs NH3 with the formation of an orange to red solid. Needles of TiCl4 *2BrCN Were prepared6''" from a solution of the compounds in CSg 61Gutman, V. t s. anorg. u. allgem. Chem., 270, 179-87 (1952). 6 2 Gutman, v., ibid., 269, 279-91 (1952). ®3Groenevold, , van Spronsen, J. W ,, Korwenhaven, H. W., Rec. Trav. Chim., 72, 950-6 (1903). K^rantassis, T7, Compt. Rend. 194, 461 (1932). 65Wohlor, F ., Ann. J73, 226-8 (18*557. 66Wohlor, F., Ann. _73, 219-21 (1850). ^Oberhaussr, ^., Schormuller, J., hoc. Cit. -13- go while -the yellow 1:1 compound Was formed by heating a mixture of BrCN and TiCl4 . Reaction With NH3 produces a brick red product. The yellow solid addition compound whose composition corresponds to TiCl4 »(CH3)20 was prepared69 from the components at high temperatures and pressure. The yellow76'7^- solid, TiCl^»2(CH3CH2)20 decomposes at 60° and is soluble in alcohol to produce a yellow solution whil?"’^ ’ the compound TiCl^CCHgCHjj)20 melts at 42-45°C., boils at 118-120°C. The sulfur analogues, thioalcohols and thioethers as well as mixed compounds containing one mole of ethyl benzonate were prepared7^: TiCl4 »C£H5 SH; TiCl4 «2C2H 5SH; TiCl4 »S(C2H 5 )2; TiCl4 *2(C2H 5 )2S are deep red crystalline solids and also prepared were TiCl^'CgHgSH'CgHgCOjjCgHg and TiC^^CgHg^S'CgHgCOjjGjjHs, In addition, Demarcay prepared the following type of compounds: 2TiCl^*E; TiCl^.E, TiCl4 *2E, and TiCl4 »EE* where E and E* represent one mole of an ester of a monobasic acid or one-halfrmble of an ester of a dibasic acid. Dimethylphthalate reacts7^ with TiCl4 in solution of CHCI3 to yield the yellow crystalline compound, TiCl^CgH^COjjCH^g. Hertel and Demmer7^ found the dimethylester of fumaric acid (fum) to react with TiCl4 in benzene solution to form four addition compounds all of which were yellow solids: 2TiCl4 *fum; TiCl4 »fum; TiCl4 *fum*2CgHg and TiCl4 *2fum. Evard76 did not disclose how he prepared the yellow 6 6 Schneider, E. A., J§. anorg. Cham. _8 , 81-97 (1895). 6 9 Loder, D. J . , Walker, K. E., U.S. Patent 2052889 (1936). TOpimitrius, Ladikos, E., Praktika (Akad. Athenan) _5, 449-54 (1930); Chem. Abs. 27, 3160 (1933). '^•'■Demoly, ^ , r*^omp-fc, Rend. Trav. Chim. _5, 325-36 (1849). 72Bedson, P. P., Ann. 180, 235-9 (1876). ^Demarcay, E <} C 0mpt. Rend. _76, 1414-7 (1873). ^Scagliarini, G., Tartarini, G., Loc. Cit. 76Hertel, E., Demmer, A., Ann. 499, 134-43 (1932). 76Evard, F., Compt. Rend. 196, 2007-9 (1933). -14** solid TiCl^»OC(CgHg)g but Scagliarini and Tartarini74 prepared it as bright yellow needles from its components dissolved in benzene. Hartal and Demmer7^ prepared TiCl^»2 C0 (CgHg) as bright yellow heedles o 76 which has a melting point of 150 C. Bright red needles of TiCl4 *2C0tC6H 5 )(GHZCHC6H5)f red crystals74 of TiCl4 »2C6H g( C H 0 ) ^ b H 2 and yellow crystals77 of TiCl^’CgHgCOCl have been prepared. Bertrand7® prepared TiCl^C^COCl from the reaction of TiCl^ with acetylchloride. It is a yellow octahedral solid melting at 25-30°C. and is very 7Q soluble in CSg and CHgCOCl. The titanium compound which corresponds to the tin compound SnCl4 »2CQHgN0 , cannot be prepared in pure form since it spontaneously decomposes. A shining red amorphous solid is formed in excess TiCl^ while a yellow amorphous solid is formed with an excess of nitrosobenzene in CC14 with liCl^. The reaction1^ of nitromethane and nitroethane with Tj.ci4 is exothermic and results in the formation of yellow TiCl^'C^HCHg and TiCl^'C^NCgHg, respectively, which Were purified by sublimation. The bond is formed through the nitro group. The yellow crystalline solid, TiCl4 »CgHgM02 was ascertained®® from the phase diagram. Compounds Were also prepared with TiCl4 and the following organic compounds: meta and para-chloronitrobenzene, meta-bromonitrobenzene, ortho-meta-and para-nitrotoluene and 1,3,4-nitroxylene. Compounds of the type TiCl4 *X and 2TiC'l4 *X where X was 7 ^Bertrand, A., Bull. Soc. Chim. (2) J54, 631-2 (1880). 7®Bertrand, ^., Bull. Soc. Chim. (l) JJ3, 403-5 (1880). 7®Reihlen, H . , Hake, A., Loc. Cit, 8 °Puschin, N. A., Ann. 551, 259-71 (1942). m~dinitrobenzene and m-dinitrotoleune have been prepared80. The existence of addition compounds of TiCl4 with meta-dinitrobenzene in various mole ratios as disclosed by Hertel and Demmer7® could not be verified by Puschin80. Hertel8'*- defended his work in a later article where he stated the nature of the cooling Gurve depended on seed materials and the addition compounds which appeared had the composition corresponding to mole ratios of 4:1; 2:1 and 3:2. Hertel maintained a compound of 1:1 does not exist. Reihlen and Hake78 prepared the 2:1 on compound from the components in CC14 solution. Crystalline compounds0 as 2TiCl4 ’X and TiCl4»X where X is meta-dinitrotoluene; 2TiCl4 ’X where7^ X is meta-dinitrobenzene; TiCl4 *X where78 X is meta-dinitrobenzene from the components dissolved in CC14 *iav0 b0 0fl formed as deep yellow o n crystals. There is no reaction between TiCl^ and trinitrotoluene and the -OH group is responsible for compound formation between TiCl4 and trinitrophenol. Molecular compounds of TiCl4 with alpha-nitroaniline and meta-nitrobenzoic acid have been prepared and all are thermally unstable. Mixtures of TiCl4 with ortho-nitrophenol, trinitrophenol or para-nitrosodiomethylaniline are explosive. Leeds88 prepared the greenish yellow needles of TiCl4 *(CgHg^NH but the pure product88 could not be obtained. Dermer and Femelius have formed the following compounds: bright yellow TiCl^^CgHg^NCOCHg, dark brown TiCl^^C^H^^NH, yellowish brown TiCl^-C^CgH^SC^H^, bright yellow TiCl4 -C6H 5CH:NC6H5, yellow TiCl4 *(CgH5 )2 C:NCgH5f orangish yellow 3TiCl4 *2CgHgN:NCgHg, orangish red TiCl4 *2CgHg:NCgH4 0C0CgHg, deep green TiCl4 *C6H5N:HNHCgH5, dark green 3TiCl4 *2C6H 5N:NN(C6Hg)2> ^Hertel, E ., Ann. _553, 286-8 (1942). 8Leeds, A. R . , Jahresber. der Chem. 500-6 (1882). 8 8 Dermer, 0. C., Pernelius, W. C., Loc. Cit. 16- brown TiCl^»2CgH,yN, white needles of TiCl^^CgH^N, yellow needles of TiCl^'CgH^-^N, violet needles of TiCl4 *2 CgH7N, and no compound formation with alpha-picolin® or chinaldine. The compound of TiGl^.6 GgHgK reported by Rosenheim84 could not be prepared by Dermer and Fernelius^8 . Leonard8*^ prepared green needles of TiCl^*CgH^^N in heptane. Violet blackish needles of TiCl^^CCgHyN)^ have been made®®. Henke87 prepared TiCl^^CHgCN as colorless crystals which Were purified by sublimation. QQ The compound TiCl4 *C,jHgCN was reported from a phase study of the pure components although Hertel and Demmer8® reported the formation of six compounds with mole ratios corresponding to 1:1, 5:6, 2:3, 1:2, 2:5 and 1:3. The 1:2 compound was also made87 as a white crystalline solid which can be distilled without decomposition. Henke^? also prepared TiCl *2CgHgCN as yellow crystals and TiCl4 *2CgH*QCM. Hertel and Demmer8® observed five compounds from phase studies of TiCl4 and benaonitrile with mole ratios of, 1:1, 1:2, 1:3, 2:3, and 5:6. TiCl^^para-CHgCgHjCN was also observed9® in phase studies. White crystals of 2TiCl4 *7CgH^2N4 *C2H 2Cl2 were prepared®-*- from CgligClg solution while TiCl4*12CgH42N4*3CHClg was prepared®^ from CHCl^ solution. Trost9 3 ’®4 prepared TiCl4 *4N(CH2CHg)3, 2TiCl4 *N(CH2CH3 )3 and TiCl^'dCHgCHgffi^ by direct reaction. Sisler, et al.®^ found that TiCl4 reacts vigorously with tetrahydrofuran, tetrahydropyran and ^Rosenheim, A., Schutte, 0., L o c . Cjt. 8 Leonard, ®. S., J. Am. Chem. Soc., J13 2618-26 (1921). ®®Schmitz-Dumont, 0 ., Motzkus, E., Bar. _62, 466-73 (1929). 87Henke, W., Ann. JL06, 280-7 (1858). ®®Ulich, H., Hertel, E., Nespital, W., g. phys. Chem. B17, 21-45 (1932). 8 ®Hortol, E., Dommer, A., L o g . Cit. ®®PusGhin, H. A., L o c . Cit. Scagliarini, G., Ivlonti, LI., Loc. Cit. ®^Scagliarini, G., Brasi, E., Loc. Cit. ®3Trost, Y3. R., Can. J. Chem., _30, ’835-41 (1952). 94Trost, W. R . , ibid., _30, 842-3 (1952). 95sisler, H. H., et. al., Loc. Cit. -17- dioxane, from carbon tetrachloride solutions. In every case the product was a yellow crystalline compound. Compounds corresponding to 1:1 when prepared from excess TiCl^ and 1:2 are obtained from excess tetrahydropyran or tetrahydrofuran. Only the 1:1 compound is produced in the presence of either an excess of dioxane or titanium tetrachloride. The above authors also prepared TiCl^CHgOCgHg. It is to be pointed out once again that this is not a complete literature survey of the addition compounds of TiCl^, but rather that enough of the field is covered so that general trends could be considered which might lead to a better interpretation of the data. Addition Compounds of Zirconium Tetrachloride. The preparation9^ ’97 of the three ammoniates, ZrCl^‘2NHg, ZrCl^*4NHg and ZrCl^/BNHg was carried out by the reaction of ammonia with ZrCl^ under different conditions. When gaseous NHg was passed into an ether suspension of ZrCl^, a precipitate was obtained whioh was shown to be ZrCl^'BNHg. This compound is stable in air at room temperature and evolves NH^Cl on heating. When gaseous NHg Was passed over solid ZrCl^ the compound ZrCl^*2Nflg was formed. At 100°C. the last reaction was found to yield ZrCl^*4NHg which Was identical to the 93 compound prepared by Paykull by heating a mixture of ZrCl^ and NH^Cl. 99 Stahlar and Denk attempted to repeat Matthews work, but obtained somewhat different results. They varified the compound ZrCl^*8NHg which was obtained by passing NHg over ZrCl^ at room temperature. At elevated temperatures the compound ZrCl^/SNHg was obtained instead of 93MattheWs, J. M. , J. Am. Chem. Soc., _20, 815-43 (1898). 97Fowles, G. W. A., Pollard, F. H . f J. Chem. Soc., 4128-32 (1953). 93Paykull, S. R., Bor._6 , 1467 (1873). " s t a h l e r , H . , Denk, B . f Ber. 38, 2611-19 (1905). -18- ZrCl *4NHn. Although Stahler and Denk attempted to reproduce Matthews 4 ° work, they did not use the same experimental methods, so it does not completely eliminate the existence of the di-and tetra-ammoniate. Furthermore, the tetrammoniate was prepared by Paykull by an independent method. The system of zirconium tetrachloride-phosphoryl chloride has been shoWn^® to yield the following three compounds: ZrCl^.*2POCI2 , ZrCl4 *P0Gl3 and 3ZrClA *2P0Cl3 ; the latter was independently reported by Katz and Gruen'*'^'*'. The ZrCl4.*P0Cl3 was found as the nonvolatile material when the excess P 0CI3 was removed from the reaction mixture of ZrGl/j. and POGlg. It was f ound that a mixture of ZrCl^ and POCl^, when heated, produced a distillate which boiled at 363°C. and corresponded to the compound 3ZrGl^*2P0Clg. Katz and Gruen found the same compound using a similar method of preparation and reported the boiling point as 360°C. The above 3:2 compound is apparently the same as the previously reported 2ZrCl^*P0Clg which Van Ankel and deBoer-*-®3 reported as distilling at 363-364°C. from the system zirconium tetrachloride-phosphoryl chloride. The latter's analytical method for zirconium undoubtedly accounts for the erroneous ratio. Paykull-*-®3 reported the preparation of a material which distilled at 325°C. and which was found to correspond to 2ZrGl^/PClg in composition. Van Arkel and deBoer reported Paykull1s Work and confirmed the compound 2ZrCl^*PClg. As previously pointed out Van Arkel and deBoer's method of analysis did not take into account the fact that the precipitate was a zirconium phosphate-zirconium hydroxide mixture. The work has not ■^®Larsen, E. M., Howatson, J., Gammill, A. M., Wittenberg, L., J. Am. Chem. Soc., J74, 3489-92 (1952). ^ 01 Katz, J. J., Gruen, D. M., J. Am. Chem. Soc. _71, 38 43-4 (1949). :*-®3Van Arkel and deBoer, Z. anorg. Chem., 141, 289-96 (1924). 103Paykull, Bull. Soc. Chem. No. 2., J20, 65-7 (1873). -19- been repeated using the "peroxy conversion" to separate'*'^ the zirconium from'the phosphorus. The system zirconium tetrachloride-phosphoryl 105 dichlorofluoride has been shown to yield at least two compounds The compound ZrCl^^POClgF was isolated from a mixture of ZrCl^ and POClgF by removing the excess POClgF within one hour at room temperature. Longer reaction permitted a halogen exchange to occur which was found to be complete in 28 days, whereupon the compound ZrClA *2P0Cl u 3 Was obtained. The possible halogen exchange is expressed in the following equation: ZrCl4 ‘2P0Cl2F + 2P0C12F « ZrCl4 *2P0Cl3 + 2P0C1F2 and/or POFg. The compound ZrCl4 *2P0Cl2F was found to thermally decompose into ZrCl4 *P0Gl2F when heated to between 25° and 115°G. Rapid removal of the decomposition product, POClgF, was found necessary if liquification occurred so that halogen exchange Would not occur. Attempts to decompose ZrCl^’POCl^F into 3ZrCl4 *2P 0Cl2F were unsuccessful. When a mixture of ZrCl4 and POC^F was heated, the chloride-exchange compound 3ZrCl4 *2P 0Gl3 Was obtained as the distillate and not the expected monofluoride derivative. A few experiments have been reported which deserve to be mentioned although they did not result in the formation 106 of molecular addition compounds. Matthews treated ether suspensions of ZrCl^ with ether solutions of PGlg and FGl^, and found that no reaction resulted. Although no etherates of ZrCl4 appear to have been reported, the compound ZrI4 *4 (C2H g )20 has been reported-*-*^ and it is possible that similar compounds of ^rCl^ may occur, ^his may account /''^Larsen, E. M., Fornelius, W. C . t Quill, L. L., "Inorganic Snythesis," The McGraw Hill Book Co., New York, 1951, Vol. 3, p. 73. •^^Larsen, E. M . , _et. a l, , Loc . Cit. ■j-CGMatthews, M., Loc. _£it. Stahler, H . f Denk, B., Loc. Cit. -2 0— for no reaction being observed with the above two phosphorous halides, or at least for the PCI5 . The'1'08 two addition compounds, ZrCl^«2CgH5C02C2H 5 and ZrCl^ZCgHgCOgCHg have been prepared by direct reaction. Larsen'1'08 also found that the system zirconium tetrachloride- phosphorous (III) Ghloride in the dry state did not result in compound formation. Phosphine-1--1-0, like other phosphorous (ill) compounds, does not react with ^rCl4 . The following addition compounds with esters, 111 aldehydes and ketones have been reported by Jantsch as being formed when an ether solution of the addition reagent was shaken with the tetrachloride at -15°C. ZrCl4 *2C6H 5C00C2H5, ZrCl^CHgCHOH C00G2H 5 , ZrCl4 -C6H 4 (0H) COOCHg, ZrCl4 »CH3CH0H G00C2H 5 , ZrCl4 •2C6H 5CH0HC00CH3, ZrCl4 *C6H4 0HG00CH3 , ZrCl4 •2C6H4 (OH)CH0, ZrCl4 * 2CH3C0C6H 5 ZrCl4 *2C6H 5 G0C6H5 , ZrCl4 ’C6Hg(0H)(0CHg)C0CH3 ZrCl4 * 2C6H 5C0G2H 5 , ZrCl4 «H0C6Hg(0GHg)C0CH3 ZrCl4 *2CgHgCH0HC0CgHg, ZrCl4 '2 acetylacetone ZrCl4 *2 benzoylacetone The last two addition compounds, the 1,3-diketone derivatives, decomposed into the di-and tri-substituted compounds at elevated temperatures. The following miscellaneous compounds have been shown not to add to ZrCl4 in ether solution; dicyanogen, formanitile, acetonitile, cyanogen chloride and benzonitrile. ■*-°®Hummus, W. S., jrt. _al., J. Am. Chem. Soc., _74, 139-41 (1952). 109Larsen, E. M., jrfc. _al., Lo c . Cit. jJ-^Holt je, R. , Loc. _£it. ■'■■'■^Jantsch, G., J. prakt. Chem., 115, 7-24 (1927). -21- Addition Compounds of Zirconium Tetrabromide. 112 Matthews prepared the following compounds by the reaction of ether solutions of the amines with ether suspensions of ZrBr4 : ZrBr4 ‘4C2H 5NH2 ZrBr4 *4C6H 5NH2 ZrBr4-2G5H5N The tetrabromideHS ^oes not yield an addition compound on mixing with ethyl benzoate. Addition Compounds of Zirconium Tstraiodide. Stahler and Dank^-Ll prepared the following series of amraoniates by the action of gaseous ammonia on Zrl4 at the indicated temperatures: ZrI4 *8NH3 at 2 2 °C., ZrI4 .7NH3 at 1 0 0 °C., ZrI4 *6NHg at 150°C. and ZrI4 *4NH3 at 2 0 0 °G. The compound Zrl^.8NH3 was also prepared by the action of liquid ammonia on Zrl4 at 60°G. The above workers also obtained the compound ZrI4 *4(G2Hg)20 by passing hydrogen saturated with diethyl ether over Zrl4 at room temperature. Addition Compounds of Hafnium Tetrachloride. The f ollDWing^--*-5,116 are the only molecular addition compounds that have been reported for hafnium tetrahalides: HfCl4 *2P0Cl3 HfCl4 ‘2P0Cl2F HfCl4 *P0Cl3 HfCl4 *P0Cl2F 3HfCl4 -2P0Cl3 The compounds HfCl4 *2P0Cl3 and HfCl4 *2P0Cl2F were obtained by removing 1 1 ? ‘‘Matthews, J. M., Loc. Cit. "'••'■^Chapman, P. W., _et. _al., J. Am. Chem. Soc., _74, 5277-9 (1952). H^Stahler, A., Denk, B., Loc. Cit. 115Lar sen, E. M . , jrfc. _al., Loc. Cit. ■*-^®Katz, J. J., Gruen, D. M., Loc. Cit. -22- the excess phosphoryl halide from -the reaction mixture at room temperature. Thermal decomposition of these compounds between 25°C. and 115°C. gave HfCl4 *POClg and HfC14 »P0C12F. The latter two compounds are decomposable but apparently not into the corresponding 3:2 compounds. Katz and Gruen obtained 3HfCl4 *2P 0CI2 as a distillate when a mixture of hafnium tetrachloride and phosphoryl chloride was heated at atmospheric pressure. Hummuset.al. prepared and characterized HfC^^CgHgCOjjCHg and HfCl4 .2C6H 5C02 C2H5. Addition Compounds of Tin Tetrachloride. Pfeiffer and Halperin^® prepared the following tin tetrachloride addition compounds by direct reaction: SnCl4 *2C0 (0C2H 5 )2 , SnCl4 *CH2 (C00C2H 5 )2 , SnCl4 *CH2 (C00CH3)2, SnCl4 *CH2 (C00C2H5 )2 , SnCl4 'CH2 (CH2C00C2H 5)2 , SnCl4 *C6H 4 (C00C2H 5 )2 , SnCl4 »2(C2H 5 )2 0, S n C ^ ^ C H g C N . All compounds decompose in air but are quite stable when stored over SnCl4 reacts'^ vigorously with tetrahydropyran and tetrahydrofuran to yield solid products corresponding to 1 mole of SnCl4 per 2 moles of ether and have no noticeable vapor pressure of ether. These reactions liberate large quantities of heat. In the corresponding totrabrromide reactions, however, little heat is evolved and the solid products have noticeable vapor pressures of the corresponding ether. Rheinboldt"*-^ and Boy reported the formation and ^Hummus, W. S., L o c . Cit. iJ-^Pfeiffer, P., Halperin, 0., Loc. Cit. •'••'-^Sisler, H. H., et al., L o c . Cit. -^C’Rheinboldt, H., Boy, R., J. prakt. Chem., 129, 268 (1931). -23- isolation of the stable dioxane compound, SnCl4 *2C4Hg0 2 . At -75°C., SnCl4 does not-*-2-*" react with N02C1. The compound, SnCl4 *2N0Cl, was prepared-*-22 from Sn, SnCl2 or SnCl4 and N0C1 at low temperatures (liquid NOCl) and under pressure at 100°G. Trost-*-23 , 424 prepared the following compounds1 SaCl4 *4N(CH2 CH3)3; SnCl4 »3N(CH2 CH3 )gj SnCl4 ‘2N(CH2CH3)3; SnCl4 *N(CH2 CH3)3; SnCl4 *SCH3CH2NH2 by direction reaction. Addition Compounds of Tin Tetrabromide. Attempts to obtain reaction-*--*-8 between SnBr^ and esters of the following carboxylic acids: oxaliG, methylmalonic, succinic, glutaric, benzoic, phthalic, were unsuccessful. Diethyl ether was reported-*--*-8 IpR to be unreactive tcraard SnBr4- Sisler, et al. have prepared SnBr4 *2 (C2H 3 )2 0 and SnBr4 *2X where X designates tetrahydrofuran and tetrahydropyran. They found that tin tetrabromide reacts with both tetrahydrofuran and tetrahydropyran at room temperatures to form a solid product. These reactions were carried out, both in the presence of an excess of the ether and in the presence of an excess of the tetrabromide. With each of the ethers tin tetrabromide forms the same product regardless of which component is in excess. Tho compound SnBr4 *2C4H30 as obtained is a tan colored, crystalline substance which melts with charring and vaporizes at about 120°C. The solid is not extremely hygroscopic as compared-*-28 to SnCl^»2C4HgO. •*-^-*-Sisler, H. H. , Batey, H. H., J. Am. Chem. Soc., _74, 3408-10 (1952). 122parkington, J. R., Whynes, A. L . , J. Cham. Soc., 1952-8 (1948). 123Trost, W. R., Can. J. Chem., _30, 855-41 (1952). 124Trost, W. R . f ibid., _30, 842-3 (1952). J-2 5 Sisler, H. H., J. Am. Chem. Soc.,_73, 426 (1951). -*-2 8 Sisler, H. H., et a l ., Loc. Cit. -24- The compound SnBr^*2Cp.H^Q0 is a pale yellow crystalline substance. Bromine is evolved"*-^ when SnBr^ is treated with NOgCl. Gutmann^-^ studied the system SnBr^-POClg and found no evidence of a solid solvate but the solution was conducting which he considered to be evidence for the ion SnBrgB . Addition Compounds of Tin tetraiodide. Tin tetraiodide does not react^ 8 with tetrahydrofuran, tetrahydropyran, or^ with CHgCN, diethyl ether or esters of the following carboxylic acids: oxalic, malonic, succinic, cinnamic or phthalic. Iodine is evolved^l as a result of the vigorous reaction between and NOgCl. ■'-27Q.ur(;mannj y ., L o o . Cit. -'-‘^Sisler, K., Schilling, S., Graves, W. 0 ., J. Am. Chem. Soc., 73, 426-9 (1951). III. PREPARATION AND PURIFICATION OF REAGENTS Titanium. The titanium used in the preparation of the titanium tetra-bromide and-iodide was prepared by the thermal decomposition^9 of titanium tetraiodide at Battelle Memorial Institute^0. The metal was converted to Ti02 and analyzed spectrographically for all metallic impurities. A Vicker Hardness number of 80 for the pure massive metal is additional critereon for the extent of purity. It is to be noted that a more precise analysis could have been obtained by radioanalytical techniques at Oak Ridge, Tennessee, but the six month delay seemed prohibitive. Element Impurity Detection Limit Ti Major ----- Fe 0.05$ 0.001$ Si 0.01 0.001 Al 0.005 0.002 Mn 0.010 0.0005 Sn 0.010 0.0005 Cr 0.005 0.001 Mg 0.001 0.0001 Pb 0.005 0.001 Ni 0.001 0.0005 Cu 0.001 0.0001 No other metallic elements were detected. Bromine. The bromine used in the preparation of titanium tetrabromide was furnished by the Dow Chemical Company. No further purification was deemed necessary as it was iodine and chlorine free as per Dow Company ■^^Campbell, I. E., Trans. Electrochem. Soc.,_93, (6 ), 271-85 (1948). •'•^Bat telle Memorial Institute, 505 KingAve., Columbus, Ohio. -25- -26- Specifioa-fcions. See Appendix I for a discussion of the significance of the chlorine impurity. Iodine. The iodine as supplied by Mallinclcrodt Chemical Works was used without further purification. Titanium Tetrabromide. Titanium tetrabromide, a yellow crystalline solid with a melting point*3'1- of 38,23°C., and a boiling point*3* of 231.6°C., was prepared by the direct reaction of titanium metal and liquid bromine. In a typical run the apparatus was assembled as depicted in Figure 1. The entire unit was heated with infra red heat lamps and simultaneously purged with dry argon through side tube (A). This was continued for about one hour to remove air and moisture. The side tube (A) was then sealed off and the argon purge gas admitted through tube (B). Water was then passed through the condenser and one pound of liquid bromine was added after the glass cooled to room temperature. The bromine was brought to the boiling point with a Glascol heating mantle and titanium turnings Were dropped through the condenser into the boiling bromine. The rate of addition of the titanium was governed by the boiling point of the liquid mixture and the heat transfer capacity of the reflux condenser. At the outset the liquid was essentially / 0 pure bromine (B.P. of 58.78 C.) but as the experiment progressed the concentration of TiBr4 increased* 33 and the boiling point gradually approached that of pure TiBr4 (231.6°C. at 760 mm.). The titanium *3*0 ffice Naval Research Contract Nonr. 1120(00) Status Report No. 2. 132s0e Appendix II. -27- Argon purge gas i Figure I. Apparatus for preparation of TiBr4 -28- usually did not react immediately but was inhibited by a very thin film of TiC>2 Which had foimed during the machining process, i.e., the process of producing titanium chips from titanium rod. Thus, there was a slight induction period for the reaction, but the rate of addition was such as to have some titanium reacting at all times. If too large a quantity of metal reacted at any one moment, Br2 and TiBr4 were vaporized so rapidly that the capacity of the reflux condenser was exceeded and mater ial was lost from the system. Further external heating was not necessary once the reaction was initiated since the process is exothermic. The reacting titanium moved rapidly over the liquid surface and apparently at red heat. At times, titanium particles would adher to the wall of the Vycor ring and reside there until completely converted into TiBr4.. Thus, the necessity for the VyGor ring, for if it were not present, the titanium Would adher to the wall of the Pyrex flask and burn a hole through the flask Wall. Figure 2 is a photograph of the reaction pot utilized in the first preparation which resulted in failure and necessitated the change in equipment design that is shown in Figure 1. Two grams of titanium were added in excess of the stoichiometric quantity (68 grams) to completely utilize all available bromine, for the bromine was more difficult to remove than any non-volalite lower bromides which might form. The resulting mixture was then fractionated in on all glass pyrex distillation column (30 theoretical plate). The pure TiBr^ Was collected and stored in vacuo in glass ampoules equipped with break seals. See Figure 3. -30- D A. 10 mm. II B .. 2 0 mm. x 6 C. 10 mm. D. Break seal B F i g u re 3 Titanium tetrabromide storage ampoules -31“ Chemical Analysis of TiBr^ Mola Ratio Tx Br ' T i "; IF" Experimental 13.2% 8 6.8% 1 : 3.94 Experimental 13.1 86.7 1 : 3.97 Theoretical 13.04 86.96 1 : 4.00 Spectrographic Analysis. The titanium tetrabromide was converted to TiOg and analyzed for all metallic impurities. Element Impurity Detection limit Ti Ma jor B 0.003% 0.005% Si 0.020 0.001 Mg 0.003 0.0001 A1 0.0015 0.002 Mo 0.020 0.0005 Cu 0.008 0.0001 3n 0.020 0.01 Ca 0.0008 0.0001 No other elements were detected. 1,4-Dioxane. The method of Fieser^^ was used in purifying 1,4-dioxane (Carbide and Carbon Chemical Corporation). Two liters of 1,4-dioxane were mixed with 200 ml. of water and 28 ml. of concentrated HC1 and refluxed for twelve hours. A stream of argon was passed through the mixture during refliix to entrain the acetaldehyde impurities driven off. The solution was cooled and K0H pellets Were added slowly with stirring until they no longer dissolved and a second layer had separated. The two phases were allowed to separate and the dioxane was decanted. More K0H pellets were added to the dacantate to remove adhering aqueous I33p0^ser) "Experiments in Organic Chemistry", D. C. Heath and Co., Boston, Mass. 1941, Part II. p. 368. "32- liquor, and the dioxane Was again decanted. Metallic sodium was added to the final decantate and the mixture Was refluxed for twelve hours with argon passing through the mixture. The dioxane was then distilled from sodium under an argon atmosphere and stored in a glass vessel over sodium and iron wire. The middle fraction boiling at 100.3-100.7°C. (744 mm. Hg) was collected. The value reported in the literatur e^34 is X01.1°C. at atmospheric pressure with a dT/dP of 0.43°C. 135 per 10 mm. The freezing point of the purified 1,4-dioxane is 11.57°C, which agrees quite favorably with values of 11.5°-11,8°C. as reported in the literatur* 137^ Tetrahydrofuran. The sample of tetrahydrofuran received from E. I. DuPont de Nemours Co. was dried over calcium chloride for two days. It was then distilled over sodium and under an atmosphere of purified, dry argon. The fraction boiling at 65,2°-65,6°C. at 743 mm. was collected. The value reported in the literature^-38 is 65-S6°C. at atmospheric pressure. Tetrahydrofuran forms peroxides with great rapidity and they do not seem to be prevented by the usual peroxide inhibitors, so the tetrahydrofuran was used immediately after distillation. ■'■^Teague, P. C., Falsing, W. A., J. Am.Chem. Soc., J35, 485-6 (1943). 135q ^^6 pages 208-218 for the detailed explaination of the procedure and apparatus used for the determination of freezing points. 136Rubin, B.f Sisler, H. H., Shechter, H., J. Am. Chem. Soc., _74, 877-82 (1952). T37Kjpause, C. A., Vingee, R. A., J. Am. Chem. Soc., J35 511-16 (1934), •'•38xJangQt "Handbook of Chemistry," Handbook Publishers Inc., Sandusky, Ohio, 194-6. -33- Totrahydropyran. The sample of tetrahydropyran received from Eastman Kodak Was dried over CaCl2 for two days. It was then distilled over sodium and under an atmosphere of purified, dry argon gas. The fraction boiling at 87.1-87.5°C. at 746 mm. was collected. The value reported in the literature is 87.5-88.5°C. at atmospheric pressure. Tetrahydropyran forms peroxides with great rapidity and they do not seem to be prevented by the usual peroxide inhibitors, so the tetrahydropyran was used immediately after distillation. IV. PREPARATION OF ADDITION COMPOUNDS The Addition Compounds, TiBr4 *C4Hg0 2 . Preparation. Titanium tetrabromide (TiBr4 ) and 1,4-dioxane (C^HgC^) react rapidly at room temperature to form the red solid compound, TiBr4 *C^Hg0 2 , in a 1:1 mole ratio. This addition compound is quite stable but reacts with air and/or moisture. In a typical preparaHon the equipment was assembled as shown in Figure 4, The unit Was evacuated through tube (B) fitted at (C) and checked With a Tesla coil to see that all glass seals were tight, i.e., free of pin holes and/or cracks. The unit was then pressurized to 1 atmosphere with dry argon and the alternate evacuation and pressurization cycle was repeated four times to remove all traces of air and moisture. The system was again evacuated and the break seal (I)-ruptured with the break hammer (E) which was actuated with a small magnet. Eiask (F) containing the TiBr^ was now open to the rest of the unit. Dry argon was admitted through tube (B) until the cell pressure was at 1 atmosphere. No discoloration (yellow TiBr4 changing to red TiBrgO) of the TiBr4 was noted which indicated that little, if any, oxygen or moisture Was present. The unit was then connected to the distillation column at (C) and 1,4-dioxane distilled under an argon atmosphere into flask (D) which was cooled to 0 °C. When flask (D) was about two-thirds full of solid, the unit was removed from -34- A. 19 A 38 $ cap 19 B. 38 ? 19 C. 38 i D. 20 mm. x 6 in. H E. Iron bar encased in glass F. 2 0 mm. x 6 i n. I If G. Serum bottle stopper i \ \ caj H. 10 mm. cn If I. Break seal D Figure 4 Apparatus for preparation of addition compounds -36- the distillation column and cap (A) fitted to (C), The unit was now completely closed and consisted of solid 1,4-dioxane in flask (D), a thin film of solid TiBr'4 on the wall of flask (F) and the dead space filled with argon gas. Flask (F) was cooled to -78°C. (dry ice-acetone mixture) and the dioxane Warmed just to the melting point, 11.6°C. The dioxane Was slowly added to the TiBr4 by proper manipulation of the unit and the reaction, which is highly exothermic, Was controlled by the rate of addition of the dioxane. Extreme care was exercised at this point for the heat of reaction Was sufficient to build up 1,4-dioxane pressures of such magnitude as to rupture the equipment. The addition compound formed rapidly, some of which immediately dissolved in the excess dioxane to form a blood red liquid, and the remainder precipitating out as a red solid. The solvent dioxane with the dissolved compound Was moved several times from flask (F) to flask (D). This operation was necessary to completely react all the available TiBr^. Although the reaction was very rapid, the compound which is formed coats the surface of the TiBr^ which reduces its reactivity. The transfer of the liquid from one flask to the other effectively washed the addition compound from the TiBr^.. This exposed a fresh surface of TiBr4 which immediately reacted. After the walls of flask (F) ware completely void of any residual TiBr4 > the liquid and solid were stored in flask (F). The solid addition compound and possibly some Ti02 settled out, and the red liquid (a solution of the addition compound in 1,4-dioxane) was slowly and carefully decanted into flask (D). Twenty milliliters of the solution was removed with a hypodermic syringe through the Serum Rubber Stopper (G) and transferred to flask (A) (see Figure 5) -37- T Vacuum Figure 5 Purification of the addition compound, TiBfy * C4H8O2 -38- through Serum Rubber Stopper (B). Flask (A) was dry and filled with dry argon gas. The red liquid in bulb (A) was cooledvto 0 °C. and the unit evacuated. The excess dioxane Was sublimed off at the outset and as the quantity of solvent 1,4-dioxane decreased, the temperature was gradually raised to about 50°C. to remove the last traces of solvent 1,4-dioxane and left behind a dry, fluffy, brick red powder. See Figure 6 whore the red addition compound, small tube, can be compared to the yellow TiBr^. in the large tube. The unit Was then pressurized to 1 atmosphere with dry argon gas and the powder transferred to flask (C) which was removed and capped with a standard taper fitting (outer) and stored in a desiccator. Analytical Results^9. In the following table are found the analyses of five different preparations of the addition compound. The empirical mole ratios compare quite favorably with the mole ratios calculated for the 1:1 addition compound. Chemical Analysis of TiBr^’Dioxane. Mole Ratio Ti Br C H Ti Br 0 H Theoret ical 10.51$ 70.14$ 10.54$ 1.77$ 1.00 4.00 4.00 8.00 Prep. No. 1 10.31 69.92* 10.12 1.79 1.00 4.07 3.92 8.25 Prep. No. 2 68.7© 10.63 1.91 — 4.00 4.12 8.82 Prep. No. 3 >- - w 69.9© 10.47 |M 4.00 3.99 Prep. No. 4 10.51 69.6© 10.58 1.90 1.00 3.97 4.02 8.59 Prep. No. 5 10.74 69.5© 10.60 1.91 1.00 3.88 3.94 8.45 ■^determined gravimetrically ©determined volumetrically 1 QQ Cite Appendix 3 for analytical procedure. -39- Spectrographic Analysis. The addition compound was converted to TiC^ and analyzed for all metallic impurities. Element Impurity Detection limit Ti Ma j or ----- O o o CJ1 o B 0.0300/£ • Si 0.0100 0.001 Fe 0.0100 0.001 Mg 0.0150 0.0001 Pb 0.0005 0.001 Sn 0.0150 0.0005 Ni 0.0030 0.0005 Al 0.0050 0.002 Cu 0.0070 0.0001 Na 0.0200 0.005 Sn 0.0150 0.01 Ca 0.0300 0.0001 Elements which are not listed were not detected. TiC>2 » prepared by hydrolyzing the addition compound in ammoniacal solution, filtering and drying at 800°G., was analyzed by X-ray 140 powder techniques . The d-spacings conformed to those reported for TiOg (anatase). No new lines were observed Which indicates that any crystalline impurity, if present, Would have a concentration of less than about 5 per cent. Solubility. The solubility Was detemined by adding about 0.1 gram of addition compound to 3 ml. of solvent. It Was found to be soluble in nitrobenzene and 1,4-dioxane but insoluble in iso-octane, toluene, and xylene. ■'•'^Cite page 55. -40* SSVis & J’tV' I ygM$ti fX' ‘/ - Stft&fcih Vi*1 I X'w'i -'■ j ; V MI1 0 SS IIKBS Figure 6 . Photograph of TiBfy and TiBr4 - 6 4 ^ 0 2 -41- Molting point. The compound does not have a sharp melting point but decomposes in the temperature range of 167-180°C. The compound appears to be somewhat polar. Emulsions of the material were prepared in Nujol^^’*' and appeared to be very uniform when placed on a single crystal of sodium chloride but coagulated or clustered when pressed between single crystals. The Addition Compounds, TiB^^CgH-LgO and TiBr4 .2 C4.H8 O. Preparation. Titanium tetrabromide (TiBr4 ), at room temperature, reacts with tetrahydropyran (THP) (CgH^gO) and also with tetrahydrofuran (THF) (C4H 8 O). The product of the individual reactions is a red solid corresponding to a 1 : 2 mole ratio with the formulas TiBr4 *2 CgH^gO and TiBr^»2 C4 HgO, respectively. Both addition compounds are quite sensitive to air and/or moisture. The compound TiBr^_»2CgH^Q0 is quite stable While the compound TiBi'4 *2 C4 HgO prepared in excess TiBr4 is very stable but slowly decomposes when prepared in excess tetrahydrofuran. Since the preparation of the two compounds is identical, they will be discussed together. The reaction at 0 °C. between TiBr4 and either or C^HgO results in the formation of a red solid and a wine colored liquid. The solid slowly disappears, no doubt reacting with the excess ether, and the wine colored liquid gradually darkens' to a liquid which is red to black. When the pressure was reduced above the red to black liquid at 0°C. to remove the excess ether, no solid product was formed boiling mixture of saturated hydrocarbons. -42- but only a liquid of extremely high viscosity. Attempts to crystallize a solid from the liquid at -78°C. only further increased the viscosity. Therefore, the procedure as outlined on page 34 for the preparation of the compound TiBr^/dioxane was modified in the following manner. The ether at 0°C. was added to the TiBr^ at -78°C. in flask (F) of Figuro 4 and the reaction, which is exothermic was practically instantaneous as evidenced by the rapid formation of a deep red solid. The contents of flask (F), both liquid and solid were transferred to flask (D) and the red solid permitted to settle out. The liquid over the solid was removed by decantation and discarded. The unit was then connected to the distillation column and freshly distilled ether added to the red solid compound in flask (D). This was continued until the liquid residing over the solid was colorless indicating that the addition compound was not appreciably soluble in the ether and the decomposition product had been successfully removed by dilution and/or solution. The clear liquid ether layer Was then removed by decantation. Standard taper joint (B) was placed in (C) and the unit evacuated to remove adhering ether and to completely dry the red solid. The vacuum drying process lasted for a period of 48 hours, at the end of which time the unit was pressurized to 1 atmosphere with dry argon. The standard taper cap (A) was then fitted in (C). The entire unit was placed in a dry box, the solid removed and placed in small weighing bottles which were stored in a desiccator. It is obvious that the procedure described above involves the formation of the compound in the presence of excess base. To study the formation of the compound in excess acid (TiBr^_) the procedure was modified as follows: The ether was added to the TiBr^ at -78°G, and -43- no liquid layer was obtained, only the red solid. The unit Was removed and the cap (B) placed at (C). The pressure above the solid, compound plus unreacted T i B r ^ was maintained at 1 mm. for two days and the bulk of the uncombined TiBr^ was removed by sublimation. The temperature of the system was gradually elevated to 40°C. to increase the vapor pressure of the unreacted TiBr^ This process required seven days for the complete removal of unreacted TiBr^. At the outset of the process, the rate of removal of TiBr4 was governed only by the sublimation pressure, but as time progressed, the rate of removal was determined by the rate of diffusion of TiBr^ vapor through the solid compound, TiBr4*2 ether. All free T i B ^ was considered to have been removed when the small tube located between the bulb containing the solid compound and vacuum pump had no solid yellow TiBr4 condensed on the wall after being held at -78°C. for 48 hours. The unit was pressurized to one atmosphere argon gas and removed to a dry box. The solid addition compound was placed in weighing tubes which Were stored in a disiccator. The Addition Compound, TiBr4 *2CgH]_oO. Chemical Analysis. Mole Ratio Ti Br C H Ti Br C H Theoretical 8 .8 8 % 59.21% 22.25% 3.88% 1.00 4.00 10.00 20.00 Prep. No. 1 9.00 58.62 22.71 4.00 1.00 3.90 10.06 21.12 Prep. No. 2 9.12 59.01 21.99 3.69 1.00 3.88 9.62 19.22 Agreement between the empirical and theoretical mole ratios indicate that the addition compound can only be TiBr^*2CgH^oC» -44- The addition compound appears to be somewhat polar^-^ as concluded from its behavior in Nujol. Melting point. The addition compound does not have a sharp melting point but decomposes. The rod color of the solid turns a dark brown in the temperature range of 95-102°C. and this color gradually deepens until a wine colored liquid appears in the temperature range of 110~121°C. The Addition Compound, TiBr4 *2041-190. Chemical Analysis. Mole Ratio Ti Br C H Ti Br C H Theoretical 9.36 / 62.5 / 18.772 3.15/. 1.00 4.00 8 .00 16.0 Prep. No. 1 9.73 64.55 18.30 3.72 1.00 3.98 7.50 18.17 Prep. No. 2 9.94 64.80 1.00 3.91 — M Prep. No. 3 9.57 64.62 19.77 3.88 1.00 4.05 8.24 19.26 The data tabulated above were obtained from the addition compound obtained in excess TiB^. Chemical Analysis. Mole Ratio Ti Br C H Ti Br C H Theoretical 9.36/ 62.5 / 18.77/ 3.15/ 1.00 4.00 8 .00 16.0 Prep . No. 1 9.64 61.33 -- 1 .00 3.82 m m *• m Prep. No. 2 9.74 61.33 19.20 3.44 1.00 3.78 7.86 16.79 Prep. No. 3 9.54 61.60 19.12 3. 31 1.00 3.87 7.99 16.48 l42See page 41. -45- The data tabulated above Were obtained from the addition compound obtained in excess C^HgO. It is apparent from the agreement between the empirical and the theoretical mole ratios that the addition compound is TiBri|*2C^HgO irrespective of whether it is prepared from excess ether or TiBr^ The compound appears to be somewhat polar as concluded from its behavior in Nujol as pointed out on page 41. It is not soluble in cci4 or chci3 . It was previously mentioned that solid TiBr^ and liquid C^HgO react at 12°C. to yield a wine colored liquid and a red solid precipitate. The red solid slowly disappeared and the resulting liquid was red to black. All attempts to obtain a crystalline material from this liquid failed and the end product was a liquid of low fluidity. The liquid is more stable in the presence of air and/or moisture than is TiBr^ It is insoluble in CCI4 , isooctane, and xylene but dissolves in dry diethyl ether to produce a yellow liquid. On the basis of solubility alone, it can be concluded that the liquid is indeed polar. The addition of water leads to the formation of a two-phase system: an aqueous acid and an oily layer. It is to be noted that the oily layer, Whose density is greater than one can not be pure C^HgO for it has a density less than one and moreover, is completely miscible With Water. Also, the oily liquid is very soluble in diethyl ether. The table below, preparation 2, gives the analysis for the viscous liquid prepared by distilling cold C^HgO directly into solid TiBr^. The bromine to titanium mole ratio was found to be 3.56. ^his agrees quite well with the mole ratio of 3.57 found in preparation 1, the addition of cold C4H3 O to a solivtion of TiBr4 in CCI4 . 46- Chemical Analysis Mole Ratio Ti Br C H Ti Br C H Prep. No. 1 7.84% 46.6852 24.90/2 4.35/2 1.00 3.57 12.7 26.4 8.00 47.50 1.00 3.56 Prep. No. 2 25.65 4.72 1.00 2.19 Thus, it Would appear as though some bromine atoms are lost as a result of the reaction. This could be possible either by direct loss of HBr or by the formation of HBr which then brominates the organic residue. The analytical procedure utilized in the bromine analysis would not detect bromine combined in an organic molecule. It is also interesting to note that the carbon analysis for the two preparations differ by only 0.87% and the hydrogen analysis by 0.38% which is well within the experimental error of the determination. The hydrogen to carbon mole ratio is 2.08 and 2.19 for preparation 1 and preparation 2, respectively. It is to be pointed out that the analyses were not run on a dry solid but on a viscous liquid. The infra red spectrograml^S 0f freshly distilled tetrahydrofuran is shown in Figure 7 and can be compared with Figure 8 , the spectrogram of the viscous liquid obtained as a result of the reaction of solid TiBr4 with liquid tetrahydrofuran. The spectrogram of the viscous liquid was the same whether it Was prepared with or without carbon tetrachloride as a solvent. Although the spectrograms shown in Figures 7 and 8 are apparently identical from 3 to 8 -microns, the viscous liquid exhibits a strong absorption at 8 -microns, has three other new bands at ca. 9.9, 10,5 and 10.7-microns which are probably the result of frequency shifts. The very strong absorption band at about 9.3 microns due to •*-^Cito page 184for a complete discussion of the spectrogram. Percent transmittance Percent transmittance 100 100 0 5 0 5 2 iue . nr rd pcrga o vsos iud s rsl o te ecin Ti 4 n Tetrahydrofuran. and r4 iB T f o reaction the of result a as liquid viscous of spectrogram red Infra 8. Figure iue . nfa rd pcrga f etrahydrofuran. T of spectrogram red fra In 7. Figure 4 6 ae egh n microns in length Wave v lnt i microns in length ave W 8 10 12 . 025 mm. 5 2 .0 0 A. . lt t plate to Plate B. .14 16 ■o i -48- C-O-C stretching, is present on both spectrograms and thus the reaction apparently does not effect the ether linkage. If no reaction occurred between the two reactants, then the resulting spectrogram would merely be the summation of the absorption frequencies of two individual reactants. Wherever two reactants absorb at the same frequency, if that were the case, the resulting absorption band Would be more intense. In no case Would the presence of the dissolved substance alter the location of the band but would merely change the intensity. Thus, the presence of the four new bands in the viscous liquid is not indicative of a reaction for they could be due to TiBr^, the spectrogram of Which is unknown. Figure 9 is the spectrogram of the solid addition compound, TiBr4 *2Tetrahydrofuran, in Nujol. Comparison of Figures 8 and 9 leads to the immediate conclusion that the two spectrograms are different and thus the viscous liquid is not the addition compound dissolved in tetrahydrofuran. Thus, the thought that the viscous liquid was simply the result of a solution of the addition compound in tetrahydrofuran, where the large and bulky addition compound literally trapped solvent molecules in its free volume was ruled out. The principle difference in the two spectrograms is -the absence of the band at ca. 8 -microns and the C-O-C stretching band at ca. 9.3-microns in the addition compound, Figure 9, which indicated the reaction had taken place at the ether linkage. The viscous liquid was dissolved in a large volume of distilled water with the resultant formation of a two phase system which Was treated in two ways: 1) the aqueous layer was removed by decantation Percent transmittance 100 50 - 50 iue . nr rd pcrga o Ti 4 2 erhdoua i nujol. in Tetrahydrofuran 2 • r4 iB T of spectrogram red Infra 9. Figure ae egh n microns in length Wave -50- and the tan colored oily liquid, density greater than one, was dried over at 0°C.; 2) the tan colored oily liquid was extracted with diethyl ether, dried and the ether removed by evaporation. The spectrogram of the water free liquid as obtained by either Method 1 or 2 was the same and is shown in Figure 10. It is to be pointed out that the strong absorption band at 3-microns is indicative of an -OH vibration frequency as would be found in a primary alcohol. The spectrogram apparently does not correspond to any reported substituted or unsubstituted alcohol. The principle objection to the above procedure is that the tetrahydrofuran ring is easily openedT44 by heating With mineral acidsT45 -fco give the 4-halobutanol-l. Therefore, since this possibility existed in the above procedure, it was decided to dissolve the oily liquid in absolute diethyl ether and p.ttpify by passing through an absorption column composed of a 50-50 mixture of activated AI2 O3 and celite (diatomaceous earth). This procedure proved to be quite adequate for decolorizing the liquid. The solvent ether Was vaporized leaving behind a colorless oily liquid which did not freeze at 0°C. and whose boiling point was between 100-110°C. Greater accuracy in the boiling point determination could not be attained since the liquid appeared to char or polymerize. The infrared spectrogram of the decolorized liquid is given in Figure 11. This is the extent of the experimental work done on the viscous ■'•^Organic Synthesis, J/7, 84 (1937). 145Richter, G. H., "Textbook of Organic Chemistry," John Wiley and Sons, Inc., New York, 1943, p. 91. The halogen acids show a marked difference in reactivity in splitting ethers; hydriodic acid will cleave an ether in the cold, hydrobromic acid only on heating, and hydrochloric acid only at elevated temperatures. -51 liquid. Neither -the composition of the oil nor the hydrolysis product was detemined but it seems appropriate to report the results obtained even though they are inconclusive. Conclusions. Solid titanium tetrabromide reacts almost instantaneously and exothermically with 1,4-dioxane at 12°C. to form the blood-red, solid, addition compound. A saturated solution of the complex in 1,4-dioxane was removed from the solids consisting of the addition compound with perhaps some TiO£, and the excess solvent dioxane removed by sublimation at reduced pressure. The complex is very sensitive to moisture but is quite stable as it does not decompose under reduced pressure nor when stored under dry argon or its own vapor. Chemical analysis of the pure complex conclusively proves that the empirical formula is TiBr^•C^Hg0£ . The addition compound is polar, soluble in 1,4-dioxane and nitrobenzene, insoluble in iso-octane, toluene and xylene, and does not have a sharp melting point but decomposes in the temperature range of 167-180°C. Tetrahydrofuran reacts almost instantaneously at 0°C. with solid titanium tetrabromide and with a carbon tetrachloride solution of titanium tetrabromide to form a red solid addition compound and a wine colored liquid. A solid product could not be crystallized from the liquid and removal of excess tetrahydrofuran produced a liquid of low fluidity. Chemical analysis of the viscous liquid showed that some ionic bromine is lost as a result of the reaction as the mole ratio of titanium to bromine is 1 to 3.6. The infrared spectrogram of the liquid does not indicate ring cleavage of the ether nor the presence of a carbon to bromine bond. Hydrolysis of the liquid resulted in the Percent transmittance 100 0 5 iue 0 I r ed setorm o wat islbe i d. id u liq insoluble r te a w of spectrogram d re fra In 10. Figure ae egh n icrons m in length Wave Percent transm ittance 0 0 1 0 5 iue I I r ed setorm o vsos iud fe psig hog a oun f 2 e t i l e c - 3 l20 A of column a through passing after liquid viscous of spectrogram d re fra In II. Figure ae egh n microns in length Wave CO 71 £7 If 1 -54- formation of a compound which was not identified but whose infrared spectrogram showed the presence of a primary alcohol functional group. Chemical analysis showed the solid addition compound to be the same irrespective of whether it was prepared from either excess TiBr^ or excess ether and the empirical formula to be TiBr^’BC^HgO. This complex is polar, insoluble in tetrahydrofuran, chloroform and carbon tetrachloride. Solid titanium tetrabromide reacts almost instantaneously with tetrahydropyra n at 0°C. to form a red solid addition compound and a Wine colored liquid. Attempts to crystallize a solid product from the liquid were unsuccessful and removal of the excess tetrahydropyran resulted only in increasing the viscosity. The viscous liquid Was not investigated by chemical analysis. The solid complex is very sensitive to moisture but is quite stable as it does not decompose under reduced pressure nor when stored under dry argon or its own vapor. Chemic&l analysis of the pure complex conclusively proves that the empirical formula is TiBr^*2CgHgO. The addition compound is polar, insoluble in tetrahydrofuran, does not have a sharp melting point but undergoes a gradual color change in the temperature range of 95-102°C. with the formation of a liquid in the temperature range of 1 1 0 -1 2 1 °C. V. X-RAY DIFFRACTION ANALYSIS Introduction. X-ray diffraction techniques afford a suitable and yet simple method of characterizing the solid crystalline addition compounds of titanium tetrahalides. Every crystal has an X-ray pattern which is unique. The determination of geometrical structure can be ascertained from a consideration of diffraction patterns and the problem of isomorphism, the occurrence of different chemical compounds with the same crystalline form, can be investigated. It is to be understood that X-ray diffraction patterns are characteristic of the crystal form and spacing and thus of chemical compounds rather than of elements or chemical groups. The method of powder analysis, although generally referred to as the Debye-Scherrer, should actually be^®2 -termed the Hull-Debye-Scherrer method. It was independently devised by Hull-^®11-47,148 ^n the United States and Debye and Scherrerl49»150 in Germany. The essential features are shown in Figure 12. The incident beam of homogeneous X-rays as supplied by a Philips Model 5100-X-ray 146Hull, a . W.,- Phys. Rev.,_9, 84-7, (1917). 147ibid., 9, 564-7 (1917). 148lbid., ~10, 661-97 (1917). 149j30by0> p,f Scherrer, P., Physik S., _17, 277-83 (1916). ISOlbid., 18, 291-301 (1917). -55- -56- diffraction unit Was passed through a filter^l -to eliminate characteristic IC-beta-*-^ radiation, after which the K-alpha rays were collimated by a lit or pinhole system. The resulting narrow beam of X-rays enveloped the crystalline powder composed of randomly oriented ”15 3 particles housed in a small cylindrical tube (0.03-0.05 ram. I.D.) . Sections of the various diffracted cones impinged on the photographic film. Inspection of Figure 12 shows how this arrangement permitted the recording of sections of the cones or halos diffracted both in the forward direction (29 less than 90°) and in the back-reflection region (29 greater than 90°). All diffracted rays from sets of planes with spacing d^ generated a cone of semi-apex angle 29^, planes of spacing d£ generated a cone of angle 20£ and so oni^ Thus, a flat photographic film placed perpendicular (asymmetric position) to the axis of the sample yielded a pattern of concentric arcs produced by these cones of diffracted rays. Wave Length of K-alpha K-beta ______Radiation______Filter absorbed doublet K-alpha-1 K-alpha-2 Cu 1.54M 1.54051 1.54433 Ni 97.7% Co 1.790 1.78892 1.79278 Fe 98.9 Fe 1.937 1.93597 1.93991 Mn 98.7 The K series consists of three lines, a very close doublet K-alpha-1 and K-alpha-2 and a K-beta line. Normally the doublet cannot be resolved. •^2 / \ Electronic transitions v"A associated with the production M I' of characteristic X-ray spectra. •L^Lindemann glass capillary tubes obtained from Caine Sales Co., 3020 N. Cicero Ave. , Chicago 41, Illinois. ^54The reflection angle, as measured, Was 29 for the 114.6 mm. camera and 9 for the 57.3 mm. -57- Figure 12 Geometrical features of the Debye- Scherrer technique -58- Tho diffraction lines on a film are located at characteristic angular positions relative to the undeviated X-ray beam. The angular distances measured from the film’1'®5 were converted into interplanar spacings, d, which is expressed by the Bragg-^ reflection condition for X-rays of wavelength, \ : n X b 2 d sin 9 Where the diffraction angle, 9, for the cylindrical camera is 9 (in degrees) e 45 — h — tt r with "n" assumed equal to unity, "L" equal to the distance between corresponding lines on opposite sides of the undoviated beam, and "r" equal to the film radius. Thus it is obvious that the value of "d" can be calculated for each line. The relative intensities of the lines were estimated visually. As mentioned above, the relationship among the wavelength of X-rays, the incident angle of the X-rays and the interatomic distance is given by Bragg's law, where n B the order of the diffraction. Thus "n" is equal to 1, 2, 3, etc. but the values of "n" are limited since sin 9 cannot exceed 1 and n X can never be greater than 2 d. For a given sot of lattice planes, (100) or (11 0 ) planes, d is fixed, X has a definite value and thus the possibility of obtaining maximum reflection will thus depend on 9, the glancing angle. As 9 is increased a series of positions is found, corresponding to n equal to 1, 2 , 3, 4, at which reflection is at a maximum. These are separated l55Films Were measured on a Norelco illuminator and measuring device capable of reading to + 0.05 mm. 156s qq Appendix 4. -59- by regions in which the reflected X-ray beams from successive lattice planes differ in length by a fractional number of wave lengths; the rays are then "out of phase" and so cancel each other to a great extent, thus resulting in a decrease of intensity. Thus, the X-ray spectrum consisted of a number of fairly strong reflections separated by regions of low intensity. Pattern preparation is completely dependent on the nature of the material as a diffractor of X-rays. Many crystalline substances give such sharp powder patterns that they are detectable when present to the extent of 0.1 to 2 per cent in a mixture. Other materials give such poor patterns that, although they can be readily identified when alone, they may not be detected when present in a mixture even to the extent of 50 per cent. It is also to be noted that when a sample is rotated, that the proportion of crystallites contributing to the useful section of the halo which is recorded on the film, is usually less than 35 per cent and may be as little as 2 per cent. Experimental Procedure. Addition compounds of titanium tetrabromide are extremely sensitive to moisture and/or air which complicate X-ray specimen preparation. Therefore, all samples had to be prepared in a dry box and then hermetically sealed into Lindemann glass capillary X-ray tubes. A typical preparation for any hygroscopic material would be as follows. A dish of fresh, dry phosphorous pentoxide Was placed in a dry box so the solid drying agent had a maximum of exposed surface. The essential equipment placed in the dry box consisted of at least -60- three Lindemann X-ray capillaries which were supported'*-57 in a vertical position, solid glass rods of such diameter to fit inside the capillary tubes, an agate mortar and pestle, a spatula and a lump of dry ice. The dry box was closed and purged with dry argon as well as the carbon dioxide generated from sublimation of the cake of dry ice within the dry box. This drying process was continued for several hours. A small quantity of the addition compound was removed from a storage bottle to the agate mortar Which was located on the dry ice cake. The necessity for the dry ice Was to lower the temperature of the solid since the pulverizing process tended to compact the solid. The low temperature reduced this troublesome effect and the pulverized solid behaved as a loose dry powder. A small quantity of the powder was placed in the capillary tube with the spatula and then tamped or packedtinto a tight and uniform cake at the tip of capillary tube with the solid glass rod. More material was added and again packed. This procedure was continued until a sufficient quantity, about 3/4- inch, of tightly packed powdered solid was contained in the capillary tube. The glass rod was left in the capillary and was supported by the packed solid. The other sample tubes were filled in the same manner. The dry box was opened and the capillary with the glass rod was removed; the glass rod raised a short distance from the solid surface and the capillary tube sealed between the sample surface and the glass 157 The capillary tubes (0.5 mm.) were supported in a cork fitted into the mouth of a beaker. The cork was drilled with holes which were of sufficient size to permit the capillary tube to be hold rigidly in the vertical position. This arrangement was convient since the fragile tubes were not handled with the cumbersome rubber gloves of the dry box and also permitted observation of the quantity of material in the capillary tube. -61- rod. This affectively prevented moist air from diffusing into the tube during the sealing off process. Results and Discussion. TiOg, Anatase. The purpose in studying TiC^ Was twofold: (1) To learn the techniques involved in the preparation and and interpretation of an X-ray powder photograph and (2) To ascertain the magnitude of the absorption correction for titanium compounds. The interplanar (d) spacings for TiC^, anatase, are listed in 158 Table 1 and were obtained by Swanson and Tatge utilizing copper radiation from a G-E X-ray spectrometer. Data given in Table 2 and Figure 13 were obtained from a North American Philips wide range Geiger counter X-ray spectrometer unit using cobalt radiation. Agreement in the values for the d-spacings is quite good as Would be expected from a comparison of data obtained from a spectrometer, irrespective of the radiation source. Diffraction patterns of TiO^ were taken with molybdenum, copper, and iron radiation produced by a North American Philips X-ray diffraction unit, Model 5100, and the data are given in Tables 3 through 7, and Figure-14. The data in the following tables have column headings which have the significance: a,) Line, designates the position of the diffraction line with reference to the front reflections. As the line number increases, so does the angle of reflection. 158 Swanson, H. B , , Tatge, E., JC., Fel. Reports, N.B.S. (1950); A.S.T.M. X-ray card file, Sei; 4, 3rd Suppl. (1950). 62 b) Scale readings, left and right of the pinhole are measured in millimeters, one-half the sum of left and right gives the center of the pinhole. c) Z/Io i-s ‘the relative intensity, measured visually, of the lines with the values of I/I0 equal to 100 for the most intense line. d) The observed distance of a line from the center of the pinhole is designated 4 S for 29 less than 90° and 4S for 29 greater than 90°. e) 9 or 29 is the angle of reflection which is obtained from 4S (or 4S* ) taking cognizance of film shrinkage. f) Observed d-spacings, measured in angstroms (l0“®cm) and Were calculated from the angle of reflection, 9. This operation was carried out with the aid of conversion tables for K-alpha 1 radiation. As previously pointed out the wave length was not resolved into its components, thus, only those d-spacings with lines designated as K-alpha 1 or K»alpha 2 are to be used. All other spacings were computed on the basis of the K-alpha unresolved wavelength. Data in Tables 4 and 5, were obtained from the same film in order to check the consistency in the determination of d-spacings from the photograph. It is to be noted that all the d-spacings are not recorded in Table 5, but only a sufficient number to establish an adequate check. Data in Tables 7 and 8 were obtained with the same sample of Ti0£ to check the reproducibility of the diffraction pattern. Agreement between values for the d-spacings as determined from powder patterns is quite -63*- good and although the data are salf consistent they appear to disagree with those observed with the spectrometer. The d-spacings at small angles of reflection obtained by powder photographs have numerical values lower than those obtained by the spectrometer, although the values are almost identical at large angles of reflection. Also, the deviation is greater the softer the radiation, that is, the longer Wavelength. A phenomena of this type, that is, where all things being equal, the d-spacings are dependent on the source of radiation, can be attributed to X-ray absorption by the sample. This effect is negligible for the spectrometer. The variation in the values for the d-spacings of anatase as a result of X-ray abosorption Was determined by the following: method. The lattice constants for a tetragonal crystal structure can be calculated by equation 1 a o d (1 ) where d is the d-spacing in (hkfl) are the Miller Indices, and a Q and cQ are the lattice parameters for the crystal. In light of the fact that the spectrometer data agree quite well with the data of Swanson and Tatge, it can be assumed that the axial ratio, a 0 /c0 , will be the same in both cases. Any small change in either a 0 or c Q will not appreciably change the axial ratio. Also, the d-spacings were assigned (hkfl) values by comparison with spectrometer data. Values for a Q were then calculated using equation 1 and the observed d-spacings ■'"'^Taylor, A , f Floyd, R. W., Acta. Cryst._3, 285-9 (1950). -64- compute d for K-alpha 1 and K-alpha 2 radiation where applicable; data are given in Table 9 where the summation symbol represents the sum of the squares and the square root symbol represents the square root of the sum of the squares. A plot-*-®® of a 0 versus Figure 15, where each point is identified with its Millar indices, yielded a straight line and extrapolation to 0 s 90° gave the true value, that is, where the absorption effect Was negligible, for aQ of 3.7865.S which deviates by 0.09/-O from the value observed by the spectrometer. Using the value of a Q and the axial ratio as determined, from the spectrometer, the true values of the d-spacings, where the absorption effect was taken into account, were calculated utilizing equation 1 . The d-spacings determined with the spectrometer and those calculated from the diffraction pattern taking cognizance of absorption are tabulated for comparison in Table 10. In view of the good agreement for the d-spacings as determined with the spectrometer and those calculated from diffraction patterns it can be concluded that any apparent deviations in the. observed d-spacings are duo largely to X-ray absorption. -65- TABLE 1 Interplaner Spacings (ASTM) ^ 0 for TiOg as Obtained From a G. E. Spectrometer. K-alpha-X^T Miller indices intensity d-Spacings,A (hki) . ■t/^o 3.51 101 100 2.435 103 9 2.379 004 22 2.336 112 9 1.891 200 33 1.699 105 21 1.665 211 19 1.494 213 4 1.480 204 13 1.367 116 5 1.337 220 5 1.264 215 10 1.250 301 3 1.171 303 2 1.1609 312 3 1.0869 118 3 1.0433 321 3 1.0173 109 2 0.9550 316 4 0.9461 400 3 0.9189 325 2 0.8960 219 3 0.8877 228 2 0.8311 327 < 1 0.8268 415 3 0.8100 309 1 0.7990 424 3 Radiation: Copper (K-alpha-l) Wave length: 1.5045 Sample: T i 02 (Purity: Temperature: 26-27°C. Spectrographic analysis Filter: Nickel shows Si02 = 0.07%, no Crystal Structure: Tetragonal other impurity greater a 0» 3.783 than 0 .01 /2. cne 9.51 R ^60_American _Society f or ^Testing Material s. For information on the use of the file and indexes, refer to ASTM Bulletin No. 160, page 18 (September 1949). **66 - TABLE 2 Interplaner Spacings for TiC>2 as Obtained From a Fhilips X-ray Spectrometer. Reflection Angle K-alpha-1 Intensity 26, Degrees d-Spacing, J? IA 0 29.59 3.50 88 43.30 2.424 3 44.30 2.372 15 45.30 2.323 3 56.50 1.890 19 63.70 1.695 11 65.10 1.662 11 73.70 1.491 2 74.50 1.478 7 82.10 1.361 3 84.05 1.336 4 90.10 1.264 6 100.40 1.164 2 126.10 1.003 2 North American Philips Wide Range Geiger Counter X-Ray Spectrometer. Sample : TiO£ supplied by Baker Chemical Company Radiation : Cobalt Filter : Iron X-Ray Slit : 4° Scatter Slit : 1° Receiving Slit : 0.006" Scan Rate : 1 ° per min. Chart Speed : 30" per hour TABLE 3 Measurement of TiO£ Film and Calculation of d-SpaGings Molybdenum K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetic Position; Film No. 14A Capillary Size, 0.5 mm., Exposure Time, 3-£ hours. I I •< O 1 1 1 1 d-Spacings, .8 Sea le Reading K-alpha Radiation (mm) Unre jine Left Right 26, Degrees 1 solved 1 1 97.35 120.85 100 11.75; 3.46 3.47 2 91.75 126.45 80 17.35 2.35 2.35 3 87.25 130.95 90 21.85 1.871 1.875 4 84.20 134.00 80 24.90 1.645 1.648 5 81.15 137.05 80 27.95 1.468 1.471 6 78.10 140.10 50 31.00 1.327 1.330 7 76.20 142.00 70 32.90 1.252 1.254 8 73.45 144.75 60 35.65 1.157 1.159 9 68.95 149.25 20 40.15 1.033 1.035 10 67.00 151.20 10 42.10 0.9873 0.9892 11 65.25 152.95 10 43.85 0.9497 0.9516 12 63.55 154.65 10 45.55 0,9161 0.9179 TABLE 4 Measurement of Ti02 Film and Calculation of d-Spacings Copper K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetic Position; Film Shrinkage Factor: 1.00014; Film No. 15A Capillary Size, 0.5 mm., Exposure Time, 6 Hours. d-Spacings & Scale Reading K-alpha Radiation (mm) --- ...... ■ Bnre^ Li Left Right 1/1q 4S 28, Degrees 1 2 solved 1 124.40 30 25.125 25.128 3.54 3.54 2 73.40 125.15 100 25.875 25.878 3.44 3.44 3 61.85 136.70 30 37.425 37.430 2.40 2.40 4 60.90 137.65 50 38 .3)7,5; 38.380 2.343 2.345 5 60.10 138.45 30 39.175 39.180 2.297 2.299 6 50.70 147.85 90 48.575 48.582 1.873 1.874 7 44.85 153.70 80 54.425 54.432 1.684 1.685 8 43.80 154.75 80 55.475 55.483 1.654 1.655 9 36.05 162.50 70 63.225 63.234 1.469 1.470 10 30.00 168.55 50 69.275 69.285 1.355 1.356 11 28.50 170.05 50 70.775 70.785 1.330 1.331 12 23.80 174.90 70 75.625 75.636 1.256 1.257 13 22.80 175.75 30 76.475 76.486 1.244 1.245 14 15.65 182.90 60 83.625 83.637 1.155 1.156 4S‘ 15 193.55 365.00 30 94.275 94.288 1.051 1.052 16 194.55 364.00 30 95.275 95;288 1.042 1.043 17 197.80 360.80 30 98.525 98.539 1.016 1.017 18 199.10 10 99.825 99.839 1.007 1.008 TABLE 4 (Continued) d-Spacings 5 Scale Reading K-alpha Radiation (mm) Unre Line Left Right I/Iq 4S' 26, Degrees 1 2 solved 19 200.60 357.90 10 101.325 101.339 0.9958 0.9966 20 206.85 351.65 40 107.575 107.590 0.9546 0.9553 21 208.30 350.10 20 109.025 109.040 0.9459 0.9466 22 alpha 1 213.15 345.25 40 113.875 113.891 0.9190 0.9197 23 2 214.25 -- 10 114.975 114.991 0.9133 0.9156 0.9140 24 " 1 217.80 340.75 10 118.525 118.541 0.8961 0.8968 25 " 2 218.30 340.25 70 119.025 119.042 0.8938 0.8960 0.8945 26 " Vn 219.45 20 120.175 120.192 0.8886 0.8893 27 221.70 30 122.425 122.442 0.8790 0.8790 28 1 230.15 328.25 50 130.875 130.893 0.8468 0.8475 29 " 2 230.85 327.50 30 131.575 131.593 0.8445 0.8466 0.8452 30 " 1 236.45 322.00 50 137.175 137.194 0.8273 0.8280 31 2 237.4-0 321.15 30 138.125 138.144 0.8247 0.8265 0.8253 O O 33 1 249.10 309.35 80 149.825 149.846 0.7977 0.7983 34 " 2 250.30 308.20 60 151.020 151.041 0.7955 0.7975 0.7962 TABLE 5 Measurement of Ti02 Film and Calculation of d-Spacings Copper K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetic Position; Film Shrinkage Factor: 1.000695; Film No. 15A Capillary Size, 0.5 mm., Exposure Time, 6 Hours. d-Spacings 5 ir Scale Reading /V*-alpha Radiation (mm) Unre Line Left Right I An 4S 20, Degrees 1 2 solved 2 77.85 12 9.30 100 25.825 25.843 3.44 3.45 6 55.00 151.95 90 48.475 48.509 1.875 1.876 7 49.15 157.80 80 54.325 54.363 1.686 1.687 8 47.90 159.05 80 55.575 55.614 1.651 1.652 12 28 .00 178.95 70 75.475 75.527 1.258 1.259 4S1 alpha 1 221.90 344.80 10 118.425 118.507 0.8962 0.8969 2 226.30 --- 30 122.825 122.910 0.8768 0.8790 0.8775 1 2 34.45 332.30 50 130.975 131.066 0.8462 0.8469 " 2 235.10 331.60 30 131.625 131.716 0.3441 0.8462 0.8448 " 1 240.55 326.10 50 137.075 137.170 0.8274 0.8281 " 2 241.60 325.15 30 138.125 138.221 0.8244 0.8264 0.8250 " 1 247.25 319.45 50 143.775 143.875 0.8102 0.8108 2 248.10 318.60 30 144,625 144.726 0.8082 0.8102 0.8088 1 253.35 313.35 80 149.875 149.979 0.7975 0.7981 " 2 254.45 312.25 60 150.975 151.080 0.7954 0.7974 0.7960 TABLE 6 Measurement of Ti 02 Film and Calculation of d-Spacings Copper K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetic Position; Film Shrinkage Factor: 1.00041, Film No. 21A Capillary Size, 0.5 mm., Exposure Time 54 Hours. d-Spacings A Scale Reading ______K-alpha Radiation______(mm) Unre- Line Left Right I/IQ 4 S 28, Degrees 1 2___ solved 1 84.65 134.80 30 25.055 25.085 3.54 3.55 2 83.85 135.60 10 0 25.875 25.886 3.44 3.44 3 72.30 147.20 30 37.475 37.491 2.40 2.40 4 71.50 148.00 50 38.275 38.291 2.349 2.351 5 70.70 148.80 30 39.075 39.091 2.302 2.304 6 61.20 158.30 90 48.575 48.595 1.872 1.873 7 55.35 164.10 80 54.375 54.398 1.685 1.686 8 54.15 165.30 80 55.575 55.598 1.652 1.653 9 46.55 172.90 70 63.175 63.201 1.470 1.471 10 40.60 179.00 50 69.275 69.-304 1.355 1.356 11 39.00 180.50 50 70.775 70.804 1.330 1.331 12 34.20 185 . '25 70 75.525 75.556 1.257 1.258 13 33.20 186.25 30 76.525 76.557 1.243 1.244 4S1 14 204.20 375.15 30 94.475 94.514 1.049 1.050 15 205.00 374.35 30 95.275 95.315 1.042 1.043 16 208.30 371.20 30 98.575 98.616 1.016 1.017 17 209.70 369.65 10 99.975 100.017 1.005 1.006 TABLE 6 (Continued) d-Spacings $ _ Scale Reading K-alpha Radiation (mm) Unre Line Left Right 4S 20, Degrees solved ie 217.40 361.95 40 107.675 107.720 0.9538 0.9546 19 218.85 360.50 2 0 109.125 109.170 0.9451 0.9458 20 223.75 355.60 40 114.025 114.072 0.9180 0.9187 21 224.80 354.55 10 115.075 115.123 0.9126 0.9133 22 alpha 1 228.25 351.05 10 118.525 118.574 0.8959 0.8963 23 alpha 2 228.85 350.50 70 119.125 ' 119.175. 0.8932 0.8954 0.8939 24 alpha 1 232.25 347.10 30 122.525 122.576 0.8782 0.8789 25 alpha 2 232.80 346.55 30 123.075 123.126 0.8759 0.8781 0.8766 26 alpha 1 240.70 338.60 50 130.975 131.030 0.8464 0.8471 27 alpha 2 241.35 337.90 30 131.625 131.680 0.8442 0.8463 0.8449 28 alpha 1 247.10 332 ;20 50 137.375 137.432 0.8266 0 0.8273 29 alpha 2 247.90 331.45 30 138.175 138.233 0.8244 0.8264 0.8250 30 alpha 1 253.40 325.85 50 143.675 143.735 0.8105 0.8111 31 alpha 2 254.30 324.95 30 144.575 144.635 0.8084 0.8104 0.8090 32 alpha 1 259.55 319.70 80 149.825 149.887 0.7976 0.7982 33 alpha 2 260.80 318.50 60 151.075 151.138 0.7954 0.7974 0.7960 TABLE 7 Measurement of TiC^ Film and Calculation of d-Spacings Iron K-alpha Radiation; Camera Diameter 57.3 ram., Film in Asymmetric Position; Film Shrinkage factor: 0.99944-, Film No. 14J Capillary Size, 0.5 mm., Exposure Time 5 Hours. d-Spacings Scale Reading K-alpha Radiation (mm) Unre- Line Left Right i A n 4S 6 , Degrees 1 solved 1 215.90 244.90 20 14.675 14.667 3.82 3.82 2 214,35 246.10 40 15.875 15.866 3.54 3.54 3 214.00 246.45 10 16.225 16.216 3.47 3.47 4 - - - 253.10 10 22.875 22.862 2.49 2.49 5 206.00 254.50 60 24.275 24.262 2.356 2.358 6 205.45 255.00 30 24.775 24.761 2.311 2.313 7 199.15 261.30 10 31.075 31.058 1.876 1.877 8 195.30 265.20 70 34.975 34.956 1.690 1.691 9 194.55 265.95 70 35.725 35.705 1.659 1.660 10 --- 271.35 70 41.125 41.102 1.472 1.473 4S1 11 275.50 50 45.275 45.250 1.363 1.364 12 276.65 50 46.425 46.399 1.337 1.338 13 280.25 60 50.025 49.917 1.264 1.265 14 281.00 20 50.775 50.747 1.250 1.251 15 2§6.55 354.00 40 56.325 56.294 1.164 1.165 16 296.25 344.30 20 66.025 65.988 1.060 1.061 17 297,30 343.25 40 67.075 67.038 1.051 1.052 18 298.25 342.20 40 68.025 67.987 1.044 1.045 19 302.20 338.30 20 71.975 71.935 1.018 1.019 20 304.20 336.35 20 73.975 73.934 1.007’ 1.008 21 306.40 334.05 20 76.175 76.133 0,9970 0.9977 TABLE 8 Measurement of Ti0£ Film and Calculation of d-Spacings Iron K-alpha Radiation; Camera Diameter 57.3 mm., Film in Asymmetric Position; Film Shrinkage Factor: 1.00014, Film No. 15J Capillary Size, 0.5 mm., Exposure Time, 5 Hours. d-Spacings Soale Reading K-alpha Radiation (mm) Unre- lin e Left Rieht I / I c 4S 8 , Degrees 1 solved 1 84.50 114.05 20 14.75 14.752 3.80 3.80 2 83.35 115.25 40 15.95 15.952 3.52 3.52 3 83.00 115.60 100 16.30 16 .302 3.44 3.44 2.40 2.40 1 4 75.50 123.10 30 23.80 23.803 -q 2.35 2.35 5 74.95 123.65 60 24.35 24.353 Y 6 74.50 124.10 30 24.80 24.803 2.31 2.31 7 71.15 10 28.15 28.154 2.051 2.052 8 68.20 130.40 90 31.10 31.104 1.874 1.875 9 64.25 134.35 70 35.05 35.055 1.685 1.686 10 63.45 135.15 70 35.85 35.855 1.653 1.654 11 140.50 60 41.20 41.206 1.470 1.471 4S' 12 144.55 10 45.25 45.256 1.363 1.364 13 145.70 10 46.40 46.406 1.337 1.338 14 149.30 229.30 10 50.00 50.007 1.264 1.265 15 150.10 228.45 10 50.80 50.807 1.249 1.250 16 155.35 222.90 30 56.05 56.058 1.167 1.168 17 165.35 213.20 10 66 .05 66.059 1.059 1.060 18 166.30 212.30 30 67.00 67.009 1.052 1.053 TABLE 8 (Continued) d-Spacings Scale Reading K-alpha Radiation (mm) Unre- Line Left__ Right I/I0 4S1 6 , Degrees 1 solved 19 167.30 211.25 30 68.00 68.010 1.044 1.045 20 171.25 207.35 10 71.95 71.960 1.018 1.019 21 173.35 205.25 10 74.05 74.060 1.007 1.008 22 175.45 203.15 10 76.15 76.161 0.9969 0.9976 TABLE 9 Calculation of Absorption Effects for Anatass (TiC^) Miller d-Spacings, $ o cos^8 cos2 e Indices h2 ^2 jj2 (ia0/c0)^ a Q r A 0 , Degrees £ d(obs.) Radiation f sin 8 6 (h k S ) 1.042 unre 321 9 4 1 0.158238 13.158238 3.62743 3.7798 47.6575 0.577 1.016 solved 109 1 0 81 12.817278 13.817378 3.71716 3.7766 49.3080 0.528 11 0.9546 316 9 1 36 5.696568 15.696568 3.96189 3.7820 53.8600 0.400 II 0.9180 325 9 4 25 3.955950 16.955950 4.11776 3.7801 57.0360 0.325 0.8959 alpha 1 219 4 1 81 12.817278 17.817278 4.22105 3.7816 59.2870 0.278 II 0.8954 2 219 3.7795 59.5875 0.272 II 0.8266 1 415 16 1 25 3.955950 20.955950 4.57777 3.7840 68.7160 0.126 i II 0.8264 2 415 3.7831 69.1160 0.121 05 II I 0.8105 1 309 9 0 81 12.817278 21.817278 4.67089 3.7858 71.8675 0.089 11 0.8104 2 309 3.7853 72.3175 0.085 II 0.7976 1 424 16 4 16 12.531808 22.531808 4.74677 3.7860 74.9435 0.061 11 0.7974 2 424 3.7851 75.5690 0.055 TABLE 10 Calculation of Absorption Effects for Anatase (Ti0 2 ) a 0 /cQ b 0.39779 Miller d-Spacings, JT Indices (ian/c n )2 ^ \l K-alpha-1 Radiation (hki) d(ca"Tc7X dT5b?71 d(ASTM) 101 1 0 1 0.158238 1.158238 1.0762 3.518 3.44 3.51 103 1 0 9 1.424144 2.424144 1.5570 2.432 2.40 2.434 004 0 0 16 2.531812 2.531812 1^5912 2.380 2.35 2.379 112 1 1 4 0.632953 2.632953 1.6227 2.333 2.30 2.336 200 4 0 0 0 4.000000 2.0000 1.893 1.872 1.891 105 1 0 25 3.955956 4.955956 2 .2262') 1.701 1.685 1.699 211 4 1 1 0.158238 5.158238 2.2712 1.667 1.652 1.665 116 1 1 36 5.696576 7.696576 2.7743 1.365 1.355 1.367 220 4 4 0 0 8 . 000000 2.8284 1.339 1.330 1.337 215 4 1 25 3.955956 8.955956 2.9925 1.265 1.257 1.264 301 9 0 1 0.158238 9.158238 3.0263 1.251 1.243 1.250 321 9 4 1 0.158238 13.158238 3.6274 1.0439 1.042 1.0433 109 1 0 81 12.817297 13.817297 3.7172 1.0186 1.016 1.0173 316 9 1 36 5.696576 15.696576 3.9619 0.9557 0.9546 0.9550 400 16 0 0 0 16.000000 4.0000 0.9466 0.9451 0.9461 325 9 4 25 3.955956 16.955956 4.1178 0.9195 0.9187 0.9189 219 4 1 81 12.817297 17.817297 4.2210 0.8971 0.8959 0.8960 415 16 1 25 3.955956 20.955956 4.5778 0.8271 0.8266 0.8268 309 9 0 81 12.817297 21.817297 4.6709 0.8106 0.8105 0.8100 424 16 4 16 2.531812 22.531812 4.7468 0.7977 0.7976 0.7990 100 8 0 6 0 4 0 20 v V A . Lw>mvL^ LA~/L CM00 CVJ CM GO CM 00 CM Radiation CoK-olpho, Fe filter, X-ray slit = 4°, scatter slit * 1°, receiving slit = 0.006", scale factor = 40, mult. = 0.8, RC = 4 sec., 9ma, 30KV, chart speed 30”/hr., scan rate l°/min. FIGURE 13. X-ray spectrometer data for TiOg X-RAY DIFFRACTION PATTERNS OF TIOg (ANATASE) Film No. 21A, Copper Radiation Film No. 14J, Iron Radiation. Figure 14. 3 .8 0 0 Qn- 3 .7 8 6 5 A 3 .7 8 0 o 3 .7 7 0 3 .7 6 0 3 .7 5 0 0.00 0.100 0.200 0 .3 0 0 0 .4 0 0 0 .5 0 0 1 rcos2 # cos 2 Lsin & Figure 15. Determination of lattice constant, a0 , for TiO 2 ( an a ta s e ) -81- Titanium tetrabromide, as prepared and purified by the procedure given on pages 26 > was invesitgated by X-ray powder diffraction techniques. The d-spacings for TiBr^ as reported Kringstand are shown in Table II. This experiment Was oonductod for the purposecof verification of the previous work and to prove the specimen preparation technique for hygroscopic materials to be adequate. The diffraction pattern was obtained from a sample of yellow TiBr^. hermetically sealed in a 0.5 mm. Lindemann glass X-ray capillary tube and submitted to the K-alpha radiation of iron for five hours. Analysis of the resulting photograph, angles of reflection and d-spacings are given in Table 12, whereas only the d-spacings determined from the second and third reading of the same film are given in Table 13. Figure 17 is a photograph of the X-ray diffraction pattern. Comparison of the values for the observed d-spacings, Tables 12 and 13, with the literature values, Table 11, shows the literature values to be high in every case. This is exactly what Would be expected where absorption factors are appreciable. It is a Well known fact that titanium compounds are excellent X-ray absorbers and especially of the soft iron radiation used in this experiment. Thus, it seemed quite necessary to recalculate the d-spacings taking cognizance of absorption effects. Titanium tetrabromide was reported by Hassel and Kringstad to crystallize in the cubic system with the lattice constant, aQ , equal to 1 1 .202.8 . b-fciiizing this value of a 0 in conjunction with equation 2 : (2) *®Hlassel, 0 ., Kringstad, H., 2. Phys. Chem., 15, 274-80 (1932). -82- the square root of the sum of the squares of the Miller indices was approximately evaluated. Absolute values for the individual Miller indices were then determined with the aid of the data found^ ® 2 Klug and Alexander. A new value for the lattice constant corresponding to each set of Miller indices was calculated from equation 2 by utilizing the observed values for the d-spacings and the Millar indices. These data are shown in Tables 14 and 15. In order to obtain the absolute value of the lattice constant, that is, the value of a 0 when 0 *= 90° and absorption is negligible, a 0 was plotted against & 1 , as! shown in Figure 16. L s m 0 0 J Extrapolation of fCos2e cos2el to zero " 90°) yielded a * U i n r + — - J value for a 0 of 11.292.8. Use of the extropolated value of aQ and the Miller indices with equation 2 lead to the absolute (calculated) values for the d-spacings; absolute in the sense that absorption factors have been accounted for. The observed, calculated and literature values for the d-spacings are tabulated in Table 16. There are several obvious features which should be pointed out. Although the agreement between the calculated and literature values appears to be quite good, fewer lines were reported by Hassel and Kringstad than were found in our work. This feature could possibly be explained by the fact that they did not obtain the linos of Weak intensity due to a short exposure time. This seems logical since all the so-called extra lines in the present investigation have intensity 162Klug, H. P., Alexander, L. E., "X-Ray Diffraction Procedures", John Wiley and Sons, Inc., New York, 1954, p. 679. -83- value, of 20 or less. Not to be overlooked is the fact that the extra weak lines could be.attributed to an impurity, such as for example, an hydrolysis product of TiBr^. The latter argument does not appear to be feasible since the sample of TiBr4 did not undergo any apparent color change even after storage for several days; hydrolysis of ^iBr^ produces a change from yellow to red. It is to be pointed out that TiBr4 crystallizes in a body centered cubic structure and the d-spacings were indexed on that basis, although the Miller indices corresponding to d-spacings of 4.84, and 2.065$ do not conform to a body centered cubic structure. The reason for this apparent discrepancy is not known. TABLE XX Interplaner Spacings (ASTM) for TiBr4 K-alpha-1 MiXXer Indices Intensity d-Spacings, ^ (hkit) I/In 3.26 222 100 2.82 400 70 1.99 440 80 1.70 622 60 1.63 444 10 1.41 800 20 1.29 662 30 1.26 840 30 1.15 844 40 666 1.09 10.22 40 0.998 880 10 0.953 10.62 30 Radiation: Copper Wavelength: 1.5405 .8 Diameter: 5.8 cm aQ - XX.282 A Crystal Structure: Cubic HasseX, 0 ., Kringstad, H., Z, Phys. Cftem. 15, 274-80 (1932) TABLE 12 Measurement of TiBr^ Film and Calculation of d-Spacings Iron-K-alpha Radiation*; Camera Diameter 57.3 mm., Film in Asymmetic Position; Film Shrinkage Factor: 0.99972, Film No. 14J Capillary Size, 0.5 mm., Exposure Time, 5 Hours. d-Spacings Scale Reading K-alpha Radiation (iron) Unre- Line Left Right l/ln 4S 8 , Degrees 1 solved 1 113.05 135.95 30 11.45 11.447 4.88 4.88 2 112.95 137.05 30 12.55 12.546 4.46 4.46 3 --- 138.25 20 13.75 13.746 4.07 4.07 4 108.40 140.55 40 16.05 16.046 3.50 3.50 5 106.75 142.25 100 17.75 17.745 3.18 3.18 6 104.00 145.00 90 20.50 20.494 2.76 2.77 7 102.75 10 21.75 21.744 2.613 2.615 8 100.30 --- 10 24.20 24.193 2.362 2.364 9 98.00 151.00 20 26.50 26.493 2.170 2.172 10 96.50 152.55 20 28.05 28.042 2.059 2.060 11 95.00 154.00 1 0 0 29.50 29.492 1.966 1.968 12 93.00 156.00 10 31.50 31.491 1.853 1.854 13 --- 156.75 1 0 32.25 32.241 1.814 1.816 14 89.35 159.55 1 0 0 35.05 35.040 1.686 1^687 15 88 .50 160.45 40 35.95 35.940 1.649 1.650 16 87.60 161.35 40 36.85 36.840 1.614 1.616 4S' 17 173.05 255.95 -- 48.55 48.536 1.292 1.293 18 174.80 254.25 50.30 50.286 1.258 1.259 19 181.90 247.20 — 57.40 57.384 1.149 1.150 20 187.65 241.40 M *“ 63.15:: 63.132 1.085 1.086 -86- TABLB 13 Measurement of TiBr4 Film and Calculation of d-Spacings Iron K-alpha Radiation; Camera Diameter 57.-3 mm., Film in Asymmetic Postion; Film Shrinkage Factor: 0.99972, Film No. 14J Capillary Size, 0.5 mm.,' Exposure Time, 5 Hours. 2nd Reading 3rd Reading o d-Spacings, i? d-Spacings, A K-alpha Radiation K-alpha Radiation Unre- Unre- 1 solved 1 solved 4.84 4.84 5.55 5.55 4.44- 4.44 4.85 4.85 3.48 3.48 4.4-7 4.47 3.17 3.17 4.03 4.03 2.77 2.77 3.49 3.49 2.616 2.618 3.19 3.19 2.374 • 2.376 2.78 2.78 2.176 2.178 2.46 2.46 2.065 2.066 2.176 2.178 1.962 1.963 2.065 2.066 1.855 1.856 1.970 1.971 1.809 1.810 1.854 1.855 1 . 6 8 6 1.867 1.820 1.821 1.647 1.648 1.720 1.721 1.609 1.610 1.686 1.687 1.398 1.399 1.650 1.651 1.290 1,291 1.612 1.613 1.259 1.260 1.540 1.541 1.160 1.161 1.520 1.521 1.150 1.151 1.481 1.482 1.085 1.086 1.422 1.423 1.074 1.075 1.403 1.404 1.384 1.385 1.300 1.301 1.291 1.292 1.259 1.260 1.160 1.161 1.150 1.151 1.131 1.132 1.085 1.086 0.996 0.997 TABLE 14 Calculation of Absorption Effects For Ti3r4 (1st Reading) ■jTcos^Q cos2e] d(obs.) (hkt) k^ S \/ an, 1 8, Degrees |_sin 8 6 J 4.88 200 4 1 0 5 2.23607 10.9120 11.447 4.824 4.46 211 4 1 1 6 2.44949 10.9247 12.546 4.368 4.07 220 4 4 0 8 2.82843 11.5158 13.746 3.952 3.50 310 9 1 0 10 3.16228 11.0680 16.046 3.320 3.18 222 4 4 4 12 3.46410 11.0158 17.745 2.953 2.76 400 16 0 0 16 4.00000 11.0400 20.494 2.480 2.613 411 16 1 1 18 4.24264 11.0860 21.744 2.301 300 2.362 332 9 9 4 22 4.69042 11.0788 24.193 2 . 0 0 1 2.170 510 25 1 0 26 5.09902 11.0649 26.493 1.764 431 2.059 520 25 4 0 29 5.38516 11.0880 28.042 1.624 432 1.966 440 16 16 0 32 5.65685 11.1214 29.492 1.506 1.853 600 36 0 0 36 6 . 0 0 0 0 0 11.1180 31.491 1.358 1.814 611 36 1 1 38 6.16441 11.1822 32.241 1.306 1.686 622 36 4 4 44 6.63325 11.1836 35.040 1.132 1.649 631 36 9 41 46 6.78233 11.1841 35.940 1.081 1.614 444 16 16 16 48 6.92820 11.1821 36.840 1.032 1.292 662 36 36 4 76 8.71780 11.2634 48.536 0.551 1.258 840 64 16 0 80 8.94427 11.2519 50.286 "0.498 1.149 844 64 16 16 96 9.79796 11.2578 57.384 0.317 1.085 666 36 36 36 108 10.39230 11.2756 63.132 0.207 10.22 TABLE 15 Calculation of Absorption Effects For TiBr4 (2 nd Reading) £ cos2 g cos29 k2 *2 0, Degrees _sin 6 9 . d(obs.) (hkO . y aoi ft - 4.84 210 4 1 0 5 2.23607 10.8226 11.531 4.786 4.44 211 4 1 1 6 2.44949 10.8757 12.579 4.356 3.48 310 9 1 0 10 3.16228 11.0047 16.123 3.302 3.17 222 4 4 4 12 3.46410 10.9812 17.770 2.948 2.77 400 16 0 0 16 4.00000 11.0800 20.466 2.484 2.616 411 16 1 1 18 4.24264 11.0987 21.714 2.306 330 2.374 332 9 9 4 22 4.69042 11.1350 24.060 2.015 2.176 510 25 1 0 26 5.09902 11.0955 26.406 1.772 431 2.065 520 25 4 0 29 5.38516 11.1204 27.954 1.632 432 1.962 440 16 16 0 32 5.65685 11.0987 29.501 1.505 1.855 600 36 0 0 36 6 . 0 0 0 0 0 11.1300 31.448 1.361 1.809 611 36 1 1 38 6.16441 11.1514 32.296 1.302 1.686 622 36 4 4 44 6.63325 11.1836 35.042 1.132 1.647 631 36 9 1 46 6.78233 11.1705 35.990 1.078 1.609 444 16 16 16 48 6.92820 11.1475 36.988 1.025 1.398 800 64 0 0 64 8 . 0 0 0 0 0 11.1840 43.827 0.716 1.290 662 36 36 4 76 8.71780 11.2460 48.619 0.548 1.259 840 64 16 0 80 8.94427 11.2608 50.266 0.499 1.150 844 64 16 16 96 9.79796 11.2676 57.355 0.318 1.085 666 36 36 36 108 .10.39230 11.2756 63.195 0.206 10.22 TABLE 16 0 Calculation of Absorption Effects For TiBr^ a 0 * 11.292A Miller d-Spacings, Indices / Calc. obs ASTM (hkJl) ' Reading 1 2 210 2.23607 5.05 4.88 4.84 211 2.44949 4.61 4.46 4.44 220 2.82843 3.992 4.07 310 3.16228 3.571 3.50 3.48 222 3.46410 3.260 3.18 3.17 3.26 400 4.00000 2.823 2.76 2.77 2.82 411, 330 4,24264 2.662 2.613 2.616 332 4.69042 2.407 2.362 2.374 510, 431 5.09902 2.214 2.170 2.176 520, 432 5.38516 2.097 2.059 2.065 440 5.65685 1.996 1.966 1.962 1.99 600 6 . 0 0000 1.882 1.853 1.855 611 6.16441 1.832 1.814 1.809 622 6.63325 1.702 1.686 1.686 1.70 631 6.78233 1.665 1.649 1.647 444 6.92820 1.630 1.614 1.609 1.63 800 8 . 0 0 0 0 0 1.412 . 1.398 1.41 662 8.71780 1.295 1.292 1.290 1.29 840 8.94427 1.262 1.258 1.259 1.26 844 9.79796 1.152 1.149 1.150 1.15 6 6 6 , 10.22 10.39230 1.086 1.085 1.085 1.09 11.500 11.400 a Q = It. 2 9 2 11.300 1.200 □ o 1.100 1 1 .0 0 0 10.900 10.800 0 .2 5 0 .5 0 0.75 LOO 1.25 i [ cos+ cos2f f l 2 ‘■sin 0 0 -* F ig u re 16. Determination of the lattice constant, a0 , for TiBr 4 X-RAY DIFFRACTION PATTERN OF TiBr4 Figure 17; Film No, 14J3 Iron Radiation -92- TiBr.'Dioxane. 4______ Samples from five different preparations of the solid addition compound, TiBr^Dioxane, contained in a sealed Lindemann glass X-ray capillary was exposed to the K-alpha radiation of cobalt (Table 17), copper (Tables 18 and 19) and iron (Tables 20 and 21). It was necessary to acquire the addition compound from different preparations to check the reproducibility of the preparative method as well as to insure the absence of hydrolysis before or during the irradiation by X-rays. Photographs of the diffraction patterns are shown in Figures 18, 19 and 20. Inspection of Tables 17 through 21 shows that no lines due to back reflection were obtained. The data found in babies 17 and 19 were corrected for film shrinkage and this accomplished only with the aid of fiducial points (notched film). Thus, the values for the d-spacings as well as any value calculated from the observed d-spacings will be in slight error, •'■he data in Table 17 which were obtained from an eight hour exposure of the sample to K-alpha radiation of cobalt were used to calculate the lattice constants for the addition compound. Of the graphical devices most widely used are the Hull-Davey ChartslSJJ \jhich are based on the expression, logiod s log aQ - £log (h^ -f k2 ) + - l for tetragonal cl - crystals. The charts are prepared by plotting the axial ratio, c0 /a0 against log d for all the theoretical possible index triplets, (hkJU, T^Bell, J. Austin, A. E., Battelle Indexing Charts for Diffraction Patterns of Tg-fcragonal, Hexagonal and Orthorhomic Crystals. -93- constituting a primitive lattice pattern. To index this pattern, which was found to be tetragonal, the observed values for the d-spacings were plotted along the edge of the strip of paperl6^ to the same logarithmic scale as that of the indexing chart. While being kept in a horizontal position, the strip was moved over the chart until a fit was found between all the plotted d-spacings and the lines on the graph. It can be seen that this procedure is the mechanical equivalent of varying the parameters a0 and o0 /a0 until the experimental data agree with the theoretical. Once the fit was obtained, the indices of the lines, Table 23 and the approximate axial ratio, a 0/cQ equal to 2.4S3, was read directly from the chart. A more accurate value for a 0 was obtained by utilizing equation 1 in the manner disclosed on page a o As previously stated, denotes the values for the observed o d-3pacings, in A, corresponding to the Miller indices of (hkSt) and a 0 /c0, the axial ratio, whose value is 2.463. Thus, a value of aQ was computed for individual lines and the data shown in Table 2 2 . A plot of a 0 versus is shown in Figure 21 from which an extrapolated value of aQ equal to 18.446^ was obtained. This value is not very precise due to the scatter in the data and more important, the absence of d-spacings with 9 values between 50 and 85 degrees, which necessitated a long extropalation. Using equation 1 in conjunction with the extrapolated value of a0, the Miller indices and 164. Klug, k. P., Alexander, L. E., Loc. Gjt., p. 351-3. -94- axial ratio from the Hull-Davy Gbart, nett values for the d-spacings ttere computed and are given in Table 23. ! TABLE 17 Measurement of TiBr^/Dioxane Film and Calculation of d-Spacings Cobalt K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetic Position; Film Shrinkage Factor: 1.00278, Film No. 14J Capillary Size, 0.5 mm., Exposure Time, 8 Hours. . - d-Spacings, & Scale Reading K-alpha Radiation (mm) Unre- Line Left Right I/I0 4S 26, Degrees solved 1 85.30 121.50 100 18.10 18.150 5.67 2 84.00 122.80 50 19.40 19.454 5.30 3 81.60 125.20 10 21.80 21.861 4.72 4 80.35 126.45 10 23.05 23.114 4.47 5 79.55 127.25 10 23.85 23.916 4.32 6 75.90 130.90 50 27.50 27.576 3.75 7 74.35 132.45 40 29.05 29.131 3.56 8 73.35 133;45 20 30.05 30.134 3.44 9 71.55 135.25 60 31.85 31.938 3.25 10 70.10 136.70 40 33.30 33.392 3.11 11 68.25 138.60 60 35.20 35.298 2.95 12 66.70 140.10 30 36.70 36.802 2.83 13 66.05 140.75 40 37.35 37.454 2.78 14 63.60 143.20 10 39 .80 39.911 2.62 15 62.80 144.00 10 40.60 40.713 2.57 16 60.50 146.30 20 42.90 43.019 2.44 17 58.35 148.45 10 45.05 45.175 2.33 18 57.60 149.20 20 45.80 45.927 2.29 19 56.30 150.50 10 47.10 47.231 2.23 20 54.65 152.15 10 48.75 48.886 2.16 TABLE 17 (Continued) d-Spacings, A Scale Reading K-alpha Radiation (mm) Unre- Line Left Right I/I0 4S 26, Degrees solved 21 53.85 153.05 20 49.65 49.788 2.12 22 53.10 153.65 20 50.25 50.390 2.10 23 52.35 154.45 20 51.05 51.192 2.07 24 -w- 157.10 10 53.70 53.849 1.97 25 158.60 10 55.20 55.353 1.93 26 161.10 10 57.70 57.860 1.85 27 163.50 10 60.10 60.267 1.78 28 164.80 . 10 61.40 61.571 1.75 29 --- 166.15 10 62.75 62.924 1.71 30 Mki»> 172.35 10 68.95 69.142 1.58 31 176.20 10 72.80 73.002 1.50 32 179.80 10 76.40 76.612 1.44 TABLE . 18 Measurement of TiBr^/Dioxane Film and Calculation of d-Spacings Copper K-alpha Radiation; Camera Diameter 114-6 mm., Film in Asymmetic Position; Film No. 1M Capillary Size 0.5 mm., Exposure Time, 6 Hours. d-Spacings, 5 Scale Reading K-alpha Radiation (mm) Unra- dn Left Right I/I0 29, Degrees solved X 99.85 131.05 100 15.59 5.68 2 98.50 132.40 50 16.94 5.23 3 96.90 134.00 30 18.54 4.78 4 95.65 135.25 30 19.79 4.48 5 94.70 136.25 10 20.79 4.27 6 91.65 139.25 80 23.79 3.74 7 90.40 140.50 40 25.04 3.55 8 89.25 141.65 50 26.19 3.40 9 88.15 142.75 100 27.29 3.26 10 86.65 144.25 40 28.79 3.10 XX 85.10 145.80 100 30.34 2.95 12 83.15 147.75 70 32.29 2.77 13 81.35 149.50 30 34.04 2.63 14 78.55 152.35 40 36.89 2143 15 76.00 154.90 50 39.44 2.28 16 75.20 155.75 40 40.29 2.24 17 73.55 157.35 30 41.89 2.15 18 72.90 158.00 30 42.54 2.12 71.75 159.15 50 43.69 2.07 TABLE 18 (Continued) d-Spacings, A Scale Heading K-alpha Radiation (mm) Unre- Line Left Right I/Iq 28, Degrees solved 20 --- 161.50 30 46.04 1.97 21 68.45 162.45 30 46.99 1.93 22 66.35 164.55 30 49.09 1.85 23 65.45 165.50 30 50.04 1.82 24 64.35 166.60 50 51.14 1.78 25 63.15 167.80 30 52.34 1.75 26 62.00 168.95 50 53.49 1.71 27 61.45 —- 10 54.04 1.70 28 10 -- -- 29 57.20 173.75 20 58.29 1.58 1.56 30 56.10 174.80 20 59.34 31 55.15 175.80 20 60.34 1.53 32 53.20 177.70 20 62.24 1.49 33 50.90 180.00 10 64.54 1.44 34 49.70 181.20 10 65.74 1.42 35 48.55 182.40 10 66.94 1.40 36 47.75 183.15 10 67.69 1.38 37 45.95 10 69.54 1.35 38 44.15 186.85 10 71.39 1.32 39 --- 188.20 10 72.74 1.30 40 ---- 198.35 10 B2.89 1.16 1.06 41 ^ 208.10 10 92.64 TABLE 19 Measurement of TiBr^Dioxano Film and Calculation of d-Spacings Copper K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetic Position; Film Shrinkage Factor: 1.00181, Film No. 4J Capillary Size 0.5 mm., Exposure Tima, 6 Hours. d-Spacings Scale Reading K-alpha Radiation (mm) Unre- ine Left Right l/l0 4S 29, degrees solved 5.71 X 88.45 119.40 100 15.475 15.503 2 m »»» 120.75 80 16.825 16.855 5.24 3 122.40 10 18.475 18.508 4.79 4 *• m 123.65 10 19.725 19.761 4.49 5 124.65 10 20.725 20.762 4.27 6 80.25 127.60 80 23.675 23.718 3.75 3.56 7 128.85 40 24.925 24.970 8 129.85 60 25.925 25.972 3.43 3.33 9 130.65 40 26.725 26.773 10 76.80- 131.00 80 27.075 27.124 3.28 11 132.55 20 28.625 28.677 3.11 12 73.70 134.15 10 30.225 30.280 2.95 2.83 13 >->■> 135.50 50 31.575 31.632 14 71.60. 136,15 90 32.225 32.283 2.77 15 ^ 136.85 10 32.925 32.984 2.71 16 137.85 20 33.925 33.986 2.64 2.4-2 17 140.90 20 36.975 37.042 2.28 18 » 143.40 70 39.475 39.546 2.23 19 144.25 60 40.325 40.398 20 145.55 50 41.625 41.700 2.16 21 146.45 50 42.525 42.602 2.12 TABLE 19 (Continued) d-Spacings Scale Reading K-alpha Radiation (mm) Unre- i ini Left Right I/In 4 S 26, Degrees solved 22 •1 -S *1 147.15 50 43.225 43.303 2.09 2.07 23 MMM 147.55 50 43.625 53.704 1.93 24 MM M 150.95 20 47.025 47.110 1.85 25 MMM 153.10 30 49.175 49.264 1.82 26 MMM 153.95 40 50.025 50.116 1.78 27 •.MM 155.00 50 51.075 51.167 28 156.30 40 52.375 52.470 1.74 1.71 29 MMM 157.25 50 53.325 53.422 1.60 001 30 MM*. 161.45 10 57.525 57.629 1.55 31 MMM 163.20 40 59.275 59.382 1.53 32 M M M 164.05 20 60.125 60.234 1.49 33 M M M 166.05 10 62.125 62.237 1.44 34 M M M 168.50 10 64.575 64.692 1.39 35 M M M 170.90 10 66.975 ■ 67.096 1.32 36 175.00 10 71.075 71.204 80.170 1 .20 37 MM M 183.95 10 80.025 85.329 1.14 38 M M M 189.10 1 0 85.175 1.07 39 M M M 196.25 10 92.325 92.492 TABLE 20 Measurement of TiBr4 *Dioxane Film and Calculation of d-Spacings Iron K-alpha Radiation; Camera Diameter 57.3 mm., Film in Asyrametic Position; Film No. 15J Capillary Size 0,5 mm., Exposure Time, 2 Hours. d-Spacings, & Scale Reading K-alpha Radiation (mm) Unre- Line Left Right I/Io 20, Degrees 1 solved 1 ' 27.65 47.20 100 9.75 5.72 5.72 2 26.60 48.30 40 10.85 5.14 5.14 3 22.35 52.60 50 15.15 3.76 3.70 4 21.50 53.45 30 16.00 3.51 3.51 5 2 0 . 1 0 54.80 80 17.35 3.25 3.25 TOT 6 19.10 55.75 60 18.30 3.08 3.08 7 : 18.15 56.75 80 19.30 2.93 2.93 8 16.80 58.10 80 20.65 2.74 2.74 9 12.25 62.70 30 25.25 2.269 2.270 10 11.55 63.35 40 25.90 2.216 2.218 11 9.20 65.50 50 28.05 2.058 2.059 12 — 67.75 10 30.30 1.919 1.920 13 5.80 69.10 10 31.65 1.845 1.846 14 3.60 10 32.85 1.784 1.785 15 3.10 ---- • 10 33.35 1.761 1.762 16 4.20 70.75 10 33.30 1.730 1.731 17 --- 72.15 30 34.70 1.700 1.701 18 ---- 73.85 30 36.40 1.631 1.632 19 0.55 — 10 36.90 1.612 1.613 20 ---- 75.50 30 38.05 1.570 1.571 TABLE 21 Measurement of TiEr^'Dioxane Film and Calculation of d-Spacings Iron K-alpha Radiation; Camera Diameter 57.3 mm., Film in Asymmetic Position; Film No. 14J Capillary Size, 0.5 mm., Exposure Time, 2 Hours. d-Spacings, 5 Scale Reading K-alpha Radiation (mm ) Unre jin Left Right I/lQ 29, Degrees solved X 132.60 152.30 10 0 9.80 5.69 2 131.65 153.35 30 10.85 5.14 3 127.40 157.60 40 15.10 3.72 4 126.50 158.50 10 16.00 3.51 102 5 125.15 159.85 100 17.35 3.25 6 124.10 160.90 40 18.40 3.07 7 123.20 161.80 60 19.30 2.93 8 121.85 163.15 80 20.65 2.74 9 120.15 164.80 10 22.30 2.55 10 118.85 166.15 10 23.65 2.41 11 168.35 2 0 25.85 2.22 12 170.55 30 28.05 2.06 13 175.75 1 0 33.25 1.76 14 177.25 10 34.75 1.70 15 -- 178.90 10 36.40 1.63 16 -- 180.55 10 38.05 1.57 17 182.95 10 40.45 1.49 TABLE 22 Determination of Lattice Constants for TiBr^'Dioxane COS^Q ( 003^8 3(obs.) (hid) £ Jd £ H a 0/cn)2 s a Q , JZ 9, Degrees a „sin 8 9 2.44 44-2 16 16 4 24.264 56.264 7.5009 18.3022 21.5095 2.334 2.23 323 9 4 9 54.594 67.594 8.2215 18.3339 23.6155 2.066 2.12 42 3 16 4 9 54.594 74.594 8.6368 18.3100 24.8940 1.925 1.97 443 16 16 9 54.594 86.594 9.3056 18.3320 26.9245 1.724 1.93 603 36 0 9 54.594 90.594 9.5181 18.3699 27.6765 1.656 1.78 304 9 0 16 97.056 106.056 10.2986 18.3309 30.1335 1.456 i EOT TABLE 23 Determination of LattiGe Constants for TiBr^»Dioxane a 0 ■ 18.446 R, a 0 /c0 b 2.463 d( obs.) (hkSQ h 2 k2 %2 (laQ/cn )2 \! d(calc.) 5.67 5.30 4.72 301 9 0 1 6.066 IS. 066 3.8815 4.75 4.47 410 16 1 0 0 17.000 4.1231 4.47 4.32 330 9 9 0 0 18.000 4.24264 4.35 3.75 331 9 9 1 6.066 24.066 4.9057 3.76 3.56 112 1 1 4 24.264 26.264 5.1248 3.60 104' 3.44- 202 4 0 4 24.264 28.264 5.3164 3.47 3.25 5,11 25 1 1 6.066 32.066 5.6627 3.257 440 16 16 0 0 32.000 5.65685 3.261 3.11 530 25 9 0 0 35.000 5.91608 3.118 2.95 441 16 16 1 6.066 38.066 6.1698 2.990 2.83 601 36 0 1 6.066 42.066 6.4858 2.844 332 9 9 4 24.264 42.264 6.5011 2.837 2.78 422 16 4 4 24.264 44.264 6.6531 2.772 2.62 502 25 0 4 24.264 49.264 7.0188 2.628 432 16 9 4 2.57 512 25 1 4 24.264 50.264 7.0897 2.602 2.44 442 16 16 4 24.264 56.264 7.5009 2 .459 2.33. 223 4 4 9 54.594 62.594 7.9116 2.332 2.29 313 9 1 9 54.594 64.594 8.0371 2.295 2.23 323 9 4 9 54. Sgi- 67.594 8.2215 2.244 TABLE 23 (Continued) d(obs.) (hk ji) h 2 Jk^ (Ian/on)2 X ..... ~ r ^ ~ d(caXo.) 2.16 333 9 9 9 54.594 72.594 8.5205 2.165 2.12 423 16 4 9 54.594 74.594 8.6368 2.136 2.10 ------2.07 433 16 9 9 54.594 79.594 8.9215 2.068 503 25 0 9 1.97 443 16 16 9 54.594 86.594 9.3056 1.982 1.93 603 36 0 9 54.594 90.594 9.5181 1.938 1.85 104 1 0 16 97.056 98.056 9.9023 1.863 1.78 304 9 0 16 97.056 106.056 10.2986 1.791 1.75 324 9 4 16 97.056 110.056 10.4908 1.758 X-RAY DIFFRACTION-PATTERN OF TiBr4*DIOXANE Figure 18; Film No. 14J, Iron Radiation Figure 19; Film No. 14J, Cobalt Radiation Figure 20; Film No. 4J, Copper Radiation = 18 .4 4 6 £ 18.45 . 18.40 603 324 °0 > 18.35 107' 3 0 4 ,423 442 18.30 0 0.50 1.00 1.50 2.00 COS 2 6 > cos z e 2 _s i n O 6 Figure 21. Determination of the lattice constant, a0 , for TiBr4 • Dioxane 108- TiBr4 *2Tetrahydropyran. Samples from three different preparations of the solid addition compound, TiBj.^*2Tetrahydropyran, contained in a sealed Lindemann glass X-ray capillary were exposed to the K-alpha radiation of copper. The data are summarized in Tables 24, 25, and 26 and a photograph of the diffraction pattern is shown in Figure 22. The evaluation of the Miller indices, axial ratio, lattice constants and recalculation of the d-spacings was conducted in the same manner as outlined on page 81 for TiBr^/Dioxane. ^he data are given in Tables 27, 28, Figure 23 and can be briefly summarized as: the crystal form is tetragonal with a value for the axial ratio, a0/c0 of 1.757 and aQ of 12,2645. TABLE 24 Measurement of TiBr4 *2Tetrahydropyran Film and Calculation of d-Spacings Copper K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetic Position; Film Shrinkage Factor: 1.00223, Film No. 10J Capillary Size 0.5 mm., Exposure Time, 6 Hours. d-Spacings, S. Scale Reading K-alpha Radiation (mm) Unre- Line Left Right I/In 4S 29, Degrees solved 1 85.85 106.85 1 0 0 10.4875 10.511 8.41 2 82.50 110.25 90 13.8875 13.918 6.36 3 81.35 111.40 80 15.0375 15.071 5.87 4 80.70 112.05 70 15.6875 15.722 5.63 5 75.60 117.10 50 20.7375 20.784 4.27 601 6 73.70 119.05 50 22.6875 22.738 3.90 7 72.15 120.60 70 24.2375 24.292 3.66 8 70.95 121.75 70 25.3875 25.444 3.50 9 68.90 123.80 90 27.4375 27.499 3.24 10 66.85 125.85 10 29.4875 29.553 3.02 11 66.15 126.60 50 30.2375 30.305 2.94 12 64.85 127.85 50 31.4875 31.558 2.83 13 62.75 130.00 20 33.6375 33.712 2^66 14 61.95 130.75 40 34.3875 34.464 2.60 15 61.30 131.45 20 35.0875 35.166 2.55 16 60.40 132.35 20 35.9875 36.068 2.45 17 58.95 133.80 10 37.4375 37.521 2.39 18 58.10 134.65 40 38.2875 38.374 2.34 19 56.75 136.00 10 39.6375 39.726 2.27 20 55.90 136.85 10 40.4875 40.578 2.22 TABLE 24 (Continued) d-Spacings, Scale Reading K-alpha Radiation (mm) Unre tin Left Right I/In 4S 29, degrees solved 21 54.55 138.20 50 41.8375 41.931 2.15 22 53.90 138.85 10 42.4875 42.582 2.12 23 139.55 10 43.1875 43.234 2.09 24 -- 140.20 10 43.8375 43.935 2.06 25 -- 140.90 10 44.5375 44.637 2.03 26 50.90 141.85 20 45.4875 45.589 1.99 27 49.95 142.80 40 46.4375 46.541 1.95 28 4-6.30 146.45 50 50.0875 . 50.199 1.82 29 45.15 147.60 50 51.2375 51.352 lv78 30 42.20 150.55 10 54.1875 54.308 1.69 Oil' 31 40.35 152.40 20 56.0375 56.162 1.64 32 -- 154.65 10 58.2875 58.418 1.58 33 -- 155.60 20 59.2375 59.370 1.55 34 -- 157.30 10 60.9375 61.073 1.52 35 158.60 10 62.2375 62.376 1.49 36 16 0.50 10 64.1375 64.280 1.45 37 -- 162.20 10 65.8375 65.984 1.41 38 163.60 10 67.2375 67.387 1.39 39 -- 165.95 10 69.5375 69.743 1.35 TABLE 25 Measurement of TiBr^^Totrahydropyran Film and Calculation of d-Spacings Copper K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetic Position; Film Ho. 1M Capillary Size 0.5 mm., Exposure Time, 6 Hours. d-Spacings, .£ Scale Reading K-alpha Radiation (mm) Unre ■ins Left Right l/l < 29, Degrees solved 1 95.80 116.80 100 10.4875 8.42 2 92.40 1 2 0 . 2 0 90 13.8875 6.37 3 91.30 121.35 80 15.0375 6.89 4 90.60 122.05 70 15.7375 5.63 5 85.50 127.15 70 20.8375 4.26 6 83.60 129.05 70 22.7375 3.91 7 81.95 130.65 80 24.3375 3.65 8 80.90 131.70 100 25.3875 3.50 9 77.00 MM 10 29.2875 3.05 10 76.00 136.60 50 30.2375 2.95 11 74.80 137.80 50 31.4875 2.84 12 m» 140.15 30 33.8375 2.65 13 m m 140.75 40 34.4375 2.60 14 141.45 40 35.1375 2.55 15 70.25 142.40 30 36.0875 2.49 16 143.00 10 36.6875 2.45 17 143.90 10 37.5375 2.39 18 6 8 . 0 0 144.65 40 38.3375 2.35 _ _ 146.00 20 39.6875 2.27 146.85 20 40.5375 2.22 TABLE 25 (Continued) d-Spacings, Scale Reading K-alpha Radiation Js>d i. (mm) Unre tin Lgft Right l/l0 26, Degrees solved 21 64.4-5 148.15 80 41.8375 2.16 22 148.70 10 42.3875 2.13 23 149.35 10 43.0375 2 . 1 0 24 --- 150.00 10 43.6875 2.07 25 -- 150.85 10 44.5375 2.03 26 --- 151.70 20 45.3875 2 . 0 0 27 59.85 152.80 30 46.4875 1.95 28 156.35 30 5010375 1.82 29 55.00 157.60 40 51.2875 1.78 30 160.45 10 54.1375 1.69 31 ...... 162.45 10 56.1375 1.64 32 » — 163.50 10 57.1875 1.61 33 ------164.60 10 58.2875 1.58 34 16 5.70 10 59.3875 1.56 35 168.85 10 62.5375 1.48 36 170.65 10 64.3375 1.45 37 ^ ^ 172.40 20 66.0875 1.41 38 ^ 174.25 10 67.9375 1.38 39 M M »■ 176.15 10 69.8375 1.35 --- 181.60 10 75.2875 1.26 TABLE 26 Measurement of TiBr4 »2Tetrahydropyran Film and Calculation of d-Spacings Copper K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetic Position; Film Shrinkage Factor: 1.00167, Film No. 20M Capillary Size, 0.5 mm., Exposure Time, 6 Hours, d-Spacings, Scale Reading K-alpha Radiation, (mm) Tlnre- Line Left Right I/In 4S 28,. Degrees solved 1 92.10 113.20 100 10.55 10.568 8.36 2 88.60 116.70 90 14.05 14.073 6.29 3 87.65 117.65 80 15.00 15.025 5^89 113 4 86.85 118.40 70 15.75 15.776 5.61 5 81.70 123.55 70 20.90 20.935 4.24 6 79.90 125.40 70 22.75 22.788 3.90 7 78.30 126.95 80 24.30 24.340 3.65 8 77.25 128.05 80 25.40 25.442 3.50 9 75.20 130.10 90 27.45 27.496 3.24 10 72.25 133.00 80 30.35 . 30.401 2.94 11 71.20 134.05 80 31.40 31.452 2.84 12 68.45 136.90 10 34.25 34.307 2.61 13 138.60 10 35.95 36.010 2.49 14 64.45 140.85 20 38.20 38.264 2.35 15 62.05 143.20 10 40.55 40.618 2.22 16 60.75 144.55 60 41.90 41.970 2.15 17 56.30 148.95 30 46.30 46.377 1.96 18 52.75 152.60 20 49.95 50.033 1.82 19 51.45 153.80 10 51.15 51.235 1.78 20 48.75 156.55 10 53.90 53.990 1.67 TABLE 26 (Continued) d-Spacings, j§ Scale Reading K-alpha Radiation (mm) Unre Line Left Right 4S 2 0 , Degrees solved 21 46.25 «*»« 10 56.40 56.494 1.63 22 — 168.35 10 65.70 65.810 1.42 23 178.20 1 0 75.55 75.676 1.26 * 1 1 TABLE 27 Determination of Lattice Constants for T iBr^•2T etrahydr opyran cos2 0 ^ cos*1 d( obs.) ( h H ) h 2 k2 j|2 (Han/cQ )2 3 n» A. 0, Degrees sin 0 0 a. $5 512 25 1 4 12.348 38 .348 6.1926 12.0756 23.2705 2.108 1.82 442 16 16 4 12.348 44.348 6.6594 1 2 . 1 2 0 1 25.0995 1.903 1.78 532 15 9 4 12.348 46.348 6.8079 12.1181 25.6760 1.843 1.69 .114 1 1 16 49.392 51.392 7.1689 12.1154 27.1540 U 7 0 3 1.64 214 4 1 16 49.392 54.392 7.3751 12.0952 28.0810 1.621 1.58 304 9 0 16 49.392 58.392 7.6414 12.0736 29.2090 1.528 1.55 533 25 9 q 27.783 61.783 7.8602 12.1833 29.6850 1.490 1.52 60'3 36 0 S 27.783 63.783 7.9864 12.1393 30.5365 1.426 1.49 414 16 1 16 49.392 66.392 8.1481 12.1407 31.1880 1.379 1.41 504 25 0 16 49.392 74.392 8.6251 12.1614 32.9920 1.256 434 16 9 16 1.35 205 4 0 25 77.175 81.175 9.0097 12.1631 34.8715 1.142 TABLE 28 Determination of Lattice Constants and Miller Indices for TiBr4 *2Tetrahydropyran a 0 s 12 .264 5;. (aQ/c0 )2 = 3.087 d( obs.) (hid) h2 k2 I2 (hn/cj2 ^ V d(calc.) 4.27 211 4 1 1 3.087 8.087 2.8438 4.312 3.90 310 9 1 0 0 1 0 . 0 0 0 3.1623 3.878 3.66 221 4 4 1 3.087 11.087 3.3297 3.683 3.50 301 9 0 1 3.087 12.087 3.4766 3.528 3.24 112 1 1 4 12.348 14.348 3.7878 3.238 3.02 321 9 4 1 3.087 16.087 4.0108 3.058 400 16 0 0 0 16.000 4.0000 3.066 202 4 0 4 12.348 16.348 4.0432 3.033 2.94 212 4 1 4 12.348 17.348 4.1651 2.944 410 16 1 0 0 17.000 4.1231 2.974 2.83 330 9 9 0 0 18.000 4.2427 2.891 2.66 331 9 9 1 3.087 21.087 4.5921 2.671 2.60 302 9 0 4 12.348 21.348 4.6204 2.654 2.55 421 16 4 1 3.087 23.08 7 4.8049 2.552 2.45 430 16 9 0 0 25.000 5.0000 2.453 500 . 25 0 0 0 25.000 5.0000 2.39 510 ‘ 25 1 0 0 26.000 5.0991 2.405 2.34 tm - tm - - -- >— pm 2.27 402 16 0 4 12.348 28.348 5.3242 2.303 431 25 0 1 3.087 28.087 5.2999 2.314 501 2.22 113 1 1 9 27.783 29.783 5.4574 2.247 2.15 440 16 16 0 0 32.000 5.6568 2.168 TABLE 28 (Continued) d(obs.) (hkJQ j£ ( f a a / c n ) Z J L £ Z d(calc.) 2.15 521 25 4 1 3.087 32.087 5.6645 2.165 2 03 4 0 9 27.783 31.783 5.6376 2.175 2.12 213 4 1 9 27.783 32.783 5.7256 2.142 2.09 530 25 9 0 0 . 34.000 5.8309 2.103 2.06 441 16 16 1 3.087 35.087 5.9251 2.070 2.03 223 4 4 9 27.783 35.783 5.9819 2.050 600 36 0 0 0 36.000 6 . 0 0 0 0 2.044 1.99 531 25 9 1 3.087 37.087 6.0899 2.014 502 16 9 4 12.348 37.348 6.1113 2.007 432 16 9 4 1.95 512 25 1 4 12.348 38.348 6.1926 1.980 1.82 442 16 16 4 12.348 44.348 6.6594 1.842 1.78 532 25 9 4 12 .348 46.348 6.8079 1.801 1.S9 114 1 1 16 49.392 51.392 7.1688 1.711 1.64 214 4 1 16 49.392 54.392 7.3751 1.663 1.58 304 9 0 16 49.392 58.392 7.6415 1.505 1.55 533 25 9 9 27.783 61.783 7.8602 1.560 1.52 603 36 0 9 27.783 63.783 7.9864 1.536 1.49 414 16 1 16 49.392 66.392 8.1481 1.505 1.45 424 16 4 16 49.392 69.392 8.3302 1.472 1.41 504 16 9 16 49.392 74.392 8.6251 1.422 434 1.39 514 25 1 16 49 .392 75.392 8.6828 1.412 1.35 205 4 0 25 77.175 81.175 9.0097 1.361 X-RAY DIFFRACTION PATTERN OF TiBr4 •2TETRAHYDR0PYRAN Figure 22; Film No. 10J, Cooper Radiation. - - 12 2 6 4 £ 1225 12.20 533 A 504 414 ,603 532 ,-442 1 2 .1 0 3 0 4 512 12.05 Q 5 0 1.00 1 5 0 2.00 2.50 1 fcos. cos2ff] 2 [sin 6 O J Figure 23. Determination of the lattice constant, a0, for TiBr4 • 2 Tetrahydropyran 120- TiBr^^Tetrahydrofuran. Samples from two different preparations of the addition compound TiBr^*2Tetrahydrofuran prepared from excess Ti^r^ and one sample from excess tetrahydrofuran, sealed in a Idndermann glass X-ray capillary were exposed to K-alpha radiation of copper. The data and analysis of the data (see pages 92 for the procedure of analysis) are summarized in Figure 24 and ^ables 29 through 32 for the compound obtained from excess ^iBr^, ldiile Figure 27 and Tables 33 and 35 contain the data for the compound prepared from excess Tetrahydrofuran. Figures 25 and 26 are photographs of the diffraction pattern. The crystal form of the compound is tetragonal. The addition compound obtained from excess TiBr4 ^ias an ratio, a 0 /cQ of 2.410, aQ equal to 13.883$ while the axial ratio of 1.927 and aQ equal to 16.150$ was calculated for the compound prepared from excess tetrahydrofuran. TABLE 29 Measurement of TiBr^'STetrahydrofuran Film and Calculation of d-Spacings Copper K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetic Position; Film No. 30A Cap il lary S iz e, 0.5 mm., Exposure Time, 6 Hours. Excess TiBr^ V d-Spacings, i? Scale Reading K-alpha Radiation (mm) Unre Line Left Right I/I q 29, Degrees solved 1 106.00 128.40 100 11.20 7.89 2 103.00 131.40 50 14.20 6.23 i i—* 3 1 0 1 . 0 0 133.40 20 16.20 5.47 to »-* 4 97.90 136.50 - 50 19.30 4.60 I D 6 92.05 142.40 40 25.20 3.53 7 91.50 142.90 30 25.70 3.46 B 89.25 145.15 20 27.95 3.18 9 88.15 146.30 70 29.10 3.07 10 87 w60 146.90 10 29.70 3.00 11 85.65 148.75 30 31.55 2.83 12 84.40 150.00 30 32.80 2.72 13 83.70 150.70 30 33.50 2.67 14 83.30 151.10 30 33.90 2.64 15 82.30 152.10 10 34.90 2.57 16 81.20 153.20 20 36.00 2.49 17 80.05 154.35 20 37.15 2.42 18 78.20 156.20 10 39.00 2.31 19 77.35 157.10 10 39.90 2.26 TABLE 29 (Continued) d-Spacings, A Scale Reading K-alpha Radiation (mm) Unre- Line Left Right I/Iq 29, Degrees solved 20 74.80 159.55 20 42.35 2.13 21 73.80 « B M> « • 20 43^40 2.08 22 73.55 10 43.65 2.07 23 72.70 161.70 10 44.50 2.03 24 70.90 163.50 20 46.30 1.96 25 164.55 10 47.35 1.92 26 6 8 . 1 0 166.30 10 49.10 1.85 27 168.60 10 51.40 1.78 28 64.10 170.45 10 53.25 1.72 29 172.20 10 55.00 1.67 30 173.90 10 56.70 1.62 31 «• 175.20 10 58.00 1.59 32 tm M 179.05 10 61.85 1.50 33 180.90 10 63.70 1.46 TABLE 30 Measurement of TiBr^*2Tetrahydrofuran Film and Calculation of d-Spacings Copper K-alpha Radiation; Camera Diameter 114.6 mm.,. Film in Asymmetic Position; Film Shrinkage Factor: 1.00209, Film No. 11J Capillary Size, ,05mm., Exposure Time, 5 Hours. Excess TiBr4 d-Spacings, .§ Scale Reading K-alpha Radiation (mm) Unre Line Left Right M e 4S 2 0 , Degrees solved 1 85.10 107.50 100 11.25 11.274 7.84 2 82.20 110.30 60 14.05 14.079 6.28 3 80.05 112.45 10 16.20 16.234 5.46 to CO 4 76.95 115.55 40 19.30 19.340 4.59 ( 5 6 70.60 121.90 20 25.66 25.714 3.46 7 68.35 124.25 10 28.00 28.058 3.18 8 67.30 125.25 30 29.00 29.061 3.07 9 65.00 127.50 30 31.25 31.315 2.85 10 63.55 128.95 30 32.70 32.768 2.73 11 62.35 130.15 10 33.90 33.971 2.64 12 61.30 131.25 10 35.00 35.073 2.56 13 60.25 132.25 30 36.00 36.075 2.49 14 59.00 133.50 10 37.25 37.328 2.41 15 56.70 135.80 10 39.55 39.633 2.27 16 54.00 138.50 10 42.25 42.338 2.13 17 51.50 141.05 10 44.80 44.894 2.02 18 47.20 145.30 10 . 49.05 49.152 1.85 19 --- 147.50 10 51.65 51.758 1.76 TABLE 30 (Continued) d-Spacings, Scale Reading K-alpha Radiation (mm) Unra- Line Left Right I/lQ 4S 28, Degrees solved 20 ...... 149 .40 10 53.15 53.261 1.72 21 151.20 10 54.95 55.065 1.67 22 m ^ 154.00 10 57.75 57.871 1.59 23 158.05 10 61.80 61.929 1.50 24 to »n to* 160.30 10 64.05 64.184 1.45 25 167.70 10 71.45 71.599 1.32 26 173.80 10 77.55 77.712 1.23 i TABLE 31 Determination of Lattice Constants and Miller Indices for TiBr4 *2Tetrahydrofuran (Excess TiBr^) (a0 /co )2 b 5.808 cos2 8 cos* d( obs.) (hkii) h 2 k2 X.2 (£an/cf))2 Z I ,, R 9, Degrees _sin 8 8 *] 2.41 440 16 16 0 O' 32.000 5.6569 13.6331 18.6640 2.780 2.27 322 9 4 4 23.232 36.232 6.0193 13 w6638 19.8165 2.585 2.13 332 9 9 4 23.232 41.232 6.4212 13.6772 21.1690 2.381 1.85 442 16 16 4 23.232 55.232 7.4318 13.7488 24.5760 1.959 1.76 223 4 4 9 52.272 60.272 7.7635 13.6638 25.8790 1.823 1.50 443 16 16 9 52.272 84.272 9.1800 13.7700 30.9645 1.395 T 2 S TABLE 32 Determination of Lattice Constants and Miller Indices for TiBr^^Tetrahydrofuran (Excess TiBr^) (a0/c0 )2 » 5,808; a 0 * 13.883 £ d(obs.) (hkS) k2 £ (Xan/cn )2 7. r ~ d(calc.) 3.46 311 9 1 1 5.808 15.808 3.9759 3.492 3.18 321 9 4 1 5.808 18.808 4.3368 3.201 3.07 420 16 4 0 0 20. 0 0 0 4.4721 3.104 2.85 002 0 0 4 23.232 23.232 4.8200 2.880 2.73 430 16 9 0 0 25.000 5.0000 2.777 500 25 0 112 1 1 4 23.232 25.232 5.0231 2.764 2.64 202 4 0 4 23.232 27.232 5.2184 2.660 2.56 520 25 4 0 0 29.000 5.3851 2.578 2.49 431 16 9 1 5.808 30.808 5.5505 2.501 501 25 0 2.41 440 16 16 0 0 32.000 5.6569 2.454 2.27 322 9 4 4 23.232 36.232 6.0193 2.306 2.13 332 9 9 4 23.232 41.232 6.4212 2.162 1.85 442 16 16 4 23.232 55.232 7.4318 1.868 1.76 223 4 4 9 52.272 60.272 7.7635 1.788 1.67 403 16 0 9 52.272 68.272 8.2627 1.680 1.59 42 3 16 4 9 52.272 72.272 8.5013 1.633 1.50 443 16 16 9 52.272 84.272 9.1800 1.512 1.45 603 36 0 9 52.272 86.272 9.2883 1.495 004 0 0 16 92.928 92.928 9.6399 1.440 f 13.90 Og - 13.883 A 13.80 A 4 3 a. LZl 13.70 13? 0.50 1.00 1.50 300 I f cos2g . sin2? ] ^ Lsin 6 0 j Figure 24. Determination of the lattice constant a,,, for T i Br4 ■ 2 Tetrahydrofuran (excess TiBr4) X-RAY DIFFRACTION PATTERNS OF TiBr4 *2TETrtAHYDROFURAN Excess Copper Radiation. igure 26; Film No. 30A, Excess Tetrahydrofuran, Copper Radiation TABLE) 33 Measurement of TiBr4 *2Tetrahydrofuran Film.and Calculation of d-Spacings K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetric Position, Film No. 30A Capillary Size 0.5 mm., Exposure Time, 6 Hours. Excess Tetrahydrofuran d-Spacings, J? Scale Reading K-alpha Radiation (mm) Unre- Line Left Right I/I0 28, Degrees solved 1 94.60 120.55 1 0 0 12.975 6.82 93.00 122.15 40 14.575 2 6.07 129 3 91.65 123.50 60 15.925 5.56 4 90.20 124.95 50 17.375 5.10 5 87.15 128.05 10 20.475 4.33 6 84.70 130.40 10 0 22.825 3.89 7 82.95 132.15 40 24.575 3.62 8 81.85 133.30 60 25.725 3.46 9 80.55 134.60 40 27.025 3.30 10 79.05 136.10 50 28.525 3.13 IX 77.40 137.75 40 30.175 2.96 12 76.50 138.65 10 31.075 2.88 13 141.40 20 33.825 2.65 14 72.15 143.00 50 35.425 2.53 15 69.65 145.55 30 37.975 2.37 16 68.45 146.75 10 39.175 2.30 17 66.60 148.55 50 40.975 2 .20 18 .— 150.95 10 43.375 2.03 19 61.60 153.55 30 45.975 1.97 20 60.55 154.60 20 47.025 1.93 21 156.25 10 48.675 1.87 TABLE 33 (Continued) d-Spacings, .8 Scale Reading K-alpha Radiation (mm) Unre Line Left Right I/Iq 29, Degrees solved 22 — 157.45 10 49.875 1.83 23 158.75 10 51.175 1.78 24 159.80 10 52.225 1.75 25 162.10 10 54.525 1.68 26 --- 162.90 10 55.325 1.66 27 --- 164.95 10 57.375 1.60 28 —- 168.70 10 61.125 1.51 29 --- 170.40 10 62.325 1.48 30 --- 184.65 10 77.075 1.24 oei TABLE 34 Determination of Lattice Constants and Miller Indicies for TiBr^*2Tetrahydrofuran (Excess THF) (a0 /c0 )2 » 3.713 V -1 I i f cos29 , c o s 2 8~[ d(obs.) (hkjQ _h£ _k^ (Han/cn) 2-i _V_____ an, J? 8, Degrees L.sin 8 - 8 J 2.20 333 9 9 9 33.417 51.417 7.1706 15.7753 20.475 2.483 1.97 214 4 1 16 59.408 64.408 8.0248 15.8088 23.000 2.140 1.93 224 4 4 16 59.408 67.408 8.2102 15.8457 23.525 2.077 1.93 533 25 9 9 33.417 67.417 8.2108 15.8468 23.525 2.077 1.87 324 9 4 16 59.408 72.408 8.5093 15.9124 24.350 1.984 1.83 404 16 0 16 59.408 75.408 8.6838 15.8914 24.975 1.916 131 1.78 424 16 :.4 16 59.408 79.408 8.9111 15.8618 25.600 1.851 1.60 215 4 1 25 92.825 97.825 9.8907 15.8251 28.726 1.567 TABLE 35 De-termination of Lattice Constants and Miller Indices for TiBrA ^Tetrahydrofuran (Excess THF) (aQ/c0 )2 s 3.713; a Q - 16.15, &■ d( obs.) (hkg) h 2 k2 j2 Q a n/ Q 2 _ 2 _ d(calc.) 4.33 311 9 1 1 3.713 13.713 3.7031 4.361 3.89 410 16 1 0 0 17.000 4.1231 3.917 3.62 420 16 4 0 0 20.0 0 0 4.4721 3.611 401 16 :vo 1 3.713 19.713 4.4399 3.637 3.45 331 9 9 1 3.713 21.713 4.6597 3.466 3.30 421 36 4 1 3.713 23.713 4.3696 3.316 3.13 510 25 1 0 0 26.000 5.0990 3.167 2.96 431 16 9 1 3.713 28.713 5.3584 3.014 501 25 0 1 2.88 402 16 0 4 14.852 30.852 5.5545 2.908 2.65 441 16 16 1 3.713 35.713 5.9760 2.702 2.53 601 36 0 1 3.713 39.713 6.3019 2.563 502 25 0 4 14.852 39.852 6.3128 2.558 432 16 9 4 2.37 522 25 4 4 14.852 43.852 6.6221 2.439 2.30 323 9 4 9 33.417 46.417 6.8130 2.370 442 16 16 4 14.852 46.852 6.8448 2.359 532 25 9 4 14.852 48.852 6.9894 2.311 403 16 0 9 33.417 49 .417 7.0297 2.297 2.20 333 9 9 9 33.417 51.417 7.1706 2.252 423 16 4 9 33.417 53.417 7.3087 2.210 2.08 503 25 0 9 33.417 58.417 7.6431 2.113 433 16 9 9 TABLE 35 (Continued) d(obs.) (hkfl) h'j _k£ (ia0/c0)^ J d(calc.) 1.97 443 16 16 9 33.417 65.417 8.0881 1.997 214 4 1 16 59.408 64.408 8.0255 2.012 1.93 533 25 9 9 33.417 67.417 8.2108 1.967 224 4 4 16 59.408 67.408 8.2102 1.967 1.87 324 9 4 16 59.408 72.408 8.5093 1.898 1.83 404 16 0 16 59.408 75.408 8.6838 1.860 1.78 424 16 4 16 59.408 79.408 8.9111 1.812 1.68 514 25 1 16 59.408 85.408 9.2417 1.748 1.60 205 4 0 25 — 96.825 9.8400 1.641 215 4 1 25 92.825 97.825 9.89.07 1.633 i SEX 16.10 16.05 16.00 15.95 .A ,324 134 15.90 4 0 4 424 15.85 r- 215 15.80 ,333 15.75 I______l______I______l______I______i_ 0 Q50 1.00 1.50 2.00 2.50 i fcos2ff . cos2g~l "2" [sin O 6 J Figure 27. Determination of the lattice constant, a0, for TiBr4 ■ 2 Tetrahydrofuran (excess THF) -135- Conclusions. The d-spacings, Miller indices and lattice parameters for tetragonal crystalline anatase, ^iOg, *ere determined from data obtained with an X-ray spectrometer and from ponder photographs. Data from the powder photographs were corrected for both film shrinkage and X-ray absorption effects. There is excellent agreement between the literature values and those determined in this investigation. Miller indioes, lattice parameter and d-spacings for body centered cubic titanium tetrabromide were determined from an X-ray diffraction photograph. Agreement between the literature values and those determined in this investigation can be considered as excellent. A greater number of lines were observed in the present work and this oan be attributed to the difference in exposure time. Lattice parameters, d-spacings and Miller indices have been determined for the three addition compounds, TiBr^C^HgC^, TiBr4 »2C^HgO, TiBr^*2CgH^pO which have the tetragonal crystal form. VI. NEUTRALIZATION EQUIVALENT WEIGHT Introduction. The neutralization equivalent height of an acid is the number of grams of the compound required for the neutralization of one liter of one normal alkali. For monobasic acids it is identical with the number representing the molecular weight; for polybasic acids it is a sub multiple of this number. The hydrolysis of a titanium tetrahalide, TiX^, where X s Cl, Br, I, can be expressed by the following reaction TiX4 + 6 H 20 — *- T i 02 (S) + 4 X“ + 4HgO. (3) The total equivalents of hydronium ion can be detemined from the volume of standardized hydroxide required to neutralize the solution. Indeed, as evidenced from equation 3, one mole of tetrahalide produces four moles of hydronium ion, the total equivalents of tetrahalide and hydronium ion are equal and the neutralization equivalent weight of the tetrahalide is one-fourth the formula (molecular) weight. Thus, it should theoretically be possible, to ascertain the neutralization equivalent weight of any hydrolyzable tetrahalide. Historical. An aqueous solution of titanium tetra-bromide or iodide is very acid, and addition of alkali neutralizes the solution. Thia was observed and the pH-neutralization curve which was experimentally -136- -137- determined had a point of inflection at a pH of about 6 . This inflection point is not observed in the neutralization of aqueous solutions of titanium tetrachloride. Therefore, a literature survey was made to determine if other metallic halides exhibited this behavior. By way of introduction to this subject, some of the previous reports on pH of precipitation studies will be briefly summarized. It is to be recognized that this is not the problem at hand, but should prove enlightening as to the difficulties encountered in the investigation of a neutralization curve determined in the presence of a solid reaction product. This literature survey is not intended to be complete, but only that part of the field was investigated which was deemed applicable to a better interpretation of the data. 165 In early studies of this nature, there seemed to be more emphasis on the effect of cation (M+ ) concentration rather than the effect of the particular anion (X").present. From the data presented, it would appear that the pH of precipitation of some metal hydroxides is independent of the anion present, whereas for other metal hydroxides the anion present may greatly influence the pH of precipitation. Britton^ ® 6 precipitated ThCbHj^.yyX from ThX^ (XBNO3 , Cl, SO4 ) and found that appreciable amounts of alkali (NaOH) had to be added before the commencement of precipitation (pH of 3.51-3.57). In the case of the nitrate and chloride solutions, there was a distinct tendency for a constant pH to be maintained during the addition of the greater portion 165Hildebramd, J . H., J. A m . Chem. Soc.,_35, 847-72 (1913). 166Britton, H. T. S., J. Chem. Soc., 127, 2110-20 (1925). -138- of -the alkali. It is probable that this corresponds to the separation of a precipitate of uniform composition, ^he solutions became alkaline before the stoichiometrical quantity of alkali had been added and the precipitate formed in each titration was basic. Protracted inflections produced during the last stages of precipitation were less basic. The solid suffered some decomposition on further addition of alkali. The amount of acid radical retained by these precipitates was too great to be accounted for by adsorption from such dilute ( M/100) solutions. Halla*6^, while investigating Th(N0 g )4 found that at room temperature, the solution became alkaline to phenolphthalein on the addition of 3.54 equivalents of potassium hydroxide and on boiling, with 3.60 equivalents. Britton'*’6 6 also noted that alkali ranging in amounts from 0.78 to 2.21 equivalents to one of thorium salt had to be added before the appearance of a precipitate. These amounts varied with the nature of the anion and the precipitate. There seems to be no possible explaination of the mechanism whereby the thorium hydroxide or basic complex is held in solution until the attainment of the pH requisite for precipita tion. It is to be noted, that "soluble basic salts" are generally formed by those metals having a valency greater than two, although this is not applicable to the trivalent rare-earths or to bivalent beryllium Which has a remarkable property of forming these basic solutions. Britton*66 also investigated the reaction between Zr(S04)2 and N/10 NaOH. The plot of pH versus volumn> of alkali added resulted in a curve with two inflection points, the first of which occurred when the *6 %alla, F., Z. Anorg. Chem., _79, 260-2 (1912). 168Britton, H. T. S., J. Chem. Soc., 127, 2120-41 (1925). -139- alkali added was equivalent to three moles to one mole of ZrCSO^jg. At this point precipitation was complete and further addition of alkali caused the partial decomposition of the solid which resulted in the second point of inflection. Among the characteristics of the gallium-indium-thallium family essential to its systematic study and trends are variations in basicity. The combined effects of small size Ga+3 In+3 Th+3 Ionic radius, J?., 0.62 0.81 0.95 and comparatively high charge among the tripositive ionscbf these elements should render all of them quite highly acidic. The pH of precipitation-*-®9 of idium (III) hydroxide was practically independent of the anion (SO^, Cl, NO3 ) present. Flocculation always occurred before a three OH" to one In+3 equivalence was attained, suggesting w* j . Q the formation of basic salts. If the OH to In ratio at the point of flocculation be considered to be the same in the precipitate existing at that point, these precipitates were then of the composition, In (OH)2#5g (N03 )q^£l» In ^0H^2.62 C10.38 an® In (°H ^2.32 ^So4^0.34 The lower basicity of the sulfate being due to the greater flocculating power of the sulfate ion on the positive sol first formed. Even though flocculation Was noted before the theoretical ratio of three OH" to one +3 In was reached, was indicated by the fact that equilibrium was always attained more slowly in the 0H"/In+^ region of 2.5 to 3.0, that none of 169Moeller, T.f J. Am . chem. Soc., 63 2625-28 (l94l). -140- the curve became abruptly steep in this region, and that significant changes in pH ceased only when a three OH" to one In ratio had been attained. An increase in temperature lowered both the pH and the amount of hydroxyl ion necessary for initial precipitation. 3.70 Thallium (III) is more acidic than gallium or indium. Increased values for pH of precipitation with chloride and bromide solutions indicate increased reduction in the concentration of uncomplexed thallium III ions. The slightly greater degree of complexing indicated for the bromide solutions is in agreement with the values of stability constants given by Benoit^-*-. In the investigation^ ^ 2 of gallium (III) solutions of bromide and chloride the anion was sufficiently weakly basic in character to contribute comparatively nothing to any observed alterations in the hydrogen ion concentrations in solution. Therefore, any alteration of pH could be ascribed to the acidic characteristics of the gallium (III) ion. It was assumed, as a first approximation, that the governing hydrolytic process in dilute solutions to be either 4+4 - 4 Ga 4 H 2 O GaOH 4 H (4) or +4-4 -j- 4 Ga 4 H20 GaO 4 2H (5) Ionic hydration and complexion formation were neglected. Reaction dfour is characteristic of a number of other tripositive ions. Reaction two is probably never a primary process, but a product such as GaO+ 170 Ibid., 75, 4852 (1953). I7lBenoit ,"~R., Bull. Soc. Chim. France, JL6 , 518-24 (1949). ll72Moeller, T . , I^ng, G. L . , J. Phys. and Colloid Chem., 54, 999-1011 (1950). -141- or its hydrate Ga(OH)* could conceivably result from the secondary hydrolysis of Ga(0H)++ . The appearance of the coagulation point before the theoretical equivalent amount of alkali is added has been interpretated as signifying the formation of basic salts with the hydroxyl ion deficiency being 173 made up by the anion present in solution. Larson and Gammill point out that it could be assumed equally well, that the extensively hydrolyzed species already present, reacted further with water to form the neutral metal hydroxide or hydrated oxide and hydronium ion, the 1*74 latter ion being titrated to the end-point. Moeller and Kremers11-''^ investigated the precipitation of trivalent hydrous rare earth oxides or hydroxides. They found the apparent decrease in pH either at incidence or precipitation or at mole ratio 0H"/R - 0.4 closely paralleled the decrease in ionic radius. It is logical to conclude then, on the basis of precipitation data, that the basicities of the rare earth elements decrease fairly regularly in the series lanthanum to lutecium, yttrium occupying a position commensurate with its ionic radius. The smallest ions in the series should form basic salts the most extensively. Basic salts did form as was indicated by the slowness with which equilibria were established in the precipitation regions. In these regions, the addition of each increment of alkali caused the observed pH to rise to a maximum. The pH then decreased slowly and gradually approached a reasonably constant value. Apparently, basic salts were first precipitated and then reacted with more hydroxyl ions from the solutions. Thus, the relative basicities of a •'■'^Larson, E. M . , Gammill’,, A. M . , Loc. Cit. 174Moeiler, T . ; Kremers, H. E., J. Phys .”(?hem., 48 395-4U7 (1944). -142- homologous series of ions are functions of their ionic radii, the order being an increase in basicity with an increase in ionic radius. Hence, lanthanum is the most basic of the rare earth ions in the plus three oxidation state since its radius is the largest. Experimental data supporting this are its higher solubility product for the hydroxide. The recent study^7^ of zirconium and hafnium support this postulate, since hafnium, having a larger ionic radius, was found to be more basic than zirconium. This was shown by the fact that hafnium hydroxide precipitated at a higher pH than zirconium in all cases under similar conditions. This difference was small 0.15$, however, as would be expected due to the small difference in the ionic radii of zirconium and hafnium. It was also noted that an increased anion concentration produced an inarease in the pH of precipitation. Because the radius of Ti+4r is much smaller than that of Zr+4, A it is expected that Ti would have Ti+'4 Zr+ 4 Th+4 Ionic radius, $., 0.68 0.80 0.95 I a considerably lower pH of precipitation. This conclusion is supported by Belknap , Klimenko and Syrokomski who reported a pH of 1.5 for the initial precipitation of titanium hydroxide from a 0.013 molar titanium (IV) sulfate solution. Britton lists a pH of 2 for the pH of precipita-tion of titanium (IV) hydroxide but no reference could be found to the original work. •^Larson, E. M., Gammill, A. M.,Loc. Cit. l^Belknap, H. J., The sis at University of Mississippi, 1942. 177Klimenko, N. G . , Syrokamski, U.S., Zavodskaya Lab.jJj}, 1029-34 (147) as abstracted in Chem. Abstracts 43 4083 (1949). 143- Results and Discussion. The hydrolysis of a titanium tetrahalide (chloride, bromide, or iodide) can be depicted by the following reactions TiX4 + 3H20 TiO + 4X" + 2H30 (6) (7) where the degree and nature of hydration of Ti02 has been neglected. In this connection, it can be pointed out that the unhydrated oxide does not dissolve appreciably in either acids or bases but the hydrated forms are somewhat soluble ini both. The two hydrates, TiC^'HgO and Ti0 2 *2H2 0 are known. Latimer^ 78 states"there is apparently no •j* proof that the principle ion is TiO (titanyl) in a saturated solution or in 1 Molar acid, but an approximate value for the free energy of Tio"*"*" is -138 kcal which is consistent with the solubility product." It is quite apparent that, if the above equations are representative of the complete hydrolysis reaction, four moles of hydronium ion are produced per mole of the tetrahalide. Thus, the addition of alkali should neutralize the available hydronium ion and shift the equilibrium to the right; i.e., the equilibrium will be shifted and the reaction will tend to go to completion with the formation of the precipitate of Ii02 . Therefore, the neutralization equivalent weight should be obtained by merely titrating the hydronium ion With alkali, the end point of the neutralization titration being determined ■*-^8 Latimer, W. M.f "Oxidation Potentials,” Prentice Hall Inc., New York, N. Y., 1952, 267. 144- by direct measurement*^® of the pH of the solution after each addition of alkali. The pH-neutralization curve was .actually determined and the equivalence point found experimentally. A typical plot is shown in Figure 28. It can be shown theoretically that, as a general rule, the change of pH for the addition of a given amount of titrant tfill be a maximum at the equivalence point and so the latter Gan be identified as seen in Figure 29. The accuracy with which this point can be detected depends on the magnitude of the inflection in the pH-neutralization curve. This inflection is more marked the stronger the acid and base. The theoretical end point or stoichiometric point would be at [ h J ' B I0 "'7 or P^ " POH ■ 7, at room temperature, since at this point the solution contains the ions of the salt, NaCl. Carbon dioxide was excluded from the system by use of the apparatus shown in Figure 43. Nitrogen was bubbled through and/also blanketed the solution. Actually the system does not conform to a reaction between a strong acid and strong base but behaves in a complex way which is dependent on some form of the reaction product, ^ic^, or on the presence of the organic residue. This can be observed from inspection of Figures 28 through 42, Tables 37 through 51 and the Summary in Table 36. Even so, it is quite apparent that the neutralization equivalent weight for both a pure titanium tetrahalide and for a pure titanium tetrahalide addition compound can be determined to within 2-3 per cent of the theoretical value. The value for any particular pure sample was reproducible to ± 1 per cent. *^®The pH was measured with a Glass Electrode pH meter, Beckman Model H-2. The meter was standardized at pH-7 with Beckman buffer solution. -145- It is indeed rather amazing that -the neutralization equivalent weight can be determined for these addition compounds. The hydrolysis reaction produces halide, hydronium ions, the organic molecule and presumably titanyl ion. The organic molecules are completely miscible with water but will no doubt undergo cleavage in acid solution to form a halogenated alcohol and/or a mixture of alcohol and alkyl halide. 180 Of the halogen acids, hydriodic will cleave an ether at room temperature, hydrobromic requires a slightly higher temperature and hydrochloric is poorly suited to the splitting of an ether. The extent of this reaction was not investigated, since the procedure did produce the desired results, namely the theoretical neutralization equivalent weight. In this connection it may be pointed out, that the titanium was precipitated and removed by filtration for one experiment with TiBr4 *2tetrahydropyran (Table 53). The resulting pH-neutralization curve was that of a reaction between a strong acid and strong base and the neutralization equivalent weight had a value about two per cent higher than when the precipitate was permitted to remain in solution. Although the organic molecules ether, alcohol or alkyl halide, are miscible in water the extent is not knosn to which they were adsorbed on the gelatinous precipitate and subsequently removed. It is quite conceivable that the presence of the ether could account for the limited accuracy in the determination. If the ether molecule does react with hydronium ion, the pH of 7 would be attained permaturely. A neutralization equivalent weight determination which is consistently higher than the theoretical value can be explained by an error in the sample wieght, error in strength of the alkali, or the Q. Brewster, Loc. Cit. -146- attainment of neutralization before reaching a pH of 7. Any error in the pH meter would be constant and would be of no consequence since the neutralization point was determined by plotting the volume of titrant against the change of pH per volume of titrant. Thus, it is not the absolute magnitude but only the change in pH that is important. It is to be pointed out that the pH meter was checked with standard buffer solution and by determining the pH-neutralization curve for acid-base solutions of known concentration. The error in sample weight is an indeterminate error but can be neglected since the data are reproducible. Any error in concentration of alkali can be ruled out inasmuch as the data are reproducible while utilizing several different concentrations of alkali. Therefore, the only possible explaination lies with the nature of the precipitate which actually affects the neutralization point as well as the accuracy of the j i H e determination. Belknapreported the coagulation point of titanium to be at a pH of 3.3 - 3.7 and the coagulation pH value increased with increasing concentration which corresponded to a solid of composition Ti(0H)^“X where (X) ranged from 3.5 in 0.005 molar solutions to 3.3 in 0.4 molar. The normal precipitate that formed with the addition of sodium hydroxide solution was dissolved by the addition of acid and with vigorous stirring. In almost every experiment the pH of the acid solution, after the precipitation of the titanium, would slowly increase while in basic solution the pH would slowly decrease. This effect can not be attributed to a slow rate of reaction between hydronium and hydroxyl ions or to mixing. There is no available data -147- with which 'to determine the nature or composition of the solid species, therefore, the following discussion is purely speculative. The composition of the solid species can be though of from two points of view, the formation of hydrous oxide or a basic salt. The hydrolysis of a tetrahalide compound resulted in a clear solution which is acidic. As the pH is altered by the addition of alkali the equilibrium is slowly shifted toward the formation of Ti0 2 , hydrated or unhydrated. TiX4 + 3H20 TiO++ -+ 4X- + 2H30+ (6) + + + TiO + 3H20 = Ti02 + 2H30 (7) Reaction (6) probably goes to completion but an equilibrium is set up in Reaction (7). The addition of alkali temporarily reduces the concentration of hydronium ion and in order to maintain the pH level, the equilibrium as depicted by reaction (7) is shifted to the right with the formation of hydronium ion. In strong acid solution, pH of 2 or less, the concentration of the oxide is so small as not to exceed its solubility product and the solution remains clear. At pH of approximately 2 , the solubility product is exceeded and material precipitates out although the pH remains approximately constant. But after the available titanium has completely reacted, that is, the equilibrium depicted by reaction (7) has been shifted the pH of the solution will change rapidly with small additions of alkali. In this case, one mole of hydronium ion is consumed per mole of hydroxyl ion added and the pH-neutralizat ion curve appears similar to that of a strong acid-strong base up to a pH level of about 6 where the first inflection appears, the pH-neutralization curve Would appear similar to that of a strong acid-strong base over the entire range of pH were -148- it not for the presence of the titanium precipitate. In the pH range of about 6 to 7 the pH does not change very rapidly with addition of alkali an diin fact there is a definite break or plateau in the pH-neutralization curve. This feature can not be explained by assuming the. solid has the composition of a true hydroxide. The mere fact that an insufficient number of moles of alkali were added to produce Ti(0H)4 , 3.9 moles of alkali per mole of titanium, would tend to discount a solid of this composition. It is to be noted however that the amphoteric hydroxide could be expected to behave as a base in acid media as shown by the following reaction. H4Ti04 Ti(0H)g + OH" (8 ) and a phenomena of this type was detected as the pH did gradually increase with time. The fact that a mole ratio of hydroxide to titanium which is less than four would indicate the formation of a basic salt of composition Ti(oH)^~y (4-y)X, where y is a number from zero to four. The addition of alkali would now be consumed in the reaction with the basic salt. The net result would be a very slow change in pH with the addition of alkali and a plateau or break would occur in the pH-neutralization curve. At this point their are two competing reactions for the hydroxyl ion, namely the reaction of hydroxyl ion with basic salt and/or hydronium ion. As the value of y approaches 4, that is, the basic salt is completely decomposed to hydrous oxide the reaction between hydroxyl and hydronium ion becomes more important and the pH-neutralization curve again rises, although not sharply and appears similar to a curve representative of a reaction between a strong base and weak acid. The reaction in which the basic -149- salt is formed and slowly reacts with the added hydroxyl ion Was probably observed experimentally. After the solid had precipitated, the addition of alkali resulted in a rapid increase in pH which slowly fell off to a constant value. This phenomena could be attributed to the resolution of the solid. From a pH level of 7 to the end of the titration, the pH gradually increased after the addition of alkali and the pH-neutralization curve appeared similar to that of a weak acid with a strong base. This slow increase of pH with time could be attributedtto the ro-solution of the amphoteric solid in basic solution as shown by reaction H4Ti04 + OH- — H 3Ti03" + H20 (9) which would give rise to the observed decrease^.of pH with time. TABLE 36 Summary of Neutralization Equivalent Height Data Holes 0H- Volume of 8 ase SnmDla Equiv. pH at Equiv. Neutral Equivalent Per Hole Required to obtain SVt. Normality pt., ml. equiv, of Grams ob-calc. of Ti at 4 Holes of 0H- Compound Table Figure Grams of Base of Base Foint 3ase Empirical Theoretical (.0 1) calc. Neutral Point Per Hole of Ti TiBr4 37 28 2.0283 0.5040 43.10 5.40 0.021722 93.33 91.89 1.625i 3.936 43.80 ml. TiT 4 39 30 2.1067 0.5034 29.40 5.81 0.0148 0 0 142.34 138.90 2.48 3.903 30.13 40 31 1.6805 0.5034 23.47 5.56 0.011815 142.24 2.40 3.906 24.03 41 32 2.4927 0.5034 34.65 5.16 0.017443 142.91 2.SB 3.888 35.65 TiBr4 *Dioxane 42 33 0.4762 0 . 1 0 0 1 40.81 4.77 0.0040851 116.57 113.9 2.34 3.909 41.76 43 34 0.4102 0.5034 7.02 6 . 2 0 0.0035339 115.08 1.91 3.926 7.15 TiBr .-2Tetrahydrofuran 44® 35 2.3092 0.5040 34.65 5.50 0.017464 132.23 127.99 3.31 3.874 35.81 45® 36 1.3734 0.5040 20.74 4.90 0.010450 131.39 2 . 6 6 3.895 21.30 46b 37 0.1644 0.3002 4.2 6.42 0.0012608 130.39 1 . 8 8 3.925 4.28 4 7 b 38 0.2872 0.3002 7.2 6.41 0.0021614 132.88 3.82 3.851 7.48 TiBr4*Tetrahydropyran 48 39 0.3335° 0 . 1 0 0 1 23.70 7,42 0.0023724 140.58 134.96 4.17 3.840 24.69 . 49 40 0.3826 0 . 1 0 0 1 27.65 5.24 0.0027678 138.23 2.40 3.905 28.32 50 41 0.9934 0.5040 14.48 5.41 0.0072979 136.12 0 . 8 6 3.966 14.60 51 42 0.6743 0.5040 9.86 5.94 0.0049694 135.69 0.54 3.978 9.914 “Prepared from excess TiBr 4 . ^Prepared from excess Tetrahydrofuran. °Preoipitate filtered off and the solution «as titrated to the end point. -151 TABLE 37 TiBr4 (2.0283 grams) Vol. NaOH Vol. NaOH (0.504ON) pH (0.504ON) pH 0.00 ml 1.59 40.47 ml 2.88 4.69 1.64 40.69 2.92 8.07 1.68 40.92 2.99 10.06 1.70 41.17 3.07 17.30 1.82 41.38 3.13 20.66 1.90 41.61 3.22 25.66 2.01 41.93 3.33 26 .57 2.04 42.12 3.49 27.60 2.08 42 .39 3.72 28.77 2.12 42.67 4.17 29.66 2.15 42.31 4.52 30.67 2.18 42.98 4.99 31.57 2.21 4-3.17 5.60 32.68 2.26 43.30 5.99 33.69 2.30 43.47 6.21 34.69 2.35 43.60 6.42 35.62 2.40 43.80 6.62 36.68 2.47 44.09 7.09 37.27 2.50 44.38 7.64 37.60 2.52 44.76 8.96 38.97 2.66 45.02 9.46 39.22 2.69 45.39 10.03 39.47 2.71 45.77 10.46 39.73 2.76 46.22 10.78 39.97 2.79 46.66 10.97 40.23 2.83 47.87 11.25 IQ- 3 9 4 04 2 4 3 4 4 4 5 4 6 4 7 Volume (ml.) of 0 .5 0 4 0 N NaOH Figure 28. Neutralization curve for TiBr 4 (2.0283 grams) -153- TABLE 38 TiBr^ (2.0283 grams) Vol. NaOH Vol. NaOH (0.5040N) pH A pH (0.5040N) pH A pH 41.0 ml. 3.00 — 43*3 m l . 5.97 0.25 41.1 3.03 0.03 43.4 6.14 0.17 41.2 3.06 0.03 43.5 6.28 0.14 41.3 3.09 0.03 43.6 6.41 0.13 41.4 3.13 0.04 43.7 6.52 0.11 41.5 3.17 0.04 43.8 6.63 0.09 41.6 3.21 0.04 43.9 6.77 0.14 41.7 3.25 0.04 44.0 6.92 0.15 41.8 3.31 0.06 44.1 7.09 0.17 41.9 3.36 0.05 44.2 7.27 0.18 42.0 3.41 0.05 44.3 7.48 0.21 42.1 3.47 0.06 44.4 7.73 0.25 42.2 3.55 0.08 44.5 8.04 0.31 42. 3 3.63 0.08 44.6 8.43 0.37 42.4 3.73 0.10 44.7 8.77 0.34 42.5 3.85 0.12 44.8 9.05 0.28 42.6 4.01 0.16 44.9 9.25 0.20 42.7 4.21 0.20 45.0 9.43 0.18 42.8 4.45 0.23 45.1 9.60 0.17 42.9 4.73 0.28 45.2 9.76 0.16 43.0 5.04 0.31 45.3 9.91 0.15 43.1 5.41 0.37 45.4 10.04 0.15 43.2 5.72 0.31 ApH /O .l ml. 30 .3 0 40 .4 0 0 .5 0 0.20 0.10 2 4 iue 9 Vlme f oH ess O. ml; ape Ti r4(2.0283 iB T sample: l.; m .I /O H p A versus NoOH of e Volum 29. Figure rms) gram ume ml) f 5040N IMoOH N 0 4 0 .5 0 of l.) (m e m lu o V -154- 4 4 544 3 6 4 155- TABLE 39 Til^ (2.1067 grams) Vol. N a O H Vol. NaOH (0.5034N) pH (0.5034-N) pH 0.00 ml. 1.61 27.00 2.69 0.29 1.67 29.09 4.29 0.56 1.69 29.40 5.80 0.70 1.70 29.73 6.80 0.99 1.71 29.86 6.92 1.27 1.72 30.00 7.06 1.87 1.74 30.12 7.21 2.90 1.76 30.30 7.49 4.51 1.78 30.41 7.60 6.10 1.80 30.70 8.05 8.92 1.87 30.87 8.40 10.95 1.90 31.41 9.60 13.11 1.95 31.99 10.44 16.32 2.02 32.50 10.80 17.88 2.09 32.78 10.89 19.80 2.15 33.27 11.03 22.09 2.19 34.60 11.10 23.11 2.25 35.46 11.21 24.10 2.32 36.71 11.32 25.42 2.45 39.07 11.48 10 892 3110 ml 156 ,5.81 •29.40 ml 5 4 2 7 2 8 2 9 30 32 34 35 Volume (ml.) of Q5034N NaOH Figure 30. Neutralization curve for T il 4 (2.1067 grams) -157' TABLE 40 Til^ (1,6805 grams) Vol. NaOH Vol. NaOH Vol. NaOH (0.5034N) p H (D.5034N) p H (0.5034N) pH 0.00 ml. 1.92 9.86 ml. 2.30 22 .94 ml. 3.79 0.11 1.93 11.12 2.34 23.05 4.01 0.21 1.94 12.75 2.39 23.14 4.22 0.33 1.96 13.92 2.43 23.25 4.65 0.42 1.98 15.29 2.49 23.33 4.89 0.54. 1.98 16 .62 2.53 23.44 5.51a 0.65 1.99 17.64 2.60 23.52 5.78 0.76 1.99 18.38 2.65 23.63 6.17 0.94 2.00 19.81 2.78 23.70 6.29 1.05 2.00 20.13 2.81 23.86 6.69 1.15 2.00 20.82 2.89 24.02 7.00 1.25 2.01 21.06 2.92 24.13 7.30 1.37 2.03 21.15 2.95 24.41 7.93 1.50 2.06 21.25 2.98 24.62 8.27 1.62 2.07 21.45 3.00 24.94 9.06 1.72 2.09 21.62 3.04 25.11 9.25b 1.85 2.10 21.81 3.10 25.37 9.70 2.03 2.10 21.96 3.15 25.60 9.99 2.20 2.11 22.10 3.19 25.92 1 0 .1 1 ° 2,43 2.12 22.32 3.28 26.26 1 0 .22d 3.31 2.13 22.43 3.32 26.85 10.52 4.05 2.16 22.53 3.39 28.31 10.88 4.61 2 . 18 22.64 3.48 29 .44 11.15 5.35 2.20 22.71 3.56 31.33 11.32 7.16 2.23 22.84 3.63 33.95 11.48 36.38 11.55 aInitial value of pH ** 5.31 which increased with time to pH B 5.51. pH ° PH ^ Time PH oGnin.) 9.40 10.30 5 10.36 9.38 10.29 8 * 10.34 9.35 10.26 12 10.32 9.33 10.22 16 10.30 9.31 10.19 22 10.27 9.29 10.15 25 10.25 9.26 10.12 28 10.22 9.25 10.11 30 10.22 9.25 10.11 32 10.22 9.25 10.11 -158- 1 0 - pH '556 '2 3 .4 7 22 > 2 4 2 5 26 Volume (ml.) of 0 .5 0 3 4 N NaOH Figure 31. Neutralization curve for Til4 (1.6805) -159- TABLE 41 Til^ (2.4927 grams) Vol. NaOH Vol. NaOH (0.5034N) pH (0.5034N) pH 0.00 ml. . 1.80 35.67 ml. 7.24 2.20 1.84 35.89 7.60 7.48 1.92 36.07 7.86 12.60 2.00 36.27 8.19 17.78 2.09 36.40 8.40 24.21 2.20 36.60 8.77 27.66 2.31 36.80 9.09 30.89 2.53 36.90 9.28 32.11 2.70 37.29 9.80 32.69 2.80 37.53 10.07 33.18 2.95 37.80 10.29 33.36 3.01 38.22 10.51 33.56 3.13 38.51 10.63 33.80 3.29 39.38 10.89 34.07 3.55 40.67 11.11 34.37 4.10 41.86 11.22 34.52 4.59 43.28 11.37 34.74 5.51 45.58 11.50 34.97 6.05 49.13 11.63 35.34 6.70 II 10 pH 0 6 1 ' 30 31 32 3 3 34 35 36 37 3 8 39 40 Volume (ml.) of 0.5034N NaOH Figure 32. Neutralization curve for Til4 (2 .4 9 2 7 grams) I 161- TABLE 42 TiBr^’Dioxane (0,4762 grams) Vol. NaOH Vol. NaOH (0.1001N) pH (0.1001N) PH 0.00 ml. 2.07 40.54 ml. 4.01 3.02 2.10 40.73 4.48 8.98 2.15 40.97 5.25 12.06 2.20 41.15 5.60 16 .26 2.24 41.38 6.00 22.07 2.28 41.57 6.21 27.99 2.32 41.80 6.59 31.77 2.43 42.09 7.11 34.15 2.50 42.35 7.56 36.16 2.60 42.82 8.36 37.27 2.70 43.33 8.97 38.01 2.79 43.72 9.30 38.62 2.88 44.07 9.44 38.88 2.93 44.48 9.53 39.41 3.09 44.85 9.59 39.98 3.33 45.37 9.78 40.32 3.63 pH 162 36 38 39 4 037 42 4344 45 46 47 48 49 Volume (ml) 0.1001N NoOH Figure 33. Neutralization curve for TiB r4 • Dioxane (0.4762 gram s) I I -16 3- TABLE) 43 •v TiBr^/Dioxane (0.4102 grams) Vol. NaOH Vol. NaOH (0.5034N) PH (0.5034N) PK 0,00 ml. 2.27 7.13 ml. 7.20 1.05 2.32 7.25 8.31 1.89 2.39 7.38 9.52 3.19 2.49 7.60 10.30 4.43 2.61 7.68 10.44 4.77 2.67 7.90 10.66 5.55 2.81 8.17 10.81 5.84 2.90 8.42 10.86 6.42 3.21 8.70 10.97 6.60 3.41 9.74 11.20 6.79 3.83 10.54 11.31 6.95 4.89 13.08 11.54 7.06 6.42 10- 8- 7 - pH 164 5“ 4 - Volume (ml) O.IOOIN NoOH Figure 34. Neutralization curve for TiBr4 Dioxone (0.4102 grams) -165- TABLE 44 TiBr^.2Tetrahydrofuran (2.3092 grams) Excess TiBr^ s Vol. NaOH Vol. NaOH Time (0.504ON) pH Time (0.5040N) pH 1005 hrs. 0.00 ml. 1.58 1525 hrs. 35.08 ml. 6.53 1015 3.22 1.63 1525 35.58 «• 1025 4.88 1.68 1531 35.58 6.73 1035 6.75 1.71 1535 35.58 6.92 1045 9.50 1.74 1540 35.58 7.10 1055 12.50 1.89 1715 35.58 7.59 1105 14.69 1.95 1715 36.08 *«■ M 1115 19.39 2.05 1720 36.08 8.57 1125 22.90 2.18 1725 36.08 8.74 1135 25.04 2.24 1730 36.08 8.78 1145 25.59 2.28 1735 36.08 8.79 1155 26.00 2.29 1740 36.08 8.79 12 05 28.48 2.42 1740 36.54 wm *» 1215 29 .-06 2.47 1745 36.54 9.79 1225 31.26 2.69 1751 36.54 9.81 12 35 31.68 2.70 1757 36.54 9.81 1245 31.96 2.80 1800 36,54 9.81 1255 32.22 2.87 1800 36.99 — 1305 32.63 2.97 1805 36.99 10.49 1315 32.96 3.07 1810 36,99 10.47 1325 33.22 3.17 1815 36.99 10.43 1335 33.51 3.30 1820 36.99 10.40 1345 33.88 3.54 1827 36.99 10.37 1355 34.19 4.00 1835 36.99 10.31 1405 34.38 4.45 1840 36.99 10.31 1415 34.65 5.50 1840 37.99 1425 35.08 6.18 1841 37.99 11.11 1430 35.08 6.27 1845 37.99 11.11 1435 35.08 6.33 1845 39.03 1440 ■35.08 6.40 184-6 39.03 11.42 1445 35.08 6.42 1849 39.03 11.41 1450 35.08 6.44 1851 39.03 11.40 1455 35.08 6.47 1857 39.03 11.40 1515 35.08 6.52 1857 40.04 --- 1520 35.08 6.53 1858 40.04 11.57 -166- 5.50 *34.65 35 36 3734 38 Volume (ml.) of 0.5040 N NaOH Figure 35. Neutralization curve TiBr4 • 2 Tetrahydrofuran (2.3092 grams) prepared from excess TiBr4 -167- TABLE 45 TiBr^*2Tetrahydrofuran (1,3734 grams) Excess TiBr^ Vol. WaOIl Vol. NaOH (0.504QN) pH (0.5040N) pH 0.00 1.69 20.08 3.76 0.62 1.70 20.25 3.32 2.70 1.75 20.48 3.68 4.72 1.31 20.62 4.21 5.72 1.86 20.80 5.20 7.36 1.91 20.98 5.94 10.08 2. 00 21.13 6.51 12 .10 2.10 21.35 7.16 14.09 2.20 21.57 8.08 15.59 2.30 21.75 8.89 16.77 2.39 22.04 9.85 17.71 2 .50 22.29 10.31 18.38 2.59 22.53 10.52 19.05 2. 72 22.89 10.81 19.60 2.89 23.35 11.01 19.83 3.00 23.69 11.10 •*168“ 10- 4.89 ■*20.74 ' 20 21 22 Volume (ml.) of 0 . 5 0 4 0 N N a O H Figure 36. Neutralization curve for TiBr4 ■ 2Tetrahydro- furan (1.3734 grams) prepared from excess TiBr4 -169- TABLE 46 TiBr4 *2Ta-fcrahydrofuran (0.1644 grams) Excess Te-fcrahydrofuran Vol. NaOH Vol. NaOH (0.3002N) pH (0.3002N) pH 0.00 ml. 2.85 3.92 ml. 3.99 1.42 3.03 4.08 4.36 1.62 3.08 4.20 6.42 1.91 3.11 4.35 7.08 2.32 3.24 4.38 8.84 2.53 3.29 4.54 9.66 2.78 3.34 4.76 10.06 2.92 3.36 5.01 10.36 3.10 3.40 5.60 10.58 3.21 3.46 6.75 10.81 3.40 3.55 7.70 10.89 3.60 3.67 8.80 11.01 3.80 3.81 -170- PH Volume (ml.) of 0 .3 0 0 2 N NaOH Figure 37 Neutralization curve for TiBr,^- 2 Tetrahydrofuran (0.1644 grams) prepared from excess tetrahydrofuran. -171- TABLE 47 TiBi*4 *2Tetfahydrofuran (0.2872 grams) Excess Te-fcrahydrof uran Vol. NaOH Vol. NaOH (0.3002N) pH (0.3002N) pH 0 . 0 0 ml. 2.67 7.20 ml. 6.41 0.45 2.70 7.27 7.24 1.94 2.80 7.46 8.61 3.61 2.96 7.60 9.52 5.01 3.11 7.84 10.11 5.58 3.22 8.30 10.51 6.11 3.39 8.77 1 0 . 6 8 6.54 3.58 9.02 10.73 6.75 3.74 9.49 10.86 6.99 4.25 '9.02 1 75 pH 72 1 Volume (ml} of 0 .3 0 0 2 N NaOH Figure 38. Neutralization curve for TiBr4 • 2 Tetrahydrofuran (0.2872 groms) prepared from excess tetrahydrofuran. -173- TABLE 48 TiBr4 *2Tetrahydropyran (0.3335 grams) The sample was dissolved in distilled water and 18.83 ml. of 0.1001N- NaOH added. This resulted in a milky solution, which could not he filtered with filter paper. Additional base, total titer of 22.86 ml., was added to give a pH of 3.88, at which time a white flocculent precipitate formed and was filtered from the clear solution. The solution was titrated with standardized base. Vol. NaOH Vol. NaOH (0.1001N) pH Time (0.1001N) . _pH . Time 2230 hrs. 2 2 .86 ml • 3.88 0019 hrs. 23.77 ml. 8.12 2237 23.02 3.99 0020 23.83 8.42 -- 23.07 4.03 ... 23.83 8.43 2244 23.14 4.11 0028 23.95 8.79 2246 23.23 4.22 -- 23.95 8.80 23.30 4.33 0030 23.95 8.80 M M 23.34 4.45 0031 24.08 9.04 pm 23.43 4.64 24.08 9.07 •m pm 23.49 4.98 0932 24.08 9.07 pm pm 23.55 5.49 0033 24.21 9.26 2350 23.63 6.49 0034 24.21 9.28 2355 23.70 7.31 0035 24.21 9.28 — 23.70 7.33 0036 24.37 9.51 0000 23.70 7.35 0038 24.37 9.51 -- 23.70 7.37 0040 24.54 9.66 pm pm 23.70 7.38 Pm 24.54 9.68 m m 23.70 7.38 0042 24.92 9.92 0005 23.77 7.95 0046 25.09 10.02 pm pm 23.77 7.97 0050 25.09 10.02 -- 23.77 7.99 0100 25.45 10.19 23.77 8.07 0115 26.85 10.51 23.77 8.09 0130 27.95 10.67 — 23.77 8.10 23.77 8.11 -174- 10- 8 pH _L 22 23 24 25 26 27 2 8 Volume (ml) of O.IOOIN NaOH Figure 39. Neutralization curve for TiBr4 • 2 Tetrahydropyran (0.3335 grams) TABLE 49 TiBr4 *2Tetrahydropyran (0.3826 grams) Vol. NaOH Vol. NaOH Time (0.1001N) PH Time (0 .1001N) pH 1902 hrs. 0.00 ml. 2.02 2143 hrs. 27.08 ml. 3.84 1907 1.47 2.07 2145 27.30 4.13 1912 3.72 2.11 2152 27.48 4.49 1920 5.65 2.16 2153 27.63 5.09 1925 7.11 2.20 2157 27.63 5.19 1929 9.01 2.26 2158 27.63 5.19 1931 11.04 2.31 2158 27.80 5.51 1934 12 .31 2.35 2205 27.99 5.79 1936 13994 2.41 2209 27.99 5.98 1939 15.15 2.45 2210 27.99 6.00 1942 16.44 2.50 2216 27.99 6.10 1944 18557 2.59 2218 27.99 6.12 1947 19.73 2.65 2220 27.99 6.14 1951 20.60 2.71 2222 27.99 6.17 2002 20.94 2.73 2224 27.99 6.19 2006 21.22 2.75 2226 27.99 6 . 2 0 2008 21.46 2.77 2227 27.99 6 . 2 1 2013 21.80 2.79 2229 27.99 6.22 2017 22.02 2.81 2231 27.99 6.23 2021 22.25 2.83 2 236 27.99 6.26 2024 22.49 2.86 2310 27.99 6.33 2041 22.78 2.88 2315 27.99 6.33 23.11 2.89 2333 27.99 6.33 »— M 23.46 2.93 2336 28.14 6.49 2047 23.66 2.95 , 2341 28 .14 6.59 2055 23.90 2.98 2344 28.14 6.62 2100 24.20 3.01 2345 28.14 6.65 2102 24.49 3.05 2346 28.14 6 .66 2106 24.81 3.10 234-7 28.14 6 .68 2109 25.06 3.14 2352 28.14 6.72 2113 25.33 3.19 2356 28.14 6.75 2129 25.62 3.23 2358 28.14 6.78 2133 25.87 3.29 0026 28.14 6 ,86 2136 26.10 3.35 0041 23.14 6.88 2138 26.32 3.42 0042 28.14 6.89 2140 26.60 3.53 0044 28.14 6.89 2142 26.82 3.67 0045 28.19 6.89 TABLE 49 (Continued) Vol. NaOH Vol. NaOH Time (0.1001N) p H Time (0.1001N) PH 0048 hrs. 28.19 ml. 6.89 — hrs. 29.00 m l . 8.89 0050 28.49 t m *» 1 2 2 0 29.00 8.89 0712 28.49 7.74 1243 29 .00 8.89 0713 28.63 -- 1244 29.40 *■ 0714 28.63 7.83 1245 29.40 9.20 0715 28.63 7.99 1256 29.40 9.34 0735 28.63 8.23 1933 29.61 9.62 0740 28.63 8.23 1934 29.92 9.82 0741 28.80 M 1946 29.92 9.89 0742 28.80 8.52 2022 29 .92 9.91 1115 28.80 8.53 0026 30.15 10.09 1116 29.00 »*• t* 0031 31.28 10.62 1117 29.00 8.70 Mi M 32.47 10.89 1136 29.00 8.93 33.90 11108 29.00 8.91 36.20 11.27 1138 29.00 8.89 -177- pH >.24 ■27.65 27 28 30 3 226 3 3 3 4 Volume (ml.) of O.IOOIN NaOH Figure 40. Neutralization curve for TiBr4 -2 Tetrahydropyran (0.3826 gram) TABLE 50 TiBr^^Te-fcrahydropyran (0,9934) Vol. NaOH Vol. Na 0H ■ (0.504ON) pH (0.5040N) pH 0.00 ml. 2.67 14.16 ml. 3.91 2.87 2.73 14.32 4.29 4.08 2.78 14.48 5.42 4.78 2.79 14.67 5.81 6.28 2.83 14.84 6.17 7.05 2.86 15.06 7.39 7.79 2.87 15.42 9.17 8.87 2.91 16.10 10.31 12 .78 3.33 17.07 10.69 13.09 3.40 17.78 10.82 13.59 3.52 18.70 10.98 13.92 3.69 20.09 11.11 -179- 7 7 7 Volume (ml.) of 0 .5 0 3 4 N NaOH Figure 41. Neutralization curve for TiBr4 • 2 Tetrahydropyran (0.9934 gram) -180- TABLE 51 TiBr,‘gTetrahydropyran (0.6743) Vol. NaOH Vol. NaOH (0.504ON) pH (0.5040N) pH 0.00 ml. 2.82 7.02 ml. 3.27 0.55 2.87 7.39 3.30 0.87 2.89 7.57 3.34 1.16 2.90 7.87 3.39 1.46 2.92 8.12 3.44 1.77 2.94 8.42 3.49 2.17 2.97 8.69 3.57 2.48 2.99 8.99 3.67 2.95 3.00 9.33 3.86 3.50 3.02 9.50 4.03 4.13 3.06 9.68 4.49 4.41 3.08 9.85 5.89 4.7:9 3.09 10.07 7.08 4.98 3.10 10.39 9.15 5.27 3.12 10.70 10.00 5.77 3.15 11.36 10.53 6.09 3.18 11.80 10.69 6.38 3.20 12.78 10.91 6.74 3.23 -181- 8.26 10.23 Volume (mUof 0.5040N NaOH Figure 42. Neutralization curve for TiBty • 2 Tetrahydropyran (0.6743 grams) -182- Figure 43. Neutralization equivalent weight apparatus -183- Conclusion. The neutralization equivalent weight was determined for the compounds TiBr4 , Til4 , TiBr4 *C4H8 02 , TiBr4 *2CgH100 and TiBr4 *2C4 H 80. The value for any particular sample was reproducible to within + 1 per cent and always higher than the theoretical value by 2-3 per cent. Hydrolysis of a titanium tetrahalide compound or addition compound produces four moles of acid per mole of tetrahalide. The acid was neutralized with alkali and the pH-neutralization curve which was experimentally determined had a point of inflection at a pH of 5 to 6 . This result was interpreted as reaction between a strong acid and strong base in the pH range of about 1 to 6 and the reaction between a weak acid and strong base from about pH of 6 to 10. Carbon dioxide was excluded from the system. The inflection point can be attributed to the solid species formed as a result of the addition of alkali. This precipitate was removed by filtration, the acid filtrate neutralized with alkali and the resulting pH-neutralization curve had..-.no point of inflection and was characteristic of a curve obtained as a result of the reaction between a strong acid and strong base. Composition of the solid species was not determined although the presences of an amphoteric oxide or basic salt would explain the break in the pH-neutralization curve. VII. INFRARED ANALYSIS Introduction. The infrared portion of the spectrum extends from the long wave length limit of sensitivity of the human eye to the region of ultra short radio waves, that is, from about 7500.8 (0.75 jx) to about 350,OOo8. One Angstrom, l8 , is equal to !CT8 cm. The units most often used in designat ing portions of the infrared spectrum are: wave-length unit, micron or one u s 10,OOQA E 10"4 cm); and so-called frequency unit, wave number or cm"-*- [ lcm”T b cm ]. The various subdivisions of the infrared X spectrum within very approximate limits are! -fche photographic region from 0.75 micron to 1.3 microns; the overtone region from 1.3 micron to 2.5 microns; the fundamental vibration region from 2.5 microns to about 25 microns; and the rotational region from 25 microns to 350 microns. Although each is important and capable of yielding much valuable information, primary interest centers in the fundamental vibration region. Except for special cases where intermolecular action occurs, the amount of light transmitted by a sample is governed by Beer's Law, T /T - o“kyCX -r *-v • ■L0 |/- c ± 0 v is the radiation incident on, and l v the radiation transmitted by, the sample at the frequency v ; kj, is the absorption coefficient of the sample material at the frequency v ; c is the concentration of a given material in the sample being studied; and x is the length of the optical path or thickness of the absorbing layer, of sample. In general, the infrared data sh’OWn -184- -185- are presented as a plot of I v /I as ordinates versus v (or X ) ° v as abscissas. The value of the constant kj, will be appreciable only when v is an infrared-active fundamental, overtone or combination frequency. In general, kv will have a larger value for polar than for non polar compounds, ^hus, for example, water, alcohol, and acetone absorb infrared very strongly while the hydrocarbons absorb weakly.. The value of kj, is fairly insensitive to pressure and, except in special cases, is practically independent of temperature. However, k v is not entirely a unique function of molecular structure for slight variations in its values occur between the solid, liquid and vapor phases of the same molecule. These changes appear as small shifts in the frequencies or intensities of maximum absorption, that is, maximum k v values, and are caused by the varying extent to which the internal vibrations of one molecule are affected by those of its neighbors. The atoms of any molecule, not at absolute zero, are constantly oscillating about their positions of equilibrium. The amplitudes of these oscillations are extremely minute (lO"9 to 10“T° cm) and their frequencies are high (lO^ -to llA* cycles per second). Since these frequencies are of the same order of magnitude as those of infrared radiations, some direct relationship might be expected to exist between the motions of the atoms within molecules and their effects on infrared radiation incident upon them. Actually those molecular vibrations which are accompanied by a change of dipole moment, so-called "infrared active" vibrations, absorb, by resonance, all or part of the incident radiation, provided the latter coincide exactly with those of the intramolecular vibrations. Thus, if a sample of molecules of a single kind is -186- irradiated in succession by a series of monochromatic bands of infrared, and the percentage of radiation transmitted is plotted as a function of either wave length or frequency, the resulting graph may be interpreted in terns of intramolecular motion. Results and Discussion. The infrared spectrogram of liquid tetrahydrofuran, 1,4-dioxane and tetrahydropyran are shown in Figures 44, 45, and 46 with the intensity and location of the absorption bands summarized in Tables 5 2 , 53 and 54. The position of the absorption bands was determined from the spectrogram itself and not from the wave-length dial which Would have been more accurate. The intensities of the bands were determined by observing that the background at long wave lengths was less than at short Wave lengths and then approximating the background over the entire spectrogram. It is to be pointed out that this procedure is not exact but will suffice for the present investigation. The data as determined by Rhreve and HeetherTSI, for the absorption bands of the three epoxy compounds is given in Table 55 while the data of Burket and Radger^®^ for 1,4-dioxane and tetrahydropyran is given in Table 56. Agreement of the data can be considered quite good as the small deviations in the location of any particular absorption band can be attributed to 1he method of ascertaining the location. •^Shreve, 0. D., and Heether, M.R., Anal. Chem. _23, 277-82 (1951). TR^jjurket, s. C . F and Badger, R. M,, J. A m . Chem. Soc.,_72, 4397-4405 (l95u). Percent transmittance 100 iue 4 Ifae setorm f Tetrahydrofuran. of spectrogram Infrared 44. Figure v length ave W A. 0.025 mm. . at o ate la p to te la P B. Percent transmittance 100 50 0 iue 5 Ifae setorm f 1,4-dioxane. of spectrogram Infrared 45. Figure L J ae length Wave 8 el thickness: Cell . lt t plate to Plate A. Percent transmittance 100 50 iue 6 Ifae setorm f erhdoya; el hcns, lt t plate. plate to cell thickness, Tetrahydropyran; of spectrogram Infrared 46. Figure ae egh n microns in lengthWave 681 -190- Due to the similarity of the three liquids under consideration, all of which are epoxy compounds, there are certain regions in the spectrogram where the vibrational frequencies are almost identical for all three compounds. Thus, it seems appropriate to discuss these vibrational frequencies in a very general way. The absorption bands in the frequency range from 3333 to 5000 cm“^ can be considered as overtone bands which are much weaker than the fundamentals and the intensity of absorption was magnified by increasing the thickness of the absorbing layer. Bands in the range from 333 to 2500 cm*"* appear to be characteristic of the in-phase, v, , and the out-of-phase, r2 » vibrations (carbon to hydrogen stretching of the valency bond) of the hydrogen atoms in the CH^ group which are shown below: Figure 47. Modes of Vibration of the Imaginary CH2 Molecule. The CH2 group can still retain these frequencies when joined to other groups, although in some cases interaction with similar frequencies arising from other parts of the molecule or with harmonies of lower frequencies m y modify or increase the number of bands observed. Fox 183 and Martin have shown that CH2 groups in an ordinary straight chain or unstrained ring compound have two intense absorption bands approximately at 3.4-microns (2941cm’"■L) and 3.5-microns (2857cm*'•’•) ^•®^Fox, J. J. and Martin, A. E., Proc. Roy. Soc. A167, 257-81, (1938). -191 corresponding to the in and out of phase vibrations. When, however, the CH2 group forms part of a strained ring, the two bands occur with somewhat changed frequencies so long as only one CH2 group is present in the molecule. With two CH2 groups in a slightly strained condition, the two normal bands are accompanied by two weaker ones at intermediate frequencies. Roberts and Chambers'*-8^ have shown that the frequencies of the CH2 baaids increase and the intensities decrease progressively as the ring size becomes smaller. They conclude, therefore, that the electrical character of the C-K bonds is a continous function of ring size. In l»-4-dioxane and tetrahydropyran, presumably due to the presence of the oxygen atoms, the effect of band spliting becomes more pronounced and four intense and well separated bands are obtained while only three bands are observed for tetrahydrofuran. It is to be noted that Bellamy^8® points out that no correlation or reasonable explaination has been suggested for the 2850 to 2500 cm”"*-, although a number of hydrocarbons absorb in this region. The strong, well defined band at approximately 1460 cm”T can be attributed to CH2 deformation or bending vibrations, 186 Barrow and Searles made the following observations from their study of the spectra of cyclic ethers of which tetrahydrofuran was included. The strong trimethylene oxide band at 1 1 .1 microns (901 cm”^) shifts or breaks up in the substituted compounds and bands of somewhat longer wave length appear. In this region both ring and CH2 rocking vibrations are expected. The tetrahydrofuran spectra follow a similar pattern to that found for the trimethylene oxides. 184R0berts, J. D., Chambers, V. C., J. Am. Chem. Soc.,J73, 5030-4 (1951). 185Bellamy, L. J., "The Infrared Spectra of Complex Molecules," John 1 Wiley and Sons, Inc., New York, N. Y., 1954, p. 16. 8 Barrow, G. M., Searles, S., J. Am. Chem. Soc., 75, 1175-7 (1953). -192- The principal characteristic of the 5-membered rings is a strong band occuring at 9.1 micron (1099 cnT^O to 9.3 micron (1075 cm**1), attributed to the C-O-C stretching frequency. In addition to the CHg band at 1460 cm"! a CH2 vibration shows up at 1368 cm“^-. The rather broad band of medium intensity at 1183 cm*^" is probably due to a OH2 Wagging motion. In tetrahydropyran the infrared bands at 1012, 1050, 1033 £(A^u(Au)J , 1097 [(Eu(a)(Bu )J and 875 on"^ [(3u(b)(Au)J have been assigned by Burket and Badger"1-8^ to ring stretching vibrations. The strong band at 1202 cm”^ is apparently a "A” wagging vibration allhough Barrow and ^earle s^-88 have attributed the 1097 cm”l band to be the C-0 vibration of type A". This assignment is not accepted by Burket and Badger but it is not in series disagreement with their work. The intensity of the 875 and 1122 cm"l infrared bands for 1,4-dioxane is so great compared to the 1453 cm”^ scissors band that they can probably be eliminated as methylene bands. The scissors band is generally the most intense band in the infrared spectra of ether except for the carbon-hydrogen stretching band. The ring stretching bands are then assigned as 875 cm"^, 1122 cm“^ and 1086 cm**l. The 1052 cm1-^ frequency is not a ring stretching band but arises from a rocking vibration. The high frequency of this band may probably be attributed to the fact that the polar hydrogen are either in van der Waals contact or very nearly so. The 889 cm"^ is then the methylene rocking vibration where the polar hydrogens move in the same direction and their close proximity may be expected to have little effect on the frequency. The speotrograms for the three solid compounds, TiBr^Dioxane, TiBr4 *2Tetrahydropyran and TiBr4 *2Tetrahydrofuran are shown in -193- Figure 49, 50, 51, and the data summarized in Tables 57, 58 and 59. Figure 48 is the spectrogram of Nujol. The infrared absorption spectrogram of pure liquid 1,4-dioxane and the solid addition compounds, TiBr^Dioxane, mulled in Nujol appear identical to approximately 8 microns. Slight shifts in the location of the absorption peaks can be expected since two states of matter, liquid and solid, were irradiated as well as the effect of not studying a pure ether addition compound. The intense C-0 ring stretching vibration at 1122 cm"**- 1ms completely disappeared in the addition compound. Of course this is to be expected since both oxygen atomsi.in the 1,4-dioxane molecule are not as free to move about due to the formation of a bond with TiBr4 . The 1052 cm’"^ frequenoy due to CH2 wagging, the 1086 cm"! frequency due to ring vibration, and the 889 cm"-*- frequency due to CH2 rocking are present in both spectrograms. It is not apparent what happened to Uie rather intense 875 cm”^ frequency ascribed to ring vibration in pure p-dioxane. Three new bands in TiBr^Dioxane can not be ascribed to any type of vibration since the mathematical calculation is prohibitive and the infrared spectrogram of pure TiBr^ is not available. It could be surmised, therefore, that these bands result from some mode of Ti-Br vibration, possibly a new ring vibrations of the organic molecule due to the attachment of the inorganic molecule or possibly are unique to the entire TiBr^Dioxane molecule. The infrared absorption spectrogram of pure liquid tetrahydrofuran and the solid addition compound, TiBr4 *2Tetrahydrofuran, mulled in Nujol can be compared in the following way. The spectrograms are identical to 8 microns (1250 cm’"-*-) with two exceptions: the pure liquid has bands at 1949 and 1290 cm"*- which do not appear in the addition 100 0) uc o 50 Q>c U Q> Q. Wave length in microns Figure 48. Infro red spectrogrom of nujol; cell thickness, plate to plate 100 a E cCO o 50 Wave length in microns Figure 49. Infrared spectrogram of TiBr4 ■ Dioxane mulled in nujol; cell thickness, pl.ate to plate. Percent Transmittance 0 0 1 0 5 iue 0 Ifae setorm f ir • Ttayrprn uld n uo; el hcns, lt t plate. to plate thickness, cell nujol; in mulled Tetrahydropyran 2 • TiBr4 of spectrogram Infrared 50. Figure ae egh n microns in length Wave S6 T Percent transmittance 100 0 5 iue 1 Ifard pcrga o TB4-2 erhdoua i nujol. in - Tetrahydrofuran 2 TiBr4 of Infra spectrogram red 51. Figure ae egh n microns in length Wave 961 -197- compound. I*b was previously pointed out that no mode of vibration has been ascribed to these frequencies. Methylene wagging vibrations in pure liquid tetrahydrofuran at 1183 c m ’"'*- could still possibly be present in the addition compotmd (1170 c m ” '*-), although, if they are, they contribute quite a bit less to the spectrogram. Ring vibration attributed to C-0 motion at a frequency of 1 0 7 6 cm"I was very broad and intense for the pure liquid but appears to be present to only a small extent in the addition compound. This effect is due to the oxygen to metal bond in the addition compound. The addition compound, has new bands at 1 0 4 4 cm”^-, 946, 919, 813 and 721 cm"I. Of course there would be some correlation between the presence of the 919 cm"^ band in the addition compound and the 909 cm”^ band in pure liquid attributed to ring vibration. The new band at 813 c m ” '*- is quite broad and intense while the band at 721 c m ” '*' is quite broad. The infrared absorption spectrogram of pure liquid tetrahydropyran and the solid addition compound, TiBr4 *2Tetrahydropyran mulled in Nujol, appear to be identical to approximately 1 1 1 0 cm"'*- with the one exception, namely, the presence of the 1261 cm“T frequency in the pure liquid. The pure liquid exhibits a very sharp and strong frequency at 1100 c m ” -*- which has been attributed to the C-0 ring vibration. This band, although apparently present in the addition compound, is reduced almost to extinction and no doubt would be, were it not for the fact that two C-O-C groups are available per molecule of addition compound. There are three addition groups in the 1090 to 1000 cm-'*' frequency range which have been attributed to ring stretching modes of vibrations and in the pure liquid exhibit decreasing intensity with increasing wave length. In the addition compound the intensity changes from medium, weak and -198- strong with increasing wave length. Thus, the ring vibrations for tetrahydropyran have been altered due to reaction with TiBr4 and formation of the addition compound, but then this is not an unexpected result. Pure liquid tetrahydropyran has a sharp band of medium intensity at 97° cm-1 which is apparently not present in the addition compound. There are two very intense bands at frequencies of 996 and 946 cm"^- in the spectrogram of the addition compound. These can not readily be attributed to any particular vibrational mode. The spectrum from 910 to 700 omm\ can be summarized: the pure liquid has adsorptions bands at 874, 854 and 818 cm"^ of strong, medium and medium intensity while the addition compound has two medium bands at frequencies of 886 and 867 cm“^, a sharp intense band at 859 cm"*-, a shoulder at 798 cm”l and a very broad and intense bands at 780 and 725 om”^. TABLE 52 Absorption Bands for Tetrahydrofuran Prepared with a Baird Infrared Spectrometer. Cell Thickness of 0.025 mm. Absorption Bands Percent Tran smission p (microns7 cm1"-*- I y / l 0;y 2.35 4255 12 2.85 3509 11 3.44 2907 84 3.56 2809 84 3.80 2632 28 5.13 1 9 4 9 1 5 6.85 1460 59 7.31 1368 38 7.75 12 90 37 8.45 1183 52 9.35 1070 71 11.00 909 70 -200- TABLE 53 Absorption Bands for Tetrahydropyran Obtained From a Baird Infrared Spectrometer. Cell Thickness, Blate to Elate. Absorption Bands Percent Transmission p. (microns) cm’*-*- ty' '7lT °v 3.44 2,907 69 3.56 2809 57 3.68 2717 14 3.76 2660 11 6.78 1475 24 6.84 1462 31 6.90 1449 31 7.19 1391 23 7.37 1357 16 7.65 1307 28 7.81 1280 25 7.93 1261 23 8.31 1203 58 8.60 1163 19 9.09 1 1 0 0 68 9.47 1056 57 9.64 1037 41 9.85 1015 36 10.31 970 16 11.44 874 57 11.67 857 16 1 2 . 2 2 818 17 -201- TABLE 54 Absorption Bands for 1,4-Dioxane Obtained With a Baird Infrared Spectrometer. Cell Thickness, Blate to Plate. Absorption Bands Percent Transmission p. (microns) cm-1 2.57 3891 3.42 2924 27 3.55 2817 31 3.70 2703 3 3.80 26 32 3 6 . 8 8 1453 16 7.27 1376 14 7.51 1330 8 7.72 1295 20 7.94 1259 42 8.87 1127 56 9.18 1089 29 9.48 1055 19 11.25 889 32 11.45 873 54 5.08 5 15 questionable 5.79 -202- TABLE 55 Infrared Spectra'*-®'*- of Epoxy Compounds Containing 5- and 6 - Membered Rings with a 0.03 mm. Cell. Tetrahydropyran Dioxane Tetrahydrofuran U (micron's)* "cm"^ u (microns) cm"l u (microns^' "otn**! 3.30 3030 3.33 3003 3.34 2994 3.36 2976 3.64 2747 3.64 2747 6,92 1445 5.03 1988 5.05 1980 7.22 1385 5.26 1901 6.85 1460 7.39 1353 5.78 1730 7.32 1366 7.68 1302 6.89 1433 7.75 1290 7.83 1277 7.32 1366 8.46 1182 7.93 1261 7.58 1319 9.34 1071 8.34 1199 7.74 1292 11.02 907 8.63 1159 7.97 1255 9.12 1096 8.90 1124 9.53 1049 9.22 1085 9.69 1032 9.53 1049 9.90 1010 11.38 879 10.34 967 11.46 873 11.68 856 12.26 816 203- TABLE 56 Infrared Spectra^®^ of Epoxy Compounds Containing 6 -Membered Rings. Cell Thickness Plate to plate. p-Dioxane Tetrahydropyran ^ A * 875 10 818 3 890 7 856 4 1052 5 875 8 1086 6 969 3 1122 10 1012 6 1256 7 1033 6 1290 5 1050 8 1321 1 1097 10 1366 4 1160 2 1453 6 1202 7 1256 3 1272 3 1296 3 1348 2 1381 4 1451 5 -204- TAHLE 57 Absorption Bands for TiBr^Dioxane in Nujol Obtained tfith a Baird Infrared Spectrometer. Cell Thickness of Plate to Plate. Absorption Bands 'microns) cm“l 6.92 1445 7.25 13 79 7.55 1325 7.71 1297 7.96 1256 9.14 1094 9.57 1045 11.27 887 11.74 852 12.00 833 13.86 722 -205- TABLE 58 Absorption Bands for TiBr^*2Tetrahydrofuran in Nujol Obtained with a Baird Infrared Spectrometer and Cell Thickness of Plate to Plate. Absorption Bands Percent Transmission u (microns) cm1"^ 1 /10 3.47 2882 22 6.82 1466 34 7.24 1381 22 7.44 1344 8 8.04 1244 6 8.17 1224 3 8.55 1170 3 9.25 1081 3 9.58 1044 10 10.07 993 21 10.57 946 3 10.88 919 9 12.30 813 32 13.87 721 7 -206- TABEiE 59 Absorption Bands for TiBr^*2Tetrahydropyran in Nujol Obtained v/ith a Baird Infrared Spectrometer. Cell Thickness of Plate to Plate, Absorption Bands p. (microns) onT^- 6 81 1468 7,.21 1387 7. 33 1364 7 62 1312 7 80 1282 8 37 1195 8 62 1160 9 .07 1103 9 27 1079 9 .76 1025 9 .86 1014 10 06 994 10 .57 946 11 29 886 11 .53 867 11 .64 859 12 .54 797 12.80 781 13.80 725 -207- Conclusion. The infrared spectrogram was obtained for the three addition compounds, TiBp^*C4 H8 O2 , TiBr^^C^gO and TiBr4*2C5HioO. The resulting spectrogram was analyzed qualitatively and most of the absorption bands attributed to definite modes of vibration. This was accomplished by comparison of the spectrograms obtained from the pure addition compound mulled in Nujol and from the pure ether. The titanium to bromine absorption band was not determined, the tetrahalide and ether definitely form a bond at the ring oxygen as this vibration, C-O-C, does not appear in the spectrogram for the addition compound. There is no evidence for the formation of a carbon to bromine bond. VIII. CRYOSCOPIC STUDY Introduction. In resolving "the question of a monomeric, dimeric or polymeric structure of the 1:1 addition compound formed by 1,4-dioxane and titanium tetrabromide, a cryoscopic investigation of the molecular weight of the addition compound was proposed. Since the addition compound is relatively soluble in excess 1,4-dioxane, it was decided to vise 1,4-dioxane as solvent. The addition of a solute to a solvent causes the freezing point of the latter to be lowered. The extent of the freezing point depression, assuming the solute does not dissociate, depends directly on the concentration of solute. The following quantitative relation is known 1 Qn to hold for ideal dilute solutions ; Mo = * ■CTTjr— 2 = K. (10) 2 lU00Lf f '‘xu; In equation (10), is the molecular weight of solid:e, _Tf is the observed freezing point lowering caused by the addition of JWg grams of solute to Wi grams of solvent. Lj[ is the latent heat of fusion per gram of solvent. ^ is the freezing point of the pure solvent, and R is the gas constant. is the freezing point depression constant or cryoscopic constant and may evidently be calculated by Kf = ,El (11) r 1000Lf ^•®^Glasstone, S., "Textbook of Physical Chemistry," D. Van Nostrand Co., New York, N. Y., (1940), p. 632. -208- -209- However, it is usually more satisfactory to obtain values of _K for a particular solvent by experimental determination. If, when titanium tetrabromide is added to 1,4-dioxane, polymerized species are formed, each polymer molecule would act as a single moleoule in lowering the freezing point, and the freezing point depression would be less than would be the case if only monomers were present. The number of titanium tetrabromide ■units per molecule of solute can be calculated as: - (12) re is the apparent molecular weight of the 1:1 addition compound calculated from the freezing point depression. M is the formula weight of the addition compound calculated from the sum of the atomic weights in the empirical formula, and ^ is the nuntoer of titanium tetrabromide units per molecule of the addition compound. The molality jn of any solution may be related to M, Wg and W]_ by the equat ion Substituting the expressions for and M as given by equations (10) and (13) respectively into equation (12) results in the expression X = (14) which may be used in calculating the number of titanium tetrabromide units in a molecule of the addition compound in solution. -210** Experimental Procedure. A G-2 Mueller bridged equipped with a platinum resistance thermometer was used for measuring the temperature- The freezing point cell was so constructed as to protect the sample from moisture and to provide constant stirring. The detailed construction of the cell is shown in Figure 52. The platinum resistance thermometer JT whioh was calbriated at the Bureau of Standards was protected from the action of the stirrer by shield _S. It entered the shield al: £ through a Teflon plug JP which was machined to fit snugly into the ground glass joint A. The thermometer _T was sealed to plug _P which Was in turn sclaed to joint A using DeKhotinsky cement. The stirrer was made of glass and was caused to move by intermittent activation of a solenoid which was fitted over the stirrer guiding chamber _G. M is a small metal slug' hermetically sealed within the stirrer arm. The ground glass joint J3 accommodated a weight burette, which was used for the addition of 1,4-dioxane to the freezing point cell J^. The entire oell was fitted into a double walled cooling jacket which was immersed directly in a cooling bath. In a typical run the apparatus was cleaned, dried, and flushed with dry argon. The platinum resistance thermometer _T and the bridge _F with stopcock closed were fitted into place. A drying tube containing phosphoric anhydride and sand was connected to the bridge JF at H. A burette containing 1,4-dioxane was fitted into the ground glass joint _B, stopcock was opened and dioxane flowed into the cell. The weight of the burette was noted before and after the addition, the difference being the weight of dioxane added. With stopcock JD closed and joint _B plugged, the addition compound, TiBr^.Dioxane, transfer cell was -211- connected.to the cell E at ground glass joint _C. The weight of the transfer cell was noted before and after the addition of addition compound, the difference being the weight of addition compound added to the freezing point cell. The freezing point cell E in jacket _J was then returned to the cooling bath and the freezing point of the mixture determined. From the known'weights of dioxane and addition compound the freezing point depression, and the oryoscopic oonstant of dioxane, the apparent number of titanium tetrabromide units per molecule of addition compound was calculated. The freezing points of the various mixtures were obtained using a platinum resistance thermometer in conjuction with a G-2 Mueller Bridge. The resistance (in absolute ohms) of the platinum resistance thermometer was measured directly on the bridge. The resistance was then converted to temperature by use of the Callender equation! where the symbols have the following meanings! R0 b ice point resistance C - steam point calibration constant ■ 0.00392557 S s sulfur point calibration constant B 1.492 J3 ~ oxygen point calibration ■ zero for temperatures above 0°C. _t B temperature in degrees centigrade Rfc B the resistance at temperature t The constants _G, _S, and J3 were supplied by the Bureau of Standards but an average value of the ice point resistance mtlst be determined - 212- Aii i Figure 52 Freezing point cell -213- by the user of the instrument. This was done using pulverized ice made from distilled Water and was found to be 25.5395 absolute ohms. It may be observed that the solution of equation (15) for jt above 0°G. in terms of resistance involves a quadratic equation. In order to eliminate the task of solving a quadratic equation each time a new temperature was determined, temperatures near the expected range of operation were substituted and the equation solved for Rfc. By proceeding in this manner it was possible to construct a plot of resistance versus temperature Jt and to read the temperature corresponding to a definite resistance directly from the graph. The freezing points of the various mixtures were determined by plotting cooling curves (resistance versus time) for each trial. Figure 53 shows a typical cooling curve. In every case supercooling 108 Was encountered and hence the method of Rossini et al. was applied to correct for this difficulty. The method merely requires the extrapolation of the cooling curve, after solid has started to form, back to the portion of the curve obtained before solid appeared. The resistance at the point where the extrapolated curve intersects the other was taken to be the correct resistance. This resistance reading was then converted to temperature as described above. Results and Discussion. The results from the determination of the molecular weight of the addition compound, TiBr^Dioxane, in 1,4-dioxane solvent are given in Table 60 and Figure 54. The apparent molecular weight was calculated 188 Glascow, A., Streiff, A., Rossini, F., J. Res. Nat. Bu. Standard, 35, 355-73 (1945). Resistance absolute ohms 26.8000 26.8200 26.7800 26,7400 26.7600 26.7200 26.7000 iue 3 Tpcl oln curve cooling Typical 53. Figure ”214” ie (minutes) Time Run □ □ — □ Check TABLE 60 Summary of Cryoscopic Data Weight Weight Molecular of Solvent, of Solute, Molality, Z\tf,oc Weight X = -jg- Run No, Grams Grams m Grams 1A 64.2049 1.1530 0,03941 0.185 454 0.99 IB 0.186 452 0.99 2A 31.6938 1.3387 0.09270 0.168 1177 2U58 2B 0.167 1184 2.60 3A 39.4002 1.3387 0.07457 0.136 1169 2.57 3B 0.137 1161 2.55 4A 48.0530 1.3387 0.06114 0.106 1230: 2.70 4B 0.106 1230 2.70 5A '15 ,4587 0.0624 0.008859 0.040 472 1.04 5B 0.039 484 1.06 5C 0.04-0 472 1.04 6A 50.5929 0.1205 0.005227 0.026 429 0.94 6 B 0.027 413 0.91 7A 30.5226 0.5976 0.04297 0.052 1762 3.86 7B 0.051 1797 3.94 8A 30,5226 0.6624 0.04763 0.065 1562 3.43 8 B 0.064 1587 3.48 9A 30.5226 1.2482 0.08975 0.182 1052 2.31 9B 0.182 1052 2.31 10A 45.3158 0.0096 0.0004649 0.002 496 1.09 10B 0.002 496 1.09 IOC 0.002 496 1.09 11A 31.6938 0.3187 0.02208 0.022 2139 4.69 Molecular weight Monomer Trimer Dimer 2200 2000 1800 1600 1200 1400 1000 0 0 8 0 0 4 200 0 0 6 0 iue 4 Mllt vru mlclr egt f diin compound addition of weight molecular versus Molality 54. Figure 0.02 oaiy mls f - adto cmon per compound addition l l- of (moles Molality 00 rm Dioxane) grams 1000 0.04 -216® .60.08 0.06 9 o 0.10 -217- with the aid of euqation 10 with the valuers for the cryoscopio constant, Kf, of 4.68 degrees per mole. In each of the determinations it was assumed that the solid separating from the freezing mixture was pure dioxane. The value reported for the molecular weight was the average value obtained for the tr-ifel and check run at each molality and is indicative of the monomeric nature of the addition compound in solutions of concentration from 4.8 x 1 0 “4 to 3.9 x 10~2 molal. All determinations which indicated the addition compound to be monomeria were obtained with freshly distilled solvent and the magnitude of the freezing point depression ascertained immediately after the addition of the solute. At the termination of these experiments, the solutions were still reddish colored with no evidence of pressure build up within the freezing point cell. At the termination of experiment 6 , solvent dioxane was removed by evaporation at reduced pressure leaving behind a red fluffy powder which appeared to be the original solute. It was not analyzed, although thejX-ray diffraction pattern was:>identical to that of the pure addition compound, TiBr^Dioxane. Inspection of Figure 54 shows a trend if not an indication of decomposition of the addition compound. Actually these additional data are disclosed, not to shed light on the molecular weight of the addition compound, but to emphasize the nature of the difficulty encountered in an experiment of this type where the investigation involves hygroscopic materials. The experiments (2, 3, 4, 7, 8 , 9, 11) which gave apparent anomolous molecular weights were conducted with solvent that had been stored over iron and sodium wire. On the additon of solute, the solution became 189 Ling, H, W.-, Thesis at The Ohio State University, 1954. "218** orange in color but immediately began to darken to brownish-black with the simultaneous increase in pressure within the freezing point cell. The resulting liquid had an odor resembling tarry materials. A result of this type can be explained by the presence of a trace amount of moisture present in the solvent which reacted with the addition compound. A pasty residue was obtained when the excess solvent dioxane was removed from the dark solution by evaporation at reduced pressure. On heating to 1 0 0 °C.J the residue became quite hard and resembled a cake of carbon. Conclusion. The molecular weight of the addition compound, TiBr4 *Dioxane, was determined by depression of the freezing point with 1,4-diaxane as solvent. The pure addition compound is a monomer, and can be regained from the solution when freshly distilled solvent is used and definitely can not be regained from solvent which has been stored even over iron and sodium wire. IX. REACTIONS OF Til4 WITH EPOXY COMPOUNDS Preparation of Til4 . Titanium tetraiodide was prepared by two methods: direct synthesis from the pure elements (equation IB) and from the disproportionation of titanium triiodide (equation 17). Ti(S) + 2I2(V * TiI4 (JU (16) 2TiI3 (S) » Til4 (g) + TiI2 (S) (17) Each method of preparation will be discussed in detail. Titanium tetraiodide is a dark metallic appearing solid when in thick layers but appears to be deep red in thin films. Itha s ^ O a melting and boiling point of 156° and 377°C., respectively. In a typical run the system Was assembled as depicted in Figure 55. The charge consisted of 1563 grams of iodine and 500 grams of iodide titanium in the form of rods (stoGhiometry of 1563 grams iodine to 147.5 grams of titanium). The reaction tube was heated (Furnaces A and JB) and the metal hot outgassed (300°C.) under full vacuum for two days. Furnace was energized and the iodine which vaporized from the reservoir was condensed in the capillary. This frozen plug of iodine served to isolate the vacuum system from the reaction tube. The temperatures were adjusted so the iodine vaporizer was at 180°C., 1 9 oCampbell, I. E., Blocher, J. M . , J. Am. Chem. Soc.,_69., 2100-1 (1947). - 219 - Capillary 3 mm. graded seal (pyrex to vycor) To trap and vacuum system Furnace Constriction for seal off Furnace A 6 4 mm. vycor Titanium rods ozz F urnace B Perforated molybdenum sheet Figure 5 5 Apparatus for preparation of titanium tetraiodide by direct synthesis -221- the titanium rods at 210-220°C. and "the bottom of the reaction tube at 175-195°C. Iodine vapor Was driven into the reaction tube Where it reacted with the titanium metal. Thus, the mass of free iodine in the iodine vaporizer was continuously reduced and to maintain a constant iodine pressure in the system, the temperature on the iodine vaporizer was gradually raised to 230°C. An excess of titanium was used as evidenced from the stochiometry cited above. Reaction was terminated!^! when all the available iodine had reacted as evidenced by the temperature increase in the now empty iodine vaporizer. The solid iodine plug in the capillary was removed while under full vacuum to remove any unreacted iodine and the system cooled to room temperature. Pressure in the system was brought to 760 mm. with dry argon and the system sealed off at the constriction. The reaction tube was placed in a dry box, broken open and the solid tetraiodide transferred to a storage flask (Flask A of Figure 57) equipped with a break seal. The flask was removed from the dry box, evacuated and sealed off under reduced pressure at side arm . Tetraiodide was also prepared by the disproportionation of pure triiodide. In a typical run the apparatus was assembled as shown in Figure 56. Purified Tilg, 200 grams, was added to the 64 mm. pyrex bulb via the fill tube. This operation was executed in a dry box. The unit was removed from the dry box, -the pressure reduced to approximately 0.1 mm. of Hg. and the fill tube sealed off. A temperature gradient was maintained, 290°C. for the Til^ collection tube, 300°C. for the connecting tube and 310°G. for the Tilg bulb, with the use of Furnaces I _A, J3 and J3. Contamination of the tetraiodide with Tilg and Tilg can !9!The total lapse time for the experiment was 7£ hours. Fill tube 64 mm. 2 0 mm. Vacuum \ ' system x j— Ti I3 Furnace B Furnace C Furnace A Figure 56 Apparatus for preparation of titanium tetraiodide by disproportionation of titanium triiodide. No. To tra p andz^. vacuum system No. 2 capillary for seal off r 1 / A B Figure 57 Purification of TiI^ -224- be neglected since their respective vapor pressures are so low at these temperatures and the disproportionation pressure of the tetraiodide is high. The experiment was terminated after 24 hours and the unit removed to a dry box where the test tube containing the tetraiodide was broken open and its contents placed in a storage flask as outlined above. Preparation of Titanium Tetraiodide from Titanium Triiodide. Purification of the tetraiodide was conducted in the apparatus as depicted in Figure 57 and flask A having been filled with Til4 in a dry box. The system was assembled and the glass surface hot outgassed (to remove air and moisture) for eight hours. The glass break seal was ruptured with the glass encased steel break hammer. Vaporizer A. was flamed such that some tetraiodide with any volatile impurity was driven through the capillary into the cold trap. The temperature of condenser tube_B was above the dew point of the tetraiodide. After this, the capillary was plugged with solid and about 50 per cent of the remaining tetraiodide driven into the condenser tube_B. The entire system Was cooled to room temperature, the solid plug in the capillary removed and the system pressured to one atmosphere dry argon gas. The condenser tube was then sealed off at the constriction and placed in a dry box where the pure Til4 was transferred to weighing tubes. -225- Analytical Analysis. Mole Ratio Til4 Ti I Ti I la; Experimental 8.55% 91.4% 1 4.03 Experimental 8.71 89.0 1 3.86 Experimental 89.7 »» » (b) Experimental 8.64 91.1 1 3.98 Experimental 8.62 90.9 1 3.98 (Theoretical) 8.62 91.38 1 4.00 (a) Direct synthesis. (b) Disproportionation of Til3. Titanium Triiodide. Titanium triiodide was prepared by the reduction of titanium tetraiodide with metallic titanium. The reaction can be expressed by equation - 18 Ti(s) + 3TiI4 (g) s 4TiI3 (s) (18) The apparatus is shown in Figure 58. In a typical preparation, the reaction bulb was placed in a dry box and loaded with appr oximsrfc ely 500 grams of pure tetraiodide. A small perforated molybdenum-1-^ disc was introduced and served to support the 13 grams of iodide titanium turnings which were then added. The tube was removed from the dry box and the glass cap sealed on with a positive pressure of argon which was maintained in the bulb at all times. The system Was evacuated and the reaction bulb slowly warmed to vaporize tetraiodide. A plug of solid tetraiodide was frozen in the capillary which served to isolate the reaction bulb from the vacuum system. Under these conditions, the 192. .' 1 1 ' ' ' ' 1' " T Molybdenum does not react with iodine at the pressure and temperature of the experiment. “226- mm. capillary 3 mm. graded seal ) e Constriction for Cap ^ seal off 64 mm. vycor Iodide titanium Furnace C turnings Perforated molybdenum disc Furnace B Pure Til4 Furnace A Figure 58 Apparatus for preparation of T iI3 -227- triiodicle which was produced condensed in the reaction tube in the area just above the titanium turnings. During the course of the experiments a temperature gradient was maintained in the reaction tube (base- 300°C.; middle- 340°C„; top- 600°C.). At the end of 96 hours, the reaction was terminated, the reaction tube cooled to room temperature, the plug of solid tetraiodide removed from the capillary and the system pressurized to one atmosphere dry argon. The reaction tube was sealed off at the constriction and removed to a dry box where the cake and acicular crystals of Til3 were transferred to storage flasks. Cite Figure 59 for a photograph of Tilg needles stored in a test tube under argon. Analytical Results. Mole Ratio Ti I Ti 1 ' Til3 Experimental 11.3% 89.2# 1 2.98 Til3 Experimental 11.2 89.4 1 3.01 Til3 (Theoretical) 11.17 88.83 1 3.00 Reaction of T H 4 with 1,4-Dioxane. Titanium tetraiodide and 1,4-dioxane react at 1 2 °C. to form both a black liquid and solid. This reaction is slightly exothermic and the resulting 1,4-dioxane pressure seldom exceed 760 mm. of Hg. In a typical experiment the equipment was assembled as shown in Figure 4 and the experimental procedure identical to that as outlined on pages 38 through 40 for the stable compound TiBr^/Dioxane. Thus, the liquid residing over the solid was removed with a hyperdermic needle and placed in the apparatus as shown in Figure. 5. Removal, by reduced pressure, of the excess solvent dioxane left behind a jet black fluffy powder which appeared to be stable after storage under argon for several 226 Figure £9 Needles of Titanium Triiodide -229- months. Qualitative analysis of -the powder for carbon, hydrogen, titanium and iodine were internally consistant but mutually inconsistent. Analytical Results. Mole Ratio Prep. No. Ti I C H T I ~ T ~ <5' 'H ~ 1 3.5 % 28.00# -- % ~ I 3.02 IMW MSB 2 mb mb 66.1 11.60 2.31 4.00 7.44 17.60 3 5.40 Ma tm HIM «B«M MB MB 4 5.83 62.5 13.93 2.80 4.05 9.53 22.82 5 -- 53.8 mb m m MB MB MB MB MM Mb 6 58.1 11.32 3.11 4.00 8.24 26.96 7 8.94 -- MB m >a tm Mm v *■ M* ^ B 8.19 36.51 Mb to 1.68 m »» MB 9 10.15 50.64 mm*m MB to* 1.88 MB » m »• Hydrolysis was not complete and in every case, a black insoluble solid remained whose density was greater than one. The dear acid liquid was filtered from the black solid and the liquid analyzed for both titanium and iodine. The black solid was insoluble in CCI4 an^ vanished on heating in air. Thus, it Would appear that the solid was composed of carbonaceous material rather than free iodine. Reaction of Til4 with Tetrahydrofuran. Titanium tetraiodide and tetrahydrofuran react at 0°G. to yeild a red liquid and solid. The solid slowly became dark on storage under the red tetrahydrofuran liquid layer. In a typical preparation, the equipment was assembled as shown in Figure 4 and the procedure identical to that outlined on page 38. Removal, by reduced pressure, of the excess solvent tetrahydrofuran, resulted in the formation of a 1 very viscous red liquid. All attempts to obtain a solid from the viscous liquid resulted in failure. The infrared spectrogram of the viscous liquid is shown in Figure 60 and was not analyzed; that is, the absorption bands were not attributed to any particular vibration. Analytical Results. Mole Ratio Ti I ~T~ 6.02% 55.6% 1 3.49 5,99 56.5 1 3.56 Addition of the red liquid to neutral distilled water resulted in the formation of a plastic-like substance which slowly hydrolyzed to yield an orange colored liquid (typical I" solution) and a black fluffy residue. This solid, whose density was greater than one, slowly dissolved in ammoniacal solution. Percent transmittance 100 0 5 iue 0 Ifae setorm f h Ti4~erhdoua ol Cl tikes pae o plate to plate thickness: Cell oil. ~tetrahydrofuran iI4 T the of spectrogram Infrared 60. Figure Wave length in microns Wave X. X-RAY DIFFRACTION ANALYSIS Til4 . Titanium -tetraiodide as prepared and purified by the procedures outlined on pages 219 through 224 , was investigated by X-ray poflder diffraction techniques. The diffraction patterns were obtained from samples contained in sealed Lindemann glass X-ray capillaries and exposed to -foe K-alpha radiation of copper (Tables 62 and 63), iron (Table 64)and cobalt (Tables 65 and 6 6 ) and are shown in Figures 62 and 63. It is to be noted that the diffraction pattern of Til4 Was obtained from direct synthesis (Table 62) and disproportionation of Til3 (Table 63). Also, the d-spacings for Til4 as obtained from representative samples of different preparations are mutually consistent and independent of the method of preparation. One sample was checked once per week for 8 weeks to see if the solid would change and thus give a different powder pattern or at least show the presence of new lines. None were found. Thus it can be concluded, that the sample'.-Which was contained in the Lindemann X-ray capillaries was indeed pure Til4 which had not undergone any hydrolysis. Therefore, the data in Table 62, which were obtained from a 26 hour exposure of the sample to K-alpha radiation of copper with a nickel filter Were used to calculate the lattice constant. The method of determining the absolute value of a0 was outlined on page 81 and are reported in Table 67 and Figure 61. Titanium tetraiodide crystallizes in a body centered cubic structure with a0 equal to 12.07.8 an<3 -the d-spacings were indexed on that basis. -232- -233- Comparison of the calculated and literature-^S values (Table 61) of the d-spacings shows a complete absence of agreement even though the a 0 value deviates by only 0.04fi. This lack of agreement can not possibly be attributed to the presence of solid impurity in Hassel and Kringstads Work unless it were present in solid solution but does indicate hydrolysis. ■^Hassel, 0., Kringstad, H., Loc. Cit. TABLE 61 Interplaner Spacings (ASTM) for Til^ K-alpha-1 Millar Indices Intensity d-Spao inga hk jj l/IQ 3.47 222 . 100 3.01 400 60 2.13 440 80 1.81 622 100 1.74 444 10 1.50 800 20 1.38 662 40 1.34 840 40 1.23 844 20 1.16 666 40 10.22 1.02 10.62 30 1.00 12.00 10 0.950 12.40 10,100 0.917 10.66 20 Reference: Hassel, 0., Kringstad, H., Z. Phys. Chem.,JL5, 274 (1932) Radiation: Copper (K-alpha-l) Wave Length: 1.5045 A Cubic crystal structure a Q b 12.026A TABLE 62 Measurement of Til^ Film and Calculation of d-Spacings Copper K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetic Position; Film Shrinkage Factor: 1.00097, Film No. 2M Capillary Size, 0.5 mm., Exposure Time, 26 Hours. d-Spacings Scale Reading K-alpha Radiation (mm) Unre Li Left Right l/ln 4S 26, Degrees solved 1 102.70 153.00 10 25.15 25.174 3.53 2 101.85 153.85 30 26.00 26.025 3.42 3 101.15 154.40 30 26.55 26.576 3.35 4 100.50 155.20 60 27.35 27.377 3.25 sez 5 99.35 156.45 20 28.60 28.628 3.12 6 98.45 157.25 100 29.40 29.429 3.03 7 89.95 16 5.75 50 37.90 37.937 2.37 8 82.65 173.10 50 45.25 45.294 2.00 9 82.00 173.75 60 45.90 45.945 1.97 10 78.80 176.85 50 49.00 49.048 1.85 11 78.10 177.60 30 49.75 49.798 1.83 12 73.80 181.95 10 54.10 54.153 1.69 13 73.05 182.60 20 54.75 54.803 1.67 14 72.10 183.60 50 55.75 55.804 1.65 15 67.30 188.45 10 60.60 60.659 1.52 IB 66.35 189.35 10 61.50 61.560 1.50 17 65.30 190.35 10 62.50 62.561 1.48 18 53.55 2 02 . 1 0 10 74.25 74.322 1.28 4S' 19 233.10 382.25 10 105.25 105.352 0.969 20 234.20 281.15 10 106.35 106.453 0.962 21 235.55 379.80 10 107.70 107.805 0.953 TABEL 63 Measurement of TiLj Film and Calculation of d-Spacings Copper K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetic Position; Film No. 16J Capillary Size 0.5 mm., Exposure Time, 13 Hours. TH 4 Prepared by Disproportionation of T H 3 . d-Spacings, 1 Scale Reading K-alpha Radiation (mm) Unre- Line Left Right I/I0 26, Degrees solved 1 84.75 136.25 10 25.75 3.46 2 83.35 137.65 100 27.15 3.28 236 3 81.25 139.75 1 0 0 29.25 3.05 4 80.90 140.10 20 29.60 3.02 5 72.75 148.25 50 37.75 2.38 6 65.45 155.55 50 45.05 2.01 7 64.60 156.40 50 45.90 1.98 8 61.65 159.35 50 48.85 1.86 9 60.95 160.05 30 49.55 1.84 10 m 163.65 20 53.15 1.72 11 »«■ ym 164.60 10 54.10 1.69 12 55.85 165.15 30 54.65 1.63 13 54.80 166.20 50 55.70 1.65 14 41.55 179.45 10 68.95 1.36 15 37.50 183.50 10 73.00 1.30 16 36.30 184.70 10 74.20 1.28 17 35.40 185.60 •10 75.10 1.26 18 33.45 187.55 10 77.05 1.24 TABLE 64 Measurement of Til^ Film and Calculation of d-Spacihgs Iron K-alpha Radiation; Camera Diameter 57.3 mm., Film in Asymmetic Position; Film Shrinkage Factor: 1.00056, Film No. 6 J Capillary Size, 0.5 mm., Exposure Time, 2 Hours. d-Spacings, Scale Reading K-alpha Radiation (mm) Unre Li Left Right I/In 4S 8 , Degrees solved 1 99.20 131.90 10 16.35 16.359 3.44 2 98.20 132.90 80 17.35 17.360 3.24 3 96.80 134.30 100 18.75 18.760 3.01 237 4 91^25 139.85 40 24.30 24.314 2.35 5 86 .65 144.4-5 30 28.90 28.916 2 .00 6 86.15 144.95 40 29 .40 29.416 1.97 7 83.80 147.30 40 31.75 31.768 1.84 8 81.15 149.95 30 34.40 34.419 1.71 9 80.20 150.90 10 35.35 35.370 1.67 10 79.45 151.65 30 36.10 36.120 1.64 11 M *» »- 154.75 10 39.20 39.222 1.53 12 156.35 10 40.80 40.823 1.48 4S' 13 160.55 1 0 45.00 45.025 1.37 14 163.65 247.35 10 48.10 48.127 1.30 15 164.70 246.30. 10 49.15 49.178 1.28 16 166.95 244.05 10 51.40 51.429 i.24 17 171.95 M »• 10 56.40 56.432 1.16 18 175.15 10 59.60 59.633 1.12 19 177.40 --- 10 61.85 61.885 1.10 TABLE 65 Measurement of Til^ Film and Calculation of d-Spacings Cobalt K-alpha Radiation; Camera Diameter 114.6 ram., Film in Asymmetic Position; Film Shrinkage Factor: 1.00118, Film Wo. 18F Capillary Size, 0.5 mm., Exposure Time, 24 Hours. d-Spacings, A Scale Reading K-al pha Radiation (mm) Unre- Lir Left Right l/l0 4S 28, Degrees solved 1 78.55 138.95 10 30.187 30.223 3.43 2 77.00 140.50 100 31.737 31.775 3.27 3 74.55 143.00 50 34.237 34.278 3.04 ■238 4 74.10 143.40 30 34.637 34.678 3.00 5 64.55 ' 153.00 50 44.237 441290 2.37 6 55.85 161.70 60 52.937 53.000 2.01 7 55.05 162.45 70 53.687 53.751 1.98 8 51.20 166.30 70 57.537 57.606 1.86 9 50.50 167.00 50 58.237 58.306 1.84 10 46.05 171.50 40 62.737 62.812 1.72 11 44.95 172.55 20 63.787 63.863 1.69 12 44.20 173.35 20 64.587 64.664 1.67 13 43.05 174.50 50 65.737 65.815 1.65 14 34.80 182.75 10 73.987 74.075 1.48 4S* 15 264.10 313.00 20 155.337 155.521 0.9152 16 265.55 311.55 20 156.787 156.973 0.9112 17 266.90 310.10 20 158.138 158.324 0.9107 -239- TABLE 66 Measurement of T 3.I4 Film and Calculations of d-Spacings Cobalt K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymnetic Position; Film No. 19F d-Spacings, i? K-alpha Radiation Unre Line I/I0 solved 1 100 3.28 2 50 3.05 3 40 2.38 4 . 30 2.02 5 50 1.98 6 80 1.86 7 30 1.84 8 20 1.72 9 20 1.68 10 90 1.65 11 10 1.49 12 20 1.36 13 10 1.30 14 50 1.28 15 10 1.265 16 20 1.240 17 10 1.230 18 10 1.16 2 19 10 1.146 20 10 1.115 21 10 1.102 22 10 1.050 23 20 0.970 24 10 0.962 25 10 0.954 26 10 0.935 27 10 0.924 28 10 0.915 29 10 0.912 30 10 0.910 31 10 0.908 TABLE 67 De-termination of Absorption Effects for Til^ a0 = 12.07 R / % r c°s^ cos^oi h£ j £ m V______a n 8 , Degrees ^ L sin 9_____ 8 J 310 9 1 '.0 10 3.16228 11.1628 12.5870 4.353 222 4 4 4 12 3.46410 11.8472 13.0125 4.198 320 9 4 0 13 3.60555 12.0786 1 3 ;2800 4.102 321 9 4 1 14 3.74166 12.1604 13.6885 3.971 400 16 0 0 16 4.00000 12.1200 14.7145 3.663 510 25 1 0 26 5.09902 12.0847 18.9685 2.726 600 ■ 36 0 0 36 6 . 0 0000 12.0000 22.6470 2.183 442 16 16 4 36 6.00000 611 36 1 1 38 6.16441 12.1439 22.9725 2.143 532 25 9 4 38 6.16441 541 25 16 1 42 6.48074 11.9894 24.5240 1.964 622 36 4 4 44 6.63325 12.1388 24.8990 1.924 710 49 1 0 50 7.07107 11.9501 27.0765 1.710 550 25 25 0 50 7.07107 543 25 16 9 50 7.07107 640 36 16 0 52 7.21110 12.0425 27.4015 1.681 721 49 4 1 54 7.34847 12.1250 27.9020 1.637 633 36 9 9 54 7.34847 552 25 25 4 54 7.34847 .2.40 144 16 0 160 12.65148 12.0569 53.9025 0.399 12.10 on - 12.070 & a0, A 12.05 640 ■241 600 12.00 34! 11.95 0 .25 0.50 0 .7 5 1.00 1.25 1.50 1.75 2.00 cos2 9 , cos2fl Figure 61. Determination of the lattice constant, aQ, for T il4 X-RAY DIFPRACTION PATTERNS OF Til4 t M to Figure 62; Film No. 2M, Gonper Radiation. ' Figure 63; Film No. 6J, Iron Radiation. Titanium triiodide as prepared and prepared by -the procedures outlined on pages 225 through 227 was investigated by X-ray powder diffraction techniques. The diffraction patterns were obtained from samples contained in sealed 0.3 nan. Lindemann glass X-ray capillary tubes and exposed to K-alpha radiation of copper (Table 68) and iron (Tables 69 and 70), and shown in Figures 64 and 65. Representative samples from different preparations gave identical diffraction patterns and the observed d-spacings are apparently independent of the source of radiation. Absorption effects which are so prominent for titanium compounds was effectively minimized by decreasing the sample thickness from 0.5 to 0.3 mm. The observed d-spacings which are given in Tables 74 and 75 and obtained from a 5 hour exposure to K-alpha radiation of iron with a manganese filter were assigned Miller indices by the procedure outlined on page 9 2 . To accomplish this, the observed d-spacings were plotted on a logarithmic scale and found to fit a Hull-Davy chart for hexagonal crystals. This result was expected since, the trihalides of 194 zirconium and hafnium as well as the tri-chloride of titanium are known to crystallize in the hexagonal structure. The lattice parameter values for a 0 of 7.175, and for c0 of 19. 38I were determined by the graphical method outlined on page and the equation 19 (19) ■^^Klemm, W., Krose, E., g. anorg. Chem. 253, 218-25 (1947). -244- The data are given in Tables 72 and 72 and Figure 6 6 . In view of the uncertainities in the procedure used to determine the axial ratio, it seems appropriate to compare the lattice parameters 195 with those of related compounds. Larason and Leddy observed the following values, c0 ,5 MC13 6.31 19.0 MBr3 6.71 19.0 UI3 7.47 19.7 where M denotes both zirconium and hafnium, Klemm and Krose observed"^^ a 0 of 6 .12^5, o0 of 17.50 for TiClg, the values*96 of a0 of 6.365 and c0 of 18.I4 for TiBrg. It is immediately obvious that the value of 7.17^5 for the a 0 of Ti l g is in excellent agreement with the data of related compounds. The value for c0 of 1 9 .30.5 is not too far out of line and a more precise value can only be obtained if a d-spacing can be found With Miller indices corresponding to (0 0 ,8). That is, when h and k are equal to zero, in which case the value of a Q can be obtained using equation 19. *96Larson, E. M., Leddy, N4onr, Aug. 1955. *96Unpublished work. TABLE 68 Measurement of Til3 Film and Calculation of d-Spacings Copper K-alpha Radiation; Camera Diameter 114.6 mm., Film in Asymmetric Position, Film Shrinkage Factor: 1.00306, Film N o . 1A Capillary Size, 0.3 mm., Exposure Time, 24 Hours. d-Spacings, -S Scale Reading K-alpha Radiation (mm) Unre Line Left Right I/I( 4S 28, Degrees solved 1 84.20 113.50 30 14.65 14.695 6.02 2 76.10 122.60 20 23.75 23.823 3.73 3 73.55 124.15 50 25.30 25.377 3.51 245 4 72.90 124.80 30 25.95 26.029 3.42 5 71.10 126.55 10 27.70 27.785 3.21 6 70.05 127.65 100 28.80 28.888 3.09 7 8 61.30 136.40 10 37.55 37.665 2.386 9 --- 138.05 10 39.20 39.320 2.289 10 39.10 138.60 20 39.75 39.872 2.259 11 54.70 143.00 100 44.15 44.285 2.043 12 50.90 146.80 10 47.95 48.097 1.890 13 49.40 148.30 10 49.45 49.601 1.836 14 N>«M 150.40 10 51.55 51.708 1.766 15 46.10 151.60 10 52^75 52.911 1.729 16 45.25 152.45 40 53.60 53.764 ' 1.705 17 39.85 10 59.00 59.180 1.560 18 38.80 .158.90 10 60.05 60.234 1.535 19 35.05 162.65 10 63.80 63.995 1.456 20 166.95 10 68.10 68.308 1.372 TABLE 68 (Continued) d-Spacings, S. Scale Heading K-alpha Radiation (mm) . Unre Line Left Right I/L, 4S 29, Degrees solved 21 29.00 168.70 10 6:9.85 70.064 1.342 22 27.20 170.50 50 71.65 71.869 1.312 23 24.55 10 74.30 74.527 1.272 24 22.35 10 76.50 76.734 1.241 25 18.00 179.70 50 80.85 81.097 1.185 4S' 26 195.60 "... 20 96.75 97.046 1.028 27 202.45 354.25 20 103.60 103.917 0.9780 28 241.10 315.50 10 142.25 142.685 0.8130 29 261.20 29 5.40 10 162.35 162.847 0.7790 30 262.15 294.45 10 163.30 163.800 0.7780 TABLE 69 Measurement of Tilg Film and Calculation of d-Spacirigs Iron K-alpha Radiation; Camera Diameter 57.3 mm., Film in Asymmetric Position; Film Shrinkage Factor: 0.99889, Film No. 19A Capillary Size, 0.3 mm., Exposure Time, 5 Hours. 1st Reading d-Spacings, 1 Scale Reading K-alpha Radiation (mm) Unre- Lin Left Right I/I0- 4S 8 , Degrees solved '1 60.60 7.9.20 30 9.30 9.299 5.99 2 55.05 84.75 40 14.85 14.834 3.78 3 53.80 86.00 50 16.10 16.082 3.49 4 53.30 86.50 10 16.60 16.582 3.39 5 52.30 87.50 10 17.60 17.580 3.20 6 51.55 88.25 100 18.35 18.330 3.08 7 49.15 90.65 10 20.75 20.727 2.74 8 46.95 92.85 10 22.95 22.924 2.485 9 45.80 94.00 40 24.10 24.073 2.373 XO 44.35 95.45 10 25.55 25.522 2.246 11 42.90 96.90 10 27.00 26.970 2.134 12 41.30 98.30 100 28.40 28.368 2.037 13 38.00 101.75 20 31.85 31.815 1.836 14 36.70 103.15 30 33.25 33.213 1.767 15 35.75 104.05 50 34.15 34.112 1.726 16 35.30 104.50 70 34.60 34.562 1.706 17 108.40 10 38.50 38.457 1.556 1 18 c- 108.95 10 39.05 39.007 1.538 4S' 19 115.80 20 45.90 45.849 1.349 20 117.20 202.80 60 47.30 47.247 1.318 TABLE 69 (Continued) d-Spacings, 1 Scale Reading K-alpha Radiation (mm) Unre jjine Left Right I/In 4S' 0, Degrees solved 21 121.00 198.90 40 51.10 51.043 1.238 22 124.55 195.40 70 54.65 54.589 1.188 23 127.65 192.40 10 57.75 57.686 1.145 24 130.15 ' 189.85 10 60.25 60.183 1.116 25 132.25 187.75 10 62.35 62.281 1.093 25 140.10 179.90 30 70.20 70.122 1.029 27 142.35 177.65 10 72.45 72.370 1.016 248 TABLE 70 Measurement of Tilo Film and Calculation of d-Spacings Iron K-alpha Radiation; Camera Diameter 57.3 mm., Film in Asymmetric Position; Film Number 19A. Capillary Size, 0.3 mm., Exposure Time, 5 Hours. 2nd. Reading d-Spacings, K-alpha Radiation Scale Reading Unre (mm) 4S 6 y Degrees solved Line Left Right I Ac 9.348 5.96 48.65 67.30 30 9 3375 1 14.854 3.78 43.10 72.80 40 14 8375 2 16.007 3.51 41.95 73.95 40 15 9895 3 16.506 3.41 74.45 20 16 4875 4 41.45 3.23 75.40 20 17 4-375 17.457 5 40.50 3.08 100 18 2875 18.308 6 39.70 76.25 2.94 10 19 1875 19.209 7 38.45 77.15 2.74 20 20 6875 20.710 8 37.25 78.65 2.486 20 22 8875 22.913 9 35.05 80.85 2.369 50 24 0875 24.114 10 33.90 82.05 2.247 20 25 4875 25.516 11 32.45 83.45 2.138 20 26 8875 26.917 12 31.05 84.85 2.034 100 28 3375 28.419 13 29.55 86.35 1.831 20 31 8875 31.923 14 26.05 89.85 1.767 30 33 1875 33.224 15 24.80 91.15 1.728 50 34 .0375 34.075 36 23.90 92.00 1.708 70 34 .4875 34.526 17 23.35 92.45 4S 44.6375 44.687 1.376 18 102.60 20 45.7875 45.838 1.349 19 103.75 40 TABLE 70 (Continued) d-Spacings, Scale Reading K-alpha Radiation (mm) Unre- _Lir Left Right l/l0 4S* 6 , Degrees solved 20 105.20 50 47.2375 47.290 1.317 21 — 106.15 im 48.1875 48.241 1.298 22 106.95 — 48.9875 49.042 1.282 23 108.95 20 50.9875 51.044 1.245 24 --- 110.50 20 52.5375 52.598 1.218 25 112.50 183.30 50 54.5375 54.598 1.188 26 115.55 180.15 20 57.5875 57.652 1.146 27 118.00 177.75 20 60.0375 60.104 1.117 28 120.25 175.45 10 62.2875 62.357 1.093 29 128.00 167.75 40 70.0375 70.115 1.029 30 130.30 165.45 30 72.3375 72.418 1.015 TABXE 71 Determination of Lattice Constants and Miller Indices for Til3 1st Reading a0 ■ 7.177.fi; c0/a0 ■ 2.70; (a0/c0)2 «. 0.1372 d(obs.) (hkt) hf kf if (la„/o»)2 h2 + bk+k2 3(h2 + hk+lc2) E J a0 , A 8, Degrees * ['si~n'I* C°8 ^ d(calc,) z IS IS 3.49 110 1 1 0 1 0 3 3.9999 3.9999 1.9998 6.9796 16.082 3.311 3.59 3.20 105 1 0 25 0 3.4300 1 1.3333 4.7633 2.1825 6.9840 17.580 2.985 3.29 2.74 203 4 0 9 0 1.1748 4 5.3332 6.5080 2.5511 6.9900 20.727 2.445 2.81 2.373 205 4 0 25 0 3.4300 4 5.3332 8.7632 2.9603 7.0248 24.073 2.014 2.424 2.246 212 4 1 4 2 0.5488 7 9.3331 9.8819 3.1436 7.0605 25.522 1.859 2.283 2.037 300 9 0 0 0 0 9 11.9997 11.9997 3.4640 7.0562 28.368 1.596 2.072 1.767 330 4 4 0 4 0 12 15.9996 15.9996 3.9999 7.0678 33.213 1.243 1.794 1.706 310 9 1 0 3 0 13 17.3329 17.3329 4.1633 7.1026 34.562 1.160 1.724 1.349 410 16 1 0 4 0 21 27.9993 27.9993 5.2914 7.1381 45.849 0.642 1.356 1.238 500 25 0 0 0 0 25 33.3325 33.3325 5.7734 7.1475 51.043 0.476 1.241 TABLE 72 Determination of Lattice Constants and Miller Indices for Tilg 2nd Reading cos^Q cos i 0 sin 9 9 -d(calc.) d( obs.) (hk n i 30> A 9, Degrees 3.51 110 1.9998 7.0193 16.007 3.329 3.59 2.74 203 2.5511 6.9900 20.710 2.448 2.81 2.369 205 2.9603 7.0730 24.114 2.009 2.424 2.24-7 212 3.1436 7.0637 25.516 1.859 2.283 252 2.034 300 3.4640 7.0458 28.419 1.592 2.072 1.767 220 3.9990 7.0662 33.224 1.242 1.794 1.708 ' 310 4.1633 7.1109 34.526 1.162 1.724 1.349 410 5..2914 7.1381 45.838 . 0.642 1.356 X-RAY DIFFRACTION PATTERNS OF Til3 Figure 64; Film No. 1A, Copper Radiation Figure 65; Film No. 19A, Iron Radiation. 7J9 7 177 A 717 715 713 711 310 ^ 709 |205 I 707 ,220 z 100 705 **e 703 701 ,110 _I 697 0.25 0 .5 0 0 .7 5 1.00 1.25 1.50 1.75 2.00 2 .5 0 2 .7 5 3 .0 0 3 .2 5 3.50 ' cot1 > . C O * . * » I Figure 66. Determination of lattice constant, a0 for T ils XI. THEORETICAL DISCOSSION Titanium tetrahalides, like boron trifluoride, zirconium hafnium, tin and germanium tetrahalides, can be classed as Levis acids. That is, the compounds are capable of accepting pairs of electrons from molecules, atoms or ions shich have pairs of electrons to share. Compounds containing such elements as oxygen, nitrogen and sulfur, vhich have unshared pairs of electrons, are capable of acting as Levis bases. The formation of addition compounds or coordination complexes can be thought of as Levis acid-base reactions. These are not cases of highly ionized compounds reacting metathetically, rather, they are cases vhere a covalent compound forms a coordinate covalent bond vith another covalent compound. The forrmtion and stability of these addition compounds depends upon a number of other factors. A fev of these involve the radius of the central atom, electronegativity of the central atom and doner group, the number and type of stable unfilled orbitals of the central atom and steric factors vhich arise from the geometrical structure of the donor group. -256- Pauling-^7 reported the following values: Crystal radii Univalant radii Get4 0.535 0.765 Ti+4 0.68 0.96 Sn+4 0.71 0.96 and the metal to halogen distance for tha metal tetrahalides are reported-*-88 as follows: Sn Ti 5e Chloride 2.30b 2.18s 2.08b Bromide 2.44a 2.31a 2.29a Iodide 2.64a 2.51200 2.50a The values for titanium tetrahalides fall between those for the elements germanium and tin. Aocording to Pauling*88, the electronegativity, a measure of the pcwer of an atom to attract the electron pair in a covalent bond to itself, decreases from tin to titanium: Ge-1.7; Sn-1.7; Ti-1.6. From this alone, one would expect that titanium tetrahalides would exhibit only a slightly less tendency to attract electrons from a donor than Pauling, L., The Nature of the Chemical Bond, Cornell University Press, Ithaca, N. Y., 1940, p. 346. 188Hildebrand, J. Chem. Phys., 15, 727-36 (1947). (a) Lister, M. W. Sutton, L."-!!., Trans. Faraday Soc., _37, 393 (1941). (b) Brockway, L. 0., Rev. Mod. Phys., J3, 231-66 (1936). (c) Lipsoomb, N . , Whittaker, A. G., J. Am. Chem. Soc., _67,2019-21 (1945). 188Pauling, L., Ibid., p. 64. 2OO]}0utsch and Loonam, Consultants, 70 East 45th St., New York. Private communication. 257- would tin tetrahalides, although it is to be recognized that a difference of 0.1 unit in the electronegativity soale is of little significance. The electronegativity of the halogens are: chlorine 3.0; bromine 2.8; iodine 2.4. Thus, for a given metal to halogen bond, one Would expect the percent ionic character of the covalent bond to decrease from the chloride to iodide. The metal chloride compound Would form more stable addition compounds than the corresponding metal iodide compound; in other words, the.metal chloride would be a stronger Lewis acid than the corresponding metal iodide. The hydrolysis of metal tetrahalides is believed to be initiated by the coordination of a water molecule which weakens the metal to halogen bond sufficiently to allow complete hydrolysis to the oxide^Ol. This fact would then suggest ihat the tetrahalides of a given series Would show an increasing tendency to behave as acids with increasing atomic weight due to two factors; (l) the decrease in the energy difference between the orbitals which are available for coordination; (2 ) the coordination sphere of the metal atom of low atomic weight to be blocked off so completely by the halide atom as to prevent any reaction. The question as to whether there is sufficient space around the central atom of the tetrahalide molecule for another group to coordinate can best be approached through a consideration of radius ratio and coordination number. Pauling, in considering the formation of complex ions by the coordination of anions about cations, has made calculations based on the assumption that there is contact between all the coordinating groups and the central atom which indicate that a minimum value for the ^•^Sidgwick, N. V., "The Electronic Theory of Valency," Oxford 1927 p. 157. "•258- radius ratio exists below which a certain coordination number can not be achieved. Below this value for the radius ratio between cation and anion there is no more room around the central atom for more atoms to coordinate without anion to anion contact. The minimum value for the radius ratio which will allow a coordination number of six is given by Pauling202 as 0.414. Calculation of the radius ratio between the metal and halide ion is given in the following table: Ge Ti Sn Chloride 0.42 0.53 0.53 Bromide 0.39 0.49 0.49 Iodide 0.35 0.44 0.44 These values would seem to indicate that only the tetrabromide and tetraiodide of germanium would be unable to exhibit six coordination and the germanium tetrachloride would be borderline. Although the figures used in the above discussion assume purely ionic bonding, they may be assumed to apply in a general way even though the bonds in the tetrachloride molecule are largely covalent in character203. Brown and A d a m s 2 0 4 point out, on the basis of studies with boron trifluoride, that the basicity (ability to share electrons) decreases in the order of tetrahydrofuran, methyl, ethyl and isopropyl ethers. The difference in basicity of the various ethers can be attributed to several factors, all of which may operate simultaneously. Oxygen has an electronegativy of 3.0. However, the electron density or extent to which 202pauiing > Ibid., p. 382. ^O^Rice, 0. K., "Electronic Structures and Chemical Binding," McGraw and Hill Book Co., Inc., New York, 1940, p. 315. 204srown, H. C., Adams, R. M., J. Am. Chem. Soc. 64, 2557-63 (1942). -259- the atom is electrically satisfied is dependent upon resonance and inductive effeots created by the other atoms to which it is bonded. Resonance effects are considered to counteract the inductive effeots. A very basic ether should show a greater tendency toward formation of a complex than.one with low electron density about the oxygen. Also to be considered are steric effects, i.e., the extent to which the groups about the oxygen hinder the ether molecule from coming into contact with the metal tetrahalide molecule. Thu 3 , in the case of diethyl ether as compared to diisopropyl ether it might be that the electron density of the oxygen atom in diisopropyl ether would be greater than the electron density of the oxygen atom in diethyl ether due to inductive effects. However, because of the branched chains on the oxygen atom of diisopropyl ether one might expect steric hinderance to somewhat counteract the.'inductive effects. One would expect steric effects to be less significant in tetrahydrofuran tan diethyl ether, since both chains in tetrahydrofuran are, in a sense, tied back. It is generally accepted^® that the electron structures for the complexes of coordination number 6 fall into two classes; in one class, Which is designated as the "inner orbital" type, relatively stable d orbitals of lower principal quantum number (penultimate shell) are combined With the set sp3 of unit higher quantum number; in the other, designated as the "outer orbital" type, the_d orbitals have a consider ably lower stability, since they are of the same prinoipal quantum group of the ^s and jg orbitals with which they are hybridized. With these facts in mind, it is seen that titanium tetrahalides would act as stronger 2 0 5 Taube, H., Chem. Rev. No. 1, 50, pp. 85-6 (1952). -260- acids than the corresponding tin tetrahalides, since titanium would form the "inner orbital" bonding 3d24s4p3, and tin the "outer orbital" Q 2 bonding, 5s5p 5d . It is interesting to speculate about the possible structures these compounds might have. The predominate ratios of titanium tetrahalide to Lewis base in these compounds are>1:1 and 1:2. To obtain a consistent picture, each case Will be discussed in detail. In considering the addition compounds which form in a 1:2 mole ratio, it is possible to postulate^ six bonds as arranged symmetrically in space in three ways: to the corners of a regular octahedron, to those of a trigonal prism, or to those of a trigonal antiprism (an octahedron stretched or compressed along one of the trigonal axes). The octahedral bonds are formed by the configuration d^sp3 and no other. The prismatic arrangement2^ forms the valence configuration d^sp, where the two empty p orbitals of the metal atom cannot form strong ir bonds. The configuration d^p should also lead to the prismatic arrangement, but no examples are known. In the configuration, for the antiprismatic arrangement, p^d^, the octahedral symmetry should not be perfect. If however, the unshaired pair of _s electrons is promoted to a d orbital, and one of the valence pairs slips into its place, the configuration will be d2 sp3. The deciding factor here may be the possibility of double bond formation offered by the octahedral but not by -the antiprismatic arrangement. The con- \ figurations d^sp2 , d^s and d^s2 do not pemit any arrangement in which 206Kimballl G. E.f J. Chem. Phys. _8 , 188-98 (1940). 207Hultgren, R.f Phys. Rev. 40, 891-907 (1932). -261 all of -the bonds are equivalent. While the configuration d^sp^ might form bonds of a mixed type, that is, the tetrahedral d2s + the angular p2 , the bonds will be weak and the configuration unstable. Molecules Which might be expected to have this arrangement (Fe(CN)6 ) " 2 rearrange the electrons to obtain the more stable d2 sp2 configuration. For example in Fe(CN)0 the odd electron which normally should occupy a 4p orbital, instead goes to a 3d orbital making the third 4p orbital available for the formation of octahedral bonds. The 1:1 compound gives rise to three possible arrangments: 1) The formation of a long and/or branched chained polymeric structure, Where the TiBr^ molecules are linked together through the Lewis base. A determination of the molecular weight would resolve this suggestion. It is to be observed that the addition compound TiBr4 *Dioxane is monomeric as determined from cryoscopio measurements. 2) A coordination number of five is unusual20® for almost any element and this rarity is presumably due to the fact that there is no symmetrical arrangement of five atoms around another which corresponds to a minimum radius ratio intermediate between the minimum values for 4- and 6 - coordination. There are four bond arrangements possible for a coordination number of five. The stable configurations for a trigonal bipyramid are dsp2 and d®sp. The bonds directed from the center to the corners of a square pyramid, a tetragonal pryramid, give rise to the arrangement expected for the configurations d2 sp2, d^s, 208 Wells, A. F., Structural Inorganic Chemistry, Oxford, 1950, p. 90. -262- and d^p. Five bonds in a plane directed toward the corners of a regular pentagon give the arrangement for the configuration d^p^. The arrangement for the configuration d® would correspond to the case of five bonds directed along the slant edges of a pentagonal pyramid. Wells states that the only well established arrangement of five bonds formed by an atom is the trigonal bipyramidal configuration. Thus, in the formation of the addition compound there would be a conversion from a tetrahedral structure to this trigonal bipyramid. Physically, this might involve a slight shift in bond angles and bond distances but would not require an actual rearrangement of atoms. 3) On closer inspection of the Lewis acid-base reaction which results in the formation of the 1 :1 compound, it is observed that the Lewis base is always bidentate, that is, there are two centers of high electron density per molecule of base. Thus, even though the 1:1 compound appears to be five-coordinated, the possibility of six-coordination can not be ruled out since the bidentate Lewis base could conceivably occupy two sites in the octahedral configuration. In conjuction With the postulate that the 1:1 compound could conform to the octahedral configuration, it seems imperative to determine the bond distances in one molecule of a known 1 :1 compound, for example TiCl^'C^gC^. The main objective of this investigation is to calculate the oxygen-oxygen bond distance in 1,4-dioxane to see if one molecule could act as a bidentate group and fill the six-coordination sphere of -263- titanium in TiCl4 *C4 Hg(J2 » To make this calculation, it is necessary to utilize data as determined for 1,4-dioxane as it occurs in the normal state, the chair form, and assume that no oxygen-to-oxygen repulsion occurs. Inasmuch as only the order of magnitude of the bond is desired, this assumption will not effect the calculations. The following data have been reported'^’ for 1,4-dioxane! Sutton and Hassel and Brookway Viervoll C-0, bond distance, 1.4615 1.4215 C-C, bond distance, 1.51.8 1.54$ o C-C-0, bond angle, 109.5° 106.0 Calculations made utilizing data reported Oxygen-Oxygen bond distance ______by . boat chair Sutton and Brockway 2.488 3.7oJ? Hassel and Viervoll 2.32 3.58 If we assume the structure of one molecule of TiCl^'C^Hgl^ to be octahedral, then utilizing the following data it is possible to calculate the distance between adjacent chlorine atoms in the octahedral configuration. Since all six bonds are equivalent, the distance between adjacent chlorine atoms must be of the same order of magnitude as the 2ii oxygen-oxygen bond distance in 1,4-dioxane. Lipscomb and Whittaker 4-4 0 report the octahedral radii for Ti to be 1.36A. This was calculated from observed values of interatomic distances in complex ions such as (SnClg)”2 an<3 from crystals such as TiSg which has the Cdl2 structure. 2Q®Stitton, L. E., Brockway,„L. 0., J. Am. Chem. Soc. J57, 473-83 (1935). ^lOgassel, 0 ., Viervoll, H., Acta Chem. Scand.,^1, 149-68 (1947). ^llLipscomb, W. N., Whittaker, A. G., L og. Cit. -264- These correspond, not to d^sp3 bonds involving d orbitals of the shell within the valence shell, but to sp3d2 orbitals where use is made o$ the unstable d orbitals of the valence shell itself. Pauling3^ reports the bond distance to be 1.9845 for the chlorine molecule and the tetrahedral covalent radius of chlorine to be 0.99,5. This results in the distance between adjacent chlorine atoms of 3.325 in TiCl4 *C4 Hg0 2 . To carry the analogy further, it would be interesting to observe the ■ 212 distance between adjacent bromine atoms in T i B ^ ^ H e ^ . Pauling reports the normal covalent bromine-bromine band distance to be 2. 28.5 and the tetrahedral covalent radius of bromine to be l.llS. The small difference in the bond distance (0.035) may be due to the difference in the nature of the bond orbitals in tetrahedral and normal covalent compounds. This results in the distance between adjacent bromine atoms o of 3.49A in TiBr^'C^gt^. Thus, it would appear that if one molecule of 1,4-dioxane reacts with one molecule of titanium tetrahalide to give the octahedral conf iguration, the 1,4-dioxane must exist in the chair form which has the necessary oxygen-oxygen distance. From the foregoing discussion, one can arrive at the following conclusions: 1) The electronegativity of the metals in question is of little importance. 2 ) Tin tetrahalides are more acidic than the tetrahalides of silicon and germanium. Sisler213,2^ jet _al. reported that tin 2 1 2 p a u lin g , Loc . _C it. , p. 165, 179. 213sisler, Et. "K., et al., J. Am. Chem. Soc.,J70, 3818-21 (1948). 214 Sisler, H. H., et al., ibid. 70, 3821-4 (1948). ••26 5“ tetrachloride readily forms stable molecular addition compounds in the solid state with various ethers, whereas silicon and germanium tetrachloride do not exhibit this tendency. 3 ) Titanium tetrahalides are more acidic than tin tetrahalides due to the fottnation of the more stable "inner orbital" configurat ion. 4) The metal tetrachloride is more acidic than the metal tetraiodide. Pfeiffer^-*-® reported the stable S n C L j ^ ^ H s ^ O and Sisler*^®, et al. reported the thermally unstable SnBr4 *2 (02115)20 and observed no reaction between Snl4 and (c2H5)20* 5) The consideration of radius ratio indicates that titanium and tin tetrahalides should exhibit the same reactivity in the formation of six-coordinated compounds. Sisler reported the preparation of SnBr4* 2 (0 2 ^ ) 2 0 and Oberhauser'^ prepared the TiBr4 ‘2(C2H5 )20. 6 ) One molecule of 1,4-dioxane can react with one molecule of TiCl4 or TiBr4 and yield the octahedral configuration only if the 1,4-dioxane exists in some configuration similar to the chair form. The distance between adjacent chlorine atoms of 3.325 and between adjacent bromine atoms of 3.49$ in comparison to the oxygen-oxygen distance of 3.6-3.75 in 1,4-dioxane provides an interesting if not convincing agreement for the octahedral configuration. ^■^Pfeiffer, Z anorg. Chem., j87, 335-53 (1914). 2^®Sisler, H. H. _et al., J. Am. Chem. Soc.,_73, 426-9 (1951). '^Oberhauser, F,, STctwrmuller, J., Bar. 62, 1436-41 (1929). XII. SUMMARY Three addition compounds of titanium tetrabromide have been prepared* the blood red TiBr^Dioxane; the brownish-red TiBr4 »2Tetrahydropyran and the brownish-red TiBr4 *2Totrahydrofuran• Only the compound With tetrahydrofuran was prepared from the excess of either reactant. All three compounds are extremely hygroscopic and are readily hydrolyzed. They do not, however, undergo decomposition when stored for prolonged periods under their own vapor or inert gas. The compound TiBr4*Dioxane is monomeric as determined cryoscopically. Mole ratios of the addition compounds Were ascertained by analytical techniques and indirectly corroborated by determination of the neutralization equivalent weight. This latter technique is quite adaptable to transition metal tetrahalides and affords a simple, quick and relatively accurate method of analysis. The technique and precision of this method was checked on pure samples of TiBr4 and Til4. Infrared spectrograms were obtained on the solid addition compounds mulled in Nujol and serve to characterize the three compounds. A comparison is made of the spectrogram of the pure ether and the addition compound. This comparison definitely indicates the formation of a bond at the ring oxygen position and eliminates any suggestion of the formation of an alkyl titanate. Chemical analysis has eliminated the possibility of the formation of a bromo alkyl titaratd since the analytical technique successfully differentiates ionic from covalent bromine. - 266 - -267- X-ray diffraction patterns were obtained on samples of various titanium bromides and iodides, and from their addition compounds. The lines were indexed, the axial ratios, lattice parameters determined, and the d-spacings corrected for absorption effects. The addition compounds crystallize in a tetragonal structure and are isomorphic. The absorption correction was found to be appreciable as determined from the investigation of two titanium compounds (Ti02 and TiBr^,) of known structure and lattice parameters. Titanium tetraiodide did not form any detectable addition compound with either 1,4-dioxane or tetrahydrofuran. A reaction did occur as evidenced by the decomposition product with 1,4-dioxane and the formation of a very viscous liquid with tetrahydrofuran. Titanium tetraiodide, which crystallizes in a body centered cubic structure was prepared and purified by two independent techniques and the X-ray diffraction patterns were identical. Thus, the possibility of a different crystal modification due to temperature gradients and/or rate of crystal formation was eliminated. Titanium triiodide was prepared and the pure solid irradiated with X-rays. The resulting diffraction pattern was found to indicate ah hexagonal structure and the value for the lattice parameter, aQ, is in essential agreement with the values determined for related compounds. TiBr^ and Til^ react with tetrahydrofuran to give very viscous liquids with mole ratios of metal to halogen of approximately 1 to 3.5. This Would indicate loss of inorganic halogen either by direct loss as hydrohalogen acid or converted to organic halogen. XIII. SUGGESTED RESEARCH PROBLEMS (1) The infrared absorption of pure TiBr4 . (2) X-ray study on a single crystal of TiBr3 and Til3 « This would follow the present investigation on TiClg by Mr. John Reed. (3) The determination of the melting point of 1,4-dioxane. Literature values vary by several tenths of one degree. (4) Purify tetrahydropyran and tetrahydrofuran by distilling from a hydride, CaH2 or L1A1H4 and then reacting the ether with TiBr4 . (5) Investigate the structure of the two viscous liquids obtained as a result of the reaction between TiBr4 and C4 HgO as Well as Til4 and C4 HgO. (6 ) In light of references 17, 61 and 62, a study of the reaction between TiBr4 and both PBr3 and P0Br3 would be interesting. (7) There appears to be some doubt as to whether a Lewis base containing a hydroxyl group adds to or reacts with the metal halide. Note references 6 , 56, 80 and 111. (8 ) Reference 5 points out that there is little reaction between FeCl3 and dioxane as determined from dipole moment measurements. This appears to be quite add, since FeCl3 ^as necessary orbitals available for coordination. (9) ( ^ 3 )3 0 reacts mole for mole with a metal halide while (CH3CH2 ^2 ° reacts two moles of ether per mole of metal halide. A recheck of this might prove interesting. - 268 - APESNDIX I PURIFICATION OF TiBr4 BY BATCH DISTILLATION The fundamental material-balance procedure218 of Bayleigh Was used in the following calculation. Consider any instant during the distillation when the mole fraction of the more volatile component in the still is Xs, and there are J3 total moles of material remaining in the still. At this instant, assume that the vapor in equilibrium with the mixture in the still will y » Xp, and in a perfect simple distillation Will give distillate of this same composition. After a very small amount of this distillate (dS molesJ is collected, the total moles remaining in the still will be S-dS and the composition in the still will have changed slightly to Xs - dXg. It follows that: SXg b (S-dS) (Xs-dXs) + XDdS (1) The above equation ma.y be multiplied out and simplified, dropping out the negligible second-order differential dSdXs. After rearranging terms, this becomes SdXs = dS (XD-XS) (2 ) (3) 218 Rayleigh, 0. M.t Phil. Mag. 4, (6 ) 521-37, (1902). -269- -270- 0n integration between the limits of Sj and where, _i signifies initial and f signifies final *f rt dS — I dX tD-i, ■f dX, (5) Perry2*9 points that the material balance on the more volatile component can be expressed by V n B Ln+lXnfl+DXD Tn = V l + D « T„ ■ igliWt - # *D <8) n v« and substituting the value of Vn from equation 7 into equation 8, x° (9) where the symbols have the significance: Yn mole fraction of more volatile component in the vapor, Vn V moles of vapor passing from plate to plate n to n plate n+1, per unit time ^n+1 moles of liquid overflow from plate n + 1 to plate n per unit time 2*9Perry, J. H., Chem, Eng. Handbook, McGraw-Hill Book Co., Inc., New York, N. Y., 1950, page 581-591, D moles of overhead distillate withdrawn per unit time xn + l mole fraction of more volatile component in overflow, Ln + i mole fraction of more volatile component in overhead distillate R - ^n + 1 moles of reflux per unit time Using the expression, ® RD in conjunction with equation 9, RD Yn b r ST d X + fiD+D XD (10) (11) For a binary mixture the (y-X) relationship in terms of relative volatility is aX (12) Yn = 1 +ta-l)X In general the term "volatility" is used to compare the vapor pressure of one pure substance with another, the substance having the higher vapor pressure at a given temperature being tenned the mole volatile. Relative volatility is a direct measure of the ease of separation of components by a distillation process; hence, substances that are readily separate show larger values of ji. An ja of unity means no separation is possible. Equating of equations 11 and 12 -272- 1 t aX R TTFi XD b X + (a-i)X " R+X X V - (R + l)(aX) nv T-fik-nr- ^ xn * (R-t-Dax . RX D I -f (a - n s v _ RaX+aX - RX - RX2(a-I) xD r+Ta-nx ------ Xn = (Ra -f- a - R - RX (a-1) Lat B B Ra + a - R Xn 5 X (B-RX(a-X) (14) D " T + (a-i;x Substitution of the vaXue for Xp as expressed by equation X4 into equation 5 Xeads to the foiiowing expression which can be integrated as shown: rf dX« Ctxfi -X, * * ¥ s i XD “Xs i rf X n ^ f B dXg Ll+(a-l)Xs] S-? Xs [B-RXg(a-lO -Xs of [X+(a-i)Xs] dXs _ (B'-i)Xs‘ 'X|(a-1)(R+1) -273- dXs I dXs (B-1)XS - x|(a-i)(R + l) I CB-1) - Xg(a-l)'(R+l) 1 A n i l * _ Hn XS a-1 Jin Si B-l B-l-(a-l)xs(R+iJJ + CH + t)Ca-T7 1,1 jjn B-l-(a-l)Xsf(R+l) *"4? 1 J U * | f - l B-l x si B-l + R+i B-l-(a-l)Xs.(R+l) Let C = B-l b (R+l)(a-l) I n C-(a-l)XSf (R+l) H i - — J? n x sf - 1. (15) X f R + l C-(a-l)X^(R+iJ Ffhan R B 3, Xg. s 0.006 and a ■ 6.9, equation 15 reduces to the form: log 0.0424 log XSf -0.375 (23.6-17.7XSf)+0.6084. (1 6 ) The batch distillation was carried out by discarding the first 25 per cent overhead, collecting the next 50 per cent and leaving the remaining 25 per cent in the still pot. The value of X s^ at Ss/Si - 0.75 Was determined by assuming values of Xsj and solving equation 16 for the ratio of Sf/S^. A plot of log X g^ versus Sj/S^, Figure 67, was made and the value of XSj equal to 6.7 x .10”® mole fraction determined graphically. This goes into the overhead. The next 50 per cen taken off will contain (75 x 6.7 x 10"®)/50=1.0 x 10"® mole fraction TiCl4. Thus, it is obvious, that the distillation as carried out is quite satisfactory for the purification of TiBr4. -274- 0.4 0.5 0.6 0.7 0.8 0.9 Sf Figure 67. Graphical determination S f/Sj APPENDIX II MOLE FRACTION OF FREE BROMINE IN TITANIUM TETRABROMIDE The preparation of titanium tetrabromide from the direct reaction of metallic titanium and liquid bromine produces a solution whose boiling point varies with the mole fraction of liquid bromine. Although the absolute bromine impurity in the TiBr4 at the end of the reaction was not determined, an approximate value can be calculated. If the solution is assumed to be ideal, that is, obeys Raoult’s law over the whole range of concentration, then the partial vapor pressttre of any constituent is proportional to its mole fraction in the liquid at all compositions and PA * PA°XA where P^ is the partial pressure of constituent "A" of the solution p£° is the vapor pressure of pure constituent "A" is the mole fraction of constituent "A” in the mixture, the total pressure^® of the mixture of gases is then equal to the sum of the partial pressures of the constituent gases, (Daltons Law of partial pressures). ptotal B pTiBr4 + pBr2 Ptotal = P°TiBr4 X TiBr4 + P °Br2 XBr2 ^°The value for the total pressure is dependent on the accuracy in the extrapolated vapor pressure of liquid bromine. -275- -276- 2 TiBr4 + XBr2 s X xTiBr4 " 1 ” XBr2 Ptotal B ^1 "XBr2 )p°TiBr4 + p °Br2 xBr2 The vapor pressure of liquid bromine can be expressed32'1- by the equation log1 0 ^ ^ " 3 *4 4 9 l 0 6 T + 1 7 *071 and the vapor pressure of liquid TiBr4 can be expressed2 .22 by, the equation log1 0 Prnrn - 3.8117 log T + 19.4998 Utilizing these equations the mole fraction of bromine in the TiBr4 solution can be calculated for any boiling temperature of the solution. The result of this calculation is found in Table 73 and Figure 58. TABLE 73 Mole Fraction of Br2 and TiBr4 at Various Temperatures T°K P°Br2 p 0TiBr4. ptotal NB r j_ NTiBr4 331.45 760 760 1 . 0 0 . 0 340.0 1005 3.0 760 0.755 0.245 350.0 1361.4 4.9 760 0.557 0.443 370.0 2360.5 12.4 760 0.318 0.682 400.0 4775.3 40.8 760 0.152 0.848 430.0 8610.0 111.5 760 0.076 0.924 460.0 14126.0 262.7 760 0.036 0.974 485.0 19975.0 488.6 76 0 0.014 0.986 504.76 760.0 76 U 0 1 223-Wright, f j' Chem. Sqg., 109 1137. 2 2 2 o f f i C0 Naval Research Contract Nonr. - 1120 (00) Status Report No. 2, July 1, 1954. Temperature in degrees kelvin iue Ml faci Br i Ti ..s fnto o t at e ( es e 760 mm) m m 0 6 7 = re ressu (p re tu ra e p m te of function a ,.0.as r iB T in r, B f o n ctio fra Mole . 8 6 Figure 0 3 3 0 5 3 0 7 3 0 9 3 0 5 4 0 3 4 0 7 4 0 9 4 410 510 0.2 0.3 z( 8 ) 0.4 l facton o Brg B of n tio c fra ole M 0.5 0.6 0.7 0.8 0.9 APPENDIX III. ANALYTICAL PROCEDURE Determination of titanium and halogen (Br,I) in either the pure tetrahalide or addition compound was accomplished with the following analytical scheme. The sample, stored under an inert atmosphere of argon, was w e ired and transferred to a glass stoppered Erlenmeyer flask which contained 300 ml. of chilled (0°C.) distilled water made alkaline with freshly filtered ammonium hydroxide. Reaction was instantaneous with the formation of the hydrous oxide Ti(0H )4 and HBr. Cooling was necessary to remove the heat generated from the hydrolysis reaction Which would tend to decrease the solubility of HBr. The ammonium hydroxide effectively reduced the loss of HBr by lowering its escaping tendency. The White flocculent precipitate of Ti(0H )4 was filtered on ashless filter paper with the filtrate and wash water collected in a volumetric flask. It is to be noted.that this precipitate does not dissolve in an excess of alkali to form a titanate (TiOp, is readily soluble in acids when freshly prepared from cold solutions and acid insoluble when formed from warm solutions. The precipitate was heated to 800°C. in a tube furnace and the titanium determined as Ti02. The filtrate Was diluted to exactly 500 ml. Aliquots of 100 ml. were removed, acidified with dilute HNO3 , an(^ an excess of standardized silver nitrate added to form the insoluble silver halide. The solubility of silver bromide is 0.008mg./100 ml. of H2 O, silver iodide is 0. 0003mg./100 ml. of HgO at 20°C. and the silver precipitates as the oxide at a pH of 9. The silver halide can be treated - . • -278- -279- in two ways; removed by filtration and the halide ascertained gravimetrically, or removed by coagulation with nitrobenzene and analyzed volumetrical ly. One ml. of nitrobenzene was added for each 0.05 gram of bromide and two milliliters of a saturated solution of ferric ammonium sulfate containing a little halide free nitric acid was added for each 100 ml. of solution. The quantity of excess silver nitrate Was determined by titrating with a standard solution of potassium thiocyanate, the end point established at the first appearance of the faint brownish red tinge of FQ(CN)g. The problem of the silver bromide reacting with the KSCN was diminished since the silver bromide is less soluble than AgSCN (solubility of 0.013 mg./lOO ml. of H 2 O at 2 0 °C.). APPENDIX IV. DERIVATION OF THE BRAGG EQUATION FROM THE "REFIECTION" ANALOGY The atomic or molecular units in a crystal lie at the intersections of a space lattice, the prominent Grystal faces are those most thickly populated with lattice points (atoms or molecules), and that parallel to every possible crystal face or plane is a series of equispaoed identical planes. When a beam of X-rays strikes an extended crystal face and is reflected in the Bragg sense the phenomenon is not a surface reflection, as with ordinary light. Parallel to the face is an effectively infinite series of equispaoed atomic planes which the X-rays penetrate to a depth of several million layers before being absorbed. At each atomic plane a; minute portion of the beam may be considered to be reflected. For these tiny reflected beams to emerge as a single beam of appreciable intensity, they must not be absorbed in passing through layers nearer the surface as they emerge, and, far more important, the beams from successive layers must not interfere and destroy each other. If conditions can be arranged so that reinforcement, rather than destruction, occurs, all planes in the series that are not too deep, in the crystal would contribute to the reflection. Bragg demonstrated these conditions in the following manner. -280- -281- Consider -the lines pp, PiPi» P2P2> e'tc* of figure “to represent the tra:ces of a series of atomic planes of constant iirterplaner / { spacing d parallel to a crystal face. AB, A-B is a train of incident X-rays of wavelength X impinging on the planes and reflecting off in the direction CD. For the reflected wavelet from B1 -to reinforce the one reflected at C, it must arrive at C in phase with the wave ABC. This will be the case if the path difference is a whole number of wavelengths, that is if jeJ~C-BC s nX By trigonometry B1 C = d/sin 0 and BC b B1 C cos29 b d(cos20)/sin9 Substituting the value for 30 and B* C into B1 C-BC s nX d/sin 0 - d(cos 26i)/sin9 E nX -282- ■ £ IT 9 [ x - cos 2 e ] S n X but 1-cos 2 6 s 2 sin'* 9 nX r 2a sin e This is the Bragg Equation, also known as Braggs law. For a crystal of a given d-spacing, and for a given wavelength the various orders n of reflection occur only at the precise values of angle 9 which satisfies the equation. At other angles there is no reflected beam because of interference. AUTOBIOGRAPHY I, Robert Fredrick Rolsten, was born in Fort Wayne, Indiana, February 6 , 1925, I received my secondary school education in the public schools of Columbus, Ohio. I attended the Ohio State University for one quarter before enlisting in the Aviation Cadet Training Program of the United States Army Air Force. I received my wings and commission as an Aerial Navigator and held this position for the following 13 months while attending various training schools of Aerial Bombardment and Radar. Upon separation from the Air Force in 1946, I enrolled in Capital University from which I completed my undergraduate training and received the degree Bachelor of Science in 1948. After graduation I began graduate training at the University of Connecticut where I accepted an appointment as assistant in the Department of Chemistry. I held this position until the fall of 1950 when I returned to the Ohio State University to continue graduate work in chemistry and also accepted the position of principal chemist at Battelle Memorial Institute. This position was held while completing the requirements for the Degree Doctor of Philosophy.