University Microfilms, a XEROX Company, Ann Arbor, Michigan the SYNTHESES and COORDINATION PROPERTIES of SOME

Home , Locking (dance), T36 (classification)

ELLER, P h i l l i p G ary, 1947- THE SYNTHESES AND COORDINATION PROPERTIES OF SOME 1 , 2 ,3 , 4-TETRAFLU0R0PHENYLPH0SPHINE LIGANDS AND THE CRYSTAL STRUCTURES OF A TRIGONAL PLANAR COPPER COMPLEX AND A TETRAHEDRAL NICKEL NITROSYL COMPLEX.

The Ohio State University, Ph.D., 1971 Chemistry, inorganic University Microfilms, A XEROX Company, Ann Arbor, Michigan THE SYNTHESES AND COORDINATION PROPERTIES OF SOME

1 ,2 ,3, fI--TETRAFLUOROPIIEN YLPHOSPHINE LIGANDS

AND THE CRYSTAL STRUCTURES OF A TRIGONAL

PLANAR COPPER COMPLEX AND A TETRAHEDRAL

NICKEL NITROSYL COMPLEX

DISSERTATION

Presented in F artial Fu3i*illment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University

Phillip Gary Eller, B.S.

•it V e if- -it-

The Ohio State University 1971

.Approved^ v V V J .by u j J j MstryU iV » A dviser Department of Chemistry

PaJR.Gjy» ■ Aidviser Department of Chemistry PLEASE NOTE:

Some pages have indistinct print. Filmed as received.

University Microfilms, A Xerox Education Company ACKNOWLEDGMENTS

The author wishes to express his deep appreciation to

Dr. Devon W. Meek for his invaluable suggestions and encouragement throughout the synthetic and spectral investigations, and in particular for his willingness to permit a large degree of independence to the author in his studies. The author is indebted to his co-adviscr,

Dr. P. W. R. Corfieid, for his infinite patience, encouragement, and invaluable suggestions throughout the crystal structural studies. The opportunity to do x’esoarch under two advisers has provided a rich and enjoyable study environment and the coadvisers mutual cooperation is deeply appreciated.

The author also wishes to express his appreciation for fellowship support in the form of an NDEA Title IV Fellowship and Lubrizol

Industrial Fellowships.

Finally, the author acknowledges postdoctoral fellows and fellow graduate students in both Dr. Meek's and Dr. Corfield* s group for many stimulating and enlightening discussions.

i i VITA

18 August 1 9 ^ 7 ...... Born - New M artinsville, Nest V irg in ia

1967 ...... B.S. (Chemistry), West Virginia U n iv e rs ity

1967-1969 ...... NDEA T itle IV Fellow, The Ohio State University, Columbus, Ohio

Fall, 1969 ...... Teaching Assistant, Department of Chemistry, The Ohio State University, Columbus, Ohio

1969-1971 ...... L u b rlz o l I n d u s t r i a l Fellow , D ep art ment of Chemistry, The Ohio State University, Columbus, Ohio

PUBLICATIONS

' 'Syntheses of New Tetrafluoroaryl Derivatives of Phosphorous and Sulfur1 1, P. Gary Eller and Devon W. Meek, Journal of Organometallic Chemistry, 22, 63I (1970).

' 'The Crystal Structure of a Trigonal Planar Copper Complex’', P. Gary E ller and P. W. R. Corfic Id, Chemical Communications, IO 5 (l9 7 l)*

FIELDS OF STUDY

Major Field: Inorganic Chemistry

Studies in Coordination Chemistry, Professor Devon W. Meek

X-ray Crystallography, Professor P. V/. R. Corfield

i i i TABLE OF CONTENTS

ACKNOWLEDGMENTS...... "... i i

VITA ...... i i i

LIST OF TABLES...... v i i

LIST OF ILLUSTRATIONS • ...... x i

PART ONE - THE SYNTHESES AND COORDINATION PROPERTIES OF SOME 1 ,23 lf“T3TRAFLU0R0PHENYLPH0SPHINE LIGANDS I. INTRODUCTION...... 1 A. Background B. Steric and Electronic Effects of the Perfluorophenyl Ring C. Previously Studied Coordination Compounds Containing Perfluoro-carbon Ligands D. Fluorine Nuclear Magnetic Resonance Studies

II. EXPERIMENTAL...... 28 A. Chemicals B. In stru m e n ta tio n C. Fisnmr Measurements D. Elemental Analyses and Molecular Vfeight Determinations E. Gold Analyses F. Synthesis of Ligands and Intermediates G. Preparation of Coordination Compounds of FSP-CH3 H. Preparation of Coordination Compounds of SP-CII3 I. Preparation of FDP and FTP Complexes J. Miscellaneous Preparations K., Space Group Determination of Ni(FSP-CIT3)2(NCS )2

I I I . RESULTS AND DISCUSSION...... T9 A. Ligand Synthesis B. C o o rd in atio n Compounds o f FSP-CH3 and SP-CH3 1. N ickel(ll) complexes of FSP-CH3 and SP-CH3 2. Palladium(ll) complexes of FSP-CII3 and SP-CII3 5- Rhodium and irid iu m com plexes o f FSP-CH3 and SP-CH3 If. Gold com plexes o f FSP-CH3

iv C. N ickel(ll) Complexes of FDP D. N ickel(ll) Complexes of FTP E. F19 Nuclear Magnetic Resonance Studies of Dimethylpentafluorophenylphosphine Derivatives and Complexes 1. Background 2. F19 and H1 nmr studies F. F'19 Spectra of 1,2,3, ^-Tetrafluorophenyl Compounds

IV. REFERENCES...... 223

PART TWO - THE CRYSTAL AND MOLECULAR STRUCTURE OF TRIS- (TRII'ETHYLPHOSPimre SULFIDE) COPPER(I ) PERCHLORATE

I. INTRODUCTION ...... 237

A. Ter-coordination in Metal Complexes B. Tris(trimethylphosphine sulfide)copper(l) Perchlorate

I I . EXPERIMENTAL ...... 2kQ

A. Instrumentation and Computer Programs B. Preparation of [Cu(SP(CH3)3)3]C10(i. C. Crystal Selection D. Space Group Determination ---- E. Absorption Coefficients F. Determination of Accurate Cell Dimensions for Ccu(sp(ch3)3)3](cio4) G. Intensity Data Collection

I I I . DATA PROCESSING, STRUCTURE SOLUTION, AND REFINEMENT...... 253

A. Data Processing and Solution of the Phase Problem B. Structure Refinement; the Disorder Problem

IV. DISCUSSION OF THE STRUCTURE OF [Cu(SP(CH3 )3 ) 3 ] ( c i0 4 ) .... 289

V. CONCLUSIONS...... 3°6

VI. REFERENCES ...... 31°

v PART THESIS - THE CRYSTAL AND MOLECULAR STRUCTURE OF NITRCS YL-1,1 , 1-TRIS (DIET H YLPl ICS PHINO)- ETHANiSNICKEL TETRAFLUOROBORATE

I . INTRODUCTION...... 316

I I . CRYSTAL SELECTION AND PRELIMINARY EXAMINATION, DATA COLLECTION, AND DATA REDUCTION...... J2k

A. Preparation of Ni( tep) (NO)bF4 B. Crystal Selection and Space Group Determinations of Ni(tcpJ(NOJ b F^. and Ni(tep)(NO)l C. Determination of Accurate Cell Constants for Ni(tep)(NO)BF4 D. Intensity Data Collection E. Data Reduction

I I I . STRUCTURE SOLUTION AND REFINEMENT...... 332

A. Initial Refinements B. Absorption Corrections and Averaging of Equivalent Reflections C. Intermediate Refinements D. Determination of the ’'handedness1' of the Crystal and Examination of the Weighting Scheme E. Final Refinements with the Inclusion of Lagrange M ultipliers

IV. DISCUSSION OF THE STRUCTURE OF [N i{tep)(N O )]BF.t ...... 357

A. Crystal Packing + B. The Geometry in the [Ni(tep)(NO)] Cation C. The Geometry in the Disordered Anion

V. CONCLUSIONS...... 378

VI. REFERENCES ...... ■...... 38O

vi LIST OF TABLES PART ONE T able Page

1. Representative opphenylene ligands ...... 3

2. Selected properties of fluorine, chlorine, and h y d ro g e n ...... 5

3. P31 ninr shifts in pentafluorophenylphosphines ...... 12

l|-. Comparison of least-squares refined F19 chemical shifts and coupling constants determined in this study with those in reference 226 ...... 32

5* F10 chemical shifts and coupling constants in some 1,2,3,^ tetrafluoroaryl compounds ...... 85

6. Fluorine 19 chemical shifts in symmetrically disubstituted 1,2-tetrafluoi’obenzene compounds ...... 86 4 7- Molar conductivities and magnetic moments for N i(ll) com plexes o f FSP-CH3 ...... 99

8. Molar conductivities and magnetic moments for N i(ll) com plexes o f SP-CII3 ...... 100

9- Electronic spectra of Ni(ll) complexes of FSP-CH3 . . . 101

10. Electronic spectra of ili(ll) complexes of SP-CII3 .... 102

11. The solid state electronic spectra of nickel(ll) th io c y a n a te com plexes o f FSP-CH3 and SP-CH3 ...... 121

12. Molar conductivities and electronic spectra of p a lla d iu m ( ll) com plexes o f FSP-CH3 and SP-CH3 ...... 130

13. Proton nuclear magnetic resonance spectra of PdLX2 com plexes, L= FSP-CH3 and SP-CH3 ...... 135

lH. Characterization data for [Rh(FSP-CH3)ci(co)] and [Rh(SP-CHo)cl(C0) ] ...... ’ ...... llf l

15. Electronic spectral and conducitivity data for nickel(ll) FDP complexes ...... 155

16. Visible electronic spectra of planar NiLX2 complexes . . l6h

v ii rag<

Electronic spectral and conductivity data for n i c k e l ( i l ) FTP com plexes ...... 1T0

Visible electronic spectra of nickel(ll) complexes of FTP, TP, and DPP ...... 178

1H nuclear magnetic resonance data of palladium (II) complexes ...... 181

P31, H1, and F18 coupling constants and chemical shifts in I» and Lp derivatives ...... m

Nuclear spin-spin transitions in one-half of an AA'XX1 nnu’ s p e c t r u m ...... - ...... 187

Temperature dependence of F13 chemical shifts and coupling constants in (CH3)2p{o)(C3F5) ...... 193

Temperature dependence of F13 chemical shifts in Pd[(CH3 )2P (cQF5 ) ] s ...... 193 Concentration dependence of Fla chemical shifts and c o u p lin g c o n s ta n ts in [Pd(CtsFs Pf-fc2 )2Cl2 ] ...... 195 H1 and F18 coupling constants and chemical shifts in M(Lp)2X2 Cm- Ni,Pd,Pt) complexes ...... m

Fluorine-19 chemical shifts and coupling constants in sane substituted perfluorophcnyl compounds ...... 2lh

Fluorine-19 chemical shifts and coupling constants in symmeti'ic o-CgF

Fluorine-19 chemical shifts and coupling constants in in complexes of FSP-, FSP-CII3, and FDP ...... 216

v ii i PART TWO T ab le ‘ Page

29. Crystal structure of three-coordinate metal complexes . . 2 3 8

3 0. Phosphorous-sulTur and phosphorous-carbon bond lengths in trimethylphosphine sulfide and related compounds . . . 24?

3 1 . Various stages in the refinement of [Cu(SP( 0 1 3 ) 3 ) 3] “ CIO4 • 274

32. Final fractional coordinates and thermal parameters with their standard deviations for [Cu(SP(CH 3 )3 )3 ](C 104 ) . . . 276

3 3 . Weighting analysis after the final cycle of refinement. . 278

34. Final structure factors ...... 279

35* Distances and angles in the C11S3P3 coordination sphere. . 290

3 6 . Bond lengths an^ angles about phosphorous in the [Cu(SP(CH3 )3 )3] cation ...... 291

37. Bond distances and angles in the disordered perchlorate

3 8 . Selected interatomic distances averaged over thermal motion using the 11 riding1' model ...... 293

39. Root-mean-square amplitudes along principal vibrational axes (A) in [Cu(sP(CH3)3)3]C104 296

40. Distances of atoms from the plane of the three sulfur atom s 298 41. Bond lengths to sulfur in complexes related to [Cu(sp(cH3)3)3] •••«•••••••••••»••«• 299

42. Structural effects in trimethylphosphine sulfide upon coordination ...... 3®3

ix PART THREE

T able Page

I1.3. Final structure factors for [Ni(tep)(no)]BF4 ...... 35O

I (.It. Final positional and thermal parameters for [Ni(tep)(NO)]BF4 ......

^ 5 . Various stages in the refinement of [Wi(tep){NO)]BF4 .... 355

h6. Intermolecular distances less than 3.JA between the [Ni(tep)(KO]+ cation and the disordered anion ...... 360

i|-T* Intramolecular distances and angles in the [Ni(tep)(NO)]+ c a tio n ...... 3 6 1

W3. Interatomic distances 3.ess than U. OA between atoms in different £Hi(tep)(NO)]‘h cations ...... 36K

h9. Selected nonbonded interatomic distances within the [H'i(tep)(NO)]+ cations ...... '. . . . 365

30. Root-mean square amplitudes of vibration ...... 366

51. Intramolecular distances and angles in the disordered anxon 5T5

x LIST OF ILLUSTRATIONS PART ONE Figure Page

I The relationship of the ortho-para coupling constant ( j 2 4 ) to th e p a ra F 13 chemical shift ( 6p ) ...... 9 II The observed and calculated F 13 nmr spectra of 1-2-dibromotetrafluorobenzene ...... 31 III The mass spectrum of diphenyliodophenylphosphine oxide TT IV Synthetic routes used for the fluorinated ligands . . . 81 V Infrared spectrum of Cj. 9 Hi3 F4PS(fSP-CH3) and C19 H17PS (SP-CH3) in the I 2 OO-33OO cm” 1 r e g i o n ...... 88 VI Infrared spectrum of CioHi 3 F4FS {FSP~CH3 ) and C 19 H1-/PS (SP-CII3) in the I 1.OO-13OO cm” 1 re g io n ...... 89 VII The mass spectrum of CiqHi 3F4PS{fSP-CH3 ) ...... 91 VIII Major fragments in the mass spectrum of CisH.i 3 F4PS . . . 9 2 IX The mass spectrum of CisHiyPS (SP-CII3) ...... 93 X Major fragments in the mass spectrum of C 10H17PS (SP-CH3 9^i XI The mass spectrum of C 3 oN;=oF 2P4 (FDP)...... 93 XII The mass spectrum of C. 12H23FbP 3 ( f T P ) ...... 96 XIII The-stjiid- state electronic spectra of Ni(FSP-CH 3 )2Br2J N i(SP- CH3 )2 C12, and Ni(FSP-CII 3 )2 Cl2 ...... 10^ XIV The visible electronic spectrum of Ni(FSP~CII3 )2Br2 and Ni(FSP-CH 3 )2 Cl2 ...... 103 XV The mass spectrum of Ni(F3P - ) 2 ...... I l l XVI The electronic spectra of Ni(F3P )2 and N i(SP ) 2 in ca. 10"o M dichloromethano solution ...... 113 XVII The solid state infrared spectra of Ni(FSP-CH 3 )2 (rfCS)2j Ni(SP-CH3 )2 (NCS)2j Ni(RIP-CH3 {NCS)2, and Ni(SP-CH3 )- (NCS^ 2 ■ . 119 XVIII The magnetic moment (x- x- x-) and magnetic susceptibility (e—0 ■£>) of Ni(FSP-CH3 )2 (lICS) 2 as a function of temperature ...... 120 Figure Page

XIX The s o lid s ta t e e le c tr o n ic spectrum o f W.i(FSP-CH3 )2 - (NCS)2 and Ni(SP-CH3 )2(NCS)2 ...... 123

XX The C-N stretching I’egion in the infrared spectrum of Hi(FSP-CH3 )a (NCS)a ...... 126

XXI The C-N stretching region in the infrared spectrum of Pd (fSP-CH3 )2 (SCN)2 ...... 131

XXII The electronic spectra of Pd(FSP-CH3)d 2, Pd(FSF-CH3)2- (C104)2, Pd(FSP-Ja, and Pd(SP-CH3 )Gl2 ...... I33

XXIII Reactions of FDP and FTP with N i(ll) halides ...... 15^ XXIV Electronic spectra of Nl(FDP)X2 (X= Cl, Br, I, NCS) complexes in nitrom ethane ...... 15$

XXV The C=N stretching region in [Ni(FDP) (NCS )2] in dichloromethane (KBr) ...... 159

XXVI Electronic spectral band shifts upon addition of an equimolar quantity of NaX to solutions of [Nl(FDP)2]- (C104)2 in acetone ...... 162

XXVII The C-W stretching region in rPd(FDP)2'][Pd(sCI'l)4], and Pd(FDP)(liCS)(S C N ...... 166 XXVIII The visible electronic spectra of Wi(FTP)ci2, Wi(FTP)Bra, and Hi(FTP)l2 in nitrome th a n e ...... 171

XXIX The ligand field spectra of Ni(p(OC2H5 )2 (Cq Hjj) )3 ( c n )2 ‘, Wi(tas)Bra, Ni(cGH5P^2)3(CN)2, and Ni(DSPjl2 ...... 173

XXX The m eta-F 19 nmr specti*um o f Pd(CeF5PMe2 ) (NCS) (SCN) showing separation of the first-order J34 coupling ...... 185

XXXI The approximation of the meta spectrum of pentafluoro- phenyldimethylphosphine as half of an AA'XX* spin s y s te m ...... 188

XXXII The observed and calculated meta F19 nmr spectrum in Pd(c6FsPMe2)2(NCS)(sCN)...... ' ...... 189

x ii Figure Page

XXXIII The observed and calculated ortho F19 ninr spectrum of P d (C q F q P M q s(HCS) (SCN) ^ assum ing «Ji2 and Js>jj 0. , , . 190

XXXIV The observed and calculated para F19 nmr spectrum of Pd(CaF5PMe2 )2 (NCS)(SCfl)...... 191

XXXV Correlation of the ortho-para coupling constant (J24) with the para chemical shift (sp) in trans- [Pd(cGF5 )PMe2 )2X2] complexes ...... 201

XXXVI Correlation of the F19 ortho-para coupling constant (j24) with the para chemical shift in ffi (C6F5Pf-fe2)2X2 complexes . . 1 ...... 202

XXXVII The relationship of the F19 ortho-para coupling consbant («J24.) and the para chemical sh ift (6para) in CaF<5PMe2(x) derivatives ...... 2O5

XXXVIH' Correlation of the electronegativity of X with 6 para in NiClf)2X2 and PdCl^JgXa complexes ...... 20?

XXXIX Cori'elation of J2a and J23 with 6p 3n Pd(LJt02X2 c o m p l e x e s ...... 208

XL Correlation of the ortho-para («T2a) and ortho-meta (j23) coupling constants with the para chemical shift (fip) in t r a n s -N i (CaFa PMo 2) 2X2 ...... 209

XLI Correlation of the & and £ fluorine chemical shifts in symmetric CGF4X2 compounds with the electronegativity o f X ...... '. 213

XLII Correlation of the ^ and 3 fluorine chemical shifts in symmetric ortho-CmFaXj compounds with the Van der Waals radius of X ...... 213

x i i i PART TV/O Figure Page

XLIII The molecular geometry of [Cu 2 Cl2 (PPh3 )3 ] ...... 2^0

XLT.V The dimensions and morphology of crystal I and c r y s t a l I I ...... 257

XLV The model for disorder of the perchlorate group in [c u (sr(c H 3 )3 )3 ] ( c i o 4 ...... 270

XLVI The disordered perchlorate group in [Cu(SP(CH 3 )3 )3 ]C 104 after anisotropic least-squares refinement ...... 272

XLVII View of [Cu(SPMe3)3] down the pseudo-threefold axis. . . 29k

XLVIII Projection of the crystal structure of [Cu (s p (CH3 )3 )3 ] - (CIO4 ) parallel to the ' 1 a ' ' a x i s ...... 295

XLIX The P-S infrared stretching region in (CH3)3FS and [c u (s p (c h 3 )3 )3 ] ( c i o 4 ) ...... 5 0 1

L The formation of dz2s hybrid orbitals from d z2 and s atomic orbitals ...... / ...... 3°9

PART THREJ3 -J- LI Principal valence bond representations of NO ...... 3 1 7

L1I Principal valence bond representations of N O ...... $13

LIII Coordination of the nitrosyl ligand to give a M-N-0 an g le o f 1 2 0 ° ...... 319

LIV The potentially trident ate ligand te p ...... 320

LV Crystal packing diagram for [Ni(tep)(N0)]BF,t ...... 3 5 8

LVI The sodium chloride la ttic e ...... 357

xiv Figure Page ■f* LVII View of the [Ni(tep)(NO)] cation normal to the three f o ld a x i s ...... 362

LVIII View of [Ni(tep)(NO)]+ down the threefold a x is ...... 363

LIZ Approximate orbital orientation about the metal in [Ni(fcep)(lfO)] •*•.•••*•••••••*****#, yjo

LX The disordered anion viewed normal and parallel to the threefold a x is ...... 37^

xv PART ONE

The Syntheses and Coordination Properties of Some 1,2 ,2 , ^-Tc t rafluorophe nylpho sphine Ligands I . INTRODUCTION

A. Background

One of the primaxy goals of modern chemical research is to develop a working knowledge of chemical systems to such an extent that further chemical systems of predictable propex’ties may he purposefully designed and prepared. In coordination compounds the nature of the complex is determined by both the central metal and the coordinated ligands; vast changes in the chemical and physical properties of the coordination compound may often be effected by simple changes in the ligand. In order to understand thoroughly the nature of the complex, then, it is necessary to understand what properties of the ligand are responsible for producing the various pi’operties of the complex. Thus the form of many studies in coordination chemistry involves the systematic variation of aspects of the ligand and the study of changes in the resultant complexes.

Unfortunately it is rarely possible to alter only a single ligand property; thus it is tioi’mally quite difficult to unam biguously ascribe changes in the complexes to individual changes in the ligand. For example, trimethylphosphine and triphenylphosphine have vastly different coordination chemistry for several reasons, since replacing methyl groups by phenyl groups greatly altera not only the electronic properties (a" and x-bonding characteristics) but also the

1 2

steric properties of the ligand. The explicit separation of electronic and steric effects constitutes one of the most difficult tasks in interpreting the behavior of ligands in coordination compounds.

The purpose of the study described in this dissertation was to design and study ligand systems which possessed markedly different electronic properties yet were sterically quite similar. For. several reasons, comparing polydentate ligand systems containing the tetrafluoro- o-phenylene backbone with analogous unfluorinated ligands appeared particularly attractive for studying electronic effects in coordination compounds. The advantages of such ligand systems w ill now be discussed. Many coordination compounds of various unfluorinated ligands

analogous to those depicted below have been prepared; a few representative

o-phenylene ligands are compiled in Table 1. These ligands show

a rich and varied coordination chemistry, yielding a variety of

geometries and coordination numbers. The geometry of the complex produced when these ligands coordinate is very dependent upon the nature of the donor atoms of the ligand. For example, the simple substitution of one dimethylarsino group in o-phenylenebisdimeth,ylo,rsinc by one

thiomethyi group markedly alters the properties of the nickel(ll) 3

TABLE 1

REPRESENTATIVE O-PHENYLENE POLYDENTATE LIGANDS

L~L' = Astfea, 1 PPh2, 2 L=PPh2 ; I/=SMe,3 AsPh2, 4,! As Mea 6

L=AsMe2, L'=SMg 738

L'=SCH. h

complexes. In contrast to the diamagnetic, pentacoordinate N i(ll)

complexes formed by diarsine, the complexes of the mono-substituted

thiomethyl ligand are paramagnetic and pentacoordinate . r,a

It is evident that the coordination properties of the ligands

are very dependent upon the specific donor atoms. Thus, altering the

aromatic backbone of these ligands (i.e., substituting tetrafluorophenyl

for phenyl) might also produce significant changes in the resulting properties of the ligand. The availability of spectral and magnetic

data on analogous unfluorinated complexes and the likelihood that

complexes of the fluoroligands would be significantly different made

the study of .fluoroligands appealing for a comparison of the electronic

effects upon coordination properties of polydentate ligands.

B. Steric and Electronic Affects of the Perfluoro-nhenyl Ring

Selected properties of hydrogen, fluorine, and chlorine are

given in Table 2. Several important comparisons should be made.

Fluorine is much more electronegative than hydrogen. Thus, one predicts the tetrafluorophenyl and pentafluorophenyl groups to be more

electronegative than the corresponding phenyl groups. From several

different types of measurements, the electronegativity of pentafluoro-

pehnyl group has been estimated to be about 2.5, or slightly more than phenyl but less than bromide. Thus, Fild et. al. . found an electionega-livity of TABLE 2

SELECTED PROPERTIES OF FLUORINE, CHLORINE, AND HYDROGEN

Elem ent Ref HF Cl

Ionization potential (eV) 19 1 3 .6 IT. k 1 3 .0

Electron affinity (eV) 2 0 o .T 3 .5 3 .7

Pauling electronegativity 29 2.20 3-98 3 .1 6

Bond energy of X 2 (Kcal/mole) 2 3 2 1 0 3 .3 3T .0 5 7 .1

Bond energy of H-x(Kca3./mole) 2 3 2 10)|. 135 103

Bond energy of C-x(Kcal/mole) 232 99 103 79 O 0 Covalent radius (a ) 19 • 0. 6k 0.99

Van der Waals radius (a ) 20 1 .2 1.35 1 .8 0

Electronic configuration I s 1 l s s 2 s a 2p 5 l s 2 2 s2 2p 6 3 s 23p 5 6

ca. 2.5 for the pentafluorophenyl group from an examination of the

shifts in the P=X infrared stretching frequency in several R3P=X

(X=03Sj R=CqH5,CgF5) derivatives. 1‘1', 15 Thompson and Graham derived an

electronegativity of 2. *(• for the CGF5 group based upon carbonyl

s tr e tc h in g fre q u e n c ie s in (CqIIs )n (c GFs )3 -n SnMn(co)5 com pounds.16

Mossbauer studies indicate a sim ilar electronegativity for the CGFS

group; from an interpretation of isomer shifts and quadrupole splittings

in a series of RxSnX^-x compounds, Hayes found the electro

negativity of CGFs to be 2.68 + . 05 compared to 2. 56 + . 05 for CGHs . 17

Lappert and lynch correlated rates of solvolysis of XnSiH4-n derivatives with the electronegativity of X; the rate for the CGFS derivative was found to be between the bromo and phenyl rates. 13 Massey et. al.

found a slightly higher electronegativity for the pentafluorophenyl-

group, placing it between chlorine and bromine, by examining 1H nmr

shifts in (cGFG )2SnR2 derivatives.22 Finally, pentafluorophenylphosphines appear to be considerable less basic than the phenyl

analogues.23 For example, considerably more vigorous conditions are

needed to form the oxide and sulfide of tr i3-(pentafluorophenyl)- phosphine than of triphonylphosphine, presumably due to the greater electronegativity of the CGF5 group.

Although a direct determination has not been made, one would expect the tetrafluorophenyl group to be more electronegative than the o-phenylene group by analogy to CGFG. In both cases the electronegative 7

fluorine-containing rings should exert a strong a"electron withdrawing effect which would make a donor atom attached to the rings a weaker

Lev/is base (a-donor) toward a transition metal. The more electronegative

ligand should also tend to stabilize neutral and anionic complexes relative to cationic species.

A second characteristic of hydrogen and fluorine (Table l) which

should be considered is atomic dimensions. The hydrogen and fluorine atoms are quite small and of "similar size. The Van der Waals radius of hydrogen is only slightly smaller than that of fluorine (l. 2 A vs.

1.35 A.)*20 Thus, the two elements should have rather similar steric propex’ties, especially in a constrained envii'onment such as the lj2 , ^-substituted aromatic ring. Steric differences should be minimized in compaxdsons of phenyl and tetrafluorophenyl complexes since the fluorophenyl backbone is relatively remote from the co ordination site.

While both hydrogen and fluorine are invariably univalent, their electronic configurations are radically different. The extremely small size and nearly filled 2s2p 3hell of fluorine cause large inter electron repulsions in the second shell, leading to a low X-X dissociation energy and the low electron affinity compared to other halogens.21 The electron-rich, tightly bound second shell gives rise to short range but intense inter-atomic repulsions which are 8

responsible for the high volatility of fluorine compounds compared to other compounds of sim ilar molecular weight, even though the

Van der Waals radius of fluorine is small.

Hydrogen and fluorine also differ greatly in their n-bonding abilities. With the Is1 configuration, hydrogen has no capability to xt-bond, while fluorine, with an electron-rich set of p-orbitals, should be quite effective in it-donabion despite the high electronegativity of fluorine. F10 nmr spectroscopy has provided strong evidence that pn-donation from fluorine to the aromatic ring is particularly important in pentafluorophenyl compounds, including phosphines and phosphine complexes. In a survey of some seventy-three widely substituted pentafluorophenyl derivatives, Graham e t.a l., found a strong correlation between the F10 ortho-para coupling constant (J24) and para chemical shifts (<5p) and related these to the n-donor-acceptor character of the pentafluorophenyl substituent.24 20 Thus, a linear relation is found when J2.t is plotted against ap (Figure i), with substituents capable of xr-donation to the CaFs ring lying to the right

(higher 6p and lower J24) and xr-acceptors lying to the left (lower 6P and higher J24). It should be especially noted that the more electro negative substituents, which are generally good xr-donors, cause upfield F19 para shifts, in the opposite direction from that expected on the basis of electronegativity but in accord with xt-donor characteristics. When the substituent is fluorine (hexafluorobenzene) gur I. h rel i p o* he orho- a c i ant a<1:) J ( t n ta s n o c g lin p u co ra a -p o rth o e th ol* ip h s n tio la e r The . I re u ig F

^24 ( H 2 ) 6 - -4 0 4 6 2 3 2 h plot is t rm r er 25. e c n re fe re from n e k ta s i t o l p The o t a Fy c mia shift (p) Te he cl s t f i h ppm. s 00 163. ical t em a ch g The rrin u c c o ). CgIo (6p ith t f w i h CFC13, s to ical em e ch v i t a l Fly e r ra a p re a e th to 0 4 1 V 5 170 150 p(ppm) § 0 8 1 9 10 the highest chemical shift is observed whereas that for hydrogen is much lower, consistent with a relatively greater amount of px-# bonding in the case of fluorine substitution. Since hydrogen lacks appropriate orbitals, x-bonding should be nonexistent for the hydrogen substituted compound. The extremely wide range of

4 compounds for which Graham founa such a strong correlation of 6p and

Ja4r with the n-donor-acceptor nature of pentafluorophenyl substituent is excellent evidence that ^-interactions between the f.luorophenyl ring and substituents arc quite important.

Some phosphine compounds were included :i.n Graham's study and these seem to act as net ^-acceptors from the perfluorophenyl ring.

In lieu of other effects, net #(p) -> x(d) donation to phosphorous would make the phosphine a poorer x-acceptor ligand, since the metal would have to compete to a greater degree with the aromatic ring for the vacant d-orbitals on phosphorous. On the other hand, it is well known that electronegative substituents improve the x-acccptor properties of phosphines.2l,5S"58 Thus the increased x-donation to phosphorous from 11

the perfluox'ophenyl group may tend to be offset due to overall bebter

it-accepbor qualities with the more elecbronegative substituents . .

P31 nmr spectroscopy also indicates that the pentafluorophenyl

ring can aet as a better it-donor to substituents than can the phenyl ring.

Thus in pentafluorophenyl phosphines the phosphorous chemical shift

increases markedly as the number of pentafluorophenyl groups increases,

consistent with increased shielding of the 31P nucleus due to relatively

g r e a te r it* d>r donation as pentafluorophenyl groups are added to the 27-29 m o lecu le.

In the case of ligand donor atoms attached directly to a perfluoro-aromatic ring, then by the above arguments the ligand should be a weaker a-donor to a transition metal due to the inductive effect

of the perfluorophenyl ring. At the same time, the ligand could be

either a weaker or stronger it-acceptor ligand, depending upon whether

the electronegative (synergic) effect or increased jt^ — dit donation

is more important. 1 2

TABLE 3

F31 If MR SHIFTS IN PENTAFLUOROPHEHYLPHOS PHINES

Contpound 6a Ref.

(celfe)aP 6 27

(Celtj ),o P(Cq Fs ) +26.3 29

(c6i%)p(cgfs)2 . +ii-8. T 29

p (c s f d )3 •JT5 .5 29 CgF5p(CII3 )2 +Vr. 8 29

CgH5P(CH3 )2 +lj-6 27

a) Cheinlcal shifts are ux>field from 10;$ (ref. 29) and 85$ (ref. 27) phosphoric acid. 13

C. Previously Studied Coordination Compounds Containing Perfluoro-

Carbon Idgands

Complexes containing perfluoro and polyfluoroearbon groups such as pentafluorophenyl, trifluoromethyl, tetrafluoroethylene, and dichlorodifluoroethylene have been studied extensively and are the subject of several reviews (see supplementary references). The fluorocarbon complexes are quite notable for their enhanced stability relative to the unfluorinated analogues, and in many cases the fluoro carbon ligands possess quite unique chemistry. In the several cases in which the three-dimensional crystal structural analysis of analogous fluoro and non-fluorinated complexes have been performed, only a modest shoz’tening of the metal-carbon bond is seen (<.1&) in the case of the fluoro compound and no other exceptional features which would account for the enhanced stability are observed. 30

Studies of highly fluorinated ligands which do not bond via direct metal-carbon or n- bonds are considerably less common.

In 1966 Nyholm and co-workers21*31 reported the novel chelate f-diars(l) and compared directly its coordination properties to that of the familiar diars (il) towards first row transition metals. The f-diars ligand exhibited surprising differences in its properties compared to diars. Of particular relevance to the present study, the fluoro-ligand exhibited a noticeably decreased tendency to form ih

H As(CH3 )2 h^ ^ As(ch3)2 .As (CH ^ (C Hg) 2 H

I (f-diars) 11 (diars)

five-coordinate N i(ll) complexes. Thus, diars forms [Ni(diars)2X2]

(x=Cl,Br) complexes which are six-coordinate in the solid state and ionize to give the pentacoordinatc [ili (diars)2X] in solution, v/hereas

[N i(f-diars)2X2] (x=Cl,Br) remains hexa-coordinate both in solution and in the sol.id phase.

The coordination chemistry of the 3., 2-dithioltctraha.lobenzenes

IV and V have received some attention.a2-34>2Cs

Cl C l f ^ r - S H

C l IV V 15

The ligands IV and V act as fairly strong acids, undergoing ionization

in the presence of transition metals to give mercaptide complexes'

similar to other thiolene compounds. The fluoro-ligand IV readily

dissolves first row transition metals to give [m(CsF4S2)2] complexes

directly. 32

The remaining complexes that contain perfluoro-chelates which

have been reported to date have been synthesized by Cullen and coworkers.35"45 The structures of a number of these metal complexes ha\e been

^2 D F (c h3)2as c f2c f As(C h 3 )2 ^ 2 D CF- j

VI D=PPh? VIII X VII D=AsMe2

elucidated by X-ray crystallography by Trotter's group.47“b5 These

ligands were prepared in excellent yield by free-radical addition across

the respective perfluoro-olefin double bond.

F, P (Celfe )2 CFa CF 20 G, 1 atm v e .g . I |1 + HP(CGH5)2 271 Days > + SHF CF2 CF F; P(CGH3)a

95$ y ie ld 16

These addition reactions are apparently unique to the perfluoro-olefins.

The unfluor.inated structural analogues to ligands VI-X have never "been

prepared due to the unavailability of feasible synthetic routes.

Thus, "because of the structural peculiarities of ligands VI-X, it is not

possible to make rigorous comparisons with unfluorinated chelates

containing similar donor sets, for the purpose of elucidating the co

ordination effects of the perfluoro connecting linkage.

Ligands VI and VII do not form complexes with the first row

transition metals Hi2 , Fe2+, Fe3+, Cu2 , and Zn2+.42 However, planar

Pd2 and Pt2 complexes and tetrahedral Cd2 and Hg2 compounds were

obtained. It was concluded that the chelate bite of ligands VI and

VII, as a result of the strained four-membered rings, is too large to

fit comfortably about a small, first row metal.

Probably for this reason, further work with ligands VI-X has

dealt entirely with formally zero-valent transition metal polycarbonyl

complexes, where.the size of the metal and chelate-bite are more closely

matched. The chelates generally react with metal carbonyls with

displacement of a stoichiometric quantity of carbon monoxide to give

the expected adducts. Examples of some representative reactions, whose

products have been examined by X-ray crystallography, are shown below.

The reactions are quite luminiseent of related reactions of diarsine

(l, 2-bis(dimethylarsino)benzene) itself. The three-dimensional crystal

structure determinations revealed no unique features of the IT

Ref. Fe (110)4. + V III------* (c h e la te )Fe (NO )2 l\.j

Co3(CO)X2 + VII > (chelate)Co2(C0)Q U8

Mo(C0 )q + X ------^ (chelate)Mo(co)4 lj.9

(chelate)2Ru3(co)a 50 Ru3 (CO)i2 + V I I > + (chelate)Ru3(co)10 50j51

(chelate)Fe2(CO)G 53

Fe3 (C0) a2 + V II ------> +

(c h e la te )F o 3 (co ) xo 53*5^ fluoro-ligand compounds with respect to metal-metal and metal-ligand

"bonding; "bond angles and distances o-nd distances involving metal- earbonyl, metal-chelate, and metal-metal linkages generally are quite

similar to those observed in the parent binary metal carbonyl compound.

The remaining studies of perfluoro-ligands not bonded directly via metal-carbon bonds involve monodentate ligands. The stabilizing

influence which trifluorophosphine and tris(trifluorom ethyl)phosphine

impart to low-valent transition metal complexes, thus behaving much

like a carbonyl group, is well known. 2is so-b a <£iie oiectronegative

substituents in PFa cause phosphorous to be an extremely poor a"donor but an excellent n-acceptor ligand. In some cases, e.g. Pd(PI,,3)4. and

Pt(PF3)4, trifluorophosphine complexes of low-valent metals have been

isolated even where the carbonyl analogues are unknown. 18

Several groups have used pentafluorophenyl mercaptide in coordination chemistry studies.2ljE,£)"6 S

Overall, Cel'sS" acts as a typical mercaptide ligand. However, two general differences are observed between the complex chemistry of

CqF5S~ and CeHgSr l) In metal carbonyl compounds, C=0 stretching bands tend to occur at higher frequencies for complexes of the fluoro- ligand, consistent with either the greater electronegativity or better

it-donor properties of C^F^S. 2) As a result of the electronegative

Cgf5 group, CQFr3S"is less basic than CgHgST6'"35*37 Consequently, the fluoro-ligand does not form mereapto~bridged complexes nearly as readily as CqHsS . For example, monomeric [mCCgHsS)4]2- (M=Pd, Pt) species are formed readily, whereas analogous complexes of CoH^S'are infinite polymers.05 Because of the polarizability of the S atom and the weak conjugate basicity of CGF5S , CeFtjS'has been considered a pseudo-halide in its coordination properties.2lj65 Accordingly, the tetrahedral [Co(CgFsScomplexes may be isolated easily. Spectro scopic studies show that in the [CoX4]2" anions the ligand field splitting parameter 10 Dq decreases in the order NCO > NCS > CqFsO >

CqHsS > CeClsO >CgFsS > Cl > Br > I, whereas Jorgensen's 19

nephelauxetic covalency parameter P decreases in the order

C6FsO > Cl > NCO > CcClsO > NCS > Br > I > CGF5S > CGHsS. In the case of CcFrjS vs CaHgS , 10 j}q is greater and P is lover for the unfluorinated ligand, and thus C0F5S appears to be an overall weaker ligand with poorer n-acceptor properties than CelfeS . King and Efraty have reported a few palladium and platinum complexes of the trifluoro- 212 methylmercaptide anion.

Brief reports of the coordination chemistry of pentafluorophenylphosphines have occurred. Alyea and Meek recently conducted a comparative study of the ligands dimethylphenylphosphine and dimethylpentafluorophenylphosphine in some N i(ll) and Pd(ll) complexes.09

The fluoro-ligand clearly exhibits a smaller tendency to form pentacoordinate N i(ll) complexes. Thus, only the pentacoordinate

Ni(CsF5Ptfes )3X2 cyanide complex could be isolated whereas both

Ni (CQH5PMe2 )3 (Crl)2 and Ni(cGH3PMe3)3l 2 were isolated for the unfluorinated ligand. Except for cyanide, spectrochemical measurements indicated no tendency for a third dimethylpentafluorophenylphosphine to add to the planar Ni(Lf)2X2 to give pentacoordinate Ni(Lf)3X2 (x=Cl,Br,l) species, in contrast to the behavior observed with the analogous un fluorinated ligand.

Kermitt, et. al., have briefly described the synthesis and F13 spectra of a fcv palladium (ll), platinum (ll), and rhodium(l) complexes of tris(pentafluorophenyl)phosphine.70 However, the brief account gave 20

few details on the properties of these complexes which would allow a comparison with analogous complexes of triphenylphosphine.

In summary, fluorine-containing ligands seem to show a decreased propensity to form pentacoordinate compounds compared to the analogous non-fluorinated ligand. In addition, the ligands appear to be less basic relative to analogous unfluorinated ligands.

D. Fluorine Nuclear Magnetic Resonance Studies

The use of F19 nuclear magnetic resonance as a probe of molecular and electronic structure is not new. Interpretation of F10 chemical shifts in fluorobenzenes has been used elegantly to determine inductive and mesomeric (a and «) effects of substituents on aromatic rings, in addition to determination of molecular structure.

Fluorine nmr spectra are so useful because, as in proton nmr, the chemical shifts are determined primarily by the paramagnetic term in the nuclear spin Hamiltonian, except when exceptional steric effects intervene.71 Thus, the direction and magnitude of the F19 chemical shift can usually be predicted from simple considerations of the electronic interaction between fluorine and the substituent to which it is bonded. The screening constant ai for any nucleus can be ex p ressed a s '’2’ 73

a i = cri^ + ai^ + a-i° cri6 21

where cji^ = the diamagnetic contribution from the uniform circulation of electrons in the magnetic field Ho, cri^ = the paramagnetic contribution from restricted circulation of electrons in Ho (e.g. electrons in a chemical bond), 0 (e.g. ring currents) and ai = polar or polariaable group contribution

(due to permanent dipoles).

In a theoretical study, Karplus and Das7'1 assumed that the calculation of F19 chemical shifts could be restricted to p electrons centered on the fluorine nucleus in question. They concluded that in fluoroaromatic compounds, the difference in the shielding constants between two fluorine nuclei, A a±} is governed by the difference in ionic character AI and the double-bond order AP, of the C-F bonds.74

Using the above results and Jt-bond orders calculated by the Huckel method, Karplus and Das computed values of AI which substantially agreed with the experimental quantities except when substituents ortho to fluorine are present; in the latter case anomalous shifts to low field (relative to CoFq) are found.

Prosser and Goodman used a sim ilar approach for calculation of

F19 shifts in aromatic compounds; in addition they included contributions due to electrons located on the aromatic carbon atoms.75 Results similar to those of Das and Karplus were obtained, i.e ., F19 shifts could be successfully predicted considering electron density on fluorine alo n e. 22

The large *1 ortho effect'' on the F13 nmr resonance in fluoro-

aromatic compounds has been interpreted as arising in one of two ways.

First, Buckingham has suggested that ortho substituents cause increasing

contributions to from the paramagnetic term this is in keeping with the increasing magnitude of the effect with increasing size of the

substituent.76 A second approach considers the effect as due to the presence of permanent and time-dependent magnetic fields in the molecule, upon which the shielding constant directly depends.77 This

effect can arise both from polarity in the C-X bond and dipole moments

(permanent and time-dependent) in neighboring groups. Since it is

these same time-dependent dipole moments which give rise to Van der Waals

forces between non-bonded atoms, their effect upon the shielding constant o-.j_ (and thus the chemical shift) is commonly known as the ''Van der Waals

effect'* or ''fie ld effect' 1.77 Generally, the second approach has been

more successful in interpretation of F19 nmr spectra.

From a study of a number of polyfluorobenzene compounds, Caldow cL also showed for fluorine nuclei that and oi are of opposite sign *n 7*2 but that ai predominates. In certain cases, the Van der Waals second order field term, aiS is substantial and occasionally dominant in

determining chemical shifts (e.g. in ortho-substitution). Thus, aie is particularly large for substituents ortho to the fluorine nucleus and is

a function of steric crowding in the molecule, larger o-groups causing 23

shifts to lower field. Normally, however, the direction and magnitude of F19 shif bs could he predicted from considerations of alone and was found to he a linear function of the inductive and mesomeric Hammet functions and respectively, for a great variety of substituents.78

Only a few of the several F19 studies which could he discussed are cited. The following examples were chosen because they were deemed particularly illustrative for the purposes of this discussion.

The classic work of Taft and coworkers has been pioneering in elucidating electronic interactions of substituents ’with benzene rings.79-01 The F19 shielding parameters of meta and para mono- substituted fluorobenzenes (f-CoII^-x) may readily be interpreted to give values for the Hammett-Taft (y~T? functions which agree closely with those determined from chemical equilibria data.

Fluorine-19 nmr studies of transition metal complexes containing fluoroaryl functions are considerably more limited. In classic studies,

Parshall studied the electronic interactions of halogen with platinum in a series of cis and trans Pt(PEb3)2IX compounds (l=0 and m CqI^f) by comparing the nuclear shielding parameters in the meta and para fluorine complexes. 04 80 The meta parameters vary with the cr “donor character o f X} thus, the meta chemical shifts follow the order of basicity

CH3 > CgHs > FCqILi and CN > Cl > Dr > I . On the other hand, the 2k

para fluorine nuclei arc deshielded to a much greater extent and follow the generally accepted07*00 tf-acceptor nature of X, I > Br > Cl > CN, i.e ., the reverse of the basicity order.

Stone and coworkers extended this work to the pentafluorophenyl analogs trans-M(Fr!]t3)2(CoFs )C1 (m= N i,Pd,Pt).Q° These complexes have the intrinsic advantage that 6p and 6m may be measured in the same compound, thus obviating special effects of the different compounds and solutions. The order of ir-acceptor abilities of X in the CgFs complexes was sim ilar to that found by Parshall.

In a later related study, Church and Mays examined the 4* infrared, H1 nmr, and F19 nmr spectra of some trans-[P+XL(Pflt3) complexes where L= CO, P(OPh)3, p(OiMe)3, PEt3, Me2CNC, and p-McO-CqP^-NC and X= ortho, meta, and para CoH^F.90 As Par.shall noted, the F19 shielding parameters give the expected n-acceptor series of X as

CO > P(OPh)3 21 PFt3 > p(OMe)3 > ArNC > PNC. The infrared and proton nair spectra were also consistent with this order.

Fluorine-19 nmr studies have also been carried out on paramagnetic complexes containing fluorophenyl rings. Thus, Eaton, et. al. , determined the contact shifts of tetrahedral Ni(ll) complexes of the ortho, metal and para fluorophenyl ligands drawn below. 91>92 25

R i

X^F.FgS.CFg,

i OCF3 ,SCF3, Ph s o 2 c f 3

The authors concluded that a significant amount of pK backbonding from

fluorine to the phenyl ring occurs in the co.mp].exas of the ligands.

A few pentafluorophenylphosphine complexes have "boon prepared.

Kermitt et. al., have briefly described the synthesis and F19 nmr spectra

of a few ds complexes of tris(pentafluorophenyl)phosphine complexes.70

The complexes reported were the trans (H~Pd.X-Gl, Br and M-Pt,

X=C1, B r, l) and RhL2(co)c.l. The spectra show largest downfield chemical

shifts for the ortho and para fluorines. The resonance of meta fj.uorine

lies nearly yO ppm upfield from the ortho and 12 ppm upfield from the

para fluorines, a ll three sets of nonequiva3.ent nuclei resonating down

field from the corresponding positions in the free ligand. The F19

shifts in corresponding PdL2X2 and PtL2X2 are identical within

experimental error. The effects of different halogens upon meta and i para chemical shifts is exceedingly small for complexes with either metal, ranging over 0.9 ppm for platinum and 0.1 ppm for palladium

(l > Br > Cl). 26

In a similar investigation Nichols recently extended the use of F10 shifts in interpretation of electronic interaction to a series of gold(l) phosphine complexes. 03 From an examination of meta and para F10 chemical shifts in an interesting series of new linear LAuX (L= phosphine, X= m and p, - CqH^F), an 1'F13 nmr n-acceptor parameter1', pXL 6p-fio, was defined. Presumably, the larger the value of 6p-fio, the greater the gold-phenyl rt-interaction and presumably the smaller the back donation to the phosphine. The values of 6p-6o established a

ir-acceptor series for the phosphines which is totally in agreement with estimations made by other means. Overall, the R3PAu moiety appears to act as or" and ir-donors to the phenyl ring whereas halogens seem to be ir-donors but o-withdrawers. Significantly, L= CGF5P(c3H5 )2 caused a large downfield shift in 5p compared to L=P(C0I%)3, consistent with a large degree of ^-electron withdrawal into the C3F3 ring thru the 3d orbitals of phosphorous.

In summax'y, nmr s tu d ie s o f F10 s h ie ld in g p a ra m e te rs and coupling constants have previously been quite useful in elucidating bonding features in fluorophenyl metal complexes. In conjunction with the synthetic studies of tetrafluoro- and pentafluorophenylphosphine compounds, it was proposed to examine F10 coupling constants and

shifts in various perfluoroax'yl Intermediates and perfluoroaryl-

phosphine ligands, as well as selected complexes of these ligands.

Among the phosphines to be studied were FSP-CH3, FDP, and dimethyl- pe ntafluorophenylpho 3phine. 27

Statement of the problem

The purpose of the research described in section I of this dissertation was to investigate the effects of the tetrafluorophenyl backbone in o-disubstituted aromatic polydentate ligands with respect to coordination properties of the ligands and chemical and physical properties of the resulting complexes, particularly with metals having the ds electronic configuration. 28

I I , EXPERIMENTAL

A. Chemicals

Unless otherwise noted, a ll solvents and reagents were of

analytical grade and were used without further purification. 1,2, !(■-

tetrafluorobenzene and 1,2-dibromotetrafluorobenzene, obtained from

Peninsular Chemicals Company, were dried and distilled over calcium

sulfate (b.p. 91. 5"92. 5°C and 195- 0-193. 5° vs. lit. values 95°C 94

and 193"196°C 93, respectively). Phosphorous trichloride, dichlorophenylphosphine, and chlorodiphenylphosphine were vacuum distilled

immediately before use. Sulfur was recrystallized from benzene.

Diethylether, toluene, and benzene were dried over sodium wire, Nitro- raethane was dried over 1|-A° Molecular Sieves and distilled (b.p. 100-

IOO.5) before use in conductivity determinations. Reagent grade

tetrahydrofuran was refluxed over lithium aluminum hydride and distilled

(b .p . 6k°).

The ligand SP-CH3 was previously prepared.3 T rime thy lphosphine-

sulfide93 and dimethylthiophosphorylbromido97 were prepared according to jjreviously reported methods.

The inorganic complexes [Pt(FPh3)3]],90 [Pt(PPh3).j,],9° [RhCl-

(co )2] 2, 99 [EhCl(l, 5~cyclo-octadiene)]2, 100 [Rhl(l, 5-cyclo-octadiene)]2,;io:)

[lrCl(l,5"cyclo-octadiene)]2, 101 [lrCl(C0)(cyclo-octene)2] ,103 and trans-

[lrCl(C0)(pPh3)2] 103 were synthesized by literature methods. Binary precious metal salts were obtained from Engelhard, Inc. 29

B. In stru m e n ta tio n

Melting points were determined in unsealed capillaries on a

hot stage device and are uncorrected. Proton nuclear magnetic

resonance spectra were obtained on Varian A-60 and A-60-A spectrometers,

with tetramethylsilane as the internal standard unless otherwise noted.

Routine infrared spectra in the range 1j.00-1j.000 cm 1 were run on a

Perkin-Elmer Model 33T Grating Spectrophotometer as nujol or hexachloro- butadiene mulls between polished KBr plates or as pressed KBr discs.

Quality infrared spectra for the purpose of obtaining accurate

integrated intensities, band frequencies, and half-band widths in

thiocyanate complexes were determined with a Beckmann IR9 instrument,

using matched calibrated KBr cells of pathlength 0.1, 1. 0, and 10. 0 mm.

Mass spectra were run at JQeV on an AEI I£3-902 spectrometer. Magnetic

moments were determined by using a Faraday balance constructed in

this laboratory;104’:lD3 the magnetic susceptibility of every sample

was determined at two different field strengths as a test for the

presence of ferromagnetic or anti-ferromagnetic impurities. Electronic

spectra in the near infrared, visible, and ultraviolet regions were

measured on a Carey lit- spectrophotometer, either as solutions in

matched quartz cells or as nujol mulls on filte r paper supports.

Conductivity experiments were made on ca. 10 3 molar solutions in

a Fischer Scientific Company conductivity cell (cell constant *0. l) 30 at 60-1000 Hz, balanced with an International Instruments, Inc.

Model RC-16B2 conductivity bridge. Single crystal diffraction studies were performed using Enraf-Nonius precession and Weissenberg film cameras. Computer calculations were performed on IBM Models

H 3O, 709*1-, 360/ 50, and 360/75 and Electromechanical Research Model

613O computers.

C. Fxo Nuclear Magnetic Resonance Measurements

Spectra were determined using a Varian HA100 spectrometer equipped with a *1-000 hz external sideband oscillator. Spectra were run at 9*1-. 0758 Mhz in the HA (frequency sweep) mode at 32.3 + 0. 5 C.

Spectra were calibrated by the sideband oscillator technique. The solvent was a 15$ solution of hexafluorobenzene in dichloromethane, with hexafluorobenzene acting as the internal lock standard. Samples were run as 10-20$ w/w solutions. Each sample was run at least tv/ice as a check upon instrument stability. The speebrum of 1,2-dibromotetrafluorobenzene was frequently run and compared to the previously reported spectrum as a further check upon instrument resolution and calibration. A comparison is shown in Figure II and Table *!-.

D. Elemental Analyses and Molecular Height Determinations

Molecular weight determinations and analyses for carbon, hydrogen, nitrogen, sulfur, fluorine, and halogen were performed by

Galbraith Laboratories, Inc., Knoxville, Tennessee and M-H-W

Laboratories, Inc., Garden City, Michigan. Phosphorous was determined 31

K------4 0 Hz ft

Figure II. The observed and calculated P-F315 spectrum of 1,2~dlbromo- tetrafluorobenzene. The cx"F1‘i resonance is identical in appearance and occurs at 13’)*2ppm. relative to CFC13. TABLE 4

COMPARISON OF LEAST SQUARES-REFINED F19 CHEMICAL

SHIFTS AND COUPLING CONSTANTS DETERMINED IN

THIS STUDY WITH THOSE REPORTED IN

REFERENCE 226

Source 61 ^12 J 13 '23

This work 125.2332(8) 154.2320(8) -21.51(13) 2.9l(l3) 8.07(21) -19.44(21)

Reference 210 125-2 154.2 -21.70 2.85 8.02 -29.75

I , F F r ^ N S r

V ep4 r

6 = Chemical shift In ppm relative to CFC13j C6Fs "being established as 163. 00 ppm (see ref. 24).

J = Spin-spin coupling constant in Hz. Values in parentheses refer to rms errors. 33

"by the author using the 1 'heteromolybdenum blue' ’ colorim etric method. All samples were dried overnight at room temperature in vacuo prior to analysis.

E. Gold Analyses

Gold analyses were performed by thermolysis. A typical determination w ill be described.

A ten-gram glazed porcelain crucible and lid were brought to constant weight by heating with a hot Fischer burner until consecutive weighings agreed to within ± 0. 5 mg. A quantity of ca. TO nig of

Au(fSP-CH3)C1, sufficient to contain approximately 20 mg of gold, was weighed into the crucible. The crucible was partially covered

and cautiously heated with a low flame until the sample just began

to char gently. Heating was carefully continued until a ll smoking

ceased. The crucible was then heated at a dull red glow until all

carbon had been oxidized. The crucible was fully covered and heated

to redness until constant, weight (+. 5 mg) was again achieved; a period

of about two hours was usually required. The bright gold residual

then directly gave the quantity of gold contained in the original

sample.

Anal, calcd. for CiaHisAuBrF^PS:

Au, 30. 0

Found: Au, 3O.6, 28.8 (avg. 29* 7)• All determinations were performed in duplicate. For samples

weighing approximately 7° me and with roughly 3^$ gold content

hy weight, the expected relative accuracy is ca. + 0. 5^ Au.

The reliability of the method was checked by determination of

gold content in the previously characterized complex chloro-o-diphenyl-

phosphinosulfidediphenylarsinobenzene gold(l). 40

A nal, c a lc d f o r C30H2.1ASAUCIPS:

Au, 25.9 1 .

Found: Au, 2 5 .26.3 (avg 25-9).

F. Synthesis of ligands and Intermediates

(2-Bromo-j. k, 5.6-te traf luoronhenyl)dlphenylnhos'nhine

A solution of 20.0 g (O. C65 mole) of 1,2-dibromotetrafluorobenzene in 200 ml of anhydrous diethyl ether was cooled to -78° by

immersion of the reaction flask into a Dry-Ice/isopropanol bath. To

the cold, stirred solution was added dropvri.se lj-0. 2 ml of a 15. 22$

solution of n-butyllithium in hexane (0.065 mole). After the reaction mixture was stirred for 30 min. ll)-,3 g (0. 065 mole) of diphenyl-

chlorophosphine was added slowly. The resulting amber slurry was

stirred for an additional k5 min and then removed from the low

temperature bath and allowed to warm to room temperature, whereupon

a white solid separated. After 30 min at room temperature, no further change in the reaction mixture was observed. The reaction mixture 35

was hydrolyzed with water; the pale amber organic layer was separated

and dried (Ka2S04) overnight. Concentration of the solvents gave

a yellowish, gummy solid. The solid was recrystallized from 30 ml

of hot methanol to give 23.8 g (89/ yield) of white crystals,

m.p. 65-66°. Anal, calcd. for Ci8HioBrF4P: C, 5 2 .3 2 ; H, 2.h2 ; P, 7. 5% Found: C, 53*71; H, 2.^8; P, 7-59.

The quaternary methyl iodide derivative was prepared by

refluxing (ill) in a solution of ethanol and methyl iodide for 20 min.

The white solid, which precipitated from the solution upon cooling, was collected on a filte r and recrystallized from ethanol, m.p. 192-

193°. Anal, calcd. for CioHi3BrF4IP: C, fcl.1 ; H, 2 .3 5 $ . Found: C, li-lJi-; H, 2. h.

1.2-Bis(diphenyiphosnhlno)tetrafluorobenzene

A solution of 17. 0 g (0. di-ll mole) of (2-bi’omo-3,l|-, 5j6~

tetrafluorophenyl)diphenylphosphine in 25O ml of diethyl ether was cooled to -78° by immersion of the reaction vessel into a Dry-

Ice/isopropanol mixture. To the cold, stirred solution was added dropvri.se 25. 5 ml of a 15.22/ solution of n-butyllithium in hexane

(0. Olkll mole), and the resulting mixture was allowed to stir for

15 min. A solution of 9* °8 g (0. Olj.ll mole) of chlorodiphenylphosphine was added slowly and the reaction mixture was allowed to stir for lh r;

a pale yellow slurry resulted. The reaction mixture was then

removed from the -78° bath and allowed to warm to room temperature

as it stirred, producing an orange slurry over a period of k hr. The

reaction mixture was hydrolyzed with watery the orange organic layer

was separated and dried (CsS O4) overnight. The solvents were removed

by an aspirabor to give an orange syrup, which deposited a light

pink solid on addition of cold ethanol. Light yellow crystals 15*9 g

(7^*7^ yield) were obtained on recrystallization from ethanol. The

slight yellow color persisted throughout repeated recrystallizations,

m. p. 108-109°.

Anal, calcd for CaoH^oF^Pa:

c, 69.50,* H, 3.89; p , 11.95#. Found: C, 69*71; H, 3*90; P, 11.6l.

Ei si! 2- (dlnhenyjphosphino) -3, 5.6-tetraf luorophenvllnhenylphosnhine

To a solution of lU. 2^ g (0. 03^5 mole) of (2-bromo~3,l|-, 5,6-

tetrafluorophenyl)diphenylphosphine in 150 ml of diethyl ether,

precooled to -78°, was added 21-3 ml of a 15*22# solution of n-butyl-

lithium in hexane (0. O3I1.5 mole). After the reaction mixture had been

stirred for 50 min, a solution of dichlorophenylphosphine (6.60 g,

O.O369 mole) in 25 ml of diethyl ether was added. After the mixture had stirred for an additional 50 min, the amber slurry was removed 57

from the low-temperature bath and allowed to warm to room temperature.

After 30 min at room temperature, the resultant yellow slurry was hydrolyzed with watery the amber organic phase was separated and dried

(caSdj.) overnight. The solvents were removed by an aspirator to give a yellow o il which, on addition of ethanol and cooling, deposited it. 0 g of yellow, crystalline solid. The solid was recrystallized twice by dissolving it in a minimum quantity of dichloromethane, filtering, adding ethanol to the filtrate, and allowing the dichloro methane to evaporate. Yellow, crystalline needles of the triphosphine wore o b ta in e d , m.p. 173* 5_1 7 t. 5°.

Anal, calcd. for C42H25FeP3:

c, 6 5 .1 t; h , 3 .2 5 ; Pj 11.9956.

Found: C, 6t . 87 ; H, 3 .16; P, 12. 08 .

Attempted -preparation of trisfg-CdlphenvlphosPhlno)-^ , t , 5,6-tetra- fluorophenvllphosphlne. Preparation of b1s(2-(dlphenyfohosphino)-

5 .t, 5-.6-tebrafluoroT>henvl)phosphlne oxide.

A solution of 16.t g (0.0397 mole) of (2-bromo-3,t, 5*6- tetrafluoropheny 1)diphenylphosphine in 150 ml of diethyl ether was converted to the lithium derivative as described above. A solution o f 5 . t t g (0,0397 mole) of phosphorous trichloride in 5 ° ml o f diethyl ether was added and the resulting mixture was stirred for 1 hr.

The resulting pale yellow slurry was then removed from the cold temperature bath and allowed to warn to room temperature. After 30 min, no further change was observed and the slurry was hydrolyzed with

0.2 M hydrochloric acid. The fluffy white solid, which formed at the diethyl etlier-water interface, was collected by filtration. The organic phase was dried (CaCl2) overnight and the volume of solvent reduced, producing an additional quantity of fluffy white solid. The combined portions of the solid were then recrystallized from a hot

70^ ethanol/3055 benzene mixture to give T.*1- 6 (28$ yield) of white solid, m.p. 185“186°.

The IR spectrum of this compound contained a medium intensity, fairly sharp peak at 2390 cm 1, characteristic of a P-H stretching frequency.1J4The absence of any strong 0-H bands near 3500 cm 1 precludes a P-OH structure. The compound is formulated as the aryl secondary phosphine oxide.

Anal, calcd. for C2 q H2 i Pg 0P3 :

. • • C, 6O.52; H, 2.96; P, 13.00^.

Found: C, 60.65,* H, 3*15; P, 13-5^

The same compound resulted when the reaction mixture was refluxed for *1-5 mi*1 after addition of the PC13.

Synthesis of 2.5. fr-. 5-tctraf3-Uorophenvl methvl sulfide

A solution of 25.0 g (0.167 mole) of freshly distilled

1,2,3,t-tetrafluorobensene in 100 ml of purified tetrahydrofuran was cooled to -6lv° by immersion of the reaction vessel into a chloroform 39

slush hath. Over a 20 rain interval, IO3 ml of a 15.22$ solution of n-butyllithium in hexane (0.16T mole) was added, and the reaction mixture was allowed to stir for an additional 5 min, A slight excess of elemental sulfur (6 . k g, 0. 200 mole) was added directly to the reaction mixture and stirred for 15 min before adding 51.1 ml (0. 500 mole) of methyl iodide. After the black reaction mixture had been stirred for li-0 min. it was removed from the cold bath and allowed to o warm to room temperature. After *1-5 min of stirring at room temperature, the reaction mixture had changed into a yellow-white s lu r r y . The s lu r r y was hydrolyzed w ith 100 ml o f aqueous ammonium chloride solution, and the organic phase was separated and dried

(CaSO^.) o v e rn ig h t. S o lv e n ts were removed b y an a s p ir a t o r and th e remaining dark amber liquor was filtered to remove unreacted sulfur.

The filtrate was dissolved in 30 ml of methanol, cooled to -70°, and filtered through a funnel which was maintained at -78°. A light brown solid (28.5 g, 87$ yield) was obtained. This product was recrystallized twice from methanol at -78° to give a light amber, crystalline, lachrymatory solid which melted near 20°. The proton

NMR spectrum showed a complex m ultiplet centered at t3* 20 (aryl proton) in relative intensities of J.O to 0.92. The compound can also "be vacuum distilled [b.p. 62.0°

(0.6 mm)] f o r p u r if ic a tio n .

Anal, calcd. for C7II4F4S:

C, H, 2 .0 5 ; S, 16.31#,

Found: C, k$. 02; H, 2.06,* S, 16.52.

Diphenylf 2-(methy.lthio)-3. 5.6-tetraf luorophenyllphosphine (fSP-CH-^)

» A solution of 20. 3 g (O. I0f|. mole) of 2, J>,h3 5~tetrafluorophenyl

metliyl sulfide in 200 ml of anhydrous diethyl ether was cooled to

-73° by immersion of the reaction vessel in a Dry-Ice/isopropanol

bath. To the cold stirred solution was added 6^.0 ml of a 15. 22$

solution of n-butyllithium in hexane (0.10lf mole) over a 20 min

interval, producing a brown-black solution. After 20 additional min.

22.9 g (0. lOlj- mole) of chlorodiphenylphosphine dissolved in 25 nil of

diethyl ether was added slowly to the black solution. The resulting

mixture was stirred for 20 min and then removed from the -78° bath

and allowed to warm to room temperature. The reaction mixture

became a dark amber slurry on warming and after 1 hr. at room temperature,

no additional change was noted. The reaction mixture was hydrolyzed

w ith an aqueous ammonium c h lo rid e s o lu tio n and th e am ber-red o rg an ic

phase was separated. Solvents were removed with an aspirator to

give a brown o il which, on addition of $0 ml of 95$ ethanol, deposited h i

27*6 S (70.3$ yield) of a crystalline, light tan solid. The compound was recrystallized from 95$ ethanol and dried in vacuo. The proton

NMR spectrum showed a singlet at t7-65 (s-CH3 protons) and a m ultiplet centered at t2. 72 (aryl protons), integrating in the ratio 3. 0/l0. 0, m.p., 70-71O.

Anal, calcd for CisIIi3P4PS:

C, 60. 00; H, 3. Ml-; P, 8. 15$ .

Found: C, 59-93; H, 3.^5; 8.17.

Preparation of the methyl iodide derivative of FSP-CIU

A solution of 0.30 g of FSP-CH3 in methyl iodide was refluxed for 2 hr. The white crystals which precipitated as the solution cooled were collected on a filte r and washed with diethyl ether. The compound was recrystallized by dissolving it in hot ethanol, filtering the solution and adding diethyl ether to the filtrate. The resulting colorless needles were collected on a filter, washed with diethyl 4 A ether, and dried in vacuo. m.p., 173“17^ •

Anal, calcd for CaoHioF^IPSi

C, ^ 6 .1 7 ; H, 3*10$.

Found: C, U6.22; H, 3*18. h2

(g-Bromo-l|--benzylmercapto-g, 5.6 -trif luorophenyl)diphen;y.tphosphine

Freshly cut m etallic sodium (0.1613 g, 0. O266 mole) was

added to 35 ml °f ethanol to give a solution of sodium etlioxide. A

solution of 3.OO g (0.02^2 mole) of benzylmercaptan in 10 ml of

ethanol was added to form a solution of sodium benzyl mercaptide.

Powdered 2-bromo-5, if-, 5,6-tetrafluorophenyldiphenylphosphine (l0. 00 g,

0.02^2 mole) was added directly to the mercaptide solution. After

several minutes of uneventful stirring, the slurry suddenly began to

react quite rapidly to form a congealed mass of flocculent, curdy white solid. An additional 25° ml of ethanol was added, precipitating more white solid. The mixture was slowly heated, and then refluxed

for 30 min. The orange slurry was cooled, filtered, and the resulting white fluffy powder air dried (10. k ’} g). The solid was recrystallized

twice from 275 ml of hot ethanol to give 9*6 g (87$ yield) of an

analytical sample of white needles, rrup. 118-119°C.

Anal, calcd for C25Hi7BrF3PS:

C, 58.1*1-,* H, 3 . 3I,* S, 6. 21,

Found: C, 59.13; H, 3*^8; S, 6.7k

.58.97 3^3 T-52.

calcd for C25Hi7F4FS (Br substitution):

C, 65.7^J H, 3* 72; S, 7.01. G. Preparation of Coordination Compounds of FSP-CHq

Unless otherwise noted, syntheses of rhodium, iridium, and platinum complexes v/ere performed in an inert, dry nitrogen atomosphere using dry, deaerated solvents and reagents.

HitFSP-CH.OoCls.

A slurry of 0.260 g (2 mmole) of anhydrous NiCl2 in 10 ml of acetone was added to a solution of 0. 753 g (2 mmole) of the ligand .1 FSP-CH3 in 10 ml of acetone. The color of the mixture gradually deepened to a deep red and a voluminous pale-green precipitate formed.

The mixture was refluxed for four' hours, then cooled and filtered to give O.58 g (65^) of the pale green, powdery complex. The compound was recrystallized from dichloromethane-ethanol.

Anal, calcd for C3eH2SCl2FeNiP2S2:

c, 51.27^ H, 2. 9h} C l, 7 -9 6 .

Found: C, 51.1k; H, 5.17,* Cl, 8.12.

The pale-green complex forms red solutions when dissolved in common organic solvents.

Ni ( FSP-CHo )oBr-j

The ligand FSP-CH3 (0. 760 g, 2 mmole) was dissolved in 5 ml of dichloromethane and added to a slurry of 0.219 g (l mmole) of anhydrous NiBr2 in 30 ml of warm n-butanol. After a few minutes of stirring, the solution became red in color and a green precipitate

formed. After a total of three hours of stirring, the mixture was

cooled and filtered to give the pale-green complex.

Anal, calcd. for C3aH2SBr2F0NiP2S2:

C, MS. 6 1 ; H, 2 .6 8 ; B r , 1 6 . 3 2 .

Found: C, MS. 23; H, 2 . 5 1 ; B r , 1 6 . U »

The complex dissolves in acetone, ethanol, dichloromethane and chloroform to give red solutions.

Ifi(F S P -)o

A solution containing 0,1)-21 g (l mmole) of UiI2*6H20 in 15 ml of ethanol was added to a solution of 0.7 60 g (2 mmole) o f FSP-CII3 in 5 ml of dichloromethane. An immediate deep green solution resulted and bright green needles were deposited when the volume of solvent was reduced to 15 ml. The complex was redissolved in a minimum of dichloromethane and filtered into ethanol, giving bright green needles.

Anal, calcd. for C33H2oFoNiP2S2:

c, 5M78; H, 2.55; I, 0.00.

Found: C, 5M69; H, 2.67; I, 0.32.

Alternate preparation of Wi(F5P-)<.

A quantity of Ni(FSP-CH3)2Br2 (0.2 g, prepared as described above) was dissolved in 20 ml of dichloromethane to give a red solution.

The solution was allowed to stand exposed to air for forty-eight hours, solvent occassionally being added to replace evaporation losses.

After two days, the red color had completely vanished and was replaced by the characteristic deep green color of [Ki(ESP-)2]. Upon evaporation of the solvent, deep green needles formed, which were identified by infrared and visible spectroscopy to be the S-demethylated

[Ni(FSP-)a]. The demethylated complex also may be prepared by refluxing solutions of Ni(ISP-0113)3X2 (X= Cl,3r) in ethanol-DMF or by addition of iodide ion to solutions of Ni(lSP-CH3)aXa (x= Cl,Br,NCS).

Attempted realkylation of Ni(FSP-)o

The mercaptide complex N1(fSP-)2 (0. 5 g) was refluxed with no visible color change for 2h hr in a chloroform solution containing

10 ml of benzylbromide. The solution was allowed to stand at room temperature overnight, again with no color change and presumably no reaction occurring.

The demethylated complex was stirred overnight at room temperature in dimethylsulfate with no evident color change. Upon reducing the volume of solvent, the demethylated complex was recovered.

Similar results were obtained with methyliodide as the potential alkylating agent. Likewise, after refluxing a solution of [Ni(FSP-)a] in acetyl chloride for several hours, only unreacted complex was reco v ere d . U6

rMi (FSP-ClIo )B r0‘ q jf a l

The complex Ni(FSP-CH3)2Br2, prepared as described above, was stirred for fifteen minutes in hot benzene, forming deep red crystals. The well-formed, deep red prisms were collected on a filte r and washed with cold benzene.

Anal, calcd fo r C23HisLBr2P.].NiFS:

C, h h .3 3 i H, 2.82; Br, 23.62; P, 1*. 5&

Found: C, ij-5-21; H, 3*06; Br, 23.86; P, U.6L

This complex is quite sensitive to polar solvents, reverting to the

NiLsXg complex in the presence of alcohols, water, etc. The benzene solvate was retained even after drying in vacuo overnight at room temperature. f Mi(FSP-Chn)^(CNS)o1

A solution of 0.366 g (l mraole) of NifciO^Jg*6h20 and

O.I3O g (2 mmole) of LiNCS in 20 ml of ethanol was added to a solution of O.76O g (2 mmole) of FSP-CH3 in 5 ml of dichloromethane. After stirring for fifteen minutes, the brown powder which had separated / was collected on a filte r and washed with ether. Red-brown micro crystals were obtained upon recrystallization of the compound from an ethanol-dichloromethane solution. Anal, calcd for C4 oHsGFeNgNiPaS^:

C, 5 1 .3 5 j H, 2 .8 0 ; N, 2 .7 2 .

Found: C, 5 1 .0 6 ; H, 2. 83; N, 2.99* rWi(jSP-CH^)(NCS) 0 1

The brown [Ni(FSP-CH3)2(WC5)2] complex was dissolved in a minimum of dichloromethane, giving a green solution. After standing for fifteen minutes, the solution deposited a light green powder.

The complex was filtered and washed with light petroleum ether to give a fluffy, pale green powder.

Anal, calcd for C2iHi3F4N2NiPS2;

G, lf-5.^2; H, 2.36; N, 5.10; p, 5. 58.

Found: C, H5.6I; H, 2.^3; N, 5*06; P, 5.62.

This complex is extremely sensitive to polar solvents and to moisture, rapidly reverting to the brown NiLgCNCSjg species upon contact with these agents.

Attempted preparations of fNi(FSP-ClO;3~l(ci0,i.)c». rMi(FSP-CHa)r>l(NQ^);a« filifFSP-CHn )o1 (CHoCOn)'p. and Mi(FSP-CHq)o(CW)e..

Combined solutions of 1,9° g (5*0 mmole) of FSP-CH3 and 0. 765 g (2.5 mmole) of Ki(ci04)2*6h20 in 15 ml of n-butanol were stirred for three hours and then cooled. On evaporation of the solvent to

5 ml, a yellow-green solid precipitated. The solid was recrystallized from methanol-dichloromethane to give a light yellow-green, ether soluble product. The solid was identified by its infrared spectrum as being the starting ligand. Similar results were obtained when the reaction was carried out in acetone and when the solution of ligand and nickel(ll) perchlorate were refluxed for 1-2 hrs.

Mixtures of unreacted ligand and nickel(ll) salt were likewise recovered when Ni(CH3C02 )2, Ni(cw)2, o r Ni(N03 )a‘6h20 were used in place of Ni(ci04)2*6H20. rPd(FSP-CH^)cio~l

A solution of 0.295 g (l mmole) of Ha2PdCl4 20 ml of butanol was added to a solution of 0.760 g (2 mmole) of FSP-CH3 in

5 ml of dichloromethane. A yellow powder separated after the solution hod stirred for five minutes. The complex was collected on a filter, washed with ether, and recrystallized from dichloromethane-ethanol.

A nal, c a lc d f o r C i9Hi3C l2F,j.PPdS:

C, Ul. 0; H, 2.3; Cl, 12.76.

Found: C, hO. '(• h, 2 .h ; Cl, 13.60. f Pd(FSP-CIIri )Bro ~1

The ligand FSP-CH3 (0.760 g, 2 mmole) was dissolved in 5 nil of dichloromethane and added to a solution of 0.295 8 ( l mmole) o f

Na2PdCLi 311(1 0*7lli- 8 (6 mmole) of KBr in 20 ml of ethanol, giving an immediate orange coloration. The solution was stirred for two hours, then cooled and filtered to give a yellow solid. The complex was ^9

recrystallized from dichloromethane-butanol to give a yellow powder.

Anal, calcd. for CioHigBr^F^PFdS:

C, 5 5 .3 0 ; H, 2. 03.

Found: C, 35-75; H, 1.57. fPd(FSP-CH^)lo1

Solutions of O.76O g (2 mmole) of FSP-CH3 in 5 nil of dichloro methane and 0.295 8 (l mmole) of Na^PdCl* and 0.600 g mmole) of

Nal in 20 ml of ethanol were mixed, resulting in a deep red solution.

The solution was stirred for two hours, cooled, and filtered. The resulting red residue was recrystallized from dichloromethone-ethanol to give red platelets.

Anal, calcd, for Ci9Hi3F4laPPdS:

C, 30.81,* H, 1.77; P, 4-18-

Found: C, 30.38^ H, 1.77; P, M 9.

The complexes Pd(FSP-CH3)xa (x=Br, i) were also prepared "by metathesis, from Pd(FSP-CH3)ci2 in dichloromethane-ethanol solutions. rPdfFSP-CH-JfocM)-^

To a warm solution containing 0.295 S (l mmole) of Wa2PdCLt and .260 g (Ij. mmole) of IdSCN in 20 ml of n-butanol was added a solution of O.38O g (l mmole) of FSP-CH3 in 5 ml of dichloromethane. The yellow precipitate, which immediately formed on mixing the solutions, was collected on a filte r and recrystallized from dichloromethane-ethanol, giving yellow needles of the conplex.

Anal, calcd. for C^iHi3F<1I'T2PPdS3:

C, *1-1.82; H, 2.08; N, P, 5. lU.

Found: C, ill. 65; H, 2.37,* N, h. 57; P, if. 79.

{rPdtFSP-CHO^-KciQtM

A solution of 0.295 g (l mmole) of Na2PdCl,t in 20 ml of n-butanol was added to a solution of 0. 760 g (2 mmole) of FSP-Cir3 i n

5 ml of dichloromethane. After the resulting solution had stirred for one minute, a hot solution of 0. 5 g (l|-. 7 mmole) of LiC104 in

10 ml of n-butanol was added. The mixture was cooled after 10 minutes and filtered to give a yellow solid. The complex was recrystallized tv/ice from dicliloromethane-n-butanol to give a very pale yellow powder.

Anal, calcd for C3fjII260l2Fs0aP2PdS2:

C, it-2. 81; H, 2.1(6; P, 5. 82.

Found: C, 1(3*02; 2.1)6; P, 6.12. fPd(FSP-)01

Equim olar amounts o f [Pd(FSP-CH3 ) c i2 ] and FSP-CH3 were refluxed in N, N-dimethylformarnide for one hour. On reduction of the solvent bo a small volume and cooling, an orange-yellow solid precipitated. 51

The complex was recrystallized from dichloromethane-ethanol to give yellow-orange microcrystals.

Anal, calcd for C33H2oFaP2PdS2:

C, 5 1 .6 5 ; H, 2.1*1; C l, 0.00.

Found: C, 5O.65; H, 2.77; Cl, 0.32.

The compound was prepared sim ilarly from Pd(FSP-CH3)Br2 and

Pd(FSP-CH3)l2, as w ell as by heating[Pd(FSP-CH3^](C104)2. f CPd (F S P -) C ll o- i A dm f?

The complex [Pd(FSP-CH3)ci2] was refluxed in N, N-dimethylformamide for four hours. On reduction of the volume of solvent and cooling, a yellow-orange solid deposited. The complex was recrystallized from dichloromethane-n-butanol to give tan-yellow microcrystals.

Anal, c a lc d . f o r C3yH22. 3C12FqNo. 33Oo.33PsPd2S2 :

C, 1^2.93; H, 2. 31; N, 0. 88.

Found: C, 1*3.1*1; H, 2 .9 0 ; IT, 0 .8 9 .

Even after drying in vacuo overnight, the DMF solvate was retained, as shown by elemental analysis and the presence of a carbonyl infrared stretching frequency at 1660 cm 1. 52

Rh(FSP-CKo)(CO)Cl

The chloro-bridged dimer [PhCl(co)2]e (.17*1- g, 1 mmole) was dissolved in 10 ml of "benzene. To this red solution was added a

solution of O.309 g (l mmole) of FSP-CH3 in 3 ral °f benzene, giving an immediate effervescence of gas and a light yellow solution. After five minutes of stirring, the color had deepened to orange and glistening yellow-orange needles "began to form. The solvent was completely evaporated to give a homogeneous, tan-yellow fibrous material. The solid was dissolved in 5 ml of acetone and filtered

into 5 ml of ethanol. On reduction of solvent volume to 5 ml and cooling, crystallization began immediately. After standing overnight, the crystals were collected and washed with cold acetone and ether,

yielding bright-yellow micro needles.

Anal, calcd. for C2oHi3C10PSKh:

C, h j.9 h ; H, 2 .b 0 j Cl, 6.1|8.

Found: C, ^3.87,- II, 2.39; Cl, 6.51.

Molecular Weight

C alcd. : 5*1-7

Found (in chloroform): 5hh 55

Attempted preparation of fRhCFSP-CHn )cn from fRh(l. 5-cyclo-oetadiene)cilJ

In 9 ml of benzene was dissolved 0.lj-92 g (2 mmole) of

[RhCl(c0Hi2)]2 to give an orange solution. A solution of 0. 760 g

(l mmole) of FSP-CH3 was added, resulting in a slight deepening in color, and after stirring fifteen minutes a yellow precipitate began to form. The mixture was stirred forty-five minutes, cooled, and filtered. The resulting bright yellow powder was washed repeatedly with cold ethanol and ether (0. g). The complex was recrystallized from chloroform to give 0.236 g of bright yellow, triclinic prisms.

A nal, c a lc d . f o r C2ylI3 iC IF4PSflh:

c, 51-75* H, h .9 9 ; C l, 5-66

Found: G, k l . 58; H, 2.78; Cl, 13*72

Atom Ratio: Ca.90H7. 13Cl

Attempted preparation of rRh(FSP-CH.rj)ll from rRh(cyclo-octadiene)l1

The ligand FSP-CH3 (0.58O g, 1 mmole) was dissolved in 1 ml of benzene and added to a solution of the (Eh(cyclooctadiene)l]2 dimer in 5 ml of benzene. After stirring for fifteen minutes at room temperature no color had occurred, so the dark brown solution was warmed nearly to reflux. The solution rapidly lightened in color and a precipitate formed. After thirty minutes of stirring the mixture was cooled and filtered in the air. The bright light-yellow powder was washed with hexane, cold ethanol, and ether to give . 105 g of product. .Additional crops from the filtrate amounted to . 195 S*

Anal, calcd. for [Rh(FSP-CII3)l], CaoIIi3F4IPRhS:

C, 37.^0; II, 2.15j I, 20.80

calcd. for [Rh(FSP-)(cyclo-octadiene)], C2QH22F4.PEhS

C, 52.81; H, 5-75; I, 0-0

Found: C, 1*3.80; H, 3.25; 5*68

The H1 nmr spectrum contained a m ultiplet centered at 2. 58 T, attributable to the aromatic protons of FSP-CU3, but no peaks in the

5.10 -r region, implying demethylation of the FSP-CH3 ligand and the absence of cyclo-ocbadiene. The low iodine analysis also indicates parbial demethylation.

Attempted preparation of lrCl(cyc.to-octadiene)(FSP-CH3)

To a solution of 0.1*06 g (l.23 mmole) of [lr(CsHi2)ci]2 in 5 ml of benzene was added 0.1^688 FSP-CH3 (l, 23 mmole), resulting in an immediate color change from red to orange. After one-half hour of stirring, a light yellow precipitate began to form. Upon addition of f* ml of light pebroleum other and cooling, a mixture of an amorphous white solid and massive clusters of yellow crystals resulted. The mixture was recrystallized from benzene to give 0.283 g of yellox/ complex. Infrared and H1 nmr spectra indicated a 1:1 ratio of FSP-CH3 55

and cyclo-octadiene in the recrystallized complex. Upon recrystallization from a 1:1 mixture of dichloromethane and pentane, large yellow parallelopipeds were obtained.

Anal, calcd. for C27H25CIF,j.IrPS:

c, ^5. 28; H, 3. 52; Cl, it-. 95-

Found: C, lf-9.98; H, 1+. C l, k . 38.

Ir(FSP-CHa )3C13

To a red solution of .371 g (l mmole) of IrCl3**lH20 in 15 ml of DMF was added 0.900 g (2.*!• mmole) of FSP-CH3. After stirring overnight, the red solution appeared unchanged. The reaction mixture was filtered and the DMF solvent volume was reduced to 5 ml by vacuum, whereupon a fine powder began to precipitate. On addition of 20 ml ether, cooling, and filtering a pinkish powder and reddish solution were obtained. The powder was x’ecrystallized twice from ethanol/dichloromethane to give a small quantity of microcrystalline pink powder. M.p. 262-263°C.

Anal, calcd for CS7H3oCl3Fi2IrP3S3:

C, ll-T.56; H, 2.73; Cl, 709.

Found: C, 03, II, 2 .6 7 ; C l, 7 .6l . 56

Ir(F S P -) (CH-i) ( c o ) c i

The white Ir(cyclo-octene)3(C0)ci complex (0. 586 g, 1.23 mmole) was dissolved in 15 ml of refluxing benzene to give a yellow solution.

The ligand FSP-CH3 (0. Vro g, 1.23 mmole), dissolved in 2 ml of benzene, was added to the solution whereupon a deep red coloration developed. After ten minutes a precipitate formed, creating a bright orange slurry. After refluxing twenty additional minutes, no further color change was noticeable. The reaction mixture was cooled and filtered to give a bright red solution and a yellowish solid. The precipitate was washed repeatedly with benzene to produce a pure white, plaster-like powder (0.257 g, 26$). The compound was recrystallized from 250 ml of hot benzene.

Anal, calcd. for CaOHi3ClF4Ir0PS;

C, 37.77,* H, 2. 03- c i , 5. 57.

Found: C, 37.te; H, 2 .^ Cl, 5.7k 57

Attempted •preparation of Ir (FSP-CH^) (co)ci

1. via displacement of PPh3 in trons-Ir(PPh3)s (co)ci

A solution of 0.960 g (l. 2j5 mrnole^ of Vaska's compound, trans-Ir(PPh3)2(C0)ci and O.H68 g (1.23 mmoles) of FSP-CH3 in 5° ml

of dry benzene was stirred vigorously overnight with no visible color change. The reaction mixture was evaporated to dryness and the resulting yellow solid dissolved in f{-5 ml of benzene and filtered.

Upon reducing the volume of solvent, a yellow precipitate formed; on addition of ether, additional solid separated. A total of 0. k66 g

(O.571 mmoles) was recovered and identified by its infrared and H1 n.m.r.

spectrum to be unreacted Vaska’s eonipound. The recovered trons-

Ir(PPh3)2(co)ci (O.571 mmoles) was then dissolved together with 0.228 g

( 0 .6 0 mmoles) o f FSP-CH3 i n 15 m l o f benzene. The y ello w s o lu tio n was refluxed for two hours with no visible color change. Upon filtering, cooling, and reducing the volume of the filtrate, a yellow compound crystallized whose infrared spectrum was identical to that of the unreacted Vaska* s compound. 58

2. via reduction in N, N, -dimethylformamide

The method is analogous to a standard method of preparing 1S4>165 Vaska's compound, trans-Ir(PFh-a) o ( C0)C1.

To a solution of .371 g (l mmole) of IrCl3*l|-H£0 in 10 ml

BMP was added 1.1^ g (l. ill- mmoles) of FSP-CH3. I’he red solution was heated to reflux; within the first two minutes of heating, the color changed to light yellow-orange. The solution was heated for lJf hrs with no further color change being noted. The solution was cooled to room temperature and the quantity of solvent was reduced by vacuum to 6 ml, yielding a yellow solution. Despite using a great variety of solvents and conditions, and techniques (including column chromatography on alumina and silica gel) only an intractable o il was obtained from the yellow solution. The infrared spectrum of the oil contained no bands in the 2000 cm 1 region attributable to a carbonyl group.

Au(FSP-CIf.Jci

To a solution of 0.362 g (l mmole) of NaAuClt in 10 ml of anhydrous acetone was added 0.38O g (l mmole) of FSP-CII3 dissolved in Jj- ml of anhydrous acetone. After twenty minutes of stirring, the reaction mixture was filtered to remove the fine white precipitate of NaCl which separated. To the yellow filtrate was added 8 ml of ethanol, and then the acetone was evaporated until crystallization just started. After cooling the solution in the refrigerator, yellow, 59

parallelopipeds, contaminated with a small quantity of white solid, were obtained. The solid was dissolved in acetone and filtered, yielding a colorless solution. On addition of 5 ml of ethanol and reduction of the volume of solvent, white crystals separated. The crystals were washed with ethanol and ether.

M. p. 200-203°C.

Anal, calcd. for Ci9Hi3AuClF4PS:

C, H, 2. i t ; C l, 5- T9.

Found: C, 36. Oj H, 2.19; Cl, 5*66.

The Au(FSP-CH3)ci complex was also prepared by the reaction of chloroauric acid with the ligand in refluxing acetone. A second product, the pink Au(FSP*-)ci2 compound described below, also is formed in this reaction. Au(rSP-CH,JBr

The deep purple color of a solution of 0.556 g (l mmole) of

KAuBr^j. in 10 ml of 95$ ethanol was discharged with a stream of S02, yielding a turbid, murky light tan solution and a small amount of white powder. To this mixture was added 0.380 g (l mmole) of FSP-CH3 dissolved in k ml of anhydrous acetone. After . 5 hr stirring, the turbid reaction mixture was cooled in the refrigerator overnight. A mass of soft, fine, colorless needles crystallized along with a small quantity of brown sludge. The mixture was filtered and washed repeatedly with water and cold ethanol, whereupon additional white 60

solid crystallized from the filtrate. The crystals were recrystallized from hot ethanol and waGhed with ethanol and ether. M. p. l8l|--l860C.

A nal, c a lc d . f o r C i9Hi3AuBrF,tPS:

C, jh . 72; H, 1.99,* Br, 12.16.

Found: C, jh.66; H, 2.09^ Br, 1J. IT.

Molecular Weight:

C a lc d .: 657*

Found (c h lo ro fo rm ): 655*

Attempts to demethvlate AufFSP-CHOci

The colorless Au(FSP-CH3)c1 (0.25 g), prepared as described above, was refluxed for 1.5 br in 15 ml of absolute ethanol with no color change. N,N-dimethylformamide (15 ml) was added and refluxing was continued for 1. 5 hr, again with no color development. The solvents were removed under vacuum and the resulting white crystalline solid (0.25 g) was washed repeatedly with ether. The H1 nmr spectrum of the solid was identical to that of the starting material, indicating that no reaction had occurred. Similarly after refluxing a solution of

Au{FSP-CH3 ) c i and e x c e ss N al i n a 'jO/'jO ethanol-DMF mixture, unreacted complex was recovered.

The recovered Au(fSP-CII3)c1 (0.25 g) was then refluxed for four hours in 8 ml of DMF, giving a dense yellow solid and a pale 6i

yellow solution. The brilliant yellow solid (o. 1 g) exhibited no infrared absorbance in the ^OO-lj-OOO cm 1 region and was identified as metallic gold.

[ au(f s p -) c i2]

To a refluxing light yellow solution of .tlO g (l. 03 mmole) of NaAuCl*’ l|-H20 in 10 ml of acetone was slowly added a solution of

0.391 6 (l»03 mmole) of FSP-CH3 in 10 ml acetone. An immediate light yellow slurry resulted, and after 1. 5 hrs of refluxing, the reaction mixture had become a suspension of white powder in an orange solution. The small quantity of white powder (soluble in water and thus probably ITaCl) was filtered off and the orange filtrate was evaporated to give a tacky orange-yellow solid. On addition of 5 ml of ethanol, the solid became a brown, oily sludge. The sludge was washed with ether, then dissolved in acetone and filtered. The volume of the yellow filtrate was reduced until crystallization just began, and then the flask was placed in the refrigerator. A beautiful, light pink-purple microcrystalline solid crystallized. The solid was recrystallized tv/ice from acetone, and the final solid was washed repeatedly with acetone and ether. The pink crystals are only slightly soluble in acetone and even less so in other common organic solvents.

Yield 1 g. M.p. 23!J--237°C. 62

Anal, calcd. for CigHioClgF^PS, [Au(rSP-)ci2]:

C, 3 k .lk 'i H, 1 .5 9 ; Au, 31* 10; C l, 1 1 .2 0 ;

F, 12.00; N, 0.00; P, If. 89; S, 5-06.

Found: C, ~f>b. 15; H, 1.71; Au, 30.6; Cl, 11.08;

F, 12.08; N, 0.13; P, 5.5O; S, 5.O7.

H. Preparation of Coordination Compounds of SP-CH^

CM(SP-CH 3 ) l a l

To a solution of 0. 716 g (2 mmole) of SP-CH3 in 10 ml of hot ethanol was added a solution of 0.^21 g (l mmole) of HiI2'6H20 in

10 ml of ethanol. The solution immediately became red in color and after stirring for a few minutes, a brick-red solid i)recipitated.

The red solid was dissolved in dichloromethane and filtered, yielding a deep blue solution. On addition of ether to the filtrate, intensely colored blue-black needles formed. The crystals were collected on a filte r and washed with ethanol and ether.

Anal, calcd. for CioHiylgNiPS:

C, 3 6 .7 5 ; H, 2 .7 6 ; I , l|-0. 88; P, 1I-.99.

Found: C, 3?. *1-9; H, 2.1a; I, lH. 06; P, h.T5- 63

All attempts to purify the red-brown precipitate which immediately forms upon mixing Nils and the ligand yielded only the above

[Ni(SP-CH3)l2]. Preparations in other solvents gave similar results.

T Ni(SP-CHn)^(NCS)o 1

To a solution of 0.120 g (1.1(8 mmole) of NaSCN and 0.272 g

(0. 7*1- mmole) of N i(ci04.)2*6h20 in 15 nil of ethanol was added a solution of 0.Jt-57 g (l. H8 mmole) of SP-CH3 in 8 ml of dichloromethane; a red-brown precipitate formed immediately. The mixture was stirred for ten minutes, filtered, and the precipitate washed with ether. The solid was air-dried, dissolved in a minimum quantity of dichloromethane, and filtered to give a brown-orange solution. The solution was evaporated nearly to dryness, whereupon a small quantity of pale green solid precipitated. The solid was redissolved by adding a few ■ m illiliters of dichloromethane; on addition of light petroleum ether

. 30 g (51$) of brown microcrystals separated.

Anal, calcd. for O4 oH34.N2NiP2S4:

C, 60. 70; H, Jk33; N, 3. 51*.

Found: C, 60A3; H, ^.33; N, 3* 6h

[Nl(SP-CH3)(NCS)a]

The brown Ni(SP-CH3)2 (NCS)2 complex (0.20 g, 0.25 mmole) was

stirred for 15 min. in 3 ml of dichloromethane. The resulting pale

green powder was collected on a filte r and thoroughly washed with ether.

Yield 0.10 g (0.23 mmole, 92$)*

Anal, calcd. for C2oHi7NsNiPS3:

C, 52. 20,- H, 3.5 5 ; N, 5. BO.

Found: C, 52*37; H, 3 . 8I ; N, 3. 36.

In the solid state the pale green compound slowly assumes the brown

color of the Ni(SP-CH3)2( CNS)2 complex on standing for long periods of

time. The same color change is also noted upon grinding the green

compound.

CNi(SP - )a l The ligand SP-CH3 (0. 716 g, 2 mmole) and NiI2-6H20 (.^21 g,

1 mmole) were combined in 10 ml of hot ethanol yielding an immediate brick-red precipitate. The mixture was refluxed for one hour,

yielding a green solution which, on cooling and filtering deposited

a bright green solid. The precipitate was recrystallized from

dichloromethane-ethanol, resulting in bright green microcrystals of

the complex. 65

Anal, calcd. for C3oH2QWlPaS2:

C, 66.99,* H, 4.57; I,- 0. 00; P, 9.61.

Found: C, 66.74; H, 4.58; I,<0.3; P, 9.59.

Alkylatlon of Ni(sp.-)P

A solution of 0.3 g (0.4 mmole) of Ni(SP-)a in 20 ml of methyliodide was heated to the reflux. The in itial deep green color rapidly changed to red during the first five minutes of refluxing and then gradually changed to a deep blue-black color. After two hours of heating, no further color change was noted and the reaction mixture was evaporated to dryness. Upon addition of ethanol and ether to the resulting dark oil, deep blue-black crystals formed. The complex was identified as being the methylthio complex Ni(SP-CH3)l2 by its infrared and visible absorption spectra.

Upon refluxing an equimolar mixture of Ni(SP-CH3)l2 and

SP-CH3 in an ethanol-DMF mixture for thirty minutes, the characteristic deep green color'of Hi(SP-)2 was regenerated.

RhfSP-CHn) (C0)C1

To a solution of 0.174 g (l mmole) of [PhCl(C0)2]2 in 10 ml of benzene was added .308 g (l mmole) of SP-CH3; the solution gave an immediate effervescence and a yellow precipitate appeared within a few minutes. The mixture was cooled and filtered, and the resulting 66

residue was extracted with warm acetone and filtered. On reducing the volume of acetone in the filtrate and cooling, a yellow precipitate formed. The complex was recrystallized twice from dichloromethane- ethanol and washed with portions of ethanol and diethylether.

Anal, calcd for C 2 oHi 7 C1 0 PSKh:

c , 5 0 .6 0 ; h, 3 . 6 1 ; C l, TAT.

Found: c, 50.21; H, 3-59; Cl, 6 . 5 2 .

I. Preparation of FDP and FTP Complexes f Ni(FDP)o1 (c IOa )o

The ligand FDP (0.80 g, l A T mmole), dissolved in 30 ml of hot ethanol, and Ni(ci04)2. 6h20 (0.225 S> 0.6l5 mmole), in 20 ml of ethanol were combined. An immediate yellow precipitate formed upon mixing the solutions. The reaction mixture was stirred for 15 minutes, cooled, and filtered, and washed several times with ethanol and dichloromethane. The solid was virtually insoluble in ethanol, dichloromethane, chloroform, and benzene. The complex was recrystallized from DMF/ethanol to give 0. 5A g (yield, 8l$) of a yellow, powdery complex.

Anal, calcd. for CaofttoClsF-dliOsP^

C, 5 5 .6 7 ; H, 3 - l l J C l, 5 A 8 ; P, 9 -5 T.

Found: c , 55. hi; H, 3.?°; Cl, 5- 6 T; p> 9.20. r Ni(FDP)cio'l

To a solution of 0.80g (lJi-7 mmole) of FDP in 7 ml of dichloromethane was added a solution of 0.175 g (0. 755 mmole) of

NiCl2’6H20 in 15 ml of ethanol. The deep red solution was stirred for one minute, filtered, and cooled. The bright gold colored platelets were recrystallized by dissolving in dichloromethane/ethanol, filtering, and adding a small amount of ether to the filtrate.

Anal, calcd. for C3oH2oCl2F,tNiP2:

C, 55-60; II, 3.1 1 ; P, 9 .5 6 .

Found: C, 55- hZ; H, 3-27; P, 9.66. fNi(FDP)Bro1

Hot solutions of 0.800 g (1. h j mmole) of FDP in 30 ml of ethanol and 0. l6l g (0.735 mmole) of NiBr2 in 20 ml of ethanol were mixed. After stirring for fifteen minutes, the deep purple solution was filtered and cooled. Upon addition of 100 ml of ether to the solution, the complex crystallized. The complex was recrystalUzed by dissolving in 35 ml of chloroform, filtering, and adding 100 ml of ether to the filtrate. The resulting orange-brown platelets were collected on a filter and washed with ether.

Anal, calcd for C3oH2oBr2FeNiP2:

c, M3.89; H, 2.7*1-; P, 8. la.

Found: C, H8.68; H, 2.86; P, 8.61. 68

fNiCFDP)!./!

A solution of . 3O2 g (o. 735 mmole) of N1I2*6h20 was added to

a hot solution of 0.80 g (lJi-7 mmole) of FDP in 30 ml of ethanol.

After stirring for one minute, the solution deposited purple platelets. The mixture was cooled and the crystals were collected on a filter.

On recrystallization from chloroform, purple microcrystals of the

complex were obtained.

Anal, calcd for C;3oTfs oF4IsNiPa :

c, U3.36; H, 2.li-3; I, 30. 511..

Found: C, U2. 52; H, 2.36; I, 30. 2k.

r Ni(FDP)(NCS)o1

A solution of 0.269 g (O. 735 mmole) of Ni(cl04)2* 6ll20 and

0.0955 g (1.1*7 mmole) of LiNCS in 10 ml of ethanol was added to a

solution of 0.800 g (l. l|-7 mmole) of FDP in 25 ml of hot ethanol, producing a brown precipitate. The mixture was stirred for fifteen minutes, and then 100 ml of ether was added to complete crystallization.

The resulting solid was recrystallized by dissolving in 30 ml of

chloroform, filtering, and adding 100 ml of ether to the filtrate.

The light-brown fibrous, glossy microcrystals were washed with ether.

Anal, calcd for COHH2oNsFeNipQS3:

C, 55-^3; H, 2 .9 0 ; N, U. Oik

Found: C, 55-72; H, 2. 80; N, h. 00. -69 rCp(FDP)pI^

The ligand FDP (0. 750 g, 1. M6 mmole) was dissolved in 20 ml of hot ebhanol and added to a solution of 0,226 g (o. 7235 mmole) of anhydrous CoI2 in 10 ml of ethanol. The red solution was stirred for a few minutes, then cooled and filtered. The resulting red precipitate was recrystalllzed by dissolving in a minimum of dichloromethane, filtering, and adding diethyl ether to the filtrate.

Anal, calcd for CG0H1 oCoFoI2P4:

P, 8. 81.

Found: P, 9-21, 8.7H.

Pd(FDP)(NOS) (SON)

A solution of 0. 518 g (l mmole) of FDP in 5 ml of acetone was added with stirring to a solution of 0.114-7 g (o. 5 mmole) of

I'la^PdCli and . 08l g (l mmole) of NaNCS in 15 ml of ethanol. The deep red color of the [Pd(sCN)4]2 solution was rapidly discharged and a pink, highly insoluble precipitate quickly separated. The solid was collected on a filter* and repeatedly washed with diethyl ether. The pink solid was extracted with dichloromethane to give a bright ye3.1ov/- solution and an amorphous pink powder. The pink solid was warmed in N, N-dimcthylformanri.de for one hour to give, on addition of diethylether, a mixture of bright yellow needles and a pink solid.

The mixture was repeatedly washed with dichloromethane to again give TO

an insoluble pink powder and a bright yellow solution. Upon reducing the volume of filtrate and adding cold ethanol, yellow microneedles of Pd(FDP)(NOS)(SCN) crystallized.

Anal, calcd for C32H2 oF4N2P2S2 :

C, 5 1 .86; H, 2 .7 2 ; N, J .7 8 .

Found: C, *1-9.88; H, 2 .6 8 ; N, 5 .*1-5.

rui(FTP)cio1

Hydrated nickel(ll) chloride, HiCl2*6H20 (JH9 g, 1 mmole),

was dissolved in 10 ml of ethanol and added to a hot solution of

0.775 E (l mmole) of FTP in 25 ml ethanol and 5 ml of dichloromethane.

An immediate brown solution developed which gradually changed to a

deep-green color after one hour of stirring. Upon cooling in the

refrigerator, a green crystalline solid precipitated. The complex

was recrystallized by dissolving in 20 ml dichloromethane, filtering,

adding 10 ml of ethanol, and allowing the dichloromethane to slowly

evaporate; olive-green platelets formed.

Anal, calcd for C42H2S G12FgNiP3:

c, 55.80; h, 2.79; Cl, 7.89; P, 10.2a

Found: C, 55-89; H, 3. 0!|.; Cl, 7.8U; P, 9.92.

rHi(FTP)Drol

To a solution of 0. 219 g (1 mmole) of NiBr2 in 20 ml of

ethanol was added 0.775 g (l mmole) of FTP. The mixture was stirred

overnight, then cooled and filtered. The resulting green solid was 71

recrystalHzed by dissolving in a minimum of dichloromethane, filtering, adding 10 ml of ethanol to the filtrate, reducing the total volume of solvent to 10 ml, and adding just enough ether to initiate crystallization. Upon cooling the solution, olive-green micro-needles of the complex were produced.

Anal, calcd for C42H2sBr2FaNip3:

0, 50.79* H, 2.53* Br, 16.09* P, 9-35.

Found: C, 51.05* H, 2.1+0* B r, 15. 87* Pj 9 . 1+0, f Ni(FTP)lol

Hydrated nickel(ll) iodide, Ni3a'6H20 (.1+19 g, 1 mmole), was dissolved in 20 ml of ethanol and added to 0.775 g (l mmole) of FTP in 5 ml of dichloromethane. The brown solution was stirred for one hour, and then the volume of solvent was reduced to 5 ml. The resulting dark colored solid was recrystallized by dissolving in a minimum of dichloromethane, filtering into 10 ml of ethanol, reducing the total volume to 5 ml, and adding just enough ether to the filtrate to initiate crystallization. Dark blue-green microcrystals resulted* they give red solutions in ethanol, dichloromethane, and nitromethane.

Anal, calcd for C42H25FQl2NiP3:

C, 1+6. la* H, 2.32* I, 23-35; P,8.5k

Found: C, 1+6.1+6* H, 2.1+3* I , 23-15* P> 8.2 9. 72

frMi(FPP)cnBCCr>R-JA)

To a solution of 0.119 g (l mmole) of NiCl2*6li20 and 0.3^2 g

(l mmole) of sodium tetraphenylborate in 10 ml of ethanol was added a solution of 0.338 g (0,5 mmole) of FTP in 3 ml of dichloromethane.

Immediately, an orange-red precipitate formed "but within one minute had changed into a sticky brown oil. Upon addition of ether and standing, a yellow-orange solid formed. The powder was redissolved

> in a minimum volume of chloroform and filtered into 15 ml of ethanol.

The solution was cooled and the solvent was very slowly removed, but again a brown oil developed. Upon adding ether to the o il and allowing the mixture to stand overnight, a yellow orange solid formed. The complex was repeatedly washed with ether and ethanol.

A nal, c a lc d . f o r CesH4s B d F 8WiP3 :

C, 6 7 -18; H, 3 .81*; C l, 3 . 00; P ,7 .8 2 .

Found: C, 66.87,* H, It-. 00; Cl, 2.99,* P, 7-^6.

J. Miscellaneous Preparations

fr(cH^)^PSCHall)

Approximately 1 g (~10 mmole) of triraethylphosphinesulfide was added to 20 ml of methyliodide. The sulfide initially dissolved, but within a few minutes fluffy needles began to precipitate. The reaction mixture was allowed to stand overnight, and then the crystals were 75

filtered and washed with cold ethanol. Long white needles of the salt were obtained by recrystallization from ethanol. The crystals darken and emit sulfurous odors at lJ(-7°C and totally decompose at

192-19^°C.

Anal, calcd for C4H12IPS:

C, 15.21,* H, I, 50.75.

. Found: C, 1 8 .9 5 ; H, **-.89,* I , 50. 5^.

Recovery of the recrystallized product from ethanol was poor, but the crystals were of sufficient quality for single crystal X-ray examination. The compound is slightly hygroscopic. The H1 nmr spectrum shows a doublet (jp_^= 1^.6 Hz, r= 7*68) due to methyl groups on sulfur with relative peak areas J .l: ! . 0. ff (CHn )^PSGH-alBrt

A small quantity (~1 g) of trimethylphosphinesulfide was dissolved in 25 ml of ethanol. A slow stream of methylbroraide

(containing 2$ chloropicrin) was bubbled through the solution. After

1 hr, no apparent reaction had occurred so the solution was heated to the reflux for an additional hour. On cooling the solution overnight, a few colorless deliquescent crystals formed. The mixture was filtered and diethylether was added to the filtrate, giving a voluminous, amorphous white precipitate. The solid was collected on a frit, washed 7^

with diethylether, and dried under a stream of dry air. The compound was recrystallized from hot ethanol, giving a small quantity of colorless prisms.

Anal, calcd for C4.Hi^BrPS:

C, 23- 66; H, 5-96,- Br, 39-35.

Found: C, 23.6l; H, 6.15; Br, 38.91.

As for the iodide analogue, recovery of the recrystallized product from ethanol was poor hut gave crystals suitable for single crystal

X-ray examination. The bromide salt is slightly hygroscopic. The proton nmr spectrum showed doublets at t7. 67 (JV. = 1*1-. 7 Hz) and £ “0CI13 tT-68 = 1^*7 Hz) integrating in the approximate ratio 3.*t:l. 0,

Attempted demethvlation of FSP-CHn in the absence of transition metals

A solution of 1.00 g (2.63 mmole) of FSP-CH3 and O.T36 g

(2.63 mmole) of Nal in a mixture of 15 ml of ethanol and 3 ml of DMF was refluxed overnight, yielding a pale yellow solution. Solvents were removed by vacuum, cold ethanol was added to the resulting pale yellow solid, and the mixture was allowed to stand for 2 hrs. The solid was collected on a filter and recrystallized from hot ethanol to give white hexagonal platelets. The compound was identified by its infrared spectrum and melting point (69-7°°c) to be the unaltered ligand FSP-CH3. 75

Preparation of iodophenyldiphenylphosphine oxide

The method is an adaptation of McKlllop and Taylor's procedure for thallation of aromatic compounds.1S4j133

A stock solution of thallium (ill) tris-(trifluoroacetate),

Tjj(CF3C02)3, was prepared by refluxing 22. k g of thallium (lll) oxide,

T£203, in 5° ini of trifluoroacetic acid for 100 hrs under a nitrogen atmosphere and filtering off the nearly colorless solution. A 15 ml aliquot of the stock solution (0. 015 mmole of Tx(CF3C02)3), was added dropwise to a vigorously stirred solution of 8.910 g (0. O333 mmole) of freshly recrystallized, dried triphenylphosphine oxide in 10 ml of trifluoroacetic acid.

The solution turned a tea-brown color; after refluxing for two hours a sample of the light amber solution was withdrawn and its

H1 nmr spectrum determined; only a broad peak centered at 2. 75t due to unreacted triphenylphosphine oxide and a broad singlet at 1. Or due to trifluoroacetic acid were found, indicating little reaction up to this point. Thus, the reaction mixture was refluxed an additional

12 hrs. The solvent had evaporated under the nitrogen stream to give an amber solution which thickened to a syrup on cooling. The solution was diluted to the original volume with trifluoroacetic acid and the H1 nmr spectrum determined. The triphenylphosphine oxide and trifluoroacetic acid peaks wore s till very strong but additional resonances were found at 12. O^t, 9. 5°t, 6.65t, 5*93t, h. 7 5 t, and 1. M-t. 76

The peaks at 12. O^t and 1. are considered unmistakable evidence that an arylthallium species had been formed, but an analysis of the substitution pattern was obscured by the strong solvent and substrate peaks. The reaction mixture was then refluxed an additional .51 hrs; an H1 nmr spectrum of the resulting light amber solution showed little change from the aliquot collected after 1*1- hrs of reflux. The solution was refluxed another seven hours and the solvent was slowly evaporated

•i by a nitrogen stream to give an amber syrup which was soluble in ether, ethanol, and dichloromethane. Addition of 10 ml of ethanol and standing in the refrigerator overnight produced 1.2 g of white powder, identified as unreacted triphenylphosphine oxide. Addition of 100 ml of aqueous

KI solution to the filtrate gave a bright yellow precipitate. Extraction with ether produced a bright yellow highly insoluble residue which contained no infrared absorptions in the i|-00-lj.000 cm 1 range, (assumed to be thallous iodide, 2.6 g, 52$) and a yellow filtrate. The filtrate was dried over calcium sulfate, stirred over activated charcoal, and evaporated to dryness to give a yellow solid. Two recrystallizations from hot ethanol, yielded 1.Oj g (8.6$) of yellow, microcrystalline solid which was identified to be iodophenyldiphenylphosphine oxide on the basis of its mass spectrum (Eigurelll) m.p. l6l4--l67°C.. Relative % Abundance —j 0 5 2.5— gur III. Se as pcrm of ihnloohnlhshn oxide. aiphenyliodophenylphosphine f o spectrum mass She . I I I re u ig F ± 100 l F ll 200 i! t n!‘i t t *r m/e 100 • * p I '- 0 0 4 0 0 3 -j 78

K. Space Group Determination of Wi(^P-CHn)n(CNS)o

In order to verify the molecular mass and to obtain preliminary

crystallographic information about Ni(FSP-CH3)2 CWGS )g the space group was determined by x-ray crystallography. After a number of unsuccessful

attempts to grow crystals suitable for x-ray photography from a wide

variety of solvents and conditions, adequate crystals were finally

obtained by extremely slow evaporation of a chloroform solution.

A red-brown needle of approximate dimensions 0.07 x 0.15 x 0.30 mm was selected and mounted with the needle parallel-to the goniometer axis.

Oscillation, Weisseriberg, and precession photographs indicated a monoclinic crystal mounted about ''a''. The systematic absences

observed on 0k£, lk£, and 2kjJ Weissenberg and h0£ and hljj precession p h o to g rap h s w ere OkO, k=2n+l and hOl, h-**x=2n+l, in d ic a tiv e o f th e space

group P2i/n (a nonstandard setting of c|h-P2i/c, Ho. ill-).14:6 The unit

cell constants were determined by measurements of the precession and

Weissenberg photographs: a=17.6(l), b=21. l(l), c=ll. ?(l),

V=Jl-2^0\3. The c a lc u la te d d e n s ity (assum ing fo u r Ni(FSP-CH3 )2 (CHS)2 units per unit cell) is 1. hT G * / c c , in good agreement with the value determined by the flotation method in a carbon tetrachloride-ethanol

solution (l. Iv9 g./cc). The calculated linear absorption coefficients for x-radiation are: [iMoV/X = 8. 07 cm 1 /iCuKx = j h , 5 cm 1 I I I . RESULTS AND DISCUSSION

A. Lireand Syntheses

Intermediates and ligands were prepared by the reaction scheme

in Figure IV. All ligands and intermediates are air-stable compounds which may be readily purified by distillation and/or recrystallization.

The compounds were characterized by their elemental analyses, infrared

spectra, F19 and H1 nmr spectra, mass spectra, and derivatives as w ill be .described in the following sections. For conciseness, the ligands w ill be subsequently referred to by the abbreviations FDP, FTP, and

FSP-CH3, corresponding to fluorine-containing diphosphine, fluorine-

containing triphosphine, and fluorine-containing sulfur-phosphorous-

methyl ligands. The analogous unfluorinated ligands are likewise

abbreviated DP, TP and SP-CH3. In certain reactions to be described

l a t e r , th e sulfur-X Jhosphorous lig a n d s SP-CH3 and FSP-CH3 lo s e m ethyl

groups to form complexes of the corresponding mercapto-ligands,

abbreviated as SP and PSP.

The synthetic routes outlined in Figure 12 are feasible owing to

the ease of formation and relative stability of tetrafluorophenyllithium

intermediates. 110' 111 These organolithium compounds are of great

potential utility in providing convenient access to polydentate ligand

systems which in the cases of unfluorinated o-phenylene groups,

are difficult to prepare.

79 80

For example, the synthesis of o-phenylenebisdiphenyl- phosphine(DF), outlined below, involves several tedious steps of

low yield (overall yield lO^).2*313 By comparison, the analogous FDP was conveniently prepared in two steps in 67$ overall yield. The

B r HOMO ^

WH2 H B F 4 PCI? 4 7%

P Ply , BuLl r ^ j j S r P P h ' Ph 2 PC |k- 13 oe O 5 8 %

difficulty in synthesizing DP and TP appears to be the primary reason

S t 113 few metal complexes of these ligands have been reported.

The intermediate thioether VTI is a lachrymatory, foul smelling,

slightly amber liquid which melts near room temperature (20°C). The proton nmr spectrum contains a complex m ultiplet (due to coupling with

the aromatic fluorines and hydrogen) at t7* 52, assignable to the thiomethyl group and a multiplet at tJ.20, due to the aryl proton. The

relative areas of the two peaks are 3.26:1.00 respectively, confirming 8 l

0r F.. l.tyy.1 Up(c^h5)j., Tlhrrr* x x B r - ? tf -70" 11 r - .3 < X *•* 395 $ > '* (1*1), *= I; l ? F D P Cver-TH* (£)■ **2t L -F T P

a. r*ci»

tvim

Figure IS . Synthetic routes used for the fluorinated ligands. 82

the proposed structure. The reaction is an extension of a Grignard

method used to prepare pentafluorophenylthiol and tetrafluoro-

phenylthiol.28

Attempts to prepare the tetraphosphine tris(2-diphenylphosphino-

tetrafluorophenyl)phosphine {FQP) by the procedure used to prepare FDP

and FTP (Figure i) were unsuccessful. In each attempt, a sparingly

soluble fluffy white amorphous powder (Vi) was obtained, in sharp

contrast to the readily soluble, crystalline nature of FDP and FTP.

The infrared spectrum of ’/I contains a medium intensity, fairly

sharp peak at 239° cm 1, characteristic of a P-H stretching frequency.114

The absence of strong 0-H bands near 35^0 cm 1 precludes a P-OH

structure. A strong band at 1210 cm 1, which is not present in the

infrared spectrum of FTP and FDP, may be ascribed to a P=0 stretching

frequency.114The compound was too insoluble for nmr or molecular weight

measurements and did not give satisfactory mass spectra due to

decomposition on the probe. On the basis of the infrared spectrum,

physical properties, and elemental analysis, VI is formulated as the

aryl secondary phosphinc o;cide.

An in itial attempt to introduce a thioether function directly

into the tetrafluorophenyl ring via nucleophilic displacement of bromine was unsuccessful. When sodium benzylmercaptide was added to

intermediate III, a white crystalline solid was isolated whose

elemental analysis indicated that fluorine, not bromine, had been 83

F F J ^ j C H 2 S M a + v , P f S P P h 2

C - H ^ e H - S 15^ B r p 6 h Z p

displaced. The F 1 9 nmr spectrum confirmed the presence of three » non-equivalent fluorine atoms in the product. Thus, F 1 0 resonances

were observed at 98.6, 12*J. 2 and 127*^ ppm (rel. to 6 =165.0) whose Oq I'q chemical shift values and coupling constants are consistent, by

comparison with shifts and coupling constants in the related compounds

listed in Tables 5 and. 6, with substitution para to phosphorous.

Substitution para to phosphorous and meta to bromine should be

favored for electronic reasons, since in anionic Sn2 substitution

reactions phosphorous should be an ortho-para director and bromine a

meta director. Other workers have also noted the ease of displacement

of fluorine para to electron-releasing substituents in perfluoroaromatic

compounds. ;Ll5,117

Attempts to introduce sulfur to the tetrafluorophenyl ring via

addition of sulfur to Grignard reagents or by Grignard exchange with

1,2-dibromotetrafluorobenzene and intermediate III were unsuccessful. 8k F I.Mfl F 7^ _s» F p s ^ P P h a

iBr f Ic^ J I s CHj F F

F F

In each case, foul-smelling intractable oils and insoluble solids resulted. The reactions are probably not very feasible both because of the difficulty in forming a Grignard with the highly deactivated perlialoaromatic ring and because of competing side reactions due to intermolecular nucleophilic attack of the labile fluorine-carbon bond by the mercaptides which are formed. The presence of phosphorous in compound III would especially favor nucleophilic substitution in the para position.

Satisfactory H1 rrar and F'13 nmr spectra were obtained for a ll intermediates and ligands shown in Figure I3C. The F19 spectrum of

1,2-CaF4.(PPhH)2 (FDP) consists of two extremely complex m ultiplets centered at 4-1. 0 and 11. 5 ppm downfield from hexafluorobenzene, which are assigned to the fluorine nuclei a and P to phosphorous, respectively.

B oth a and P resonances in III occur downfield from corresponding resonances in 1,2-bromotetrafluorobenzene, consistent with greater itfr-dir delocalization of ring electron density in the case of the TABLE 5 a F19 CHEMICAL SHIFTS AND COUPLING CONSTANTS IN SOME 1 , 2 ,'3 , 4 -TETRAFLUOROABYL COMPOUNDS r ¥YG

Compound 62 63 64 65 J l 2? *7l3 ^23,^24 J 34 Ref. Jl43 *^25 J 353J 45 X=Y=?Ph2 122. 02' 151.1*9 X=Y=F 163.00 X=Y=C1 I 36. I 155.6 ■+20. 5, +2. 5 1 9 .1 7.1* X=Y=3r 125.23 151*. 23 -21.53,2.80 -19.63 1 0 8 X=Y=SnMe2 115.1 155.9 8.18 170 X=Y=H 11*0.16 157.09 X=PPh2,Y=Br 121.87 155.1^ 151.08 127.13 , 1*.28 22.9 ,8. 52 19.3 0. 1*5, 10.85 10.91 5 -3 5 ,2 1 .5 X=PPh2, Y=SCH3 123.68 151*. 68 152.12 129.88 x =c6^ p - (0 -CSF4 SCH3 ), } 125. 61* 15!*. 00 152.92 129.91 , k. 7 21. 8, 1*. 1* 18.8 y=sch 3 0 ,1 1 .7 11.7 1*. 7a 22.1* x=sch 3 j y=h 137.1*7 16O.1 8 156. 1*3 139.8 1

a ppm r e l a t iv e to CFCl 3 (6 =l£3 . o). Determined in 85:15 v/v dichloromethane: hexaflnorotenzene s o lu tio n s . 86

TABLE 6

FLUORINE 19 CHEMICAL SHIFTS IN SYMMETRICALLY

DISUBSTITUTED 1 ,2-TETRAFLU0R0BENZENE

COMPOUNDS8,

Substituent Ref. 6 ot

-nh2 ■lUO 165.8 176. ll

-OC2Ife 171 16 0 .1 166.9

-o ch 3 117 159.8 166. !<•

- cn 115 150 c

pph2 b 122. 0 151. 5

F all- 165.00 165.00

C l 107 1 5 6 .1 155.6

Br 210 125.2 15I1-.2

H b lll-0 .2 1 5 7 .1 S n(CH3)3 170 1 1 5 .1 155.9

a) Parts per million upfield from CFC13. b) This work.

c ) Nob re p o rte d . 87

phosphorous compound. Due to the great complexity of the AA'MM'XX1

spectrum, spectral analysis of FDP was not attempted. The F19 nmr

spectrum of intermediates III and VII (Table 5 ) cmd th e lig a n d FSP-CH 3 all consist of four we 1 1 -separated first-order multiplets, permitting direct determination of chemical shifts and coupling constants within the systems. Coupling constants and chemical shifts were assigned by comparison with known parameters in the 1,2-CsF,tX 2 compounds tabulated

in T able 6 . The F 1 9 spectra of the ligands and intermediates as well as of complexes w ill receive special attention later in this section.

The infrared spectra of FSP-CH 3 and SP-CH3 in the region

)(.00-Jj-000 cm 1 (Figures V and VI ) are quite sim ilar overall. The highly fluorinated ring manifests an increase in the C=C stretching frequency (16O2 vs 1575 cm 1), as normally occurs in aromatics containing electronegative substituents. 118

Two strong bands in the infrared spectrum of FSP-CH 3 w hich do not occur in the case of SP-CH3 are present at 812 and 86l cm x, some what lower than the C-F stretching frequencies in 1,2-tetrafluorobenzene at 988 and lOlj.8 cm 1.08 However, the introduction of heavy substituents to fluoroaromatic rings is known to significantly lower C-F stretching frequencies and the new bands are assigned thusly. 119 < G2 CC 0 co CO < 1 ! *

3 0 0 0 25 00 20 0 0 15 0 0 Figure V. Infrared spectrum o f CigHi3F4PS(FSP-CH3) and C1SH17PS (SP-CH3 ). (KBr). A A

1300 1 000 700 400 .Figure VI. Infrared spectrum, o f ----- CigHi3F4P3(F3P-CH3) ana C1 9 H1 7 PS ISF-CH3 ). (KBr). 90

S a tis f a c to r y mass s p e c tra were observed f o r FSP-CH3 , SP-CH3,

FDP, and FTP. The mass s p e c tra and c ra c k in g p a tte r n s o f FSP-CH3 and

SP-CH3, presented in Figures VII-X,. are generally similar. The strongest peak in each spectrum corresponds to loss of the methyl group from the jjarent. Interestingly, the peak ratio parent/parent-CH3 is considerably larger for FSP-CH3 than for SP-CII3 (2k. 5$ vs. Ik. 0^), indicating that cleavage of the S7CH3 bond to form the (parent-CH3) cation is more facile for the SP-CH3 compound. This is consistent with relatively greater electronegativity of the perfluoro-aromatic ring, destabilizing the positive charge on sulfur. Perhaps the most surprising aspect of the mass spectrum of

FSP-CK3 is the high relative abundance of fragments containing the C3F4 backbone, while no peaks of .even minor abundance attributable to degradation of the Q3F4 group occur, again underscoring the relative stability of the CeF^ group and its ability to stabilize positive charges despite the high electronegativity of fluorine.

The mass spectra of FDP and FTP are also readily interpretable

(Figures XIand XII). The parent peaks are observable with relative abundances of 6l and 2k$ respectively, relative to the strongest peaks in the spectra, which in both cases corresponded to loss of one tvw% M Av^

100- 25 22

25-

l i i A J J _L r 300 400

VO H g u re VII. The Mass Spectrum of C H F PS (FSP-CH) 19 13 4 3 Figure VIII • Major Fragments in the Mass Spectrum of C^gH^F^PS ( pgP-CHg) Relative % 5- L Abundance 15- 10- Figure . X I 100 h Ms Setu of Spectrum Mass The

5 3 35£3 ' s * \'A y ___ 8% igH PS Hi 7 Ci g „ ^ > 2 3X 2 > ^ „ ( p s ,100 ,100 - h c % 3)

vo PhcSCH

Figure X .M^or Fragments in the Mass Spectrum of C H PS (SP-CH ) v 2. 19 *J7 3 ■'* Figure XI. The Mass Spectrum of C3eH2cF4P2 (FDp). <0 TJ C

-Q < 100%

0) >

C v J .

CD 01 25-

100 300 500 700 Fj g u re XII. The M ass (FTP). rUm ° f C4 2H2 5 F8P3

VO CSV 97

phenyl group from the parent compound. The major peaks in the spectrum of each compound corresponded to fragments due to successive lo s s from th e p a r e n t o f CqHsj P (cgI% )2 and p (c gH5 )3. 98

B. Coordination Compounds of FSP-CHn and SP-CHa

1. Nickel(ll) complexes

Tabulations of nickel(ll) complexes prepared in this study with the sulfur-phosphorous chelate ligands K5P-CH3 and SP-CH3 are given in

Tables T and 8 . All the FSP-CH3 complexes are herein reported for

.H F H 2 F . ^ ' v p 3 C H 3

H ^ ^ j l p p h z F ' W J J ' P P h ^ H F

S P I-©LM13 FSP-CH-

the first time; incomplete characterization data have previously been reported for four of the SP-CH3 complexes.35130 Both FSP-CH3 and SP-CII3 react with nickel(ll) chloride in ethanol to produce intensely red solutions from which pale green complexes of elemental composition Ni(L-CH3)2Cl2 precipitate. The

Hi(FSP-CH3)2Cl2 and Hi(sP-CII3 )2Cl2 comp 3.exe s have e x p e rim e n ta l e f f e c tiv e magnetic moments of 3.22 and 3.15 B. M.^ respectively, typical of six-coordinate nickel(ll). 122 99

TABLE T

MOLAR CONDUCTIVITIES AND MAGNETIC MOMENTS FOR

N l ( l l ) COMPLEXES OF FSP-CH3

Complex C olor A^Ccm^ohm ^ x)

Ni(FSP-CH3 )2Cl2 pale green 3.22 1 5 .1

Ni(FSP-CH3)2Br2 apple green 3-15 8 .1

Ni(FSP-CH3 )2 (SCN)2 ta n 2 .1 8 13. h m(fsp-ch3)(scn)2 p a le g re e n 3 -W c

Ni(FSP-CH3 )Br2’ C6He p u rp le 0. 6T 1. 6d

Ni(FSP- ) 2 g re en 0 .3 0 1 .9

a) Determined by the Faraday method. b) Measured in approximately 10 3 molar nitromethane solution. c) Insufficiently soluble. d) Measured in 1,2-dichloromethane. 100

TABLE 8

MOLAR CONDUCTIVITIES AND MAGNETIC MOMENTS FOR

N l ( l l ) COMPLEXES OF SP-CH3

■t* Complex C olor (cm2ohm x )

Ni(SP-CH3)2Cl2 9 p a le g re e n 3-15 6 .k

Ni(SP“CH3) d 2 9 p u rp le diamagnetic 8 .6

Ni(SP-CH3)Br2 p u rp le 0 .0

Ni(SP-CH3)2 (NCS )2 brown 1. 22 c

Ni(SP-CH2 )(NCS )2 p a le g re e n 2.20 d

Ni(SP-CH3)l2 royal blue 0.11.7 6 .8

N i(SP- ) 2 f g re e n 0 .0 d

[Ni(SP-CII3 )2Br]C104 e purple diamagnetic 8T e [Ni(SP-CH3)2](ci04)21 tan diamagnetic e

a) Determined by the Faraday method. b) Measured as an approximately 10 3M solution in nitromethane. c) Decomposes in solution. See text. d) Insufficiently soluble. e) Reference 3. f) Inference 120. g) Not determined. 101

TABLE 9

ELECTRONIC SPECTRA OF N l ( l l ) COMPLEXES OF

FSP-CH3

Energy (cm •*•) Complexes CH2C12 Solution Nujol Mull

v Ni(FSP-CH3)2Cl2 ' 19,600(522) 1 1 ,2 00+ 300,• IT, lf00+.150

Ni (FSP-CH3 JgBrg ^ l8,900(937j2Vi-00(lOl8) 10,600+100; 16, 950+50

Ni(FSP-CH3)2 (CNS)2 b 1 1 , 5OOO1.5 ); 20, 200{ 1260) ; 12, 5 0 0 ; 18, 9 Q 0 ( s h ) ; 25,500(29^0) 2!)-,000

Ni(FSP-CII3)(NCS)2 d 8700; 10,800; 16,900

Ni (FSP-CH3 )Br2- C6He 1 9 , 0 0 0 + 3 0 ( 7 3 3 ),* 2k} 200( 1080) 18 , 000(br);26, 000

Ni (FSP- )2 16, lf00+50 ( Ikl); 2h, OOO+5O 16, 530+100; (5180) 23,700+100 a) Extinction coefficients are given in parentheses. + denotes estimated uncertainties in band positions. Solutions were ca. 10“3M. b) Structure changes upon dissolving. See text. c) Decomposes in solution. d) Insufficiently soluble. e) Sh= shoulder, br“ broad, wk= broad 10 2 TABLE 10

ELECTRONIC SPECTRA OF N l ( l l ) COMPLEXES OF

SP-CH3

Energy (cm x) Complexes CH2C12 Solution N u jo l M ull

Ni(SP-CH3)2Cl2 b ,f 29,200(Sh^; 15,620(826) 11, 100+700; 16, 11-00+150

Ni(SP-CH3)ci2 f 1 9, >i.oo( 572),* 29, itoo(sh) 19, 600;29, 00(sh )

Ni(SP-CH3 )Br2 18, 95°( 530) ,• 25, 000( 8^6 ); 18, 200(sh);20, 800; 31, 000(sh ) 25,600

Ni(SP-CH3 )2 (NCS)2 b 18, 100(sh);22, IfOO

Ni(SP-CH3)(NCS)2 d 9, 000(wk,br); l8,500(Sh);2li-,200

Ni(SP-CH3)l2 17,230(1670); 25, OOO(sh); 16,500; 23,800(sh) 29, ^OO(Sh)

Ni(SP-)a 16,500+100(150);23,700+100 16, 5OO+15O; (14-710) 22, 500+100

[Ni(SP-CH3)2](C104)2f 21, 500(259); 27, 200( 16^0) 8

[Ni(SP-CH3 )2B r] C104 f 2 1 ,200( I2 I1.O) B a)Extinction coefficients are given in parentheses. + denotes estimated uncertainties in band positions. Solutions were ca. 10 3M. b)Structure changes upon dissolving. See text. c)Decomposes in solution, dinsufficiently soluble. e)Sh= shoulder, br~ broed, wk= broad f )Reference. g)Not determined. 103

The diffuse reflectance electronic spectra (figure XHt) of the

Ni(L-CH3)2 C;i£>compounds a ls o fa v o r a s ix -c o o rd in a te geom etry. Low intensity bands near 11,000 and 17*000 cm 1, assignable to the

3A2g(P) - 3T2g(P) and 3A2g(F) -♦ 3Tig(p) transitions are observed."122 The third expected r,d-d'' transition, 3A2g(F) -* 3Tig(p), which is sometimes observed at higher energy in ligand field spectra of six-coordinate nickel(ll) complexes, is probably obscured by the intense charge transfer band commencing at 21,000 cm 1 with complexes of both ligands.

The green Ni(L-CH3)2 complexes readily dissolve in polar organic solvents such as dichloromethane to produce intensely red solutions whose visible electronic spectra consist of a single transition near 20,000 cm"1, typical of planar nickel (ll).122

The non-electrolybe nature of the red solutions precludes a pentacoordinate [Ni(L-CH3)2Cl] + structure. In fact, under appropriate conditions a red, crystalline, diamagnetic complex of composition

Ni(SP-CH3 ) c i2 may be isolated; the visible spectrum of this compound in dichloromethane is indistinguishable from that of Ni(SP-CH3)2Cl2 in the same solvent, consistent with dissociation of one bidentate ligand from the Ni(L-CH3)2Cl2 compounds in solution according to

Ni(L-CH3 )2Cl2 Ni(L-CH3 )ci2 + (L-CH3 )

p a le g re e n red ARBITRARY ABSORBANCE

H3 £ toO V H* p i , — ■■ to CO_ ct- o HS I » I e+ 7 T s m W P 7 \ ofc1 C+ 8 » P. a° i •sp 1i ° ct- Sz! § H* O a h+( hj ro o lto r ^ O H- f a

•P(0 ■fc Whi

■tlOT / / / / / / / /

] ' 1 1 1 1 1 1 1 IOkK 20 kK 25kK 30kK

F ig u re S E The visible electronic spectrum of ------Ni(FSP-CH3)2Br2 and Ui(lSP-CH3)2Cl2 in dichloromethane. 106

The preparation of Ni(SP-CH3 )ci2 had been previously reported but the recrystallization procedure often gave a product contaminated with the paramagnetic Ni(SP-CH3)2Cl2»3 A more satisfactory method of preparing Ni(SP-CH3)ci2 simply involves heating a suspension of

Ni(SP-CH3)2C!l2 in benzene and filtering the colorless, hot supernate from the resulting red crystals. The solubility of SP-CH3 i s much lower in polar solvents and thus mixtures of Ni(SP-CH3 )2 Cl2,

Ni(SP-CH3)cl2j and free ligand often result when polar solvents are used in crystallizations.

Repeated attempts to isolate a pure sample of Ni(FSP-CH3)ci2 from a variety of solvents were unsuccessful, despite its apparent existence in solutions of Ni(FSP-CH3)2Cl2* Both the ligand FSP-CH3 and its complexes are noticeably more soluble than their unfluorinated analogues and the failure to isolate Ni(FSP-CH3 )c i2 may be due to the relative solubilities.

Several bromide complexes analogous to the above chloro derivatives were isolated. Thus, mixing an ethanol solution of nickel(ll) bromide with FSP-CII3 produces an immediate pale green precipitate which analyzes for Ni(FSP-CH3 The sim ilarity of the solid state electronic spectrum of this compound (Figure XIII ) to that of the Ni(L-CH3)2Cl2 complexes and the magnetic moment (3*15 B.M.) strongly indicate a six-coordinate structure. 107

The green Ni(FSP-CH3)2Br2 complex, like the corresponding

Ni(L-CH3)2Cl2 compounds, gives a red solution in dichloromethane and the visible spectrum is consistent with a planar nickel(ll) structure

(Figure XIV). In fact, briefly heating a slurry of Ni(FSP-CH3)2Br2 in benzene and filtering off the warm liquor produces a good yield of deep red crystals of composition Ni(FSP"GH3)Br2*CqHq. The red compound is diamagnetic in the solid state and nonconducting in a dichloroethane solution. The electronic spectrum of Ni(FSP-CH3)Br2’CqBq both in solution and the solid state is consistent with a planar Ni(bidentate)-

Br2 structure and is indistinguishable from spectra of Ni(FSP-CH3)2Br2 dissolved in the same solvent. Thus, as found for the chloro derivatives, dissociation of one bidentate ligand from the six-coordinate

Ni(FSP-CH3)2Br2 to form the planar Ni(FSP-CH3)Br2 species is clearly in d ic a te d .

The Ni(FSP-CH3)Br2 compound is quite sensitive to polar solvents and when exposed to the atmospheric moisture slowly acquires the characteristic pale green color of N.i(FSP-CH3)2Br2. Grinding the red compound also produces a color change to green.

In contrast, mixing SP-CH3 with nickel(ll) bromide produces red solutions from which only the diamagnetic Ni(SP-CH3)Br2 was isolated in pure crystalline form. The visible electronic spectrum and diamagnetism support a planar geometry for this compound. The 108

Ni(SP-CH3)Br2 complex is considerably more stable than the FSP-CH3 analogue towards polar agents. Thus, prolonged exposure to air and grinding in a mortar produce no apparent color changes, in contrast to the behavior of the analogous Ni(FSP-CH3)Br2*CGHG complex.

Repeated efforts to prepare the six-coordinate Ni(SP-CH3)2Br2 analogue failed. The author1s ability to isolate the bis-ligand complexes Ni(FSP-CH3)2X2 for both X=C1 and X=Br with the perfluoro- ligand whereas only the corresponding chloro compound was obtained with

SP-CII3, the isolation of both Ni(SP-CH3j^X2(x=Cl,Br) monoligand complexes whereas only the planar Ni(FSP-CH3)Br2 was isolated with FSP-CH3, and the greater sensitivity of Ni(FSP-CH3)Br2 than Ni(SP-CH3)Bra towards disproportionation to form the six-coordinate Ni(L-CH3)2Br2 species, may indicate a stronger tendency of the fluorinated ligand than the unfluorinated ligand to coordinate to nickel(ll). ITyholm et. al. made quite similar observations concerning relative coordination abilities in his brief study of some nickel(ll) complexes with the diarsine ligands

1, 2-bis(dimethylarsino)benzene and 1, 2-bis(dimethylarsino)tetrafluorobenzene.sl>31 Unfortunately, the solubility differential between FSP-CH3 and SP-CH3 and t h e i r com plexes (and presum ably f o r Hyliclm* s lig a n d s a s well) makes it imprudent to asci’ibe these coordination differences to electronic effects In the ligands.

Mixing ethanol solutions of SP-CII3 and nickel(ll) iodide immediately produces a brick red precipitate. The red material was 109

soluble in halocarbon solvents and acetone, dissolving to produce an intensely blue solution from which deep blue-green needles of elemental composition Ni(SP-CH3)l2 crystallized. The same blue color resulted upon grinding the in itial red precipitate in an attempt to obtain a solid state electronic spectrum. The blue Ni(SP-CII3)l2 complex, is diamagnetic and non-conducting in nitromethane. The electronic spectrum in dichloromethane consists of symmetrical, intense bands at l6, 000 cm 1 and

23*000 cm 1, respectively, sim ilar to the spectrum of Ni(SP-*CH3)Br2 and by comparison is assigned a planar structure. As the band positions are not significantly different in either solution or the solid state, the same structure is retained in each state.

In contrast to the behavior of SP-CH3, a nickelous iodide complex of FSP-CH3 could not be obtained. Although reaction in a wide variety of solvents (benzene, acetone, ethanol, n-butanol, THF, and dichloromethane) was tried, the presence of iodide ion in solutions of nickel(ll) salts and FSP-CH3 or in solutions of nickel (ll)-FSP-CH3 complexes immediately gave deep-green solutions from which a deep-green complex of elemental composition Ni(FSP-)2 crystallized. Even when the reaction vas carried out at -T8°C, the same deep green demethylated species always formed. The complex 'is diamagnetic, a non-conductor in nitromethane, and monomeric in acetone (mol w t.; Calcd. 789* Found 769)* consistent with a planar con^plex of the demethylated ligand formed by the reaction N il2 + 2FSP-CH3 - N i(F S P -)H + 2CII3I 110

The loss of the methyl groups in Ni(FSP-)2 is particularly conspicuous in the H1 nmr spectrum which shows no methyl proton reso n an ce.

Despite its high molecular weight (789) the neutral [Ni(FSP-)2] was sufficiently volatile for a mass spectrum (Figure XV ), which serves as excellent confirmation of the proposed formulation. A series of peaks occurs at m/e values corresponding to parent ions of the several relatively abundant isotopes of nickel (58, 68$; 60, 26$; 6l, 1$; 62,

and 6 h, 1/). 123 No peaks were observed at higher m/e values.

An examination of the other nickel(ll) complexes of FSP-CH3 and SP-CH3 revealed that S-demethylation could be induced in these compounds as well. Livingstone has briefly described the formation of

Ni(SP-)2 when solutions of the corresponding thioether complex are

iao - heated. Addition of iodide ion, even at -78 C, to solutions of any of the FSP-Cir3 complexes listed in Table 7 instantly produced the deep green color characteristic of rNi(FSP-)2'l. Quantitative demethylation was also observed upon allowing dichloromethane solutions of

Ni(E3P-CH3 ) c i2 and Ni(FSP-CH3)2Br2 to stand at room temperature for two and seven days respectively. Alternately, 3 -demethylation to form the mercapto Ni(F3P-)2 occurred upon refluxing a 10$ DMF/ethanol solution of Ni(FSP-CH3)2Cl2 for twelve hours and of Ni(FSP-CH3)2Br2 for one hour. Q O c to ~a

Z3 S2 50“ <

ON. o > ro QJ si cr

Ai J y L L - i i A r -M-* i 1 0 0 300 50 0 7 00 n j / e

H F I G U R E 2 Z The Mass Spectrum of Ni(FSP)^* H H 1X2

Demethylation of the SP-CH3 nickel(ll) complexes to form the analogous [Ni(SP-)2] also can he induced by heating the thioether complexes, but the complexes of the unfluorinated ligand are much more stable towards dealkylation. For example, the presence of FSP-CH3 in solutions containing nickel(ll) and iodide ion instantly gave the de methylated [rii(FSP-)2], whereas, Ni(SP-CH3)l2 could be isolated easily when SP-CH3 was used.

Realkylation of [Ni(FSP-)2] was attempted using benzyl bromide, methyl iodide, and dimethylsulfate, but the unreacted mercaptide complex was quantitatively recovered. In contrast, the corresponding [Hi(SP-)2] complex readily realkylates in refluxing methyliodide to give the planar

Ni(SP-CH3)l2. The interconversion of [Ni(SP-)2] and Ni(SP-CH3)l2 with methyliodide can be repeated numerous times with little or no loss due to decomposition.

Both [Ni(FSP-)2] and [Ni(SP-)2] are assigned trans structures by analogy to the known trans-planar structure of [Ni(seP)2].213 The visible electronic spectra of [Ni(FSP-)2] and [Hi(SP-)2], shown in

F ig u re WI, are consistent with planar nickel(ll). It should be noted that the apparent ligand field strength and band intensities are slightly greater for the perfluoro-ligand.

Studies of alkylation of coordinated mercaptide groups in transition metal compounds have occasionally appeared in the literature.

The first such investigation was by Blomstrand who described 113

eooo-

4 0 0 0 -

2000 -

3 0 2 0 1 0 k K

Figure XVI. The Electronic Spectra of Ni(FSP-)2 and and Ni(SP-)2 in ca. 10 "5 m nitromethane. dealkylation and alky lotion reactions of platinum (ll) complexes with dim ethylsulfide.l25j 120 Other workers extended the in itia l work with platinuin(ll) thioether and mercaptide complexes. 1275 128 Later Ewens and Gibson discovered alkylation reactions- of sulfur in a diethyl-P- mercapto-ethylamine complex of gold(ill).139 Almost a ll subsequent

publications of alkylation of transition metal mercapto compounds have involved complexes of nickel(ll), particularly with ammine-mercapto chelate ligands such as p-mercaptoothylamine.

♦ Dealkylation of coordinated thioether compounds have occasionally been noted in the literature. The first such report by Blomstrand in

18T8j concerned formation of a methyl mercaptide complex of platinum with dimethylsulfide. 3255136 More recent investigations have involved the mixed chelate ligands shown below,' in addition to SP-CH3. - In all cases heating of solutions of the thioether complexes was necessary to cause demethylation to occur.

The kinetics of the alkylation reactions of bis(8-mercapto- quinoline) nickel( I I ) and bis[I'I-methylhis (0-morcaptoethylamine ) ] - dinickel(ll) with a variety of alkyl halides has been described.131’14rl,10s

The alkylation reaction is inteapretable in terms of nuclepphilic attack by the sulfur atom in the coordinated mercapto group on the alkyl halide, viz.

M-S-R + R' - X — M - S - R 116

The mechanism also accounts for the observation that R-Br compounds

alkylate the thioether complexes faster than analogous R-Cl compounds,

as a consequence of the weaker R-Br bond and the resulting greater

facility in displacement of Br compared to Cl.

It should be noted that the same mechanistic scheme shown

above for alkylation of the coordinated mercaptide is chemically very

feasible for the reverse process, i.e. dealkylation of the coordinated

thioether. As noted by Lindoy and coworkers,142 dealkylation by

such a route would parallel the well-known Zeisel cleavage of ethers by hydrogen halide, whose mechanism is shown below.

H R - 0 - R' + HX > [R - 0 ] + X“ 0 r '

ROH + R'X

The ability of H-X to cleave the ether is evidently a function of both

the acidity of IIX and the nucleophilicity of X .

In S-dealkylation reactions, the thioether complex would

represent the protonated intermediate in a Zeisel cleavage, and thus hydrogen and metal would play sim ilar roles in the two types of

reactions. That coordination to the metal is prerequisite for S-demcthy lation in these compounds is easily demonstrated. Thus, FSP-CH3 and iodide ion may be refluxed overnight in a 20^ v/v DMP/ethanol mixture without reaction; upon addition of nickel(ll) ion to the some solution, demethylation occurs instantly. 11T

A Zeisel-type mechanism can readily he used to explain the relative tendencies for demethylation of the FSP-CH3 and SP-CH3 complexes found in this study. The relative abilities of halides to promote

S-dealkylation of the nickel(ll) complexes of the two Ligands clearly is I » Br > Cl. This is the expected order on the basis of the nucleophilicity of X 0 since the susceptibility to cleavage increases as the nuceophilicity of X increases. It should be noted that the relative rates do not depend upon the volatility of the CH3-X product, as otherwise the opposite trend would be predicted. The

Zeisel mechanism also explains why the FSP~CK3 complexes undergo much more facile demethylation than their SP-CH3 counterparts; the inductive effect of the electronegative tetrafluorophenyl ring would increase the cationic charge on sulfur, increasing the polarization of the

S-CH3 bond and making it more susceptible to nuclcophilic attack by X .

Finally, it should be noted that the use of such s-dealkylation reactions offers distinct experimental advantages for the synthesis of mercaptide complexes. The handling of foul smelling and air- sensitive mercaptans and mercaptide salts is obviated. The alkylation reactions also provide possible routes to mixed thioether chelates which would be exceedingly difficult to prepare by other methods.

Two nickel(ll) thiocyanate complexes were isolated with both th e FSP-CH3 and th e SP-CH3 lig a n d s . When an e th a n o l s o lu tio n o f aquatcd nickel(ll) thiocyanate and a dichloromethane solution of 118

FSP“CH3 or SP-CH3 are mixed, brown solids of elemental composition

Ni(L-CH3)2(NCS)2 precipitate. The infrared spectrum of M(fSP-CH3)2-

(NCS)2 reveals two sharp, strong "bands in the CsN stretching region

(Figure XVH) at 2095 cm 1 and 20l|-0 cm 1, which are within the lim its normally quoted for N-bonded and ionic thiocyanate groups, respectively. l43“l45a The Ni(SP-CH3)2(NCS)2 complex also exhibits two sharp, strong C-N stretching frequencies at 2095 and. 2O7O cm 1.

Determinations of the magnetic moments of Wi(FSP-CH3)2(WCS)2 and Ni(SP-CH3)2(NCS)2 by the Faraday method gave the anomalous values

/I ££ = 2.25 and 1.25 M. respectively, calculated for monomeric

NiLa(CNS)2 units. The /iei.£ value for Ni(FSP-CH3)2(HCS)2 was reproducible in independently prepared samples and showed no variation with the field strength of the magnet; thus, the odd moment was probably not due to paramagnetic or ferromagnetic impurities. The magnetic susceptibility of Ni(FSP-CH3)2(NCS)2 was determined at 73 °K and 123°K as w ell as at ambient temperature (Figure XVm). As can be seen, the magnetic susceptibility obeyed a Curie-Weiss relationship and gave a Weiss constant 0 of —h-°C* The observed independence of fi ^ with temperature rules out spin-equilibrium models for explaining the anomalous magnetic moment of the complex.122 Therefore, Ni(FSP-CH3)2(lICS )2 cannot contain a pentacoordinate nickel complex which is undergoing high-low spin equilibration. The magnetic data are readily interpretible if the

Ni(L-CH3)2(CKS)2 complexes are, in fact, composed of equivalent Mi(jBP-CHr,)g (HCS)P I?l(SP-CH-Jo(NCS)p Hi (PSP-CHq j (HCS )p m(sp-ch3)(itcs)s v= 2095, goto cm"*1 v= 2C95,2070 cm”1 \»= 2IG5 cm x v= 2150,2105,2075 cm"1

1! I " i

?— 1— i— 1— r t— r I t t— 1— 1— i— r t— 1— t— r

Figure WE. The solid state (KBr) Infrared Spectra of (a) Hi(PSP-CH3 )2 (HCS ) o, H (5} Ki(SP-CH3 )2 (NCS)2 , (c ) Hi(FSP-CH3 ){UCS)2, and (d ) Hi(SP-CH3 (lICS)i. UJ VO 2-5

4. 0“ -2*0 A

- 1*5

- 1*0

2.0-

1.0 -

100 200 3 00 Qi

Figure XVIII. The magnetic moment (-sr -it -Hr) and magnetic susceptibility (*e ----- ©—) of Ni(F3?-CH3)2(KCS)2 as a function of temperature. H 8 1 2 1

TABLE 11

THE SOLID STATE (NUJOL MULL) ELECTRONIC

SPECTRA OF NICKEL(ll) THIOCYANATE COMPLEXES

OF FSP-CH3 AND SP-CH3

Compound Energy (cm”1)

Ni(FSP-CH3)2(NCS)2. 12,500; l8,900(sh); 24,800

n i (f s p - ch 3 ) ( n c s )2 8, 700; 10,800; .18,900

Ni(SP-CH3 )2 (NCs)2 18,100 (sh); 22,400

rii(sp-CH3 ) ( n c s )2 9,000(wk,br); l8,900(sh); 24,200

Sh - shoulder, vk “ weak, ’or " broad.

C' N

. 2 WCSJ . / / » 7 /

N C 8 (diamagnetic) (paramagnetic) Proposed s tr u c tu r e or? Hi(FSP-CH3 )2 (lICS )2 . 122

quantities of diamagnetic and paramagnetic nickel(ll) species. The formulation of the FSP-CH3 complex as [Ni(FSP-CH3)2(NCS)2][Ni(FSP-

CH302](NCS)s, containing a six-coordinate, high spin and planar, low- spin nickel(ll) species gives a calculated magnetic moment jl ^ f o r the paramagnetic center of 3. 08 B. M., assuming a reasonable TIP correction of 100 c. g.s. for the diamagnetic nickel species. This value foi' d is in the expected range for octahedral nickel(ll).122 The • G.t £ above formulation also is consistent with the solid state infrared spectra in the stretching region, since bands corresponding to ionic and N-bonded thiocyanate groups would be expected.

If the composition of the above thiocyanate complexes is

[Ni(L-CH3)2(NCS)2][Ni(L-CH3)2](lTCS)2, then the electronic spectra of the compounds should be a’composite due to the planar and octahedral forms.

The observed spectra may be interpreted on this basis (Table 11 and

Figure XIX ). The diffuse z’eflectance spectrum of Ni(FSP-CH3)2(NCS)2 contains weak bands at 12,500 cm 1 and 18,900 cm 1 and a much stronger band at 2^,800 cm 1, while in Ni(SP-CH3)2(NCS)2 two bands are found at

18,100 and 2^,MX) cm \ A lower energy.band is presumably present but too weak to be seen. The two low energy bands near 19,000 and

12,000 cm 1 are assigned to the 3A2g(F) -* 2T2g(F) and 3A2g(F) -♦ 3Tig(F) transitions in optimized octahedral symmetry and the high energy intense band near 2^,000 cm 1 is assigned to the 1Ai(dx2ys) ^(dxz,dyz) ARBITRARY ABSORBANCE 30 30 kK gur XX sold st e el roni pcrm of o spectrum ic n o tr c le e te ta s lid o s XIX. re u ig F nd 2n ------(PC32NS2. m(SP-CH3)2(NCS)2 IOkK Ni(FSP-CH3)2(NCS Ni(FSP-CH3)2(NCS )s 12k

transition in idealized square planai’ geometry. 173 Comparison with the spectra of the octahedral Ni (1- 0113)3X2 (x=Cl,Br) compounds then gives the usual spectrochemical series ITCS > Cl > Br (Figure XIIl).

The position of the high energy hand in Ni(SP-CH3)2(NCS)2 is close in energy to the band seen in the planar [Nl(SP-CH3)2]2+ cation

(22,^1-00 vs 21,500 cm 1) as would be required for the proposed formulation.

To verify the same assignment in the FSP-CH3 complex, numerous attempts were made to prepare the corresponding planar [Ni(F3P-CIl3)2]2+ cation as the perchlorate or tetraphenylborate salts, but only intract able oils and/or starting materials could be recovered from the reaction m ix tu res.

In order to obtain preliminary erystallographic data and to verify the molecular mass for 11 :L(F3P-CII3) 2 (Ci'/S) 2, a space group determination was performed. After considerable difficulty, a crystal suitable for single crystal X-ray photographs was obtained by slow evaporation of a chloroform solution.

The space group is the monoclinic IJ2i/c-c|j|(see experimental section) and the observed and calculated densities (lJi-9 and 1. Vf gm ) cm3 agreed closely assuming four Ni(FSP-CH3)2(NCS)2 aggregates per unit cell. Space group P2i/c contains four general positions and four independent pairs of special positions, each lying on a center of symmetry.143 Thus no erystallographic symmetry is required if. four 125

identical 1 ,Ni(FSP-CH3)2(NCS)2t' units are present in the crystal whereas in the [Ni(FSP-CH3)2(NCS)2][Ni(reP-CH3 )2](NCS)2 formulation each nickel atom would be required to lie on one of the four sets of centrosymmetric special positions^ no symmetry would be required for the ionic thiocyanate groups. Thus, in the proposed model, crystal- lographicaliy centrosymmetric octahedral and planar species would have to be assumed, in lieu of disorder in the crystal.

The brown Ni(FSP-CH3)2(NCS )2 complex exhibits moderate solubility in dichloromethane, dissolving to give a deeply colored green-brown solution. The visible electronic spectrum of this solution is similar to the solid state spectrum of Ni(FSP-GH3)(KCS)2, suggesting the same basic structure in solution despite the slight color change.

However, the molar conductance value for a 10 3 molar nitromethane solution (13A for monomer, 26.8 for dimer) suggests substantial assoc iation of the thiocyanate group in solution. 147 The infrared spectrum of a dichloromethane solution of Ni(F3F-CH3)2(HCS)2, Figure XX, supports this interpretation. A broad absorption is observed at

2078 cm 1 with an integrated intensity of 10.1 x lO^cm aM the band position and half-width clearly indicate li-bonded groups but the molar intensity is slightly low for isothiocyanato bonding. X43_l4fJ ]_ow value may be duo to the presence of a moderate quantity of bridging thiocyanate, as evidenced by absorption in the usual bridging SCN stretching region near 2 1 3 0 cm**1. gur XX. re u ig F * ABSORBANCE Ni(FSP-CH The C-N s tre tc h in g re g io n i n th e in fr a r e d spectrum o f f o spectrum d e r a fr in e th n i n io g re g in h tc tre s C-N The 2180 i23* cm ^i/2=33*0 "aP =2078 cm 3 1* x 10^ x 10*! = S a(fS2 (CH (lfCS)2. )a cm”~ 2 1 ) C12 2!00

2020 127

' Upon addition of light petroleum ether to the dark Ni(FSP~CH3)2~

(NCS)2 solution or simply upon allowing the solution to stand for a few hours, a light green precipitate of elemental composition Ni(FSP-CH3)-

(WCS)2 forms. In the case of Ni(SP-CH3)2(cNS)2, precipitation of the analogous light green Ni(SP-CH3)(NCS)2 compound occurs instantly upon dissolving the compound in halocarbon solvents; thus, it was impossible to obtain any type of solution measurements for the original

Ni(SP-CII3 )2 (CNS)2 compound.

Both Ni(L“GH3) (KCS )2 compounds are paramagnetic. The magnetic moment of Wi(FSP-CH3)(NCS)2, 3*^8 B.M., is typical for tetrahedral nickel(ll), the value being considerably above that calculated for two unpaired electrons (2.85 B.M.) because of spin-orbit contribution.

The Ni(sP-CH3)(WCS)2 compound gave an anomalously low magnetic moment for two unpaired electrons, 2.28 B.M The lot/ value is ascribed to the presence of diamagnetic impurities as a result of the preparative method (the compound was too insoluble for recrystallization in solvents in which decomposition did not occur).

Both Wi(L-ClI3) (NCS)2 compounds were either insufficiently soluble or decomposed in solvents suitable for measuring visible absorption spectra. The FSP-CII3 complex, in particular, was especially sensitive to polar solvents and moisture, forming murky brown insoluble residues^ on exposure to these substances. 128

The solid state electronic spectrum of Ni(FSP-CH3)(NCS)2 contained discrete maxima of increasing intensity at 8,70°, 10, 800, and 16,900 cm 1. The spectrum is consistent with that of tetrahedral. nickel(ll) compounds if the hand at 16,900 cm 1 is assigned to the

3Tj.(p) - sTi(f) transition and the two lower energy hands are attributed to splitting of the 3A2(f) 3Ti(f) transition in the pseudo-tetrahedral ligand field.122

In attempts to obtain solid state electronic spectra of the green Ni(SP-CH3)(NCS)2, a sample was mixed with nujol. On grinding, the color of the sample rapidly changed from pale green to a dark brown color sim ilar to that of Ni(SP-CH3)2(HCS)2. The mull spectrum contained a band at 2h, cm 1, a shoulder at 18,500 cm 1, and a much w eaker maximum a t 9 , 0 0 0 cm 1. The two higher energy bands agree substantially with the mull spectrum of Ni(SP-CII3)2(NCS )2 which contained a band at 2 2 ,^ 0 0 and a shoulder at 1 8 ,1 0 0 cm 1. The weak band a t 9 ,0 0 0 cm 1 is assigned by analogy to Ni(FSP-CH3) (iICS)2, to the

3A2(f) - 3Ti(f) band in idealized tetrahedral symmetry. 122 The weak

3A2(f) v- 3Ti(f) and 3Ti(p) - 3Ti(f) bands are presumably masked by the higher intensity bands of rii(SP-CH3)2(WGS)2 which is present in the sample after grinding. 129

2. Palladium(I I ) Complexes of FSP-CH^ and SP-CHn

A tabulation of palladium (ll) complexes of FSP-CH3 and

SP-CH3 is given in Table 12. All the complexes are planar, air-stable,

crystalline solids which are soluble in polar organic solvents.

When the ligands FSP-CH3 or SP-CH3 are added to solutions

of PdX4 in 1:1 or 2:1 molar ratios, complexes of elemental

composition PdLX2 form. The PdLJC2 (l=FSP-CH3, SP-CH3j X=Cl,Br, I,SCN)

complexes are all non-electrolytes in nitromethane (Table 12). A

molecular weight determination on Pd(FSP-CH3)l2 indicated a monomeric

structure (calcd., 740: found, J^O in chloroform), and thus the

remaining PdIX2 complexes are also assumed to be monomers since a bridged structure should be most likely in the iodide complexes.

Both the PdL(sCN)2 (l =FSP-CH3,SP-CH3 ) complexes appear to contain only sulfur-bonded thiocyanate groups both in solution and the

solid state. The infrared spectrum of a dichloromethane solution of

Pd(FSP-CIi3 ) (SCN)2 (F ig u re XXl) c o n ta in s sh arp , medium i n t e n s i t y G-N

stretching frequencies at 2124 and 2113 cm 1 (vj= 12.6 and 14.4 cm 1) with integrated intensities of 2.70 and 1.86x10 4 cm 2mol x, compared to Pd(SP-CH3)(SON)2 with C-N stretching modes at 2122 and 2112 cm 1

(vl= 21 cm 1 for combined band envelope) with a combined integrated \ intensity of 1.62xl0~4 cnf'-mol**1. The frequencies, integrated intensities, and half-band widths of the C-N vibrations in both complexes are within the ranges well documented for thiocyanato 4 130

TABLE 12

MOLAR CONDUCTIVITIES AND ELECTRONIC SPECTRA

OP PALLADIUM (I I ) COMPLEXES OF

FSP-CH3 AND SP-CH3

b Compound Ao (cm2ohm~ XM- 1) Energy (cm"1)

Pd (FSP-CH3 ) Cl2 2 .6 2 7 ,5 2 0 + i|-0 (2 5 1 0 ) Pd(SP~CH3 ) c i 2 27,500 + 100(2300)

Pd(FSP-CH3 )Br2 3 .9 25,800(3800)

Pd(FSP-CH3 )(sCN)2 1 .3 23,l|-0 0 ( l l 7 l ) Pd(SP-CH3 )(SCN)2

Pd(FSP-CH3 ) l2 8.3 22,000(^930) Pd(SP-CH3 )la 22,100(1+000)

[Pd(FSP-CH3 )2](C 104 )2 159 -

[Pd(FSP-)2] 5 .9 27,200(1+620) ; 22, 000(250) [P d (S P -)2 ] 26, 3 0 0 (2 7 5 0 ),* 21, 500(2 0 0 )

[Pd2 (FSP-)2Cl2 1- 1/ 3DMF 9 .7 28,1+00(9,900 p e r Pd)

% a Measured on 10 3M nitromethane solution. b Band positions in cm 1 with extinction coefficients in parenthesis. Spectra were measured in ca. 10"3M dichloromethane solutions.

+ Represent estimated maximum errors in band positions. y=2l24cm 12 *6 cm J <= = 1-86 xlO^crrf^lvH

^=2.113cm'

j/^.|4-4cm -l e = 2-70xl0cm”^M” ^

z/=207lcrrf *

— 1 — 2140 2100 2060

Figure XXI. She C-N stretching region in the infrared spectrum of Pd(FSP-CHs)( SCN)2. . "K 132 ✓ coordination. l43~1'tsa frequencies are essentially unchanged in th e s o lid s t a t e (2123 and 2110 cm 1, L=FSP-CH3; 2122 and 2111 cm 1,

L=SP-CH3, nujol mulls), showing that both thiocyanate groups remain sulfur-bonded. Since phosphorous is generally considered to be a better m-acccptor ligand than s u l f u r , i t is tentatively predicted that the thiocyanate group positioned trans to phosphorous gives rise to the C-N stretching frequency at lower energy.

The visible electronic spectra of the Pd(L-CH3 )x 2 (l-CH3=FSP-CH3,

SP-CH3) complexes (Table 12) consist of a single absorption band in the

20, 000-30,000 cm 1 region, in good agreement with spectx*a observed in

, . 2 0 x3202 other planar Pd(bidentatejX2 complexes. The absorbance is assignable to the 1Eg(dxz,dyz) lAig(dx2_y2^ transition in idealized

symmetry (a2 Ai in C2v)*173 The complexes form the spectrochemical series Cl > Br > SCN > I (l =FSP-CH3) and Cl > SCN > I ( l=SP-CH3 ), th e relative position of thiocyanate providing further confirmation of sulfur-coordination in the palladium-thiocyanato bond, as deduced from infrared data for both the FSP-CII3 and SP-CII3 complexes. As was observed for nickel complexes, the electronic spectra of analogous

Pd(FSP-CH3 )x2 and Pd(SP-CH3 )x2 complexes are quite similar (Table 12 and

Figure XXH) The apparent ligand field strengths of the two ligands are virtually identical in the palladium(II) conplexes, but intensities of the electronic transitions are slightly greater for complexes of the fluoro-ligand. As noted in the nickel(ll) complexes, the intensity

t * pd(sp-cir3)c i2

6000 Pd(FSP-CH3 )Cl2

Pd(FSP-ai3)2(ci04)

Pd(FSP-)2

1 4000-

30 £ 5 20

Figure XXII. The electronic spectra oF Pd(FSP-CH3)ci2, Pd(FSP-CH3)2“ (C104)2J Pd(FSP-)2, and Pd(sP-CH3)ci2 in ca. 10~3M dichloromethane solution. r$h

enhancement may be due either to greater 11 intensity borrowing'1 from the more distinct absorption edge tailing from an ultraviolet charge transfer band in FSP-CH3, or to a genuine intensity enhancement arising from greater covalent character in the bonds between palladium and the donor atoms of FSP-CH3.

Satisfactory proton nuclear magnetic resonance spectra were obtained for most of the Pd(L“CII3)X2 complexes (Tabic 1 3 ). The spectra consisted of a m ultiplet centered near t2.5, due to the aromatic protons, and a sharp singlet near t6. 8 due to the coordinated thioether group, integrating in the required ratios 10:3 (l=FSP-CH3) or 1*1 -.*3

(L=SP“CH3). Chemical shifts for the FSP-CH3 complexes and ligand occur at slightly lower field strength than the corresponding unfluorinated compounds, consistent with deshielding of the protons via the greater a-electron withdrawing power of the perfluorophenyl ring. Only a very small variation in chemical shifts for different Pd(FSP-CH3 )x a and Pd(SP-CH3)x 2 complexes were noted. In the former, the halogens form the series for t™. SCN > I > Cl ~ Br. This is the predicted C r l3 order on the basis of both the relative inductive and polarizability properties of X. "I* The [PdLs]2 cations with both FSP-CH3 and SP-CH3 were isolated as perchlorate salts. , The virtually colorless salts act as typical

2:1 electrolytes in nitromethane, indicating complete dissociation of 135

TABLE 13

PROTON NUCLEAR MAGNETIC RESONANCE SPECTRA

OF PDLXS COMPLEXES

Compound t ch3 Ta r y l

P d(FSP-CH3 ) Cl2 - 6 .7 8 2 .^ 8

Pd(SP-CH3 ) c i 2 6 .9 5 2 . 1 3 , 2 . kz

Pd(FSP-CH3 )Bra 6 .7 7 2 .3 8

Pd(FSP-CH3)(sC N )2 6 .8 5 2 .3 5

Pd(FSP-CH3 )l2 6 .8 1 Z.kk

Pd(SP-CH3)l2 6 .9 5 2. li-T

FSP-CH3 7 .6 5 2 .7 2

s p - c h 3 7 .7 0 2.76

[Pd(FSP-CH3)2](C104 )2 6 .9 0 ,6 .9 7 2 .5 0

Chemical shifts relative to tetramethylsilane (lO. 00). Spectra were measured in dichloromethane solutions. l? 6

the anions in solution. Since the infrared spectrum of the solid exhibits no splitting of the perchlorate stretching modes,151 a planar, dicationic solid state structure is also presumed. In both [Pdl^]2 complexes, intense charge transfer absorption above 27,000 cm 1 masks the expected d-d transition. Dyer, Workman and Meek3 have described an experiment in which iodide ion was added to solutions of

[Pd(SP-CH3)2]2 in DMF. In the process, a new electronic transition arose in the visible region (22,000 cm x) which they erroneously ascribed to a pentacoordinate [Pd(SP-CIf3)2I] cation. In fact, the

' 'new1’ transition occurs at precisely the same frequency as the d-d transition in an authentic sample of the planar Pd(SP-CII3)l2. Thus, ligand displacement according to the following equation, not halide

[Pd(SP“CH3)2]2+ + 21 “------» [Pd(SP-CH3 ) l 2] + SP-CH3 addition, occurs on addition of iodide ion to the planar complex.

Similar experiments with [Pd(FSP-CH3)2] ( d 04.)2 gave identical results. Thus, upon gradual addition of sodium halide to acetone solutions of [Pd(FSP-CH3)2]2^ with careful monitoring of the visible spectrum, new bands arose only at the same frequencies found in the corresponding Pd(FSP-CH3 )x 2 complexes. Under these conditions, then, it is concluded that there is no detectable tendency to form pentacoordinate palladium complexes with either ligand. 137

Livingstone has reported that Pd(SP-CI{3) c i 2 when heated in

N,N-dimethylformamide dealky bates to form the neutral mercaptide dimer

Pd2(SP-)2Cl2* l/jjDMF and, under sim ilar conditions in the presence of excess ligand, the monomeric Pd(SP-)2 complex.120 Dutta and coworkers have made similar observations with related ligands. These experiments were verified f“or SP-CH3 and were found also to occur with the Pd(FSP-CH3)x2 complexes under somewhat milder conditions. Thus ■*> after refluxing a solution of Pd(FSP-CH3 )c i2 in DMF/ethanol for four hours, the 5-demethylated dimer [Pd2(FSP-)2C12]*l/jDMF was isolated. The presence of DMF was indicated by a C=0 stretching frequency at 1660 cm x, even after drying in vacuo overnight. The

Fd(FSP-CII3)Br2 and Pd(FSP-fJII3)l2 required progressively smaller reaction periods to effect de alky lation, reflecting the increasing tendency of

S-CII3 bond cleavage with increasing nucleophilic.ity of the halide.

The nature of the bridging ligand in the dineric Pd2(L-)2Cl2 complexes was not determined with certainty. However, considering 138

the well known tendency of palladium(II) to form sulfur-bridges, the

j^-thiolo-bridged structure given above is postulated. 14231523153

Attempts to realkylate the Pd2(L-)2Cl2 complexes were unsuccessful,

providing additional support that thiolo-bridging might be present

since bridged, mercaptide complexes are not known to undergo alkylation

to form thioether complexes, 131 Although the differential was not so

great as in the nickel complexes, palladium (ll) complexes of FSP-CH3

underwent demethylation somewhat more readily than the corresponding

SP-CH3 compounds. Furthermore, although [Pd(SP-)2] reportedly has

been realkylated with methyliodide, sim ilar experiments with [Pd(FSP-)2]

were not successful. These observations again underline the importance

of the electronegative perfluorophenyl ring in stabilizing the formal

anionic charge on the mercaptide group.

It is of interest to compare further [Pd(FSP-)2] and

[Pd(FSP-CH3)2](c i 04 )2 . Both complexes are assigned trans-structures

in order to minimize steric interactions caused by the bulky diphenyl-

phosphino-groups, and in the case of the former compound by analogy

to the known trans geometry of [Ni(SeP-)2].2i3 in [Pd(FSP-CH3)2]2+

(and the corresponding SP-CII3 compound) intense charge-transfer

commencing at 25,000 cm 1 totally obliterate any d-d transitions which might be present. The neutral, S-dealkylated [Pd(FSP-)2] and 139

[Pd(SP-)2] complexes on the other hand exhibit two distinct maxima

in the visible region, one near 22,000 cm 1 and a second, more intense band n e a r 27*000 cm 1 (T able. 1 2 ). Maxima in the corresponding nickel

complexes occur much lower in energy, near 2 k, 000 and 16,500 cm 1,

due to the smaller crystal field splitting in first row metal

com plexes.

The observance of no electronic transitions below 25*000 cm 1

for the [Pd(L-CK3)2]2 complexes implies a greater ligand field

strength for the neutral ligands compared to the S-demethylated ligands*

an effect unexpected in view of the higher charge and greater basicity

of mercaptide functions compared to thioethers.

5 . Rhodium and iridium complexes with FSP-CH^ and SP-CHn

The diverse coordination chemistry of low-valent rhodium and

iridium compounds and the paucity of coordination compounds of these

metals with mixed polydentate ligands prompted the synthesis and study

of repre sentative complexes containing FSP-CH3 and SP-CH3.150 It was

hoped that the facile S-demethylation reactions observed earlier in this

study with N i(ll) and Pd(ll) might give rise to internal oxidative-

addition reactions of FSP-CH3 with rhodium, iridium, and p la tin u m .1SQ, :L59,16x> 1(33 Such reactions might be anticipated to produce complexes containing coordinated mercapto and methyl groups. Mixing solutions of FSP-CH3 o r SP-CH3 with the dimeric

[RhCl(C0)]2 results in an immediate effervescence of a colorless gas and the crystallization of needles of elemental composition

[Rh(L-CH3 )(c o )c i]. The infrared spectra of [Rh(FSP-CH3 )(c o )c i] and

[Rh(SP-CH3 )(c o )c i] contain only a single sharp carbonyl stretching frequency at 2020 cm 1 and 1995 cm 1, ' indicative of the presence of only one type of terminally-bonded carbonyl group in each complex. A molecular weight determination of [Rh(FSP-CH3)(c o )c i] in acetone indicates a monomer (found: 5^ vs. calcd. 5^-T)* These data suggest cleavage of the chloro-bridge in [HhCl(co)2]2 and displacement of one carbon monoxide upon reaction with the sulfur-phosphorous bidentate ligands. The arrangement of the carbonyl group trans to the thioether is speculative but it should be the preferred isomer in view of the better ^-bonding characteristics of the phosphine function.

The ChO stretching frequency is considerably lower in

[Rh(SP-CH3 ) (co)ci] th a n i n th e c o rre sp o n d in g FSP-CH3 compound ( 2O2O cm 1 vs. 1995 cm x). Assuming the carbonyl group is bonded sim ilarly in both complexes (i.e., trans to sulfur, or as the case may be, phosphorous), then the higher value of the C=0 stretching vibration in the FSP-CH3 compound might suggest that the fluoro-ligand is acting as a better jr-acceptor ligand towards rhodium(l). TABLE Ik

CHARACTERIZATION DATA FOR [R h(F SP “CII3 ) c i ( c o ) ]

AND [Rh(SP-CH3 ) c i( C 0)]

Compound \j°Cso(cni 1) T^CH3(ppm) A°M(cm2ohm 1M 1) c

rRh(ESP-CH3 ) ( c O ) c i ] 2020 T. 00 0 .3 rRh(SP-CHa )(co)C l] 1995 7 .1 1

Energy (cm O [Rh{FSP-CII3 )(C 0)ci] 27,800(3180),* 51,300(3750)

[Rh(SP-CH3) ( c o ) c i ] 2 7 , J|-00(J|.p30)j51, 500(!|.560)

a)lakon as a KBr pellet. hearts per million relative to TI»E at T 10.00. Measured in CDC13 s o lu tio n . c)Measured in 10 3M nitromethane solutions. d)Measured in 10“3 m dichloromethane solutions. Extinction coefficients in parentheses. e)Both compounds are diamagnetic. 142

The reaction of FSP-CH3 with [Rh(l, 5_cyclo-octadiene)ci]2 gave a crystalline yellow product whose infrared spectrum strongly suggested the presence of both FGP-CH3 and cyclo-octadiene. However, the compound was insufficiently soluble for a good H1 nmr spectrum and elemental analyses of the recrystallized product were not reproducible. A five- coordinate [RhCl(cyclooctadiene)(FSP-CIl3)] structure is tentatively formulated.

Attempts to prepare rhodium iodide complexes of FSP-CH3 were also unsuccessful, the reactions giving products whose properties suggested partial S-demethylation of FSP-CH3 and displacement of cyclo- octadiene. Thus, a warm benzene solution containing FSP-CH3 and

[R h (l, 5-cyclo-octadiene)l"js produced a yellow precipitate whose H1 nmr spectrum contained a peak attributable to the aromatic protons but none due to thiomethyl or cyclo-octadiene groups. However, elemental analysis showed the presence of some iodide (— a indicating incomplete demethy- latiorn Reaction of iodide ion with [Rh(FSF-CH3 ) ( c o ) c i ] in acetone gave only intractable oils.

Attempts to prepare oxidative-addition compounds of Rh(FSP-CIl3) -

( c o ) c i by the methods used to synthesize oxidative addition compounds of tran s-Rh(co)ci(PRo)r> complexes157"150* la l"1G3*16Q*le7*205 were unsuccessful. Thus after bubbling air or S 02 through benzene solutions of Hh(F5P-CH3)(co)ci, only the starting complex could be recovered. ik?

Addition of NOBF4, methyliodide, and acetylchloride to [R 1i(fsP-CH3)-

(co )ci] solutions did produce color changes; however, only intractable oils were obtained from the reaction mixtures.

Failure of the above reactions to produce the desired oxidative- addition compounds of Eh(FSP-CH3) (c o )c i under conditions in which tran s-Rh(PR-a )g (c o )c i compounds readily react could be due to several factors. Firstly, the donors in FSP-CII3 are weaker a "donors than the donors in the PR3 compounds normally used in such preparations; l57"*3x33,205 consequently rhodium is less electron rich and is a weaker Lewis base toward the Lewis acid molecules. Secondly, cis-geometry is required in the FSP-CH3 complexes, whereas the PR3 compounds exist predominantly in the trans form. Most previous studies of oxidative-addition to rhodium has involved complexes containing trans phosphine ligands.

Several approaches were undertaken to prepare the stoichio metric analogue to Vaska's compound, [Ir(FSP-CH3) (c o )c i]. For example, an attempt to displace the two triphenylphosphine ligands by FSP-CH3

trans-Ir(PPh3)2(C 0 ) c i + FSP-CH3 > N. R. at room temperature or in refluxing benzene gave only starting materials as products. The poorer a--basicity and the requirements for cis- geometry in the desired FSP-CII3 complex are apparently not overcome by the chelate effect. ib k

Yaska* s compound may be prepared by refluxing a solution of

I rC l3*i]-H20 and triplenylphosphino in N,N-dimethylformamide. l64»165

Similar experiments with FSP-CH3 gave only intractable oils which had no carbonyl stretching frequency.

A second approach to synthesizing Ir(FSP-CH3)(co)ci involved the theoretical displacement of coordinated olefin from Ir(cyclo- o c te n e )H( c o ) d . R eflu x in g eq uim olar q u a n titie s o f FSP-CH3 and

Ir(cyelo-octene)3(C 0 )d (which dissociates in solution to give

Ir(cyclo-octene)2(co)d) 163 in benzene gave a 28^ yield of a white, highly insoluble complex of elemental composition Ir(FSP-CH3)-

(co)ci. The colorless complex is virtually insoluble in common organic solvents such as acetone, dichloromethane, benzene, chloroform, ethanol, and DMF (some solubility was noted in hot DMF), suggesting a polymeric structure. The compound was far too insoluble for nmr or solution infrared measuz’ements. The infrared spectrum of the solid contained a single shaip, strong band at 20^0 cm"1, indicative of a terminally-bonded carbon monoxide ligand, and contained no bands attributable to the cyclo-octene moiety. A polymeric structure c o n s is te n t w ith th e co m p o sitio n I r ( l rSP-CH3 ) ( c o ) d may be ach iev ed in two diverse ways. An iridium (l) complex containing the neutral FSP~CH3 chelate and bridging chloride and/or thioether ligands could occur, giving the formulation Ir(FSP-CH3) (co)ci; several isomers may be envisaged. Alternatively, an oxidative addition of the FSP-CH3 ligand could be imagined with the resulting iridium (lll) complex of structural

constitution [Ir(FSP-) (CH3 )(co)ci] containing bonded methyl, cliloro, and mercapto (FSP-) anions, again, several isomers are possible.

The latter (iridium (lll)) structure is favored for the following

reasons: (l) chlorine and thioether bridging in iridium(l) complexes

is quite rare and appears to occur only when there is a deficiency of

suitable donors for the metal,*2055157 (2) iridium (l) conqplexes are characteristically yellow whereas iridium (lll) compounds are often colorless; 15G, 150> lcil5163 (3) carbonyl stretching frequencies normally occur below 2000 cm 1 in iridium (l) compounds and above 2000 cm 1 in

iridium (lll) complexes, and are particularly high in iridium (lll) mercaptide complexes. Qne 3evarap possible structural

isomers of Ir(FSP-)(CH3) (co)ci is shown below.

pPha PPha 1 ^6

The addition of FSP-CH3 to a benzene solution of [lr( l,5-cyclo-

octadiene)d]2 produces an immediate color change. On working up the

reaction mixture, a yellow crystalline product was isolated whose

infrared spectrum suggested the presence of both the FSP-CH3 and cyclo-

octadiene ligands. The H1 nmr spectrum of the product is consistent

with the presence of equimolar quantities of cyclo-octsdiene and FSP-CH3

but elemental analysis of the compound is poor for an

[lr(FSP-CH3) (con)ci] formulation. The irreproducible analyses of the

compound is consistent with partial demethylation of the FSP-CH3 ligand.

A penta-coordinate [lr(l, 5-cyclo-octadiene)(FSP-CH3)d ] structure,

resulting from displacement of a cyclo-octadiene group, is tentatively

proposed.

Gold complexes

The facile S-demethylation reactions observed with the N i(ll) and

Pd(ll) complexes of FSP-CIf3 suggested that sim ilar reactions might

occur with gold. One example of dealky lation of thioinethyl ligand to form a planar auric mercaptide complex has already been cited. l3't In

the case of aurous(l) complexes it was also hoped that direct gold- methyl bonds might be formed via an internal oxidative-addition reaction.

Such an isomerization would involve simultaneous oxidation of the metal to A u(lll) and cleavage of the S-CH3 bond to produce two formally anionic donors (RS and CH3 ). 1*1-7

There have been no reported investigations of oxidative-

addition reactions of the Au(l) —* A u(lll) system although one might

suspect such reactions to occur for the following reasons.

l) Aurous and auric compounds (dl^and d8 configurations, respectively)

a re is o e le c tr o n ic to M° -• M2* (M=Ni, Pd, P t ) , and s im ila r

to d° M -* d6*'!3 (M=Co, Eh,Ir) systems for which oxidative-addition

reactions are relatively common. 2) Gold has two stable common

oxidation states which in principle are easily interconvertible by a two-electron oxidation (or reduction). Stable complexes of both

the aurous(l) and auric(ill) ions are well known.20 3) The most common

coordination number for aurous and auric compounds are two (linear)

and four (planar).20An increase in coordination number by two during 1 + + two-electron oxidative additions usually occurs in the M

(M=Co, Rh, Ir) system (planar octahedral). Thus, the accessibility of

two stable oxidation states differing by two electrons (Au and Au3 ) which have associated common coordination numbers differing by two

(two and four) should provide a feasible mechanistic route for

oxidative-addition reactions. *!■) In the hypothetical case of internal oxidative addition of the thioether ligand FSP-CH3, a metal-carbon bond would (hopefully) be formed. The great stability and ease of formation of gold-carbon bonds is w ell documented. a°’ 17‘!:“1'S'G

One p o s s ib le s e rio u s draw back t o u s in g th e FSP-CH3 lig a n d f o r the proposed gold oxidative-addition reactions described above was considered in advance. This lim itation stems from the well-known reduction of A u(lll) to Au(l) by arsines17^ lro and phosphines. 17s~181

Thxis, chloroauric acid (1IAUCI4.) and triethylphosphine (PEt3) react in aqueous ethanol to produce the neutral, monomeric, linear Cl-Au-PEt3.181

As a further example, the addition of the phosphorous-arsenic ligand l-diethylphosphino-2-diethylarsinobenzene to chloroauric acid in aqueous ethanol followed by addition of KI yields [AuLa]I in 95$ yield.1/0 The structure of the latter complex contains a tetrahedral cation, as shown by X-ray diffraction, and thus comprises one of the relatively few well documented cases of four-coordinate Au^IJ.

However, the presence of gold-carbon bonds is known to stabilize auric- phosphine complexes, e.g. in (CH3)3Au P(C1I3)3.174 170 It was hoped that the unusual electronic and steric features of FSP-CH3 might permit isolation of Au(lll) complexes even though the phosphine function would necessarily be present.

Experimentally, however, it was found that FSP-CH3 reduces auric salts to give colorless aurous complexes. Thus, the ligand rapidly decolorizes yellow solutions of sodium tetrachloroaurate to yield colorless crystals of the formulation Au(FSP-CH3 )ci.

WaAuClt + FSP-CH3 Au(fSP-CH3 )C1 + NaCl

The oxidation products of these reactions have not been'investigated.

The analogous complex Au(FSP-CH3)Br was prepared by addition of the ligand to a solution of NaAuBr^. which had been treated with a llf-9

stream of sulfur dioxide. Both Au (eBP-C1I3 ) c1 and Au(FSP-CH3 )Br are nonconductors in nitromethane and a molecular weight.determination

KAuBr.]. — SOg > Au(FSP-CH3 )Br (2) .ESP-CHg on the hromo-complex showed a monomeric formulation (calcd., 657 vs. found, 655 in chloroform). The H1 nnu’ spectra of Au(FSP-CH3)x

(x=Cl,Br) clearly indicate that the thiomethyl group is not coordinated in solution, since the methyl chemical shift is not much different from that found in the free ligand (x=Cl, t-7.57; X=Br, r=7.59 J free ligand, t= 7.7°t ). Accordingly the comp],exes are assigned a linear coordination geometry with the ligand bonded to the metal through phosphorous.

Pre-reduction of the AuX^. solutions with sulfur dioxide seemed to give smoother conversion to [Au (FSP-CH3 )x ] with less interference by oils and insoluble residues.

Surprisingly, attempts to demethylate the Au(FSP-CH3)X

(X“Cl,Br) complexes to form mercaptide complexes by methods used to prepare demethylated nickel and palladium complexes of FSP- were unsuccessful. Thu^ after refluxing a solution of Au(FSP-CII3)ci in a

50:50 ethanol-DMF mixture for four hours, the starting complex was quantitatively recovered. Refluxing in neat DMF rapidly led to decomposition and deposition of gold metal. The difficulty in dealkylating the uncoordinated thioether group in the aurous complexes dramatically emphasizes the importance of the metal in promoting 150

cleavage of the sulfur-carbon bond. The mere proximity of the thiomethyl group to the metal, as in Au(PSP-CH3 )x , obviously is insufficient to significantly weaken the S-CII3 bond. Direct co ordination to the metal, polarizing the S-CH3 bond and stabilizing incipient anionic charge on sulfur, appears to be an important factor in promoting S-CIi3 cleavage to give mercaptide complexes. 215

When FSP-CH3 was added to a refluxing solution of NaAuCl4 in acetone, two products were isolated. The expected product, the colorless

Au (f SP-CH3 )c 1 , was identified by its melting point. The second product crystallized as deep-red polyhedra which were sparingly soluble in common polar organic solvents such as acetone and dichloromethane.

The same red compound was also the only characterized m aterial i s o l a t e d a f t e r r e flu x in g a s o lu tio n c o n ta in in g HAuClj. and th e lig a n d .

The non-conducting nature of an acetone solution of the complex

< 1*0 cm2ohm '’'mol L) proves that an ionic species is not present.

Complete elemental analyses for the red complex agreed with the formulation Au(FSP-)ci2, corresponding to S-demethylation of the ligand and a probable planar, four-coordinate geometry about gold(lll).

However, the visible electronic spectrum, comprised of a single broad, symmetric transition at 19, *1-00 cm 1 (e= 100), is not characteristic of gold(lll),* because of the high ligand field generated by the third row metal in the 3+ oxidation state, d-d transitions are usually shifted into the ultraviolet region and thus, auric compounds are almost always 151

colorless. 1(3 a* XG9 Furthermore, a monomeric, planar configuration does not explain the poor solubility'properties of the compound.

As part of his overall research interest in the structure of

Group lb complexes, Dr. P. W. R. CorfieId has determined the three- dimensional crystal structure of A u (P S P -)c i2 by x-ray diffraction methods. The determination did show a primary coordination sphere about gold which is square planar. However, the individual [Au(fSP-)c121 units are bridged by a long intermolecular Au — Cl contact {j.ht) to give a centrosymmetric '*dim er''. Another long intermolecular contact

Au-F) links the dimers into an infinite array in which gold is primarily planar-bonded but secondarily attached to two additional ligands (Cl and f). The metal is best characterized as tervalent; the polymeric structure explains the limited solubility.

The Au (f s P-) c12 complex is particularly remarkable in that to the author's knowledge, it is the first well-characterized Au(lll) compound containing a pliosphine or arsine in the absence of a metal- carbon bond. In this regard the soft gold-mercaptide linkage may be compared to the highly covalent gold-carbon bond.

In summary, oxidative addition reactions involving gold and the

FSP-CH3 ligand were not realized. However, these studies do provide some indication of the desirable properties which a thioether ligand should possess in order to favor such reactions. 152

The thioether ligand should be a chelate containing

a donor atom which can strongly bond to both Au(l)

and Au(lll). This is necessary to ensure that complete

complex dissociation does not occur in the aurous

oxidation state when the thioether function probably

would not be bonded.

2 ) The thioether group should be attached to groups whose

electronic properties favor S-demethylation to give

mercaptide species, yet allow remethylation to regenerate

the thioether.

The donor atom {in addition to the thioether) in the

chelate .ligand preferably should not be phosphorus or

arsenic unless gold-carbon bonds are already present,

as auto-reduction of Au(lll) to Au(l) would complicate

stabilization of the auric ion. For the same reason,

iodide ion should not be present in the complex^ it is

known that Aul3 auto-reduces to give Aul and iodine.

The ligand should not be so sterically bulky that

formation of the square planar auric complex from the

linear aurous complex is hampered.

( i ) ^ — 7 L - Au - y o r A u (lll) SCII3 155

Ligands fitting the above criteria include

X SR

R 2 ” y : X nc s

n a H, F, Cl

The interconversions outlined, above would bo of great interest in connection with studies of metal catalysis. They also could conceivably serve as sources of carbcnium ions generated under extremely mild condi fcions, agents which would be of u tility in organic s y n th e s is .

C. FDP Complexes

For the purpose of comparison with FSF-CH3 and with known complexes of DP and TP 9j ll3>la,:- several nickel(ll) complexes of

FDP and FTP were studied. The compounds were prepared according to the reaction schemes diagramed below. 1 5 ^

In previous sections, four and six-coordinate nickel(ll) complexes of the sulfur-phosphorous perfluoroaryl ligand FSP-CH3 were described. In contrast, the closely related diphosphorous bidentate ligand FDP'gives only,planar nickel(ll) compounds.

Figure XXIII. Reactions of FDP and FTP with H i(ll) Halides.

m x P_‘ 6H20 ------— -----> Ni (ftp)x2 - > [ M (FTP)x]BPh 4 Xr;CI,Br, I

ITiXo* 6 h 20 Ni (FDP)Xp X -C l,B r, N I.GNS FDP

f N i (FDP )2 1(C10^ ) 2 — —

PPh F^SpPha F F

FDP FTP 155

Thus when ethanol solutions of FDP and nickelous halides are mixed, intensely colored solutions result from which may be crystallized complexes of elemental composition Ni(FDP)x2 (x=Cl,Br,I,

NCS). The compounds are air stable, diamagnetic, and soluble in common organic solvents. The Ni(FDP)x2 complexes are non-electrolytes in solution, as evidenced by their low molar conductivity values in nitrome thane (Tab le 15).

TABLE 15

.ELECTRONIC SPECTRAL At® CONDUCTIVITY DATA

FOR NICKEL(ll) FDP COMPLEXES a

Compound Energy (cm-1) C olor A b (cm2ohm 1M 1 )

Ni(FDP)(NCS)2 22,^50(3350) Orange 1.0 N i( f d p ) c i2 21, 8 0 0 ( 1820) Ochre k.2 Ni(FDP)Bra 21, IOOC1970); 25, 000 (sh P u rp le 8 A H i( f DP)I2 18, 750(1600);25, 000(sh Tan 2 .6 [Ni(FDP)2](ci04)2 23, 050(733);27, 300(5500) Y ellow 171 a) All these compounds are diamagnetic, with corrected molar susceptibilities less than 2O5 e.g. s. b) Measured in approximately 10 aM solutions in nitrometliano. Molar extinction coefficients in parentheses. sh~ shoulder 40 00 A

Figure XXIV. Visible electronic spectrum of M( f d f )x 2j X=I3 X=Br, ------X=C13 — • — • — X=NC3 i n nitrom ethane. 157

The electronic spectra of the Ni(FDP)X2 complexes consist of a single* intense* symmetric transition near 20* 000 cm 1* in good accord with spectra reported for other Ni(bidentate diphosphine)x2 complexes

(Table 15 and Figure XXXV ). The electronic spectra and diamagnetic behavior firmly establish square planar geometry for the Ni(FDP)X2 complexes . The intense* symmetric band in the 18, 700-25*000 c m 'i region is assignable to the 1Sg(dXz*dyZ) _* 1Aig(dx2_y2) transition in idealized D4h symmeti'y. 173 In the case of Ni(FDP)l2 and

Ni(FDP)Br2, a definite shoulder occurs near 25; 000 cm 1. This higher energy band is assigned to the 1 A2 (dXy) 1Ai(dx 2 _y2 ) ligand field transition which is occasionally observed in the spectra of planar dQ complexes. 183 105,173 ^he same band is probably also present in the

Ni(FDP)ci2 and Ni(FDP)(l'ICS)2 spectra but* due to the larger crystal field splittings generated by the chloro and isothiocyanato ligands* are masked by the extremely intense charge transfer bonds commencing near 25j 000 cm 1

The I ti( FDP)x 2 complexes give the normal spectrochemical series

NCS > Cl > Br > I* indicative of bonding through nitrogen in the case of the thiocyanate ligand.20 The relative intensities of the bands produce the series NCS > Br > Cl > I, somewhat scrambled compax’ed to the 158

normally observed order I > Br > Cl > NCS. However, intensity borrowing

from the intense charge transfer band tailing into the d-d absorption

region may be responsible for disrupting the normal trend.

The infrared spectrum of Ni(FDP)(WCS)2 in the 2100 cm 1 region

(Figure XXV ) verifies the assignment of icothiocyanato coordination,

as deduced from the electronic spectra. The frequencies, half-band

widths, and integrated intensities of the C^Ef stretching frequencies

are all typical for Ni-HCS linkages. 143-145

The diamagnetic, yellow, sparingly soluble square planar

[Ni(FDP)2](ciO^Jg complex was isolated from the reaction of the ligand

and nickel(II) perchlorate. From the facts that the complex gives molar

conductivity values typical of 2:1 electrolytes in nitromethane

(Table 11) and no splitting of the perchlorate stretching modes are

detected in infrared spectra of the solids, the perchlorate groups

are presumed to be ionic in solution and in the solid state. The typical

low spin d0 electronic spectrum, consisting of bands at 23*050(755) and

27j300(5500) cm 1, further indicate a square planar structure for the

[Wi(FDP)2]2 ' cation. As expected, the band at 23,050 in the spectrum

of [Ni(FDP)2]a+ is higher in energy than the corresponding transitions

in the Ni(FDP)x2 complexes (Table 15), due to both the higher effective

charge on the metal and the greater ligand field strength when the bidentate phosphine is substituted for the halogens. -1 2093 c a - i 21.6 cm. _2 -i

T TT T

2160 2100 CM"' 2040 VJ1 VO FIGUR3 XXV. The C—IT stretching region for [Ni(FD?) (rICS in dichlor omet hane. * l.6o

Due to the close structural sim ilarity beWeen the bidentate

ligands 1, 2-bis(diphenylphosphino)tetrafluorobenzene(FDP), cls-1,2~ bis (diphenylphosprd.no )ethyle no (VPP), 1, 2-bis(diphenylphosphino)ethane-

(DPE), and diphenyl[2-(methylthio)-2,3j h , 5"tetrafluorophenyl]phosphine

(FSP-CH3) it is instructive to compare tlicir coordination properties F

F F. FDP FSP-C H3 VPP DPE toward nickel(ll) and the electronic spectra of their nickel(ll) complexes. Unfortunately, data for appropriate complexes, of 1,2-bis-

(diphenylphosphino)benzeno, the strict structural analogue to the fluorinated FDP ligand, are not available.

The nickel(ll) coordination chemistry of the neutral sulfur- phosphorous bidentate ligand FSP-CH^ ligand was described in an earlier

section of this dissertation. The ligand forms six-coordinate

Ni(FSP-CH3)2X2(X=Cl,Br), tetrahedral Hi(FSP-CH3)(NCS)a, and planar

Ni(FSP-CII3 )Br2* CljHq complexes, with no evidence of pentacoordinate

species being observed. The bidentate diphosphorous ligands FDP

(present work described earlier in this section) and DPE (previously

studied by several groups 100-187) give only planar nickel(ll) complexes, of composition NiIX2 (x=NCS,Cl,Br,l) and [Nile] (C104)a. The ligand VPP l 6 l

which contains the ethylene-linkage gives analogous planar complexes but, in addition, also forms diamagnetic pentacoordinate [Ui(VPP)2X]+ salts under appropriate conditions. 183 Since the visible spectrum does not differ appreciably in either the solid state or in solution, the VPP complexes are presumed to retain the pentacoordinate structure in both physical states. The [Ni(VFP)2X]Y complexes were assigned square-pyx’amidal geometries from an interpretation of their electronic s p e c tra . • + The pentacoordinate [Ni(VPP)2X] cations could be generated by addition of halide ion to solutions of the planar [Ni(vPP)2](ci04)2 salt.183 Similar experiments with DPE lf33>l8Q’l87' aruj fDP (present work) were unsuccessful. The spectro-chemical result of adding halide ion to solutions of [Ni(FDP)2]a is given in Figure XXVI. New bands arise in the visible region at much lower energy than in the starting complex, at frequencies corresponding closely to those found in the respective N i(F D P )xs complexes (Table 15). It is concluded that the » following displacement reaction occurs, rather than addition of halide ion to the coordination sphere.

[Ni(FDP)2]2+ + 2X~ - Ni(FDP)X2 + FDP gur XV. ectoni ral ad f- if h s band l a tr c e p s ic n tro c le E XXVI. re u ig F Absorba nee o f IIsX to s o lu tio n s o f [H i i {IS [H f o s n tio lu o s to IIsX f o 27*6 bo 0 0 0 6 o3b 0 4 0 0 3 pn ton of n quii ar iy tity n 3m). a u q 10 r la tea. iiio u eq s. an n to ace f o in. n itio 0104)2 ( d d )2l a p upon s t r~. 0 A SS*8 Ma i aC [M 18*2 Br B a N 0 0 0 7 H G\ 165

Experiments designed to prepare pentacoordinate nickel(ll)-FDP complexes by other procedures wore also unsuccessful. It is concluded that FDP shows little tendency to form any nickel(ll) complexes other

than spin-paired, four-coordinate compounds.

For the purpose of comparison, various NiLXa complexes of

FDP,FSP-CH3, VPP, and DPE are tabulated in Table 16. The spectral band frequencies are extremely sim ilar for FDP,VPP, and DPE, while the corresponding transitions of Ni(FSP-CH3)Bra occur at lower energy owing to the poorer ligand-field strength of the thioether donor. McAuliffe deduced from the same data listed in Table 16 that overall VPP exerts are higher ligand field than DPE in the NiLXa compounds and ascribed this difference to properties of the olefinic linkage. However, a close perusal of Table 12 shows that the differences in the ligand field properties of FDP, VPP, and DPE (if any exist at all) are very close to experimental error and could easily be due to concentration or other effects. In fact, the apparent ligand field strengths of VPP and DPE are reverse in the solution and mull spectra, although the inversion could easily be due to crystal packing effects.

Although the apparent ligand field strengths of FDP,VPP, and

DPE are not significantly different, Intensities in the NiLXa complexes do vary. However, except for Ni(DPE)cia, for which the intensity of the d-d transition seems anomalously low, the magnitudes of the rnolar TABLE 16

VISIBLE ELECTRONIC SPECTRA OF PLANAR

nilx2 complexes9.

Energy (cm 1 ) LX Solution 13 I 4 ill

FDP NCS 22^50(3350) VPP TICS 22, 780(2121) 22,810 DPE NCS 23,5 0 0

FDP Cl 21, 800(1820) VPP C l 21,830(1955) 22, l|-00 DPE C l 21,600(700)

FSP-CH3 Br 19, 000 (7 3 3 );, 200(1080 ) FDP Br 21, 100(1970),*26, 000(sh) VPP Br 2l,230(l908)^26,h00(l908) 21, 230,* 26, 510 DPE Br 21, 050(2185);26,600(21^0) 21, 120; 26,600

FDP I 18,750(1600),-25, OOO(sh) VPP I 19, 230(251*7 ) 19,600 DPE I I9,080(22l|-l) 1 9 ,1 3 0

a) Data for VPP and DPE complexes taken from references 183, 186 and 187. b) Molar coefficients in parentheses. sh“ shoulder. 16?

extinction coefficients are similar and do not seem to fit any trend

except for the general order NCS > I > Br > Cl.

In conjunction with concurrent studies143 conducted in this

laboratory, it was of considerable interest to investigate the mode

of thiocyanate bonding in the palladium(ll) thiocyanate complex of

FDP. On mixing solutions of ligand and [PdCsCN)^]2'" in ethanol, a

highly insoluble pink precipitate formed. The pink compound dissolved

i n warm DMF to give, on precipitation with diethyl ether, a mixture of

two complexes - a pink, highly insoluble powder, identical in appearance

to the in itial precipitate and a bright yellow compound, soluble in

common polar organic solvents. The infrared spectrum of the pink

complex showed two sharp C-N stretching frequencies at 2100 and 2120 cm 1,

indicative of S-bondcd tliiocyanate groups, and clearly indicated the presence of the FDP ligand. Attempts to prepare an analytically pure

sample of this compound were unsuccessful, giving on recrystallisation

the bright yellow compound. However, the solubility properties and

infrared spectrum of the pink compound suggest a Magnus type

formulation, i.e., [P d (F D P )2][Fd(sCN).j.].

The yellow compound, on the other hand, could easily be

recrystallized and gave, on elemental analysis, the formulation

PdL(CHS)2. The infrared spectrum of Pd(FDP)( h c s )( s CN) (Figure XXVII)

conclusively establishes the complex as another example of a coordination compound containing both N- and S-bonded thiocyanate -O = 2083 cm"1

'Qy^ =16-1 cmT* -4 -2 -I 2 =16-2x10 cm M

2125,2070

* * r T“ »— r 2300 t900 2300 1300 2100 2040 A B

Figure BCTTIFI. C-N stretching region in a) rPd(?£?) s~ f ?d (S CN) ^ ] (K3r), H c\ B) Pd.{FDP){I70S)(SCT-i) (XBr), and c) Pd(FDP)(ttC3)'(sCIi) o\ dichlorcmethane. ligands."145 In d ichloromethane solution, two C-N stretching frequencies are observed, a medium sharp band at 2122 cm 1 (v-|“ 7-T cm

6= 5 .2 x 1 0 4 cm 2 M 1) and a second stronger, broader band at 208^ cm x

(v| = l6.1 cm 1, 6= 16.2x10 4 cm 2 M 1). The characteristics of the two absorbances (vj v|- and 6) are in the middle of ranges firmly established for thiocyanato and isothiocyanato coordinated groups, respectively. *43"145a The ^ands ,jo no-fc s^ift appreciably in the solid state (2125 and 2070 cm x) and thus the same structure is retained in the crystalline form.

The Pd(FSP-CH3)(scn)2 complex described in an earlier section contained only S-bonded thiocyanate groups (v c _^= 2 l 2 ?, 2 1 1 0 cm 1). The ligands differ only by the exchange of a diphenylphosphino group for a thiomethyl group. From the sim ilarity in band positions for.S-bonded thiocyanate groups in each complex, the thiocyanato group trans to phosphorous is assigned the higher frequency in Pd(FSP-CH3)(SCN)^.

Examples of linkage isomerism in planar tliiocyanate complexes

+ containing symmetric bidentate ligands have previously been found and a few have been studied by diffraction techniques. However, even in these ' 1 ideal*1 cases it is not possible to unambiguously determine whether steric or electronic interactions (or both) are responsible for the linkage isomerism. 168

Unfortunately, the corresponding Pd(DP)(NCS)2 complex has

never been reported. The ligands DP and FDP should he virtually

identical stericly with respect to thiocyanate groups in the square planej however, they possess uniquely different electronic properties.

A study of the infrared spectrum of Pd(DP)(NCS)2 conceivably could

contribute significantly toward an understanding of the importance of

electronic effects in determining the mode of thiocyanate bonding.

D. FTP Complexes

In further investigating aspects of the nickelfu) coordination

chemistry of polydentate ligands containing the o-tetrafluorophenyl

connecting linkage, several nickel(ll) halide complexes of the

potentially tridentate phosphine ligand bis(2-diphenylphosphino-3,)|-, 5,6-

tetrafluorophenyl)phenylphosphine(FTP). were synthesized*

FTP 169

Mincing e th a n o l s o lu tio n s o f FTP and NiX2 * 6 h 20 produces intensely colored solutions from which compounds of elemental composition

Wi(l’TP)xa (x=Cl,Br, l) crystallize. The deeply colored, diamagnetic complexes dissolve in nitromethane to give molar conductance values indicative of slight ionization of halide ion according to

Ni(FTP)X2 - [Ni(FTP)x]+ + X".

The degree of dissociation decreases in the oi’der I > Br > Cl (Table IT).

The overall sim ilarity of the solid state and solution spectra also favor the same basic structure in both physical states. The addition of sodium tetraphenylborate to a solution of Ni(FTP)ci2 in ethanol, however, did lead to precipitation of the [Ni(FTP)ci]BPh4 compound.

The molar conductance of the latter compound is only slightly lower than that normally observed for typical 1:1 electrolyte, the value being somewhat decreased due to the low ionic mobility of the bulky BPh4 anion.

The diamagnetism and electronic spectrum of [Ni(FTP)cl] *" (a single symmetric band at 22,lkT0 cm x) are typical of planar Kia complexes.

The visible electronic spectra of N i(F T P )x 2 complexes, on the other hand, are x’adically different from that of [Ni(FTP)ci]BPh4 and thus different structures must be postulated (Table IT and Figure XXVIII). tabls i t

ELECTRONIC SPECTRAL AND CONDUCTIVITY DATA

FOR NICKEL(ll) FT? COMPLEXES

_ h Energv (cm 1) Compound Color Am (cm2ohm 1) Solution (nitromethane) N u jol M ill

N i(F T ? )ci2 D ark g reen 15.1 16,400(760),-23,000(3460) 15, 600; 23,100

Ni(lTP)Br2 Dark green 17.lt 15,400(560),- 22,200(2730) 1 5 ,3°0,* 22, 200

N i(F T P )l2 B lu e -h la c k 28.6 14,300(850);19,800(2320) 16, TOO; 20 ,1 0 0

[Ni{FTP)d]3Ph4 Orange 51-3 22,470(2820)

a) Measured in 10 3M nitromethane solutions. h) Extinction coefficients listed in parentheses. Estimated experimental error in hand positions + 50 cm 1 for solution spectra and + 100 cm 1 for mull spectra. 4 0 0 0

3 0 0 0

Z0 0 0

< u o

\000

pifrure 172

The conductance data and the presence of a second band near

15,000 cm 1 which was not present in the spectra of the planar

Ni(FDP)X2 complexes strongly suggest that in the Ni(lTP)x2 compounds all three phosphorous donors and both halogens are coordinated. Thus, a spin-paired pentacoordinate structure in the solid state results from, which halide ion only slightly dissociates in solution. The following observations support the above conclusions.

Interpretation of visible electronic spectra of low-spin

pentacoordinate N i(ll) complexes have been used extensively in the

past to assign the various pentacoordinate geometries, although

incorrecb conclusions were reached sometimes. The recent availability

of a number of three-dimensional crystal structure determinations of

five-coordinate N i(ll) compounds of various pentacoordinate geometries

now makes it possible to predict, with some reliability, the geometry

of the complex from consideration of its visible electronic spectrum.

The following generalizations may be made.

Spectra of compounds having the ' ' lim iting' 1 pentacoordinate

structures, the trigonal bipyramid (TBPJ and the tetragonal pyramid (TP),1315102 contain only a single symmetric transition, whereas - 1 0 0 0

- 5 0 0

3 0 kK 2 0 kK Figure XXIX.' The ligand field spectra of ( ...... ) Ki(p{0C2H5)2(c3I%))?(CN)2j ( ------) Ni(tas)3r2, ( ------) m(CsHsPMs2 )3 (CN)2, and ( ------} Hi(BSPjl2. H TBP Intermediate TP intermediate structures produce asymmetry or actual splitting of the X03 single band.

In the case of donors producing an asymmetric ligand (i.e. all five donors not identical), then even in the 11 regular1' structures

(i'BP and TP) splitting or asymmetric broadening of the electronic transitions,sometimes occur, * but nevertheless the spectra remain diagnostic of the particular geometry. The visible electronic spectra of Ni(ESP)l2, NiftasjBi^,1'^ 190 Ni(QjHaP(OEt)2)3" 107;. 130*209 in*, GO (cn)2 and [Hi(CqHsPMe2)3(CN)2] ' (Figure XXIX), whose structures have been determined by X-ray diffraction, reflect the electronic changes in the visible region in going from regular TP through successive intermediate structures to a regular TBP.

The electronic spectra of the H1(fTP)x2 complexes are best interpreted in terms of a distorted tetragonal pyramidal(TP) model; a regular TP structure should cause complete disappearance of the already relatively weak lower energy transition near 16,000 cm 1. In the

N i(FTP)xa complexes the high energy maxima may then be assigned to 175

dx^-y2 B i dz2 A dz2 Ai dxy dx2-*/2 2 E i ^ 2 dxz dyz. E 2 2 dxy B2 E3 2 « 2

TBP TP

the DiCdx'-^y2) E (d:a , dyZ) transition and the lower energy bands to the Bi(dx2-y2) - Ai(dz2) transition in the idealized geometries.170

These assignments are strongly supported by the fact that the single visible band in the planar [Hi(FTP)cl]+ cation (22,4-70 cm 1) o ccu rs v e ry c lo s e t o th e h ig h e r en erg y maximum in th e p e n ta c o o rd in a te

Ni(FTP)ci2. This phenomenon! is normally observed in TP d8 spectra, mainly because the energies of the d-orbitals involved in the

Bi(dx2-y2 ) <- d(dXz> dyZ) transition should be similarly affected by addition of an axial ligand to the square planar NiLj. coordination sphere. If the structure of Ni(FTP)x3 were a s l i g h t l y d i s to r te d TBP, on the other hand, a significant lowering in the higher energy band relative to the Bi •- Ai transition in the planar complex should occur, and this is not observed.

Three possible square pyramidal geometries may be envisaged f o r th e Ni(FTP)xa compounds. Applying the normal octahedral nomenclature to the square pyramid, the tridentate phosphine may adopt either the facial (a) or either of the two independent meridial (B and C) confor mations. The m eridial conformations are disfavored because the 11 chelate b i t e '1 of the o-phenylene connecting linkage is probably insufficiently short to allow the ligand to span trans-positions in the square pyramid. However, distortions of structures B and C cannot be totally discounted.

The rii(ll) coordination chemistry of the unfluorinated structural analogue to FTP, bis(2-diphenylphosphinophenyl)phenylphosphine(TP), and the closely related tridentate ligand bis(2-diphenylphosphinoethyl)- phcnylphosphine (])PP) have been investigated but no results have been published to date. 05104 All three ligatids give pentacoordinate N1IX2 and

PPh PPh PhlHCHgCHgPPhg)^

FT P DPP p la n a r [NiLXjBPh^ complexes. However, NiL5Ca (L-FTP,TP) are largely molecular in solution whereas Ni(DPP)xa totally ionizes to give

[Ni(DPP)x]+ in polar solvents. This "behavior could be attributed either to the greater basicity or greater steric requirements of

DPP (due to the alkyl chelate linkage), or to a genuine enhancement of the stability of the pentacoordinate species because of better

n-bonding character in the triarylphosphines.

The visible electronic spectra of NiIX2 complexes of these three ligands are tabulated in Table 18. Spectra for I'IitX2 complexes of each of the three ligands are remarkably similar. The band positions in corresponding .FTP and TP complexes are virtually identical within experimental error, although intensities are slightly higher for the

FTP compounds. One might postulate greater m-bonding between nickel(ll) and FTP compared to TP, but minute structural changes could produce the same intensity enhancement. Maxima in the DPP complexes, as expected, occur at slightly higher energy as a result of the greater basicity of the alkyl phosphine donors. As was postulated for

N i(FTP)x2 complexes, a distorted tetragonal planar geometry has been suggested for the [lli(DPP)x2] compounds.10,1 TABES 18. VISIBLE ELECTRONIC SPECTRA OP NICKSL(ll) COMPLEXES

D C OF FTP, TP, and DPP

Snerffv (cm 1 ) Compound S o lu tio n (CH3K02 )a Mull (ifrgol)

N i(FT P)ci2 16, 400(760); 23, 000(3460) 15, 600; 25,100 I'Ii(lP)Clo 16, 800(300) ,*22, 650(3200} 15,9C0;23,550 R i(D PP)ci2 16, 700(l00);25,800(3^10) 18,1805*23,53°; 27,780 Ni(FTP)Bra 15,400(560)-22,200(2750) 15,3°°; 22,200 Ni(TP)Br2 15, 300(280),* 22,000(2400) 16, 150; 22,200 Ni(DEP)Br2 16, 7005(183);25, 150(5070). 17, 200; 22, 900; 28,600 m ( f t p ) i 2 14, 300(850),-19, 800(2520) 16, 700; 20,100 N i(T P )l2 14, 450(530); 20, 050(1700) 14, 710; 20, 000 [Ei(DPP)l2]> 0. 5CH2C12 15,700(288)521,500(1840) 15,3805; 20, 700; 28, 600(7660) 27,800 [Ni(FTP)ci]2Ph4 22,470(2820) [Ki (TP) Cl]BPht 22, 500(2800) T Hi (DPP) CllBPh.^ 24,100(5550) a)>0 SM solutions. Molar extinction coefficients in parentheses. Solution spectra for [Ni(DPP)x2] are quoted for 1,2-dichloroethane solutions; dissociation occurs in CH3N02. S=shoulder. t) Reference 9. c) Reference 104. E. F10 Nuclear Magnetic Resonance Studies of Dimethylpentafluoro- pehnylphosphine Derivatives and Complexes

1. Background

As part of a more general study of the electronic properties of perfluoroaryl compounds, the I'10 nmr spectra of ten d8 metal complexes and four simple derivatives of dimethylpentafluorophenyl- phospbine were determined. The complexes described in this section ■ were in itially prepared by Dr. E.C. Alyea, who also measured their visible electronic and proton nmr spectra. The CaF5PMe2 derivatives were synthesized and their proton nmr spectra determined by Dr. E.C. Alyea and L. P e te rso n . oz>> 109:121,1 visible electronic and proton nmr spectral data to be quoted in the ensuing discussion for dimethylphonylphosphine derivatives and complexes were taken from references 69 and 199. In the remainder of this discussion, dimethylphenylphosphine and dimethylpentafluorophenylphosphine w ill be referred to as L and Lf, respectively.

The coordination chemistry of these two ligands w ill be briefly reviewed as a prelude to discussion of the F10 nmr spectra. 180

Alyea and Meek found that L gives pentacoordinate Ni( ligand )3X2

complexes in solution considerably more readily than does the perfluoro-ligand Lf, hut that in those cases where stoichiomotrically

analogous complexes could he identified (e.g. NiL3(CN)2 and

Ni(Lf)3(cn)2), the apparent ligand field strength of Lf was at least

as great as for L. The authors were unahle to offer a satisfactory

explanation of the surprising ligand field behavior of Lf. In further investigating the effects of the pentafluorophenyl ring upon the coordination properties of the phosphine, a series of palladium(ll)

complexes were synthesized.

Alyea and Meek have shown a ll the Pd(ligand)2Xa compounds

tabulated in Table 19 possess monomeric* planar geometry as indicated by the fact that all the complexes are diamagnetic* non

electrolytes in solution* and exhibit a single electronic transition

in the visible region above 20*000 cm 1, all characteristic properties . . 201*202 of planar palladium(II ) compounds.

The P d (L f )a (xa ) compounds, as was previously deduced for the

PdLaX2 com plexes (x= C l,B r, I,C!NS, N02*CN) a rc a ssig n e d a tra n s - c o n f ig u r a tio n , 204 on the basis of their I [nmr and infrared spectra. The methyl resonances

in the PdL2X2 (x=Br* I* N0H) complexes consist of a symmetric 1:2:1

trip let due to virtual coupling of the trans-dimethylphosphino groups

in the square-planar metal complex. • In the case of the Pd(Lp)2X2

complexes, symmetric triplets were observed in the proton l 8 l

TABLE 19.

1H NUCLEAR MAGNETIC RESONANCE DATA OP PALLADIUM(II) COMPLEXES

Compound T-V aluea M ultiplicity and j(P-n) value i n p.p.m . in c. p. s.

Pdl£.Cl2 8. 23b triplet,* doublet0 11. 5C Pd(LF )2Cl2 8. 05 septet 3 .6

PdL2Br2 8. 07b t r i p l e t 3-5 PdtLjp/sBrs 7 .9 1 s e p te t 3 .5

PdLpIp 7 . 8315 t r i p l e t 3 .7 ° Pd(Lp72 I 2 7 .7 8 s in g l e t

PdL2 (NCS)2 8 . 0Yb s in g l e t Pd(LF)2(sCN)2 7.90 s in g le t

PdL2 (N02 )2 8. 03 t r i p l e t 3-9 Pd (Lp )2 Cno 2 )2 8 . Hi- s in g le t

PdL2 (CN)2 8.03 s in g le t Pd(Lp)2 (CN)2 7 .7 8 s in g l e t a) Data for the PdI.2X2 Complexes are taken from reference 20^. Values for the Pd(Lf)2X2 compounds are unpublished observations from reference 199* b) Values reported earlier by Jenkins and Shaw for CHC13 solutions.204 c ) CH3OH/CDCI3 s o lu tio n . 182

nmr spectrum for X= Br, I,N02 again due to virtual coupling in the trans complex^ in addition, coupling of the methyl protons occurs with the ortho-fluorine nuclei.

For the complexes [PdL2X2] (x= NCS,CN) and [P d(L £.)2X2] (x = I,

SCN,NOa, CW) only broad singlet resonances were observed in deuterio- chloroform solutions. The half-widths for the latter complexes are ca. 8 Hz, suggestive of unresolved triplets (or septets) since Jp_H is expected to be about 5.8 Hz. Apparently fast exchange destroys the spin-spin coupling. However, the possibility of an overlap of a singlet and triplet (or septet) due to a mixture of cis and trans forms, as was observed in PdL2Cl2, cannot be completely ovez'ruled for these complexes.

The infrared spectra of the PdL2X2 and Pd(lf)2X2 (x= CN,CHS) com plexes do strongly suggest a trans configuration. In the solid state, a single sharp C-N stretching frequency is observed at 2I3O cm 1 for

PdL2(CN)2 and at 2125 cm 1 for Pd(Lf )2(cn)2, consistent with trans- cyanide groups. In the F19 nmr solvent (85:15 v/v dichloromethane/- hexafluorobenzcne), the C-N stretch occurs at 2137 cm 1 for the Lf complex;

The C-I'I stretching frequency in Pd(Lf)2(SCN)2 occurs as a single sharp band (v-f ~11 cm 1) at 2116 cm 1 in the solid state (nujol), indicative of sulfur bonded thiocyanate groups. In an 85:15 v/v dichloromcthane/hexafluorobenzene solution, however, a sharp band occurs at 2119. T cm 1 (\>t= 11.7 cm 1, e= 2.1^5x10 4 cm 2M x) as well as a broader, more intense band at 2086 cm 1 (v|-= 35*8 cm 1, e= h. 05xl0"4Gm-2M"i); the two bands are characteristic of 185

S. and N bonded thiocyanate groups, respectively. complex e x is ts p re d o m in a n tly a s P d(L f )2 (TTCS) (SCN) in th e F19 nmr so lv e n t.

The PdL2(NCS)2 complex, on the other hand, has a strong broad

C-N stretching frequency at 2090 cm 1 and a slight shoulder at 2120 cm"1 in the solid state. These data suggest that both thiocyanate groups are predominantly N bonded in the complex.

2. Nuclear magnetic resonance spectra of dimethylphenylphosphine and dlmethylpentafluorophenyl derivatives and complexes

Methyl proton and fluorine nmr coupling constants and chemical shifts in L and Lf derivatives are compiled in Table 20 . Proton spectra were determined by Alyeaf9* 133 Peterson,133 and Shaw; 2°4 F10 spectra were determined by the author. Proton spectra of the L derivatives consists of a sharp doublet due to coupling to phosphorous while the spectra of the Lp compounds show a doublet of triplets due to coupling to both phosphorous and the two ortho fluorine nuclei. The fluorine resonances occur as we 11-separated m ultiplets with the required peak areas 2:2:1 (ortho:meta:para). The first order-para spectra were analyzed by inspection to give values for the coupling constants and Jut- The meta spectrum, which was second order, could then be analyzed by separating the first order J34. splitting and treating the result as one part of an AA'XX' system (jj,3 and Ji2 assumed to be negligible ) . 1:L2 TABLE 20

P 51, H1 AID) F 19 COUPLING CONSTANTS AND CHEMICAL SHIFTS IN L AND Lp DERIVATIVES

a b 5meta Compound 6p 31 tCH3 o rth o m eta p a ra -■5para Jbjj +j 23 LJ2< +J34. vJr. —* ~^SS J12 Ji3 't'J2s

CsFsPtea j»t. b 8.k2(CDC23) 132.0 163.0 15k. 2 5 .5 5*0 2.9 15.3 2 3.2 0 9 .k 3 0 .1 1 .8

C3FsFMes (Se) 7.62(CDC13); 132.13 160.06 lk 9 . 32 10.7k lp .3 5.5 21. k 23.6 3 .5 8 .9 - • 5.2 7 . 55(ch 2c i2 )

CsF5Fi-fe2(s) -30*5 7.75(CDC13 ) 132. 0k I0 O.3 O U £ .5 3 10.77 Ik . 2 5-kB 20.5 23.O 2. 9 k 8 .5 3-5 7.77(CH2C12 ) ( 132. 8 ) (l60. If) (1*9-9) (1 0 .5 )

lkB.6 0 20.3 - CsFs?Ffe2 (0) - 29-1 8.05(CH 2C12 ) lp 2 . 56 160.69 12.19 13.9 5 .1 23.I 2 .3 9 .2 -

[C8?5?i45s (l.fe)]I 7 .6 6 (c d c i3/c h 3oh) 026.35 158.53 lk 2.k 6 16.07 lk . 6 5 .1 15.6 0 0 0 0 0 5 .8

CaHsPJ'fea 8 . 6i ( c d c i3 ) 1 .7

CsH5pte2{s) 8 .o o (c h c i3 ) [cyfePMsa(Ms)3i 7 .6 6 (c d c i3/c h 3oh) Ik .o a) Phosphorous chemical shifts in ppm up fie Id. from E 3F04. b) Proton chemical shifts in ppm relative to TJS(IOt). Ref. 159. c ) The observed fluorine shifts from hexafluorobenzene were subtracted from lop. OOppra to give the chemical shift relative to CFC13. solvent for fluorine spectra was an 85:15 v/v dichloromethane: hexafluorcbenzene solution. d) Insufficiently resolved, e) J 35 ~0. 0 in all cases, f) P3 1 shifts taken from ref. 29. Figure XXX. The met a- F 19 nmr spectrum o f Pd(Cs?s PJ'^ 2) 2 (i'ICS) (S CN), showing s e p a ra tio n of the first-order J 34 coupling to give the upfield half of the AA OCX ' (Meta-ortho) spin system (ignoring J 13). VI 186

The twelve theoretically allowed nuclear spin-spin transitions for the A part of an M'XX1 spectrum (strong coupling and large 6^ ) are n a given in Table 21- The X part is an identical upfield image of the

A part and thus only half of the A2X2 spectrum need be analyzed. The spectrum is expected to show the following characteristics: a doublet of separation N, which is the strongest feature in the spectrum (lines 1,2,3,**-) and two symmetrical quartets (lines 3,6, 7,8 and 9,10,11,12). However in all cases except for the simple derivatives only one quartet was observed experimentally. examination of Table 21 reveals that only one quartet is expected if J 1 is less than the resolvable line width. K and M would then be equal, malting quartet 3,8, 7, 0 degenerate with quartet 9,10,11,12. In support of this deduction, J35 for a ll previously analyzed pentafluorophenyl spectra have been less than 2.8 Hz for simple CqF5X derivatives and less than 1.1 Hz for a ll metal complexes (and usually much less).2 ‘~2

Thus, J35 is taken to be less than 0.5 Hz, the typical half-band width of components of the observed quartets. The remaining coupling constants J23, J23, and J25 are then obtained by simultaneous solution of the energy expressions 5,6,7,8 or 9,10,11,12. By the above procedure, both the magnitudes of J23, J ^ , and J23 and their signs relative to each other were determined to be similar to those found by Graham for related pentafluorophenyl compounds.24,23 The coupling l8T

TABLE 21

NUCLEAR SPIN-SPIN TRANSITIONS IN ONE HALF OF AN

AA' XX' NMR SPECTRUM3,

T r a n s itio n Line No. Energy Relative to R e la tiv e I n te n s i t y l S i .-> s 2 1 >:N 1 Is o _ lS i 2 1

... ls-j^ -IN 1 s -a ‘ 3 Is 2so h -1-N 1 1 a

3s o ' 2s i 5 -|-K + 1-(KS +LS )2 s in 20s

2 S - ! . ^ s o ' 6 -I k + -l( K2 +L2 ) ^ COS2 0S

Ij-so ' -* 2s i 7 I-K - I-(K2+L2 )2' COS2 0S

2 8- ! -» 3s o / 8 -|K - i(K2+L2)2 sin20s

2a o ' 2a i 9 IM + 1 (M2+L2 ) i s in 20a

2a - 2_-* lao 10 -•iM + -1 ( M2 +L2 ) 2" co s20a l a o ' -» 2a i n I-M - 1(m2+L2 )^ c o sa 0a

2a - x - 2ao 12 - i.M - l^ f KL2)^ s in 20a

a)The second half-spectrum Is superimposable on the first half-spectrum.

Taken from reference 112. 188

C H 3 \ s * CH3

y ^ J x M

K " J AA/ = Jaa

L = ^AX-1^ AX

M " JM / " Jxx>=fJsQ"J3S M « -I* Jy^/^23 + JS3

0S= -I c o s_1 rK/(K®+L2 )s ]

0a = J- c o s"'1 Cm/CI'P+L2 )^ ] i. (coo 20j.): (sin 20s): 1 = K:L:(K2+La)^

(cos 20o): (sin 20a); 1 ~ M:L: (m2 *!2 )'^

F ig u re XXXI. The approximation of the meta spectrum of pentafluoro- pb.eny;idimethyIphosphi no as half of an AA'XX' spin system and definition of terms in the spin-enorgy leve]. expressions. From rei’erence 112. 40 Hz

159*33 ppm re! to CFCSg

Figure XXXII. Observed and calculated ir.eta F19 nmr spectrum in Pd(CsFsPM32 )2(!JCS) (SC5T). 4 0 H z

129*10 ppm rel. to CFC 13

F ig u re XXXIII. Observed and calculated ortho F19 nmr spectrum o f PdCc8F5PMe2 )2 (HCS)(sCN)3 assuming Ji2 and <0H o I* 40 £3z 4

150*86 ppm rel. to CFCS 3

F ig u re XXXIV. Observed and c a lc u la te d p a ra F19 mar spectrum o f ?d(CaF5Fiyie2 )2 (!TCS)(SCN). 191 192

constant sign relationships of Ja3, J2Sj and .J2Q to J24 and J34 were therefore also assumed to be sim ilar to the results obtained by Graham using double-resonance techniques. s4',as

As a check upon the correctness of the coupling constant magnitudes and the signs of J23, Jss* and J2Q, theoretical spectra were calculated using the derived shifts and coupling constants as input to th e com puter program IIMRIT.207 A com parison o f th e t h e o r e t i c a l and observed spectra for the Pd(CgF5PM22)2 (NCS)(scw) complex are given in

F ig u re s XXXII-XXXIV. R e so lu tio n in t h i s spectrum i s t y p i c a l f o r th e

CaFaPMe2 com plexes.

The ortho fluorine spectra of all derivatives and complexes of

Lp consisted of a broad, asymmetric 1 'doublet'In order to determine whether rotameric effects might be causing the broadened spectrum, the

F19 spectra of CQFsP(o)Me2 over the temperature range +55°C to -77°C and Pd(C6F5PMe2)2Cl2 over the temperature range +33°C to -20°C (lim ited by solubility) were determined. The results are tabulated in Tables 22 and 23. Wo change in chemical shift, coupling constants, or band shapes of the ortho, meta, and para resonances were observed. The invariance of the F19 resonances over the wide temperature range tends to discredit, but not entirely disprove, the importance of rotameric effects since sufficiently low temperatures to inhibit pentafluorophenyl-phosphorous bond rotation may not have been attained. A more plausible origin for 193

TABLE 23

TEMPERATURE DEPENDENCE OP F 19 CHEMICAL SHIFTS AND

COUPLING CONSTANTS IN (cil3 )2P ( o ) (ceFS)

°c 6 o 6 m 5 p J 3 4 a J 2 4

-77 130. 25 160.61 1*1-8.3 5 2 0 .8 -2 1 -

-21 129.89 l 6 0 .63 1*1-8. 56 20.6 ~19.6 ^ . 7

- k 1 2 9 .81|- + + + -1 8 +

ik 129.5 8 + + + -1 8 4*

33 129. k9 160.6 9 H )8 .72 2O.3 -1 9 5 .1

57 229.k l + 4* + +

TABLE 23

TEMPERATURE DEPENDENCE OP F 19 CHEMICAL SHIFTS

IN [Pd((CH 3 )2P(cQFs))2(CN)a ]

■ °C 60 6m 6p J 3 4 a J 2 4

-21 229. 8 160.00 1^7- 8 - - -

33 128. 58 159.99 1*1-7.6 8 2 1 .3 - 2 1 .8 5 .7

6 v a lu e s in ppm r e l a t i v e t o C0F0. J v a lu e s in Hz. - Insufficiently resolved ft a Splitting between maxima of the ortho ' 'doublet11. + Not determined. I9h

the broadening may be the large number of components into which the

ortho spectrum should be split. Coupling to hydrogen, phosphorous,

ineta fluorine, and para fluorine should produce first order splitting

resulting in seven, fourteen, fifty two, and one hundred four lines,

respectively. Particularly because of the small „ (~1. 8 Hz) and i' —rt JV, -n (~1 Hz) values, the extensive spin-spin coupling is not expected r —1 to be resolvable, causing apparent ' 'broadening1' in the ortho

fluorine spectrum. A double resonance decoupling experiment, irradiating

at the methyl hydrogens, would confirm the above interpretation, since

all hydrogen coupling would be destroyed. A factor of seven fewer lines

would result, and individual components should then be resolved.

The F13 nmr parameters do not appear to be overly sensitive to

concentration effects. Thus, for Fd(CeF5PMe2)2Cl2 in the concentration

range 0. 083 to 0.208 M, which corresponds to the most dilute solution

” in which resonance signals could be observed to a saturated solution,

the coupling constants do not change appreciably while the chemical

s h i f t s v ary by no more th a n 0. 02 ppm.

The methyl protons in the L and Lf derivatives listed in Table 20 r + are increasingly deshielded in the order L > L=0 > L=S > L=Se [L-CH3] .

This series is consistent with the expected downfield shift upon formal

oxidation of the phosphine. Although of similar electronegativity to

sulfur, selenium deshields the methyl protons more effectively than sulfbr 195

TABLE 2k

CONCENTRATION DEPENDENCE OF F13 CHEMICAL SHIFTS AND

COUPLING CONSTANT'S IN [Pd(CGF5Ptfe2 )2Cl2 ]

Conc(M) 60 6P 6m J 24 J 34 a

.208 128.76 1 ^9 .6 1 l 6l . 21 If. 8 2 0 .7 18. ^

. 167 128.79 l ;i-9. 61 161.20 If. 7 20. If 13.5

.125 128.79 1^9.60 l 6l . 21 ~5 20.5 ~ l 8

.1 0 0 128.79 1H9 .60 161. 20 - 20.8 ~19

.085 128.79 l ,i-9. 59 161.18 - ~ 20 -2 0

.0 6 2 - - -— -

6 values in ppm relative to CGFS. J values in Ha. The concentration ranges from saturation (.208m) to a solution too dilute to observe F19 signals (.062M). a denotes separation of maxima in the ortho ' 'doublet'' in Hz.

- indicates insufficient resolution. 196

in the Lp derivatives, possibly because pjr _ d« back-donation to phosphorous is less important than to selenium. h The proton shift in the methiodide derivative, CCeFs~PWe3J , occurs very close to that in the neutral selenide derivative, possibly implying that the resonance form II is a major contributor

+ - r3P=X ^ R3P-X X'-O, S, Se

I I I in the selenide derivative, whereas in the sulfide canonical form I also is important.

The F13 shifts for the Lf derivatives, in contrast to the H1 shifts, are increasingly deshielded as the electronegativities of the substituents increase. Upon complexation of L and Lf to palladium (ll) to form PdLsX2 and Pd(Lf)2X2 (x=Cl, Br, I , CH, CHS, N02), the methyl resonance moves downfield to the ranges T 7.78-3. ill- (Pd(lf)2X2) and r 7* 83-8.25

(Pdl^Xs). For Pd(Lf)2X2, shifts of the methyl protons fall between shifts of the free ligand ( t 8. b 2.) and the sulfide derivative ( t 7 -7 5 ), while for PdL2X2 the methyl resonances occur between the free phosphine

( t 8.6l) and the methiodide derivative ( t 8 . k-2 ).

Within the PdI«X2 series the methyl protons are shifted to increasingly lower field in the order Cl > Br «UCS > N02 ~ CN > I whereas in the Pd(Lf )2X2 series the order is N02 > Cl > Br '"SCN > I '■'■'CN TABLE 25

H1 AND F19 COUPLING CONSTANTS AND CHEMICAL SHIFTS IN

M ( )3X0 (M=NiaPd3P t) COMPLEXES

6f i s b

a •UT Compound ortho met a para 5m eta- _ZJ 24: +J23 35 t ch3 "^3-i J 14 J l 2 ^13 iP +J23

N i(L f)2 (CN)2 129.88 161.2 7 150.86 10. in 3-8 20.2 22.6 3 -8 8 .0 - - - 5 .6 N i(Lf)2 (NCS)2 128.75 159.97 147. 38 12.59 5.3 19.9 23-3 - 8 .2 - - 7 .1 N i( lf ) 2Cl2 128.65 161. 49 •150. 43 11.06 4 .1 20-5 23. I - 8.5 -- 5 .4 N i(L f)2I2 129-61 161.62 151.12 10.50 3-8 2 0 .7 23. 4 - 7 .8 - - 5-6

Pd(Lf)2 (CN)2 T. 78 128. 52 159-59 147- 68 12.51 5-7 21.3 23-0 - 8 .4 -- 6 .9 Pd(Lf)2 (NCS)(SdO 7 .9 0 129.10 159- 83 147-65 12.18 5 .2 20. If 23-3 - 8.3 -- 6 .2 Pd(Lf)2 (N02)2 8. 14 129.03 159.88 147- 29 12.59 5 .1 2 1 .2 2 5 .1 - 8 .4 - - 6-5

Pd(Lf)2Cl2 8.05 128.83 161.25 149-63 11.60 4. 5 20. 0 22.9 - 8 .4 - - 5-9 P d (lf) 2Br2 7.91 12a 90 161. 49 ■150.00 11. 1# 4 .4 20. If 23-5 - 7.9 - - 6 .6 P d (lf) 2I 2 7.78 129-14 I 6I .5 0 150. 55 10.95 4 .2 2 0 .7 2 3 .7 - 7-7 - - 6 .6

P t ( lf ) 2Cl2 f 129-40 l6 L 24 150.09 11.15 ~3- 5 19-9 14.7 - - - - -

P t ( lf ) 2Cl2 129.8 159-4 ------a) ppm rel. to TM3 (lOr). b) ppm rel. to CFC13. c) Coupling constants in Hz. d) F19 spectra were determined in 15“3 ^ w/v solutions of complex in an 85:15 v/v dichloromethane-hexafluorobenzene solution, e) - represents insufficient resolution for analysis, f) Determined in a saturated 85:15 DMF-hexafluorobenzene solution. 198

the two series are similar except for the position of nitrite. The protons are thus increasingly deshielded as the n-acceptor nature of

X increases. In contrast, the ortho, meta, and para F10 nuclei are

Increasingly shielded as the ^-acceptor nature of X increases. The

simultaneous deshielding of the fluorines and shielding of the methyl

protons as X becomes more electronegative (or a poorer m-acceptor)

occurs for both the Pd(Lf)2X2 and the CeF5PMe2X derivative series. It

is difficult to interpret the seemingly contradictory trends of the

F10 and H1 chemical shifts with X in terms of simple cr~*r effects. If the upfield position of the methyl resonance in Pd(Lf)2Cl2 compared to Pd(Lf)2I2 is due to greater ^acceptor nature of I (dirPd)1 -k dir(I)) and better ;:-donor ability of Cl(dJt(Pd) p « ( c i ) , th e n upfield shifts in the fluorine resonances should also be observed

for the chloro compound. On the other hand, if the apparent deshielding

of fluorine protons on going from the iodide to the chloride complex is

due simply to the greater electronegativity of chlorine, then downfield

shifts would also be predicted for the methyl groups on phosphorous.

The dilemma may be resolved by the following explanation.

The trans-PdX2(CeF5PMe2) group may be considered a substituent

of the dimethylpentafluorophenylphosphinc group, i. e. Lf-X as in the

simple derivatives. It is believed that as the electronegativity of

substituents on phosphorous increases, phosphorous becomes a better ^-acceptor because l) the relatively greater positive charge on phosphorous may be partially (or wholly) alleviated by backbonding

(synergic effect) and 2) the vacant phosphorous 3d orbitals contract as a result of increased nucleai’ charge, allowing for generally better overlap with potential ir-donating substituents.21,50-58 Trimethyl- phosphite, tris-(trifluoromethyl)phosphine, and trifluorophosphine represent three excellent «-bonding phosphines containing highly electronegative groups. Thus, the electronegative CqF^ ring in Lf should make phosphorous a better overo.ll it-acceptor towards both the aromatic ring and suitable d-orbitals of a transition metal. By this process, phosphorous could become a sufficiently good n-acceptor such that the reduced a -electron density on phosphorous is more than compensated for by Jt-backbonding into d-orbitals on phosphoi’ous; then simultaneous shielding of phosphorous and the methyl groups and deshielding of the fluorine nuclei would result. Thus, in going from

X=I to X=C1 in the Pd(Lf)2X2 complexes, the electronegativity of the phosphorous substituents increases, increasing ^-donation to phosphorous from both the metal and the CQFs ring; as a result, the methyl groups are shielded and the fluoroaromatic ring is deshielded.

Several lines of evidence support the above contentions,

l) Although all three sets of non-equivalent F19 nuclei in the three series Ni(Lf)2X2, Pd(lf)2X2, and (CeFg)(Me)2P(x) are increasingly 200 deshielded as the electronegativity of X increases, the order always remains fimeta > Spara > 6ortho (higher to lower field). Fluorine nuclei ortho to substituents in aromatics invariably show large downfield shifts due to Van der Waals field effects. However, the fact that the para fluorine is more deshielded than meta fluorine strongly ■ suggests that resonance effects are important in determining the I1’1:3 chemical shifts. The para fluorine is physically more distant but electronically more directly integrated via the aryl Jt-system with phosphorous than the meta fluorines. The fact that op is shifted to lower field than 6m implies the presence of ir-bonding effects.

2) In simple pcntafluoropheny 1-derivatives Graham and coworkers

found an excellent linear correlation between J24 and 6p,

with both values diagnostic of the n-donor it-acceptor nature of the

substituent.24"26 Thus, good n donor groups (such as oxygen and nitrogen

compounds) cause large upfield shifts in 6p and large positive J24

values, whereas jr-acceptor groups (such as phosphines and cyanide)

produce downfield shifts in 6p and negative J24 values; substituents

such as hydrogen and alkyl groups which cannot n-bond with the CqFs

ring, produce almost aero J24 values and 6p* s close to the resonance position in hexafluorobenzene. The «J24 and 6p parameters for the two

M(Lf)2X2 (M=Ni,Pd) series each fit a linear correlation (Figures XXXV and XQCVn) which is superimposable upon Graham's plot. (Figure I ). In a ll CN

J24 C.NS (Hi)

147 148 149 150

7igure XXXV. Correlation of the ortho-para coupling constant (J24J with the para chemical shift (fip) in trans-?d(CaPsPMsp)pXg complexes. o 1

J 2 4 5-0- (Hz)

3*0 147 149 I5t ^ para {ppm.rei.io CFCI 3) Figure XXXVT. Correlation of the F13 ortho-para coupling constant (j2.-r) with the para

chemical shift in Hi(c3F5PMe2 )2X2 complexes. 202 the M(Lf)2X2 complexes, the trails-m(Cr-.Fr-.PMer,)x2 substituent acts as an apparent n-acceptor from the CSF5 ring, the degree of Jt-acceptance from the C0FS .ring increasing with the electronegativity of X. Thus, the inductive effect of a more electronegative X increases the K-boncling ability of phosphorous both to the CeF^ ring and to the metal. The same effect should be noted for aromatic proton shifts in complexes of

CeilsPMha • Spectral studies with nmr contact shift reagents unfortunately would not conclusively prove or disprove the effect since the method would depend upon coordination of the reagent to the complex, necessarily changing the chemical environment somewhat.

5) The magnitude of the '* n-acceptor' 1 parameters, 5m-6p, used successfully by other workers, although with little theoretical justification, is thought to reflect the amount of n-acceptance from . the aromatic ring.93 The series for the Lf derivatives is 0 > S Se, in Ni(Lf)2Xa NCS > Cl > I > CN, and in Pd(lf)2X2 N0a > CN > Cl > Dr >

I > (ffCS) (SON). The magnitude of 6m-6p clearly correlates with the electronegativity of X.

t) The generally higher molar extinction coefficients in the visible electronic spectra in M(Lf)2X2 cotnpared to ML2X2 is consistent with the fluoro-ligand acting as a better m-acceptor toward the metal.

This mechanism would also increase the ligand field strength of the fluoro-ligand to compensate for the loss in a-donor strength, in agreement with the observed data. 20

5) It is im plicit in the above arguments that in the

M (lf)2X2 complexes pjt(x) -* djtCm) backbonding from halogen to metal is small or at least overshadowed by other electronic effects, as otherwise opposite trends would be observed for the F19 resonance positions.

Because of the cis relationship of the phosphine and halogen ligands, there are no suitable orbitals for effective and direct transmission of ir-electronic effects from halogen to phosphorous (and ultim ately the CGPS ring). Transmission of Jt-information from metal to the CqF5 ring is also decreased by the tetrahedral angle about phosphorous.

The combination of the above geometric factors and the large number of atoms through which the effect is being transmitted act to minimize direct Jt-bonding interactions.

It should be pointed out that the variation of J24. and 6P with X in the M(Lf)2X2 complexes (m= Ni,Pd) and Lf derivatives is small.

However, the values are reproducible and the quality of the F19 nmr spectra suggests that the trends are real. In the only previous study of the F19 nmr spectra of fluorophenylphosphine complexes, Kermitt and coworkers found no significant differences in F10 chemical shifts in v a rio u s ML2X2 (M=Pd, Pt,* X= C l,B r ,l) com plexes o f t r i s ( p e n ta f l u o r o - phenyl)phosphine.70 However, their data do not appear to be as precise as that determined in the present study. Furthermore, the attachment 5-4-

5-3- Se S ©

J24 5-2- (Hz)

5-1 0 ©

5*0- 143-8 149*2 I4S-6 pora (ppm.rel.to CFC^)

Figure XXXVU. The relationship of the F19 ortho-para coupling constant (J24) and para chemical shift (5 para) in CqF5?K22(x) derivatives. 206

of three pentafluorophenyl rings (as opposed to one in Lf) to phosphorous might be expected to diminish the effect upon 6p and J24 with various halogens X.

Finally, it should be mentioned that most previous workers have investigated the F19 spectra of monofluorophenyl (meta and para) and pentafluorophenyl groups directly attached to metals. These studies produced trends in the ’1 K-acceptor'1 parameter 6m-6p with various halogens X also bonded to the metal which are in contrast to the trends found in the present study.03 Thus, in the compounds studied by Stone et. a l.. 6m-5p decreased in the order I > Br > Cl, in accord with S3 the decreasing m-acceptor nature of X. Essential differences exist between systems containing direct metal-fluoroaryl bonds trans to halogens and the cis arrangement of halogens to dimethylpcntafluoro- phenylphosphine in the complexes studied in this investigation. The

1 'cis.' ’ relationship of the C3F5 group and X in the M(Lf)2X2 complexes and the influence of the intermediary phosphorous atom certainly produce different effects from those in brans CeFg-M-X linkages, and the greatest differences w ill arise in the net jr, rather than inductive e f f e c ts .

In the CeFg-X derivatives studied by Graham, et. a j^ 24-20 correlations of 5p and J2Q and J23 were discovered. Similar plots

(Figures X0CVU.I and XKIX)for Pd(Lf )2X2 and Ni(Lf)2X2 show the same general trends, but fit a straight line very poorly. F ig u re XXXVIIT. C o rre la tio n o f th e e le c tr o n e g a tiv ity o f X w ith 6 p a ra in K i( l^ ) £X2 ( 0 ) and and ) 0 ( £X2 ) l^ i( K in ra a p 6 ith w X f o ity tiv a g e n o tr c le e e th f o n tio la rre o C XXXVIIT. re u ig F

Allred- Rochow Electronegaiivity - 5 3 - 0 3 2 f O^ ( ) complexes. ) X ( ^o fO dfL P * 0 vrgd ad _bnig o acut ( ) (lTCS)CSCN)- f)2 d(L F r o f account to S_bonding and N r o f Averaged . NCS 148 ^ para(ppm.rel.io CFCl^) para(ppm.rel.io ^ 0 5 1 152 6 r 6-6- X 4 ■■■ r24*0 0 1 1 (.6 1 ..

i i 6-4- 0

J 2 6 Br 6-3- 0 J 2 3 (Hz) (Hz) CNS 6 -2“ X 0 6 *r cm r23*0

6 0 - Ci 0 . i f ------r c H 148 1 5 0 * 5 2 & para ( ppm. re I. to CFCI 3 )

F ig u re XXXIX. Correlation, of J2g (x) and J 23 (o) with op in. Pa(L-,)2^ 2. complexes. 7 - 0 -

NCS

J26 d23 (Hz) 6*CL -2 3 -0 (Hz)

148 149 1 5 0 rel to CFCU) S p a r a 'P P ™ F ig u re XL. Correlation of the ortho-para (j26) (x) and ortho-meta (j2S) (o) coupling constants with the para chemical shift (Sp) in trans-Ni (C6F5PMe2)2X2, 2X0

l'n summary, the experimental F10 nmr spectral parameters of, dimctbylpentailuorophcnylphosphine derivatives and complexes exhibit small but significant trends which may be interpreted in terms of indirect ir-interaction of phosphorous with both the metal (in the complexes) and the pentafluorophenyl ring. The nature of the interaction is sucli as to increase ^-bonding to phosphorous from both the metal and the perfluoroaryl ring a3 the electronegativity of substituents on phosphorous increases. Similar but smaller effects are expected for aromatic protons in analogous dimethylphenylphosphine compounds. As a result of the greater electronegativity of CGF5 vs. Cq Hfj, dimethylpentafluorophenylphosphine is pr-edicted to be a better x-acceptor ligand than dime thy .lphenylphosphine towards transition metals. This expect ation is compatible with synthetic and spectral studies described earlier in the text.

F. F19 Socotra of 1, P., v>, t-tetrafluoro'ohen~/-l Compounds

The F19 spectra of thirteen 1,2,3,1l-“te trafluorophcnyl compounds, including five metal complexes, were measured. These are listed in

Tables 26, 27 and 28.

Specti'al parameters for compounds 1,11, and III have previously been reported, 100"10:3 while the remaining compounds in the Table are new. Spectra of unsymmetrically ortho substituted derivatives were all first order; thus, chemical shifts and coupling constants could be - obtained directly by inspection of the four, well separated, symmetric resonances. However, the spectra of the symmetrically ortho substituted tetrafluorophenyl compounds were not easily analyzed. Two well- separated, complicated, symmetric resonances (identical in the case of compounds I and II) were observed for compounds I,II,III, and IV. Duo to the great complexity of analyzing a six-spin, second order

AA'MM'XX' spectrum such as occurs for 1 , 2 , *i--tetrafluorobenzene, determination of coupling constants for this compound was not attempted.

The fluorine resonances were, however, sufficiently symmetric to allow accurate determination of the F1G chemical shifts by inspection.

Coupling constants and shifts for I and II, derived by refinement of previously reported parameters to fit the spectra recorded on oux* 2 erf spectrometer using computer programs NMRIT and NMREN, do not significantly vary from the previously reported values, thus providing a check upon the precision of our spectra and accuracy of the computer calculations.

Unfortunately, the geometrical nature of o-tetrafluorophenyl derivatives makes these compounds considerably less useful for elucidation of a~ and it-electronic effects than pentafluorophenyl 212

compounds. In the symmetrically substituted compounds (Xi=X2), the

^-fluorines are simultaneously ortho and meta to X, whereas the

P-fluorine is both meta and para to X. Thus, assignment of differences in chemical shifts and coupling constants to real differences in inductive and mesomeric effects of the substituents Xi and X2 is complicated due to the composite effects.

The alpha and beta chemical shifts for the symmetrically substituted compounds I-IV decrease (are deshielded) with an increase in the relative polarizibility and Jt-acceptor nature of the substituents, i. e. F > H > Cl > Br > PPh2. It should be noted that electronegativity arguments favor the reverse order. The position in this series of hydrogen, which has no jt-bonding orbitals, is especially significant since it implies that the chlorine, bromine, and diphenylphosphino groups act as increasing n-acceptors from the o-tetrafluorophenyl ring.

For compounds I and II, the F-F coupling constants are quite similar, suggesting similar types of interaction with the perfluoroaromatic ring.

Plots of and 6P vs. the Allred-Rochow electronegativity of the substituent X for compounds I-IV are given in Figure XLT. The approximately linear dependence may be coincidental since the Allred-

Rochow electronegativities of these particular substituents also roughly parallel their n-donor capacity and especially since the most electro negative substituent (x =f ) causes shifts to the highest field positions. gur XI Corel i t e th f o n tio la rre o C XLI. re u ig F A llred- Rochow Eledronegativity 2-0 - 0 - 4 ymti CFX cmons t he el ronegatviy of . -oj X. f o ity tiv a g e n o tr c le e e th ith w compounds C6F4X2 symmetric n i PPh. ------8 p rl o CFCL) rel. ppm to ( c ad p-(o and 3c) 140 ------r fl ne ce cl s t f i h s ical chem e in r o lu f cr) 170 t a b l e ; 26. FLUORINE-19 CHEMICAL SHIFTS AMD COUPLING CCNSTAIITS jETT SOI-2 SUBSTITUTED PERFLUOROPHEEYX COMPOUKPSMj c T c b l FiS Chemical Shift Coupling Constants (Hz) C ompcund Ji2 Jii JW- J15 J23 J24 JE5 J34 J35 J45

r T' 119*38 .’55*12 (5 MI 127*19 21*5 3*4 10*9 10*9 19*3 8*5 0*5 22*9 4*3 *-

2 /^ S C H : 137*47 160*18 156*43 I39*8t 21*7 7*6 2*4 18*8 8*5 1*9 20*9 2*2 9*4 O ^ H 4

2 f V CH3 130*05 152*90 154*28 123*67 22*2 4*8 12*8 21*2 5*4 - 21*5 4*8 3 ^ * P P h 0

2 | ^ SCH3 o^PlPhKCg^-SCHj) 129*91 152*92 153*97 125*65 22-9 11*7 11*7 4-7 18*8 4*4 - 21*8 4*7 - 4 2 ^l ^ ‘P-Ph- 124*26 127*39 93*59 22*3 13*7 17*6 2*2 3*7 11*2 PhCH2S ^ > B r

a) The chemical shifts are relative to CFC1S (ppa). b ) Spectra were measured in an o5:15 v/v CH2CJ.2: Cs^e solvent t nuiccure. 0.) — indicates insufficient resolution for analysis. TABLE 27 FLU0HIL2-19 CHEMICAL SHIFTS ASD COUPLING C0L3TAKT3 XL SYMMETRIC o-CeF^Xa COMPOUNDS

Table F,a Chemicc! Shift Coupling Compound

—19*63 154.18 - 21-53 2*80 8-18

I5 5 ‘3 -20-5 2*5 7*4

140*58 157*09

151*42

163*00

a) The chemical shifts are relative to CFCls and the coupling constants are in Hz. ro b) Spectra were measured in an 85:15 v/v CHsCl^tCaFs solvent mixture. VIH c) Analysis of coupling constants was not attempted for CeF-iHs and C 6F 4{P?h2 ) 2* TABIE 28, FUJORTTIE-19 CHEMICAL SHIFTS AND COUPLER CONSTANTS IN COMPLEXES OF FSP-,F3?-CH3, and. FDP.

F19-Chemical Shift Coupling Constants COMPLEX

134-87 150 08 -161*3 127-65 •PPi

133-71 149*78 -162-0 127-16 PPh

129-88 152-12 154-68 123-68

143-74 12-9

143-91 i2-2

AuCI 126-53 I52:36 158-61125-92

a) The " 3" spectrum vac not resolved h ut was assumed to H e under the large reference centerband peak at 163.00 ppm, ( ------) indicates insufficient resolution for analysis. b) 6 resonance unresolved in the region Sl -163 6. c) Only I and II gave sufficient resolution for analysis of coupling constants. d) Chemical shifts in ppm relative to CFC13. e) Samples were run as saturated solutions in dichloronethone containing 15$ v/v hexafluorobenzene as the internal lock reference ( 5 p = 163. 00). 217

The position of hydrogen falls far off the electronegativity plots for both the a and 3 fluorines* but considerably more for the former. This suggests that a factor in addition to the electronegativity and n-character of the substituent* namely atomic size* may also influence the chemical shifts of the alpha fluorine atoms. Figure XLIE contains a plot of the Van der Waals radius of X vs. the chemical shifts of the alpha and beta fluorine nuclei. A linear relationship is found for the alpha fluorine shifts except for X=H, whereas shifts of the

3-fluorine nuclei are relatively invariant to the size of X, These observations are a manifestation of the ortho Van der Waals field effect upon th e F 10 resonance position.71,76,77? 112 However, the apparent dependence of fia on the size of X may well be fortuitous since the

Van der Waals radii happen to parallel other characteristics of the substituent X, e.g. electronegativity and ir-bonding ability.

Figures XUand XLH at least indicate that (l) inductive effects * are not dominant in determining the F 10 chemical shifts in l,2,3j^~tetrafluorophenyl derivatives* ( 2 ) the Jt-bonding nature of the substituent is a major factor in determining shifts of the 3 fluorine nucleus, and

(3 ) the atomic size of the substituent may influence the alpha shift. X gur XI Corel i t ad ) uori hmia shi s t if h s ical chem e in r o lu f o) o M and ) x x ( r c e th f o n tio la rre o C XLIL re u ig F RADIUS of ! -OH i *5 - 0 * 2 110 ymti orho-w^p opud wih t a der al r us of X. f o s iu d ra Waals r e d Van e th ith w compounds -CwF^Xp o rth o symmetric n i PPh ™ T " 130 8 (p rl t CFCI^) rel. (ppm to 150 \ 170 H 03 to 219

Chemical shifts and coupling constants in the unsymmetric compounds V-XIII are assigned by comparison with compounds I-IV and with consideration of the fact that in pentafluorophenyl derivatives containing jr-acceptor substituents, the ~para chemical shift is much further downfield than the meta shift . 2 0 " 22 Thus, ^-bonding groups perturb para fluorine nuclei to a much greater extent than meta f lu o r in e s .

As an example, the four chemical shifts for compound V were assigned in the following way. From the magnitudes of the shifts, the four resonances may be readily paired into alpha and beta shifts. The two resonances at lowest field, 119*88 ppm and 127.15 ppm, were a ssig n e d to the fluorine nuclei ortho to phosphorous and bromine respectively, since the alpha resonance in the diphosphine IV (l22.lt ppm) is at lower field than the corresponding resonance in the dibromo compound

I (125.02 ppm). Analogously, the beta resonances at 151.11 and

1 5 5 -1 2 ppm were assigned to nuclei para to phosphorous and bromine respectively, since comparable shifts occur in compounds I and IV.

Once each of the four resonances has been assigned, the various coupling constants may be determined by inspection. Spectral analysis of the remaining compounds in Table 26 proceeded in a sim ilar manner.

The F 19 nmr spectrum of the thioether VI,the synthetic precurs or to the ligand FSP**CH3, contained resonances at 157.^7, 160.18,

156.^ 3, and 1 3 9 .8 1 ppm which w ere a ssig n e d t o 61, 62, 63, and 64 220

according to the numbering scheme indicated in the table. Of particular note, the resonance positions of fluorine nuclei ortho and para to the thioether function occur at only slightly lower field than the corresponding parameters in o-tetrafluorobenzene, compound III

(lt-0. 58 and 157. CS ppm, respectively). This fact implies that electronically, the thioether function and hydrogen interact with the perfluorophenyl ring similarly, and thus sulfur is involved in very

little JT-bachbonding from the fluoroaryl ring. In fact, the J 24 and 6p values, which are diagnostic of the jc-interaction in penta-

fluorophenyl compounds, are virtually identical in C 0F5II, CGFsSII, and

2 0 * ^ 2 c0f s ch3. When hydrogen in compound VI is replaced by a diphenylphosphino group to give the ligand FSP-CH3 (vil), the shifts of fluorine nuclei ortho and para to the phosphine function are shifted downfield nearly to the value found in the diphosphine FDP(lv).

However, the chemical shifts of fluorine nuclei ortho and trans. to sulfur in VII also decrease drastically compared to compound

VI. Thus 6 1 decreases from 137- hr( t o 130. 05 ppm and 6 3 d e c re a se s from 156. l|-3 to 15^. 2 8 , again indicating a large degree of electron withdrawal from the perfluoroaryl ring via u-bonding upon incorporation ■ of the phosphine substituent. In contrast, the singlet H1nmr of the thi©methyl group does not show a corresponding downfield shift upon incorporation of the diphenylphosphine group. Instead, the methyl resonances goes to higher field in compound VII. 221

The relative effects of the phenyl and the o*tetrafluorophenyl

groups upon the F 13 nmr parameters may be seen by comparing spectra

o f th e b id e n ta te su lfu r-p h o sp h o ro u s lig a n d FSP-CH 3 (VTl) and the potentially tridentate disulfur-phosphorous ligand FD3P (vill). 6 1 ,

62, and 63 are very similar for both compounds and the differences are

so small that they could be due to solvent (concentration) effects;

therefore, little interpretation can be made of these shifts. However,

64, due to the fluorine nucleus ortho to phosphorous, does exhibit

a significant downfield shift of 1 .9 8 ppm, which is in the opposite

direction predicted by electronegativity effects since the perfluorophenyl groups are more electronegative than phenyl groups.

Also, the upfield shift does not correlate with the greater size of o-CGF,t -SCH3 compared to CqHs since, as has already been shown, down

field shifts occur as substituent size increases in symmetrically disubstituted o-tetrafluoro compounds. It is tempting to ascribe the

s h i f t i n 64 in compound VIII compared to VII, to less efficient

rft- dif donation from the perfluorooryl ring since two perf luorophenyl groups are competing for electronic access to the vacant Jjd o r b i t a l s of phosphorous in VIII compared to one perfluorophenyl group in compound

VII. However, trends in the proton nmr spectra for compounds VI-VIII cannot be explained easily by a sim ilar n-bonding argument. The methyl 222

chemical shifts increase from 7. 52 to 7* 59 to J. 'JO in compounds VI,

VIII, and VII respectively, while the center of the phenyl multiplets in VIII and VII are 2-57 and 2. 72 respectively.

The F 19 nmr spectra of three nickel, two palladium, and one gold complex were determined. In general, determination of F 19 s p e c tra on complexes of FSP- was difficult due to limited solubility. Although

several other compounds were examined, resonances were observed only for those tetrafluorophenyl-containing complexes listed in Table 26 , and even these spectra were so broadened that in most cases coupling constants could not be determined. The large molecular weights and

limited solubilities (particularly of the FDP and ITP complexes) are in large part due to the presence of diphenyl- and phenylphosphine groups. It is strongly recommended that in future synthetic and nmr

studies of perfluorophenyl ligand complexes donor groups such as dimetliylphosphino, dimethylarsino-, etc., be used. These groups offer the simultaneous advantages of (l) much smaller molecular weight, with concurrent solubility advantages for the nmr method, '( 2 ) g r e a te r basicity, leading to generally more easily prepared and more stable complexes, and ( 3 ) the advantage of methyl protons which can, by means o f H1 nmr, be used to elucidate the electronic and molecular structure of the compound. 223

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295* E. L. B21nn and D. H. Busch, Inorg. Chem., ^20 ( 196 8 ).

196. G. A. Mair, H. M. Powell, and D. S. Henn, Proc. Chem. Soc., kl5 (2960).

197* J. K. Stalick and J. A. Ibers, Inorg. Chem., 8, 108k ( 296 9 ). 23*+

158. B. B. Chastain, E. A. Rick, R. L. Pruett, and H. B. Gray, j . Am. Chem. S o c ., §0, 399*!- (2568).

159* S- C. Alyea, P. G. Eller, L. Peterson and D. W. Meek, unpublished work. 200. r, b. King and M. B. Bisnette, J. Organomet. Chem., 2, 58 (1961+).

201. M. A. B. Eeg and H. C. Clark, Can. J. Chem., 32, 595 (l96l).

202. C. R. C. Coussmaker, M. H. Hutchinson, J. R. Mellor, L. E. Sutton, and L. M. Venanzi, J. Chem. Soc., 2T05 (l96l).

2 03 . E. A. Rick and R. L. Pruett, Chem. Comm., 69T (1966).

201+. J. M. Jenkins and B. L. Shaw, J. Chem. Soc. (a), 770 ( 1 9 6 6 ).

2 05. M. H. B. Stiddard and R. E. Townsend, J. Chem. Soc. (a), 2719 (19TO).

206. G. M. Coppinger, J. Am. Chem. Soc., 7 6 , 1372 (195*!-)*

207. R. C. Ferguson and J. D. Swalen, J. Chem. Phys., 1+1, 2087 (l96l), with slight local modifications.

208. G. A. Barclay, R. S. Nyholm, and R. V. Parish, J. Chem. Soc., 1+1+33 ( 3561).

20 9 . K. J. Coskran, J. M. Jenkins, and J. G. Verkade, J. Am. Chem. Soc., 2& 5*1-57 ( 0 5 6 8 ).

210. M. Ashley Cooper, Org. Mag. Res., 1, 363 ( 1 9 6 9 ).

211. L. G. Vaughan and W. A. Sheppard, J. Am. Chem. Soc., 82? 6l5l(l969).

212. R. B. King and A. Efraty, Inorg. Chem., 8 , 237*1- (1969).

213. R. Curran, J. A. Cunningham, and R. Eisenberg, Inorg. Chem., % 271+9 (1970).

21*+. P. W.R. C o rfie ld and M. B a ile y , The Ohio S ta te U n iv e rs ity , Summer Quarter, 1971.

215. D.H.Busch, Science, 171. 2*+l(l97l). SUPPLEMENTARY REFERENCES T9 Reference texts on nerfluorocarhon ligands and F nuclear magnetic resonance.

1. 11 Fluorine Chemistry Reviews", Vols. I-V, P. Tarrant, Ed.,

M arcel Dekker I n c . , 1971*

2. A. E. Pavlath and A. J. Leffler, "Aromatic Fluorine Compounds' *,

A.C.S. Monograph, Reinhold Press, 1962.

3 . 11 Compilation of Reported F 19 Nmr Chemical Shifts, 1951 to mid-

2967'% Claude H. Dungan and John R. VanWaner, W iley-Interscience,

1969.

It. W. A. Sheppard and C. M. S h a rto , 11 Organic Fluorine Chemistry'*,

W. A. Benjamin, New York, 1969*

5, ’*Advances in Fluorine Chemistry", Vols. I-VI, M. Stacey,

J. C. Tatlow, and A. G. Sharpe, Eds., Butterworth, London, 1961.

Review articles and miscellaneous useful general references pertaining to nerfluoroaryl compounds and fluorocarbon complexes.

1. R. S. Nyholm, Quart. Rev., 2^, 1, (l97l) .

2. T. Kruck, Angew. Chem. I n te r n a t. E d ., 6 , 53a^5^ ( 29 6 7 ).

3 . J. J. Lagowski, Quart. Rev., 1 % 233 (2959).

P. It Treichel and F. G. A. Stone, Adv. Organomet. Chem., 1,

i h j ( 296 I1).

5. M. I . Bruce and F. G. A. S to n e, Angew. Chem. I n te r n a t. E d ., J ,

i v r ( 2 9 6 8 ).

6 . M. R. Churchill and R. Mason, Adv. Organomet. Chem., 225 ( 2968).

7- W. J . B land, L e ic e s te r Chem. R ev., 8 , 15 ( 2 9 6 7 ). PARE TWO

The Crystal and Molecular Structure of t r i s (trim e thylphosphi ne su lfi de) c oppe r (I )

Perchlorate

256 I . INTRODUCTION

A. Ter-Coordination in Metal Complexes

One of the most unusual coordination numbers found in metal

complexes is the coordination number three. Relatively few authentic

ter-coordinate complexes have been isolated and chemically and physically characterized. It is not surprising then that relatively few

ter-coordinate metal complexes have been studied by X-ray single

crystal diffraction methods.

A search of the chemical literature reveals crystal structure determinations for sixteen compounds where the stoichiometry would be consistent with a three-coordinate metal (Table 29). Strikingly, with the exception of two compounds a ll the known structures contain metals from Group lb in the +1 oxidation state (d10 electronic configuration), all possessing polynuclear configurations.

Even before the recent crystal reports, ter-coordination was generally considered to be most common in the chemistry of the argentous

(Ag+) ion. In Ag+ complexes containing soft ^-bonding ligands such as phosphines, arsines, olefins, and halides, ter-coordination has been found20 in species such as rig(PR3)aI and Agl3 2. Primarily because of the relatively few diffraction studies of silver compounds so far reported however, only three crystal structure reports of ter-coordinate silver are known.

237 238

TABLE 29

CRYSTAL STRUCTURES OF THREE-COORDINATE METAL COMPLEXES

Compound No. Formula Geometry and Remarks Ref.

I Fe{NrSi(CH3 )3 l 2}3 C ry st. D3 symmetry 1 ,2 Fe-N= 1.91800 A II Cr[N[Si(CH3 )3 l 2}3 Isostructural to I 2,3,**- III Ptrp(cQH5)3i3 Trigonal planar P-Pt-F=122°,122°, 115° Pt-F=2.25-2.281 5 IV {Au[P(c6H5 )3 13 }B0H i ^ No details given 6 V AgC102 0 0 s h e e ts 7 VI (CqHu-CsHs )2 Ag0C103 8 VII C(C9Ha )AgC104.12 dim er 9 VIII KCu(CN) 2 roughly trigonal planar co c h a in s 10 IX kcu 2 ( cn )3h 2o roughly trigonal planar 00 s h e e ts 11 X ii-C l(C aHs )Cu 12 XI rCuCl(CaHi4)]4 roughly trigonal planar te tra m e r 13 XII Cu2Cl2 (CaHi4 )3 roughly trigonal planar 1^ XIII cu2c i2rp(cGH5 ^3*13 one tetrahedral and one closely trigonal planar Cu bridging chlorides 15 XIV cu [;s c (nh 3 )2“|2 c i Distorted T.P. <9 chain with bridging sulfurs C l— Cu=2. 8, 3. 2A. Cu-S= 2.27,2.26j2.31A (Bridging) Cu-S=2.21*-, 2.23 (term inal) 1 6 XV cu4rsc(NH2)2i,( no 3 )4 C u-S=2.29-2. ^ 7 l 17 XVI {Cu ( c=C-C6H 5)[p ( ch 3 )3 ]}4 One Td, one d is t o r t e d T. P. Cu. Cu(Td)-Cu(TP)=2.693, Cu(Td) 1- Cu(TP)=2. ii-50 1 8 239

The structure of silver chlorite, compound V, consists of sheets in which silver is trigonally coordinated in an asymmetric manner to three "bridging oxygen atoms of the chlorite group . Two other silver-oxygen contacts which are well within Van der Waals distances "but too long for fu ll bonds are also present in the structure.

Compound VI, [ (Cq Hu -Cs Hs )2Ag(0C103)], has been described by Hall and Ammn. 8 The geometry about silver is roughly trigonal planar with two olefins and a coordinated perchlorate group comprising the coordination sphere.

Amma, et. a l., have also described the only other crystal structure determination of a three-coordinate silver complex in compound

VII.9 Geometry is similar to that found in VI, a distorted trigonal plane about silver being formed by two olefinic and one bonded perchlorate groups.

Structure reports of three-coordinate copper(i) are more common than for other metals in Group lb, prim arily because of the much greater attention copper chemistry has received; tetrahedral geometry remains by far the most common for copper(i). All the three- coordinate cuprous compounds previously reported were polynuclear with bridging halogens or pseudo halogens.

The cuprous cyanides KCu ( cn )2 and KCu 2 (cn )3* H20, VIII and IX, possess very sim ilar coordination structures. :I■0,11 Compound VIII occurs as infinite chains and IX as infinite sheets of distorted trigonal planar Cu(l) bridged by cyanide ligands. 2^0

Compounds X-XII have closely related structures about the

metal. l2"14 in each case copper is surrounded by a distorted trigonal

plane of ligands consisting of two n-bonded olefins and bridging

c h lo rid e .

The crystal structure determination of compound XIII,

[Cu2Cl2(PPh3)3], revealed several unique and instructive features

(Figure X LIIl).1S

103.9

23-6 103.4 f Cu? 19J.6 if 2<19 < .\A J / 101<6f Cu 117*0'

02*9

Figure XLIII. The molecular geometry of rCu2Cl2(PPh3)3 % (Ref. 15)»

The structure contains both distorted trigonal planar and distorted tetrahedral cuprous species, connected via chloride bridges.

The structure vividly illustrates how subtle ligand effects may favor

one geometry or another for copper(l). Bond lengths to the trigonally

coordinated metal are clearly shorter than corresponding values in 2 b i

the tetrahedral metal, as would be expected from consideration of steric repulsions, charge on the metal, n-bonding, and metal hybridization in the two geometries.

The thiourea complexes XIV and XV, reported by Amma and co workers, contain quite distorted trigonal planar copper(i) units connected by thiourea bridges (sulfur bonded) to form infinite c h a i n s .17 Of particular note are the Cu-S distances, the range of values listed in Table ’1 (2.23-2. VrA) corresponding to various degrees of ligand bridging and coordination number of the metal. Terminally bonded thiourea groups are 2.23-2. Q9k from trigonal copper and ca.

2.3lA from tetrahedral copper. Bridging thiourea groups give slightly longer Cu-S distances varying from 2.51 to 2 .k lk * The terminal Cu-S distances are not appreciably shortened from that expected by summing the covalent radii of copper and sulfur, indicating little of no multiple character in the Cu-S bond.

The te tra m e r XVI, [Cu ( csC-Cq H 5)(p (CH3)3)34j is similar to XIII in that both three and four coordinate copper are present.10 Short metal-metal and metal-acetylide distances, in addition to those forming the primary coordination sphere, complicate the bonding.

Ter-coordination in the first two metals in Group lb, silver and copper, have been mentioned above. The third Group lb metal, gold, shows a much decreased propensity to form three-coordinate complexes, the preferred geometries being linear in aurous(l) compounds and 2k2

square planar in auric (ill) complexes. The structure of only one

three-coordinate gold compound, [Au(PPh3)3]B 9 HigS, has been quoted

but structural details were not given.6

Of the three complexes containing central metals outside of

Group lb which have been proven to be three-coordinate by X-ray crystal

lography (l, II, and III), all possess trigonal planar symmetry. In

I, Fe[N(SiMe3)2]3, 1,2 and presumably in the chromium isomorph II as

w ell,2”4 crystallographic D3 symmetry is required, thus demanding

trigonal planar geometry. The original postulation4 that the bulky

ligands might inhibit addition of a fourth ligand to the coordination

sphere of I and II was strengthened by the crystal structure analysis

since the large gem-dimethyl groups of the ligand are situated so as

to hinder approach of a fourth ligand from above or below the

coordination plane. A few other three-coordinate compounds of the same

or similar ligands have recently been reported.64

The structure of tris(triphenylphosphine)platinum(o), III, was recently shown to be nearly trigonal planar by X-ray crystallography.5

The metal lies only . 1ft from the plane of three phosphorous atoms and

all three ligand-metal-ligand angles are within five degrees of the

ideal value of 1 2 0 ° . The crystal structure, along with the fact

that III readily adds a fourth ligand (tetrakis(triphenylphosphine)- platinum(o) may readily be prepared), indicate that electronic as well as steric factor are quite important in the formation of the tris complex III, The analogous palladium compound, tris (triphenylphosphine)palladium(o), presumably has a sim ilar trigonal planar geom etry. 21*

B. Tris( trimethylphosphine sulfide)copper(l) Perchlorate

Tris(trimethylphosphine sulfide)copper(l) perchlorate was isolated during a synthetic study of the coordination properties of alkylphosphine sulfides.21 It was well known that many soft ligands, including phosphines, spontaneously reduce cupric solutions to yield cuprous complexes. Nicpon and Meek investigated the complexes resulting when monodentate phosphine sulfides and potentially bidentate phosphine sulfides and diphosphine disulfide ligands were used to reduce the cupric ion. In every instance except one, complexes resulted which were characterized as having the expected pseudo-tetrahedral geometry.

In the single case of trimethylphosphine sulfide, quite different results were obtained.

When trimethylphosphine sulfide and cupric perchlorate were mixed in ethanol, a colorless complex, whose elemental analysis indicated a

3:1 ligand to metal ratio, precipitated. The complex was a 1:1 conductor in nitromethane indicating that the perchlorate group was not coordinate^ at least in solution. The n.m. r. spectrum of Cu(SPC3H9)3C104 in acetone showed only a single sharp resonance at t8.00, indicating either identical or rapidly equilibrating methyl groups in solution.

The infrared spectrum in solution and the solid state showed only a single slightly broadened peak attributable to a P-S stretching frequency at 539 cm 1 (compared to 560 cm 1 in the free ligand), consistent with equivalent coordinated trimethylphosphine sulfide ligands. Nicpon and

Meek proposed two possible structures for the J>'. \ complex. The complex 2h-5

could be dimeric with bridging phosphine sulfides, giving a pseudo - tetrahedral metal geometry, or it could be three-coordinate with presumably a trigonal planar geometry. By analogy with the other pseudo- + tetrahedral Culg species which they isolated with several bidentate phosphine sulfides and due to lack of precedence for the trigonal planar structure, the former structure was favored. In order to verify the stereochemistry about copper and to obtain accurate structural details about the metal-ligand bonding, the three-dimensional x-ray crystal structural analysis of tris(trimethylphosphine sulfide)copper(l) perchlorate was undertaken.

An additional reason for determining the structure of the complex was to provide accurate structural data on the coordinated phosphine sulfide itself. Although several compounds containing phosphorous-sulfur bonds have been examined by x-ray crystallography, very few structures containing a coordinated P=S group (excluding R2PS2 complexes) have been reported. In fact, only one structure of even a trialkylphosphine sulfide has appeared in the literature, although the structures of several diphosphine-disulfides of the type RiR2P(s)-P(s)r3R4 have been determined.39 44

Van Meersche and Leonard studied the structure of triethylphosphine sulfide and found a P-S bond length of 1.86(3) A> suspiciously short compared to P=S lengths found in related R4P2S2 and binary phosphorous-sulfur cage molecules (Table 30).39 However, the structure 2 k 6

was determined by two-dimensional projection using a limited amount of

film data. D ifficulties were encountered in the analysis, the authors being unable to conclude whether the crystal was disordered or twinned.

The quoted standard deviations thus may be considerably optimistic for

the structure of triethylphosphine sulfide. The structural data to be presented in the discussion section on tris(trimethylphosphine sulfide)-

copper(l) perchlorate as well as trimethylphosphinesulfide, independently

and concurrently studied by other workers in this laboratory,24 w ill be used to show that the reported P-S length in triethylphosphine sulfide

is erroneously short. The accurate crystal structure determination of

tris(trimethylphosphine sulfide)copper(l) perchlorate thus would provide much needed structural information about the ligand as well as

data concerning the nature of its coordination to copper. TABLE 5O

PHOSPHOROUS-SULFUR AND PHOSPHOROUS-CARBON BOND LENGTHS

IN TRIMETHYLPHOSPHINESULFIDE AND RELATED COMPOUNDS

Foijnula P-S o r C-S (A) p-c(A) Ref. sc(nh 2 )2 1. 7 l ( l ) U6 sp (c 2hs )3 1 .8 6 1. 8 6 5 (14-0 ) 39 sp (ch 3 )3 1.959(2) l. 797,1.799 2)+ (C2H5)2P(s )-P(s )(C2Hs )2 1. 9 ^0 ( 5 ) 1 . 8 ^6 (3 ) k o ( CH3)( Cg Hs )p (s ) -P (s ) (CH3) ( Cq Hs ) 1 .9 8 1. 8 2 (methyl) 1. 8 8 (phenyl) k l (ch2 )5p(s)-p(s)(ch 2 )5 1.950(1*.) 1. 8 l ( l ) l*-5 k [s2p(och3 )2i 1. 9 6 0 ( 1 5 ) 28 P4S5 1.9^ (2) (term inal) 2 . 08-2.19 (bridging) 77 P4S7 1.95 (term inal) 5 8 P4S 10 (ten a in a l) 58

f3ps 1. 86 l*-2 C13PS 1 .8 5 1^5 Br3PS 1.89 it-li- (C2Hs)3PSe 1.96 (P-Se) P-C = 1.91(5) 39 [(CH3 )3P-S-CH3] + 2 . 0 5 ( 1 ) p-c = 1.78(2) 90 P-S-C=10l( 1) IX. EXPERIMENTAL

A. Instrumentation and Computer Programs

Nonius-Enraf precession and Weisseriberg cameras were used for

preliminary photographs and data collection. Setting angles for the

cell refinement of [Cu(SPtfe3)3]C104 were obtained on a Picker-Nuclear

four-circle diffractometer. Ilford G film was used for collection

of intensity data. Locally written computer programs, used in data

processing, include COZIS (cell refinement) and SFOTL (written by the

author for Weisseriberg reflection length correction, based on the

equations of Phillips53*54). Other data processing programs modified

to varying degrees include, DATRED (Lorentz-polarization and multiple

film averaging),70 SCALE (interlayer scaling),72 XLATA (Wilson P lot),71

and WABS (Weisseriberg absorption correction).69 Baur's SADIAN (bond

distances/bond angles), Corfield1 s RANGER (weighting analysis), DANFIG

(cell projections, 88 and ORFFE (error function)73 were used with little

or no change from the original forms. Zalkin1s Fourier summation program FORDAP and the least squares refinement programs NUCIS5 and

0SUIS1 68 were used in the solution and refinement of the structure.

C a lc u la tio n s were perform ed on IBM Models 709^-j 36 O-5O, 3^0-75j and

370“l65 computers except for the cell refinement which was done in

house on an Electromechanical Research Advance 613O computer. 2k9

B- Preparation of [Cu(SPC^H9)n1C104.

A sample of the compound was prepared by the method of Nicpon and Meek.21 To a stirred solution of Cu(ci04)2*6h20 (0.275ga *75 mmole) in 10 ml of absolute ethanol was added a solution of freshly recrystallized trimethylphosphine sulfide (0.325g., 6.0 mmole) in 10 ml of absolute ethanol. The light blue cupric solution immediately decolorized and a white solid began to precipitate. The reaction mixture was cooled overnight, filtered, and washed with ethanol and ether. The crude product was dissolved in a minimum volume of reagent grade acetone and filtered. On reduction of the volume of solvent, well-formed colorless platelets of suitable size for X-ray single crystal analysis formed.

C. C r y s ta l S e le c tio n

The crystals obtained from acetone solution were carefully examined under the polarizing microscope. The platelets were of mono clinic morphology, extended along a non-unique direction with the unique (b) axis perpendicular to the main faces. Two well-formed crystals which extinguished sharply under crossed Nicol lenses were isolated (henceforth, referred to as Crystal I and Crystal II). Crystal

I, which had approximate dimensions . 15 x . 20 x .40 mm, was mounted with the extended direction parallel to the goniometer axis. Crystal 13^ of 250

dimensions .2 x .25x . k mm, was mounted with the extended direction perpendicular to the goniometer axis.

D. Space Group Determination

Crystal I was examined by oscillation, precession, and

Weisseriberg photography and found to be mounted about a non-unique axis

( ' ' a11) in the monoclinic system. Photographs of the reciprocal lattice levels Okx, lkjj, and 2kA by the Weisseriberg technique and h0£, hl£, hkO, and hkl by the precession method photographs demonstrated that the crystal possessed 2/m Laue symmetry. The systematic absences observed were OkO, k=2n+l and hOjJ, jj=2n+l, uniquely defining the space group as C|h " ?2i/c (No. 14). Weisseriberg and oscillation photographs of Crystal II indicated an identical cell with mounting about the ' 'e 1' axis. Rough cell constants, obtained from the photographs, were a=6.22, b=l6. Ij-, c=22.1, and (3=97°20. The density of the crystals was determined by flotation in a carbon tetrachloride/ethanol solution.

Assuming four Cu(sPC3H9)3C104 units in the cell, the experimental densities (l.Mi-0 and 1.1|42 g/ml) are in excellent agreement with the value calculated using rough cell data (l. ^5g/ml). With four

Cu(SPC3Hg)3C104 units in the P2i/c unit cell, no crystallographic symmetry is required. Thus, the structure solution required determination of a single asymmetric unit. 251

E. Absorption Coefficients

The calculated mass absorption coefficients of the crystals

for copper and molybdenum Ya. x-radiation are (2^ ^ " 69* Ok cm” 1 and

= l6.ll cm For a crystal of thickness 0.5mm (the approximate

thickness of the data crystals), the calculated transmission coefficients

for copper and molybdenum Y& radiation are 0,13 and 0.62, respectively.

Thus, absorption is not negligible for either type of radiation but is more severe for Cul&. However, Weissenberg photographs of the crystals

were much cleaner in appearance and easier to read and index for copper

radiation. In addition, the availability of an accurate absorption

correction program was anticipated. Therefore copper radiation was

chosen for data collection.

F. Determination of Accurate Cell Dimensions for [Cu(SPMea)3](C104)

Crystal I was transferred to a Picker-Nuclear automated

four-circle diffractometer and carefully adjusted for height-centering.

The diffractometer setting angles then were carefully aligned to center

ten medium intensity reflections occuring in diverse regions of

reciprocal space with two-theta between 8.1° and 78.9° using N i-filtered

copper radiation. The values of 20, x an* 0 thus obtained were used in

a least squares refinement of the unit cell parameters. 252

C e ll D ata

Space Group C^h “ P2i/c (No. 1*4-) pc = 1. kkjg/cc po- l.^lg/cc a = 6.2075 (19) A Z = 14- b = 16.^650 (5*0 A Cos P = -0.132911-9 ( iW ) c = 22.1^35 (TO) A C ell Volume = 22^3. 0 A3

Mol. Wt. = ^87- lj-5

G. Intensity Data Collection

Reflections were collected by the equi-inclination, multiple- film Weisseriberg technique for Crystals I and II. A total of six levels were collected for each mounting, 0kjf>-5kj£ Crystal I and hk0-hk5 for

Crystal II. In order to obtain a usable distribution of intensities each of which could be multiply estimated, two separate timed exposures of ca. four and sixty-six hours duration each were taken for each level.

In each exposure, three films were placed in the film packet, allowing each r e f l e c t i o n to be e stim a te d a maximum o f s ix tim es. D eveloping and fixing of films was carefully controlled using chemicals freshly prepared at the beginning of data collection. Films for each data set were taken from separate boxes of freshly opened Ilford Industrial

G film. Despite seemingly identical processing conditions, films for the two complete data sets after processing were of noticeably different colors, the ' 1 a *1 axis set possessing the usual bluish cast while the ' 'c 1' axis set had a suspiciously greenish hue. Despite the disturbing

color variation between the two sets of films, data from each set were processed in the same way.

A calibrated photographic strip was prepared by exposing film

to a typical medium order Weisseriberg reflection (2,0,10) of Crystal I

for a range of measured times. The same strip proved satisfactory for

estimation of intensities collected from both Crystals I and II. The »> strip was then visually compared to each reflection in the two data

sets to give the set of experimental raw intensities. Intensities were

estimated if their relative intensities were between 2 and 1^0 on the

reference scale. A total of kf hl7 reflections (1775 non-zero) were

collected with crystal I ( ''a *1 axis dataset) and I386 reflections

(668 non-zero) were obtained with crystal II (,lc,, axis dataset).

I I I . DATA PROCESSING, STRUCTURE SOLUTION, AND REFINEMENT A. Data Processing and Solution of the Phase Problem

Multiple estimations for each reflection were averaged using

computer program DATRED.70 Only reflections with intensities between

7 and 110 on the relative calibration strip were used in averaging.

Ratios Rij between films were calculated according to 254

where Ii and Ij refer to equally weighted estimations of the same reflection on sequential films i and j and the individual ratios are summed over NME, the to tal number of multiple estimations.

The average discrepancy factors are defined by

NP NE 100 s 2 ^0 " j =1 i=i ij where is the averaged raw intensity of reflection j, is the i estimation of reflection j (a total of NS estimations per reflection), and the sum is taken over all the NP planes in the layer. Although the average discrepancy factors were somewhat higher than expected

(~8*9$)* the calculated film ratios for the " a " axis set overall fit quite well to the expected increase in film ratios at higher levels

(due to increased effective film thickness with increased Weisseriberg setting angle ji).67 The individual *'a 1' axis ratios were *' smoothed’1 to the theoretical increase (a factor of secant ti) in film ratio by simple linear least squares. The film ratios used for the levels

Oki - 5kjJ were 2. 87(2. 58), 2.89(2.94), 2.96(5. 07), 3- 09(5-05),

3.30(3.39), and 3.66(3.50). The values in parentheses are the ratios observed before smoothing. The least squares-determined ratios were then applied to the entire 11 a' 1 axis data set.

The average discrepancy factors for the ,l cM-axis d a ta s e t on averaging multiple estimations of the same reflection (~10.4$) were even higher than for the ' ’a1'-axis dataset. The calculated ' 'c lf-axis 255

film ratios did not increase slightly as ejected on going to higher

Weisseriberg levels but actually decreased rather drastically, an effect which is difficult to explain. Since the ' ‘c^-axis i s long ( 2 2 .1A) the predicted increase in film ratio for the hk5 is relatively small, amounting to only secu=l.02 times the ratio for the hkO level.

Therefore, arbitrary film ratios chosen to reasonably reflect the probable observed ratios as well as to dampen the unreasonable decrease in ratio at higher levels were used instead of the calculated ratios f o r th e ' 'c^-ax is data. The film ratios used for the hkO - hk5 levels were 2.86(2.76), 2.86(2.82), 2.62(2. 53)j 2.00(2.05), 2.00(1.90), and

2.00(1.7^-). The values in parentheses are the ratios observed before smoothing. The discoloration noted previously for the 11 c '' -axis film may have been responsible for the highly suspect calculated film ratios.

After individual films were averaged on both data sets, Lorentz and polarization corrections were applied to give the in itial set of structure factors.70

Using the Wilson plot program XDATA, an approximate overall scale factor was calculated and applied to place the reflections on an absolute scale. The overall temperature factor (b ) derived from the

Wilson p lo t was 1)-. 0 Xs.

Using a ll data above background from the ' 1 a '1-axis dataset only, an unsharpened Patterson function was then calculated. Not unexpectedly, a rather smooth distribution of heavy peaks containing 256 promising features was obtained. However, after many weeks of study and pursual of several false Patterson solutions a structure solution was not obtained and the in itial Patterson was abandoned.

Both datasets were then corrected for Weissenberg spot extension using the computer program SPOTL w ritten by the author using . the equations of Phillips.53,34 A visual check of numerous reflections showed the calculated corrections to be accurate even for low-order reflections where extension is greatest, and thus no data were rejected because of severity of spot extension.

Approximate absorption corrections were applied to both datasets using program WABS.69 Both data crystals were lost and sketches made during preliminary alignment of the crystals had to be used to complete indexing. The indexing was performed by correlating optical goniometer measurements and drawings with Weissenberg photographs and sketches, together with the calculated interfacial angles for the respective p la n e s .

Using a Gaussian grid of sixty four integration points, data sets for crystal I (a-axis) and Crystal II (c-axis) were corrected for absorption. Transmission factors for crystal I ranged from 0.266 to

0. U80 with roughly 75# between 0 .5 2 and 0. 1^2 (crystal volume =

0.0106 mm3). Transmission factors for the slightly larger crystal II ranged from 0. 112 to 0 .3 5 9 with roughly 75# between 0 .2 0 and 0 .3 3

(crystal volume = 0. 0l 6 l mm3). ^ -.20-

.4 - * c

vf ->C

- > c 100 -»C

k— -.2— >!

M B

Figure XLIV . The dimensions and morphology of Crystal I (a ) and Crystal II (b ). ro vn -3 258

The two datasets were next averaged together using computer program SCALE . 72 Program SCALE first sorts the datasets into a single sequential file based on the indices; reflections common to both datasets are used to derive scaling factors between the various layers within each dataset and between the two entire datasets. The scale factors thus obtained were used to average equivalent reflections and to place reflections in the entire merged dataset on the same scale.

The weighting scheme used in averaging equivalent reflections was

(weight)^ (iSTpiTlFir and ( w e i g h t ) ^ ( s c ) ^ x 10 (l?2 < 10)

(f ).2= (weight)i(f2)i + (weight)g(Fg)a 1 (weight)i + (weight)2 where (F2?! = the square of the structure factor of the reflection for estimation i and (sc)i = the scaling factor of the reflection for estimation i d e fin e d by ’ (sc)i (*hki>

The effect of this weighting scheme is to reduce the importance of reflections with small scaling factors and small iR the averaging process. These generally are weak reflections from the higher level photographs. 259

As a test of the effect of the absorption correction upon the two original datasets, SCALE was run both before and after the absorption correction was performed. The overall agreement factors for averaged equivalent reflections, defined by

N |(f2)x - (f 2 )2 | H = S "------L i = l S [F2 ! where F2 = the weighted average of (F2), and (f2)2 and where F2 = the weighted average of (F2)x and (F2)2 and where N = the number of ■- i multiple estimations are 52.£$ and 22 . before and after the absorption correction. These values are considered high, although the absorption correction seemed to help the agreement considerably.

After correcting several weak mis-indexed reflections, a sharpened, origin-removed Patterson function was computed using sharpened coefficients derived from a Wilson plot. The features of this

Patterson were generally similar to the original unsharpened Patterson calculated from the a-axis data only, but the sharpening produced peaks which were much better resolved. From the sharpened Patterson, tria l coordinates were deduced for copper, two sulfur, and three phosphorous atoms. Coordinates for the third sulfur atom and chlorine were also suggested but the heights of some of the expected Patterson vector peaks, particularly Harker peaks, were weaker than expected.

The tria l structure was indicative of trigonal planar geometry about 260

the metal. Patterson vectors calculated for these eight atoms comprised almost a ll the important features of the experimental map with approx imately the expected weights.

B. Structure refinem ent; the disorder -problem

All refinements were by the method of fu ll matrix least squares using the computer programs 0SU-IS1 and NUCIS5 60 (for group refinements of the perchlorate anion). The refinements were based on

F with the function minimised being c

Sw(|Poj - |F c | ) 2 where w is the weight assigned to the observation and Fo and Fc are the observed and calculated structure factors. The unweighted and weighted agreement factors, referred to in the subsequent discussion, are defined by

R = 100 s | |Fo|-)Fc| | ElFol and 3lTw( | Fo | - J Fo | ¥ Rw = 100 vy(Fo)i

Initially the X-ray atomic scattering factor curves for all atoms were taken from Ibersf tabulation.30

Using unit weights for individual reflections and refining positional and individual isotropic temperature factors for the CUS2P3 model derived from the sharpened Patterson map, three cycles of least 26l squares refinement were performed with reflections of zero intensity

"being omitted (N0=270l, NV=20). The agreement factors R and Rw then stood at 37* 5 ^3-1$ indicating an essentially correct structure.

A difference Fourier summation was computed using phases determined by the CuS2P3 unit. The remaining sulfur atom and chlorine clearly stood out as the strongest peaks in the map (l7. 0 e/A 3 and l 6 .lt e/A 3 ) at coordinates close to those suggested by the sharpened

Patterson map. The nine carbon atoms appeared as distinct peaks with heights 2.3"5*2 e /\a. However, even at this early stage of refinement, either highly anisotropic thermal motion or disorder of the perchlorate oxygen atoms was evident; large streaks of electron density appeared at distances from chlorine which would be reasonable for Cl-0 bonds.

Three distinct maxima occurred with heights of 2. 3j 2.9 and 2.9 e/A 3 , but coordinates for the fourth oxygen atom were taken at a bulge

( 1 .7 e/A 3 ) on a long diffuse streak of electron density. These coordinates w ill be subsequently referred to as 01, 02, 03, and 0^.

Two cycles of least-squares refinement of positional and individual isotropic temperature factors for a ll atoms plus an overall scale factor (N0= 2629, NV= 85) reduced R and Rw to 17. k and 20.1$ for the averaged dataset. The refined temperature factors for the cation heavy atoms ranged from 2.5 for phosphorous to 3* 8 for copper, whereas temperature factors of atoms in the perchlorate group were Ij-.lj- for 262

chlorine and 12.6, 9* 9» 22.6 and 23.8 for 01, 02, 03, and Olj., respectively. The high values for 03 and 0^ indicated an inadequate model for the anion.

Scattering factors accounting for anomalous dispersion of

X-rays from copper, phosphorous, sulfur, and chlorine30*32 were introduced and the weighting of reflections was changed from unit weights to a

Hughes' type scheme:

o(Fobs)= •OSB’obs FobS>W and "

(F . = ). Since the overall scale factor was about 0,3, F < lj-0 obs scale ^ ~ was true for all but the quite strong reflectionsj thus, constant weights were used for a ll the medium and weak reflections while strong r e f l e c t i o n s were le s s h e a v ily w eighted. One c y c le o f re fin e m e n t (NV=85) gave a slight reduction of R to . 166 and to . 200. However, temperature factors for 03 and Olf continued to increase to unrealistical- ly high values of 26.5 and 29- 3> respectively. A bond angle/bond distance calculation showed the cation to be essentially unchanged from the original refinement but indicated gross deviations 263 from tetrahedral geometry in the perchlorate group. The 0-C1-0 angles

ranged from 83.9-1^5.5° and Cl-0 distances ranged from 1. lj-l-l.t-9A.

A difference Fourier synthesis was computed using phase *

contributions from the above cation and anion. Of the fifteen highest peaks (ranging from 1.2 to 2-5 e/A 3 ), thirteen occurred in the vicinity

of the copper, sulfur, and phosphorous atoms and clearly indicated

anisotropic thermal motion for these atoms. The second highest peak

(2 .3 e/A 3 ) occured as a bulge on long streaks of electron density about

the chlorine coordinates at an appropriate distance for a Cl-0 band. The

coordinates of this bulge w ill henceforth be referred to as 0-5*

On the basis of the electron density map, the copper, sulfur, phosphorous, and chlorine atoms were allowed to refine with anisotropic temperature factors together with the isotropic carbon and oxygen atoms

(NO = 2697,NV = 125). After one cycle but omitting a final structure factor calculation, the predicted new weighted R factor was , 17.2$, a significant improvement upon the inclusion of anisotropic heavy atom refinement. However, the isotropic temperature factors for O3 and 0i|. continued to rise beyond reasonable values (28.2 and 3^.3, respectively) and the anion model was s till considered unrealistic.

At this point it was decided to obey the strong suggestion of the previous electron density map by replacing Ot with the distinct peak at 05. One cycle of least squares was run after substituting 05 for OU and resetting the temperature factor for 03 back to 12. 0 (NO = 2697>

NV = 125). The predicted new Rw after refinement was .165 which would 26k be a slight but significant improvement in agreement. Furthermore, the refined isotropic temperature factors for 03 and 05 were at much more reasonable (but s till high) values of 18. it- and 16. Tj respectively.

The geometry of the new perchlorate model also improved slightly but

s till deviated markedly from tetrahedral geometry; the 0-C1-0 angles ranged from 9^*2 to 136. 7° and the Cl-0 distances were 1.38-1. 53&*

Because of the unsatisfactory geometry of the perchlorate group and the relatively high R factors, a difference Fourier was computed using phases determined by a ll the atoms except the oxygens for the purpose of re-examining the anion region in detail. The structure factor calculation omitting the oxygen contributions produced R= lit-. 9 and Rw= 19. The two highest features on the map (it-. 2 and 3*3 e/A 3 )

corresponded to 02 and 01. The next highest peaks (2.6 and 2.1 e/A 3 )

corresponded to 05 and 0-3. The remaining peaks ranged from 1.2 e/A 3 downward, with roughly ninety peaks greater than 0.6 e/A 3 . The oxygen peaks were quite extended into long streaks, as observed in the previous

electron density maps; 05 and 03 were in particularly distorted broad

regions of electron density. A distinct bulge of 1.2 e/A 3 , th e f i f t h

highest feature in the map, occurred at the previously discarded 0-lj- position. Thus, the map generally agreed with high anisotropic thermal motion in the perchlorate group with 05 and 03 vibrating much more than

01 and 02, but indicated that even this model for the anion was

inadequate. 265

Following the features suggested by the difference Fourier map, a least squares refinement was performed including anisotropic thermal parameters for the oxygen atoms. All atoms except carbon were now anisotropic (N0= 2697, NV= 1*4*5 )* The model reached near convergence after one cycle with R= .129 and Rw= . 165 before refinement and the predicted new %= . 159, compared to R= . 136 and Rt/= . 172 for the isotropic oxygen mode. Thus, the inclusion of anisotropic motion for the oxygen atoms improved the agreement only slightly (but significantly39). The geometry of the perchlorate group did improve slightly; the 0-C1-0 angles ranged from 92.5 to 135*2° (average 107-8°) and the Cl-0 distances ranged from 1*37 to 1. 1|*8 A (average 1.1|-10 A).

In response to lingering doubts about the quality of ' 'c 1' a x is data and its inclusion with the ' 'a 1' axis data to produce the averaged set of structure factors, the anisotropic perchlorate model was refined using the unaveraged ' 1 a11 axis data. In addition, six individual scale factors were refined, requiring the addition of five variables

(NV= 150, N0= 263*4-)-

After one cycle of least-squares refinement, R and Rw were reduced to 12* 2 and lU.2$, a drop of 1. 7$ in weighted R compared to refinement with the averaged data. Because of the better agreement, the ’’a’1 axis was subsequently used in all refinement of the structure. 2 66

At this point an examination of the original data films for

reflections for which the calculated and observed structure factors were markedly different indicated twenty eight planes which were either truncated by or in the shadow of the cassette screen. When possible, these erroneously estimated reflections were estimated on the top half of the data films and hand corrected for Lorentz-polarization, spot-

length contraction, and absorption and were then reincluded in the data

se t.

To weight more reasonably the medium and strong reflections, a

Cruickshank weighting scheme was adopted. Thus, *75(*25 + \1 * ^obs + * ^^obs vhere ihe Fq^s have been placed on an approximate absolute scale by division by the appropriate scale factor and where

(weight)Fobs = l/cr2).

The constant coefficients were chosen so that very weak reflections had essentially constant weights, strong reflections had cr's about I0j& o f FQbs, and the medium in te n s ity planes had

At this point the scattering factor tables were changed to the more recent compilation of Hanson (Cu,S,P,Cl, and o ) , 85 and Cromer

(anomalous dispersion from Cu,S, and P)33. In addition, several more reflections for which mis-indexing or error in data reduction was obvious were corrected. 267

At this stage in the refinement, the structure factor least squares program NUCIS5 "became available.55-58 The program is a modified version of Busing, Martin, and Levy's OEFIS but in addition incorporates features which permit refinement of sets of atoms as groups with fixed geometry. The position and orientation of the group within the structure is defined by three positional coordinates and three orientation angles, all of which may be independently refined.

For the perchlorate group, perfectly tetrahedral geometry was defined with a Cl-0 distance of 1.1+30A* This value was selected on the basis of a survey of structure determinations of the perchlorate group.50-66,79 The value 1. ^30/v has also been used by other investigators in rigid perchlorate group refinements.64

Using in itial orientation angles for the perchlorate group calculated by computer program RBANG,91 four cycles of least-squares refinement were performed (N0= 2621, NV= 115). Near convergence was reached with R= 11.63 and Rw-= 15*^3 (predicted new 1^= 15.33)* The largest shifts in the structural parameters in the cation and anion were for isotropic temperature factors on O3 and 05, which rose to 20.2 and

31-2A2j respectively, compared to 13* HA2 for both 01 and 02. Chlorine,

01, and 02 had refined to within . 15°A of their positions in the previous non-rigid isotropic perchlorate refinement. 268

The requirement for rigid tetrahedral geometry in the anion

was next relaxed and the positional and isotropic temperature factor parameters for Cl, 01, 02, 03, and 05 were allowed to refine

independently (W0= 2622, HV= 125)* After three cycles of least-squares,

near-convergence was reached with R= 11*35 and Rw= 15-17 (predicted

new Rw= 15*01*.). According to Hamilton's R-ratio test, the drop in Rw

upon addition of nine variables indicates that the unconstrained,

isotropic perchlorate model is better than the rigid group model at the

99* % confidence level.29 Temperature factors for atoms in the

perchlorate group were also slightly more reasonable in the uncon

strained model. Thus, the B's were 5* 5a 12.7, 12.2, 2l*.8, and 16.8?2

for Cl, 01, 02, O3, and 05 respectively.

The same perchlorate group was then assigned anisotropic

temperature factors. The least-squares refinement converged after

three cycles with R= . IO5O and Rw= . 1599 (N0= 2622, NV= 150). The

7. 0$ drop in R^ upon the addition of twenty-five variables is highly

significant.29 Geometry in the perchlorate group, however, remained poor. Thus, Cl-0 lengths ranged from 1.2^ (ci-03) to 1.4lA (ci-05) while 0-C1-0 angles varied from 100 (Ol-Cl-05) to 123° (OI-CI-O3).

To test the adequacy of the ordered but distorted anisotropic perchlorate model in accounting for electron density about chlorine, a

difference Fourier was calculated. The highest peak, 1.35 e/A 3,

corresponded to the position of Ol*., which had been found on the very

first difference map but rejected in subsequent refinements in favor 269

of 05. The remaining peaks ranged from . 77 e/A3 downward. Several of the peaks occurred in the vicinity of potential hydrogen positions; however, a ll the potential hydrogen peaks were not present and

numerous spurious peaks of equal or greater magnitude were also present.

Therefore the inclusion of the peaks as hydrogen atoms was not considered justified.

The features of the difference Fourier map, the relative positions of Ofy and 05, the fact that 01 and 02 have relatively large

amplitudes of vibration which nevertheless are substantially smaller

than those of 03, 0i|., and 05 (in earlier refinements), and the geometry

about chlorine would be consistent with a perchlorate group disordered

as shown in Figure XLV.

The disorder would result from an approximate two-fold rotation disorder axis lying approximately in the plane bisecting 01-C1-02 and tilted slightly away from the 01-C1-02 plane towards 05. Note that this differs slightly from disorder resulting from reflection of the tetra hedron across a mirror plane passing through chlorine and normal to the

Cl-Olj. o r C l-05 bond in t h a t 01, 02, and 03 would th e n be a ffe c te d identically. Thus, partial atoms 0U- and 05 do not lie exactly at the apices of a regular trigonal bypyramidal CIO^ unit.

Consistent with the difference electron density map and the previous least-squares refinements, a least squares refinement of a model containing a perchlorate group with fu ll atoms Cl, 01, 02, and 03 and Figure XLV. The model for disorder of the perchlorate group in [Cu (SF(cH3)3)3]C104. The disorder may he visualized as resulting from an approximate n-rotation of the primary tetrahedron (solid lines) to produce a second orientation (hachured lines) for the perchlorate group. 271 p artial atoms 01*-, and 05 was attempted. All atoms in the anion were assigned anisotropic temperature factors and refined independently*. In addition a variable 0i describing the occupancy factor for 05 (&) and

Olf (l~o;) was refined. The refinement converged after four cycles with R= I0.0l»- and Rw= 13-37 (W0= 2622, NV= 160). The 3.8$ drop in upon addition of ten variables to the model is highly significant according to Hamilton's R-ratio test.29 The geometry of the disordered perchlorate group after refinement is shown in Figure XLVI.

After refinement the occupancy factors for 0U- and 05 are not equal but .382 and .618 respectively. The observed geometric distortions would be consistent with non-symmetric occupational disorder.

The pseudo n-rotation disorder axis lies approximately in the plane bisecting 01-C1-02 and only slightly displaced from the 01-C1-02 plane. The effect of the disorder is to leave 01 and 02 almost undisplaced in position and unchanged in geometry; the main effect on these atoms is a large apparent amplitude of vibration normal to the

Ol-Cl-02 plane. Oxygen-3, on the other hand, is considerably shifted upon application of the disorder rotation; thus, a very large amplitude of vibration normal to the 01-C1-02 plane is expected. The large anisotropic coefficients would lead to an apparently short Cl-03 bond both because of the disorder effect and because of 1 ' riding'' motion. A close examination of directions and magnitudes of the thermal ellipsoids of vibration in fact does bear out these expectations. An examination of the packing diagram for CuCsPjcHsJa^ClO* reveals no obvious factors 272

127(2 )

113(1) 118 ( 2 ) 81 ( 3) 8 0 (2 )

103(1) 100 1 ( ) 9 0 ( 2)

170(2)

Figure XLVI. The disordered perchlorate group in [Cu(SP(CH3)3)3 C104 after anisotropic least-squares refinement. 275 which would strongly favor one orientation of the perchlorate group over the other. Strictly the C10 3Qy0i-(y model for disorder is only approxi mate in that additional partial atoms corresponding to 01, 02, and 03 could he introduced. Alternatively, a refinement with two rigid per chlorate groups might be tried. Undoubtedly refining anisotropic thermal parameters for the nine carbon atoms would also improve the agreement between and However, a completely anisotropic structure could not be refined since interlayer scale factors along 11a* ' were refined. If all atoms were anisotropic, correlation between the P n 1 s and the scale factors would result in a singular least-squares matrix.

The refinement was terminated at this point for the following reasons, l) The model does approximate the actual disorder, at least as far as it could be determined from examinations of difference electron density maps and least squares refinements. 2 ) The particular anion model did not have an appreciable effect upon the structure of the cation. Thus, bond angles and distances in the coordination sphere did not vary by more than one standard deviation with the various anion models listed in Table 3 1 . 3 ) The anion was not of primary interest in the structure.

Results of various stages in the refinement are summarized i n T ab le 5 1 • The R factors for the final, fully refined structure a re R= 10. Olf and Rw= 13. 3 7 . In the final cycle of refinement the maximum s h i f t was . H 8 s ta n d a rd d e v ia tio n s ( P n f o r Olf); th e maximum shift in the cation was . 26 estimated standard deviations (x-coordinate TABLE 3 1

VARIOUS STAGES IN THE REFINEMENT OF [Cu(SP(CH3 )3 )3 ]C104

— ‘ " ‘ ------. . . — ■■■ .. -

NV NO R R a ( p r e .) Comments nr

20 2701 37.5 k-3-1 Initial CuS 2P3 atoms from Patterson. Averaged dataset. 85 2629 17. k 2 0 .1 Isotropic refinement of a ll non-hydrogen atoms in structure. 85 2629 l£ .6 2 0 .0 Anomalous dispersion correction included. Hughes weighting scheme. 125 17.2 Cu, S, and P atoms refined anisotropically. 125 16.5 Replaced Ck with 05. lk5 2697 12.9 1 6 .5 15.9 All non-hydrogen atoms, including perchlorate group, refined anisotropically. 150 • 263k 1 2 .2 lk . 2 Refinement on 1’a-axis* ’ data only. Lata corrections made and scattering factor tables changed. Cruickshank weighting scheme introduced. 115 2621 1 1 .6 15. k3 1 5 .3 3 Isotropic, rigid group perchlorate refinement. 125 2622 11.35 15.1 7 15. ok Non-rigid, isotropic refinement of perchlorate group with 05. 150 2622 1 0 .5 0 1 3 .9 9 Anisotropic perchlorate refinement. ISO6 2622 10. ok 1 3 .3 7 Disordered anisotropic C10 3 Qx01_^ refinement a) Rjj(pre.) is the predicted, new weighted R-factor in those cases where a structure factor calculation was not performed after the final cycle of refinement. b) Final refinement. 275

f o r Cq ), and the error in an observation of unit weight was .7*1-19.

Pinal positional and thermal parameters are contained in Table 32 .

Final structure factors are tabulated in Table 3^ •

A valid least-squares refinement requires that the observations be weighted properly. A weighting analysis performed after the final cycle of refinement did indicate reasonable weighting (Table 35 )• The primary systematic trends seem to be l) a slight overweighting of planes at low sin q/\ and 2) a slight f'bowing'' dependence of with the index h. The first effect might be related to the disorder problem and the fact that hydrogen atoms were not accounted for in the refinements; only the low order planes would be greatly affected because the scattering power of light atoms fall off rapidly with sin ©/lambda. The second effect is presumably related to the refinement of interlayer scale factors along the ,raff a x is .

The above effects represent only minor deviations from an ideal weighting analysis and were not considered important enough to warrant further alteration of the weighting scheme. TABLE 32 a FINAL FRACTIONAL COORDINATES AND THERMAL PARAMETERS (XlO5) WITH THEIR

STANDARD DEVIATIONS (IN PARENTHESES ) FOR

[cu(SF(GH5)5)5]clOit

ttom x z y B n or B b22 B33 B l2 B13 B23

01 -.0 6 3 7 (3 ) . 0284 (1 ) .27970(8) 2441(270) 390(8) 291(4) 26(17) 2 3 6 ( 1 2 ) 12(4) s i - . 2235(6 ) . 1510(2 ) .2492(1) 3250(293) 4 5 0 ( 1 4 ) 178(6) 290(32) 239(22) 32(7) S2 0471(6 ) 0003(2 ) • 5798(1) 4126(294) 3 9 0 ( 1 3 ) 186(6) 402(33) 259(23) 36(7) S3 . 0161( 8 ) -. 0585 (2 ) .2099(2) 6 1 3 0 (3 2 8 ) 359(13) 2 3 8 (8 ) 340(38) 629(31) 52(8) Pi -.3524(5) . 1992 (2 ) .3193(1) 1682(278) 3 1 3 ( 1 0 ) 184(6) 62(25) 134(18) 13(6) P2 . 1201(6 ) -. 1 023(2 ) .3965(2) 2o38{292) 359(13) 229(7) 164(29) 227(23) 42(7) P3 . 0652( 5 ) . 0 120(2 ) .1392(1) 2984(281) 3 2 1 (1 1 ) 16 6(6 ) 71(25) 296(29) ”7(6) Cl -.1496(24) . 232 0 (8 ) •3788(6) 4 . 3 5 (2 8 ) 02 -. 5315(25) . 1298 (9 ) •3520(6) 4 .9 9 (3 1 ) C3 - . 5112(2 6 ) .2864(9) .2944(7) 5. 2 0 (3 2 ) cij, 0177(3 7 ) -.1884(13) .3595(10) 8.08(50) C5 . 1506(3 7 ) 1260(1 3 )' .4761(10) 8.29(52) C6 . 3708 (3 6 ) -. 1058 ( 13) . 3 6 7 0 (1 0 ) 3. 0 6 ( 5 0 ) 07 . 2 37 3(2 6 ) .0979(9) .2634(7) 5.07(31) C8 . 200 1 (2 5 ) -.0 4 4 6 (8 ) .0859(6) 4 .9 6 (3 0 ) 09 -.1763(29) .0494(10) .0989(8) 6 . 01(3 6 ) TABLE 32 — continued

Atom x y z P n £22 £33 P12 $13 $23

C l .3564(7) .3015(2) .4987(2) 263 4 (3 0 2 ) 595(18) 259(9) 99(58) 262(27) -43(10)

0 -1 .4980(33) .2914(13) .5520(9) 8021(940) 1445(140) 690(72) 1232(2 8 6 ) -1077(205) -332(81)

0 -2 . 15522(2 8 ) .3272(14) .5079(8) 4775(731) 1871(169) 596 (6 0 ) 930(272) 472(156) -173(81)

0 -3 .4072(65) .3162(27) .4456(15) 20982(2568) 3215(569) 1044(135) -635(795) 3905(542) 114(182)

0 - 4 .5972(90) .3870(21) . 5050(2 2 ) 12108 (2 8 7 0 ) 482(170) 6 1 1 (16 6) ■-3 0 3 (52 1) 3 2 8 ( 5 13) -206(126)

0 - 5 . 3 206 (3 7 ) . 218 3 ( 1 5 ) .4820(14) 4098(981) 8 1 8 (1 3 9 ) 791(119) - 6 2 (2 5 8 ) 94(238) - 3 7 0 ( 1 00)

a) Anisotropic temperature factors are of the form exp[-(Bnh2 + 633 k2 + P33j£2 + 2$i2hk + 23i3h 1 + 2$a3ke)] h) The occupancies of 04 and 05 are «58 and * 62 (3 ) } respectively. 278

TABLE 33

WEIGHTING ANALYSIS AFTER THE FINAL CYCLE OF REFINEMENT

Range o f sin fi/x R (i;A2

o - .3 1 5 1 0 .2 1. 00 0 1 5 - .3 9 7 8 .0 •39 • 397 - 9 .6 .hS . 1 ^ - .5 0 0 9 .^ •3^ .5 0 0 - .539 1 0 .7 •3 ^ .539 - .372 1 3 .9 .5 7 2 - . 6 O3 1 6 .6 .hh .6 0 3 - .6 3 0 1 6 .2 •35 .6 0 3 - 1 0 .2 .3 0

Range o f FobB R JS2 - ■ 1 ■ 0 - 1 0 .2 2 7 .7 • 55 1 0 .2 - 1 3 .8 1 9 .0 -5h I 3 .8 - 17.3 I 3 .6 • 37 1 7 .3 - 21*5 1 1 .1 . k o 21.5 " 27-9 9 .6 . h i 2 7 .9 - 3 6 .8 9 .3 • 55 3 6 .8 - 51.5 T-3 .5 1 51.5 " 7 .6 • 79

h R

PINAL STRUCTURE FACTORS FOR [Cu(sp(CH 3 )3 )3 ;]C104

It P m A / r H K L Ft *TT 9 F t Vei 6 9 0 T Tffrr 71 *T" " -r, J ■ " fl Y 10 J lT r - 7 m 5 . / 0 0 2 4.? 1*9 c 9 96.9 -9P.9 C.4 0 4 I® - 1 1 .2 C* 3 f 0 196.8 -C .8 r 66. 9 64. 7 -C.fr c 9 ZP 2 1 .2 0*9 c 0 fl.fr 1*9 0 9 26*4 22.4 C.8 r 9 71 14.7 3 .2 0 0 -9 4 .2 -0*1 p 19.9 -14.9 P . 9 0 9 22 - 9 ,8 - C .l c 0 41.1 - f .1 0 39.9 24,2 l . l p 10 9 6 4 .2 -C .l 0 0 12.7 0 9 lfr.fl 11.9 1.1 0 10.... 1.. t 7#.* c 0 Zfr.P P .! 0 9 24.1 24.3 —0.2 0 10 2 4 7 .6 C .l 0 0 12.9 -C*9 0 9 31.) -P . 2 c 10 3 7.4.7 -f.,9 0 1 • 79.fr 3.1 0 9 U . l - I 2 l l 1*0 0 10 4 0 1 - I t 1*9 t* a 0 9 22.4 21*9 C .l 0 19 4 -fr.fr - 0 .0 p 1 31.9 -0.9 r 9 1 4 .) 24. 1 0 10 fr 7 3 .) -3 .1 c t 21. 7 C. 9 0 9 37.9 4 2 .) -C.8 c to 7 9 .9 C .2 0 1 34.7 - 1 ,9 0 9 21.fr -2 1 .4 n* 0 c 10 9 2 4 .2 C .4 0 I -29*9 1*8 0 9 1 6 .) - IP . 8 0 .8 0 in 4 -1 2 .2 1 .0 p 1 -8 0 .9 1*1 0 6 96*3 ICT.fr -1 .2 0 IC 1C 26*4 0*9 0 1 - I t.r 1.0 0 4 99.2 -4 6 .7 -3 .0 r 10 11 -17*3 3*1 0 1 41.7 -<•0 0 6 42.9 -99.1 r,6 e 10 13 4 1 .0 0 .6 0 1 3C. 9 1*3 ts * 2 8 .4 -39.4 0 10 14 -10.7 -0,3 p 1 90*9 3.7 0 6 39*3 1). 9 c . ) 0 10 19 —3) * fr -C .4 0 1 -44.1 C.4 e 6 1 9 .) 1C .4 I.C 0 10 16 2 4 .4 - 0 .1 0 1 -I5 .C P *4 0 « 9 .6 -4* 2 l . ) 0 19 17 12*3 - 0 .4 p I 14.4 1*9 0 4 90.4 9 0 .) c .o 0 10 18 Ifr. 7 C.4 c 1 30.fr - t.C c 6 1C.7 8*6 0.4 0 10 14 -9 * 3 0 .0 p 1 —13 * 4 0 ,9 0 6 92. C -44*2 0.4 c 10 21 - 9 . ) 0 *2 c 2 -9 6 .7 -c.s D fr 44.fr -4 0 .4 C.fr 0 10 21 7 .7 -0 .1 9 7 -1 6 9 .2 -2 .4 0 6 19.1 11.8 1.1 0 10 22 2 0 ,0 - 0 .4 c I 119*4 -0.4 0 fr 41.9 34.4 C.4 0 10 24 -1 1 .9 0 .2 G 2 -1 1 9 .7 C»2 r fr 2 7 .) 26*2 C.2 0 11 1 -1 2 . 7 * C*1 0 2 -17*4 -2*2 0 fr 19*0 -1 2 . 1 1*2 e 11 2 -19*7 3 .9 0 2 -119.7 3.9 9 fr 28. C -2 4 .7 -Q* 3 0 11 3 24.1 C .l 0 2 -1 9 .4 -C .9 P fr 94.fr 28.9 1*1 0 ‘11 4 - 3 4 .7 -C .2 e 2 49*1 -C .l 0 fr 24. P -2 6 .4 0 11 4 3 9 .4 0 .1 c 2 -54.C 3*7 ■ 0 1 42,1 -4 9 .4 - 0 .2 c 11 6 9 2 .4 C.fr 0 2 IT. 1 2*3 0 t . . “C *4 p 11 7 28.fr -C .2 p 2 76.4 C .9 0 1 izlfr' • h . ’fl ‘ e 11 8 - 1 9 ,0 C.2 0 2 - i i e . i C.4 0 7 93.9 - 44.4 -C .l 0 11 9 - 1 9 .8 0 .2 p 2 -2 1 . 9 C .l 0 T 94.1 - ) 5 ,9 - t . ) c 11 19 -10.fr 3 .3 c 2 62.4 3.9 0 7 97.fr 84. 3 C.) 0 11 11 -21*8 0*1 0 2 2 9 .) r.fr P 7 4 9 .) 43*6 0 *3 0 11 1) 3 1 .7 - 0 ,4 0 2 -fr4.fr C.9 0 7 4 ). 1 -4 ).2 - c .o 0 11 14 1 7 ,0 0 .4 G 2 -22*9 C.T 0 7 67*7 -7 9 .4 - 0 .7 0 11 19 10. C 0 , fr 0 2 16*8 C.9 0 7 24.7 24*7 0.3* c 11 16 -18*9 1*4 r 2 -29*4 C.9 0 7 2 0 .) 14.4 1*1 c 11 17 - 1 0 .0 0 ,7 0 1 -91* 7 -7 .8 c 7 11 .4 9.7 P ,4 0 11 18 14,8 - 0 .0 0 9 -8 2 * t C.9 0 7 8*9 -4 .0 1*2 0 12 C -1 1 .0 -3*1 0 9 -127.7 -C.9 0 7 29.2 79.4 —C* 1 0 12 1 -3 9 ,2 -0 ,7 0 1 -4 3 . 0 r»4 p 7 lfr.fr -14*1 C.4 0 12 2 10,0 0 .9 0 5 -4P*8 0*7 c 7 2 4 .) -23.4 C .l 0 12 3 tf r .2 -3 .4 G 9 109*1 -1.3 0 7 9 ,4 - 2 .9 1.4 c 12 fr -9 P .9 -C .4 c ) 3C.4 C.9 0 7 11.3 — 8.4 r*T c 12 fr -18*9 1 .2 p 1 -94.9 C.9 0 7 34, 8 -34*7 c .o 0 12 7 -4 3*1 -C .l 0 1 -1C 9.4 C.3 0 7 24.4 22*2 0 .4 0 12 8 3 3 .8 -C .2 0 9 29.1 C, 8 c 7 2 29,2 26*3 - 0 ,2 c 12 9 2 4 ,0 - C .l 0 9 27*9 1.4 0 18.fr 12.4 i . ) 0 12 IP —30 .4 -C .2 0 9 -7 7 .3 C *4 0 9 11.4 4.2 1.9 0 12 11 - 1 5 ,9 1 .) 0 1 •29*8 C.4 0 9 92.6 -97.9 —9 , 5 0 12 W -1 1 .8 3 .) 0 9 29*9 3.3 0 9 99 .C 91*4 -C.O 0 12 1) 49*0 0.1 6 9 -49*3 t.fr c 9 82.9 -98.0 -C.fr 0 12 Ifr - I 9 .P P . 9 9 9 -1 4 .8 C *2 0 9 40.0 -6 5 .C -C.4 0 12 14 —3 2 ,4 -0*1 0 1 -2 4 .9 H?,2 p 8 4 0 .9 -3 6 . 7 C.T 9 12 tfr 16*1 C.9 0 9 19.1 C.4 p 8 8 9 ,n 8b*3 O.Z 0 12 17 11.2 1 .0 . 0 9 i! . 9C.) G.C 0 9 71. 4 77.4 —0. f 0 12 19 • 1 4 .7 -0 .8 e 9 i t -19*9 -0.2 c 8 32*0 •2 9 .1 C .4 A 12 14 — 11, 8 -0 * 4 9 9 -1 P .6 C.3 0 8 39.9 -44.7 ?*7 0 12 2C 3 .9 1.4 c 4 101.9 -1 .9 0 9 17,4 -19,1 0*6 0 12 21 1 9 .4 -C.fr 0 4 48* 1 -2 ,0 0 a 37*9 -3 2 .7 r .9 9 12 23 12*0 - 7 .1 1 .2 0 4 -41*9 -C.fr 0 8 14,0 14.1 -0 .2 0 1) 2 44.C -44,8 -0 .1 0 4 4 .4 1.9 c 8 1 1 .) - ll .f r C* 4 0 1 ) 9 - 4 2 .0 0 .2 c 4 -3 9 .9 C*1 c 8 17.9 -19.1 - 0 .) c 1) 4 16.9 C .4 0 4 14.9 1.7 0 8 16.1 19*4 0,1 0 1) 4 2 7 ,0 2,1 0 4 12*4 -1.1 c 8 16 .4 11.2 1.1 0 1) fr ? i . » 7*4 0 4 13*2 -C .8 c 8 9 .9 —4 , 1 9 .4 p 1) 7 —29 . ) . 0 .2 c 4. 3.7 1.9 0 8 10*9 -1C.9 -0# 1 0 1) 8 -9 .9 0*3 0 4 -24*8 1.1 0 9 7.6 -9 .2 -0 ,4 0 1) 9 - 1 1 .4 -C .4 0 4 I 1C,8 -<• 1 G 9 8 ,0 -4.fr 9.1 c 1) II -1 0 .4 1 .7 0 4 -8 8 .9 -C.fr 0 9 7,0 - 9 .4 C.fr 0 19 12 -1 1 ,9 1 .0 0 4 92*) C.9 c 9 4.1 -2 .2 C .9 0 1) 14 12*0 0 .4 0 4 70.1 C.T 0 6 44.7 -4 1 .1 -C .4 0 1) 14 - 9 .) 0*4 0 4 •9 0 .2 -3 .2 0 8 19.0 1 1 .) C.9 0 19 Ifr - 1 2 .9 -P . 6 0 4 29*9 P.P 0 4 31*9 39.4 *0 *7 e 19 17 -1 0 ,9 -C.fr 0 4 74.fr C.4 0 9 27.0 31.7 -0 .9 0 19 19 8*4 -C .l c 4 -17*4 3.4 p 9 19*9 17.7 C.4 9 13 19 - 3 .4 1.0 c 4 - 4 3*4 -P. 2 0 9 24.4 29.7 -0*3 C 14 1 -33.3 *0,5 p 4 11*1 1,1 0 f •3.1 -99*3 0 .4 0 14 3 2 3 .7 -0 ,0 0 4 76*4 0.9 0 4 49,2 -44*9 f .9 0 14 4 -5 * 4 C.fr 9 4 -1 C .I C .l 0 9 42.9 63.9 •0*1 0 14 9 -19*2 -3 ,4 c 4 9.7 0 .4 0 4 19,1 -1 3 .9 1.2 0 14 4 1 4 .4 C .2 p 5 6 7 .7 -0 .4 0 4 31.fr -32,9 -C.4 0 14 7 2 0 .2 • 0 ,3 0 5 41.0 P .2 0 4 42.fr 4 0 ,1 C.fr 0 14 9 11*8 3 .4 0 9 116*1 - 1 .) 0 9 29.1 24*7 C.O 0 14 9 * 26* 2 •2 4 * 4 C*4 0 9 -6 9 .0 -r,o 0 4 17.2 14.2 9.4 0 16 19 -16*4 -C.O p 9 •9 9 .4 -0.8 0 9 19.2 •1 2 .3 0* 7 0 14 11 - 4 ,6 0.9 0 5 104.4 ^ ,1 f 4 10*6 -1 1 .2 - C .l 0 14 U 28.9 -C*4 280 TABLE 3^- continued

H K L P« P t K K L a. HKL ^ j r - S t * '- y - - v r / . I 1B 1 1 12 1T.C -)4 » i : •> ' I ’ 4 t s , r - r *8 "T*— 1 4 69. T c i* IS -C*l 1 I 14 7C»4 - 6 t ,4 C,2 -1*7 1 4 16.7 -fi. 1 3 1* 16 - r ,B 1 1 IS 1B.S I t . t -0*1 1 4 37*7 -c ,0 a 1* 1 1*4 t 1 16 IS.S 12.4 ?*7 I t 6 C»4 1 1 IT 16.3 -3 4 .7 1 4 77,3 C.2 0 1* 13*0 r C.2 1 1 I t 27*4 -21.1 C*4 I 4 2*3 1* 1 4 16*6 c IS 7 —3*1 1 1 21 15,Q 70.9 —C.4 0 IS 1.1 1 1 22 t s . s - t s . s f *r 1 4 39*1 —( *9 4 f *3 1 1 23 9.6 -I C.T -: .3 1 4 VI, 9 7* I p IS 19,4 a IS 1 1 24 T.l -S.2 C.S 1 4 -* *2 1 4 25. 3 C.) 0 IS — f .2 1 1 23 6 .3 1*3 I . ) 0 IS e • 6 *3 .2 I 2 -2 * 4 .r -6S.4 3.3 1 4 41.2 t. *4 9 C.l 1 2 - 3 34, S -33.3 r, 2 1 4 Td.S C *4 0 I * 96.4 A IS i t *( *4 1 2 - 4 33 *T U,l 3*0 1 4 r . ) 0 IS 12 1 2 -S 31,2 - 2 2 .0 1.3 1 4 21*1 < *4 c IS 13 - f , 6 1 2 -6 J S .t 74.6 l . t 1 4 19. 4 r IS 14 f .4 Tt.t -34,5. 2*7 1 4 22.7 r ! i 0 IS IS 1.4 1 2 - I t 1C9.9 If 9. 1 C.l 1 4 9.2 - 3.1 34. 1 IS 16 - f . s 32,7 -S 3.3 1 4 f *6 0 1 2-11 C *4 1 4 IB.4 IS IT 1 2 -12 1)3.S -IJC.l C«) -7 .1 0 1 4 10*6 0 IS Zt C.T 23.7 -1 9 .0 C* 9 3*4 1 4 - r . 2 3 IS r . 3 1 2 -14 73.9 70,7 C.6 78*C C 16 3 .2 1 2 -IS 12.C T.T 1.3 1 4 13 .3 C.3 1 4 , 32.1 0 16 C.T 1 0 .T 6 , t (* 9 16 6 C.3 1 2 *1T 11*9 -11*2 -C *1 4! 122.r1 -3.6 c 24*9 n 16 1? 1 2 -IB 21,3 T0,| (*2 1 4 - l . S 1 4 96*9 0 IT a r .4 I 2 -19 9 .3 - 2 ,2 1.7 1*3 1 4 4C.8 0 IT S -r .4 1 2 -23 9.) ■ -fl.9 3 *1 1 -7*1 -f*3 11,2 - l ) , f 1 4 21*3 0*7 e IT -C. 6 6*2 - c .l c * 0.2 B ,S 6*6 c*s 1 4 IT 88*2 0 IT 12 -C .s 1 2 1 64,» -71.7 -1*3 1 4 • 1 .3 1 4 36.1 0 IT IS 1.1 1 2 2 77. f, -88,7 — 1.4 1*1 -C.O 48,2 49*4 -r ,2 1 4 58. 1 - l . S 0 18 3 1 2 3 69,8 * 4 -C.3 1 2 4 46, C 24.1 ?*s 1 4 - 1 .4 I t 56,9 C.4 114,6 -T t.C 1 4 3.1 0 I t S 1 2 S r , t 54.8 r . 4 r IB 6 1 2 6 )S*S -10.6 f .? 1 4 -1*1 19.3 -1 6 ,9 1 4 21 .6 c . t 0 I t 1 2 T 22*c - c . i 3 I t t -C .3 1 2 6 45*B 43.9 -c * s 1 4 1 4 2C.C - r . 1 C 12 C .l 1 2 9 s o ,l - s i .n .5 *i IB 1 4 24,1 3*7 0 IS 4 -C*l 1 2 11 10.6 -1C.6 r . o 19 S - f .1 9 ,6 -13.0 1 4 33* C C .l 0 1 2 12 -1*3 1 4 11.5 1 2 13 1S.1 12,9 0*5 C*1 c 19 9,2 0 19 t c*e 1 2 14 44,4 36,9 1*2 1 4 : . z 70 - r ,** 1 2 16 2d,2 -76,6 1 4 9*3 - 0*1 0 c C .3 6*8 1 2 IT 2C.C - 7 2 . t — f * 4 1 4 - c . l 0 20 . T?*S. 2 9,3 -4 -2*4 1 2 It 32*9 32,7 0*0 1 S 2*3 1 0 1 9 171. 6 - 0 .9 1 2 19 13.1 - I S .) -3 ,3 t C •6 2*2 32*3 r * t 1 2 2C 19,6 -7 1 ,0 —C* 3 1 3 1 0 -8 -1*7 1 S 8*3 i « r 1 0 • I f -C.S 1 2 22 21 *6 2 2 .B 0 .2 20.2 j 1 2 27 7.B -t *9 -3,3 1 S -1*6 I -12 40 C .l 1 9 23*6 - C .i t 0 -1 4 C.T 1 1 r 87*3 96,2 • l*o 1 S 86. C 1*2 1 a -16 C,» 1 3 -1 7T.B 82,5 - f *6 4 4 .C 1 .0 1 9 C.T 1 0 - I t -C.S 1 3 -2 43*2 39.) 43*6 1 3 - 3 36.T 77,8 1 3 9*2 1 c - z r C.4 1*6 43, 8 1 c -72 —C .6 13-4 131.6 136.B -C,4 1 > ?•>. 1 0 -24 3.1 1 3 -S B, ) -11*7 -C.T 1 S 14,7 2*2 1 n 4 2*1 1 3 -6 177*4 -176.9 C.l 1 9 73 .8 9*4 1 3 C .l 1 3 -T 46*6 48.1 —3 ,2 I S 41. 1 1*1 1 0 t -C .l 1 1 - t 1C8* 7 1 Cl* A 1 S 33*1 t 0 1C - f .B 1 1 -9 74.C -22*7 r*i 1 S 42*4 c :•« K c 12 9*1 1 3 * 1C 17*4 11*4 1*1 1 9 41.1 C* 3 1 0 14 1*0 1 3 - U 34*4 -31,1 C.S 1 S 4»*4 C.S 1 0 16 r*6 1 3 -12 31.2 JC ,4 C .l 1 9 4B.9 C.S 1 0 I t 1 3 -13 33*4 4 0* 2 C .t 1 TS 34* S - c . 1 1 0 2C -C.S 1 3 -14 16,3 13.6 C.2 1 '3 31*6 -f .2 1 5 22 C.4 1 3 -IS 8*4 -6*8 3.4 1 9 13* 7 -0*2 1 0 24 -C.S 1 3 -16 33.3 -36*3 1 S 11*4 -C .2 1 1 -3 C.4 1 1 -IT 11.1 10*7 C,1 1 9 13,6 -1*1 & 1 -4 l.B 1 3 - I t 13*9 13*9 f*S 1 9 11* 1 - f * 2 1 t -S 1.6 1 3 -19 28.5 -72,C 1*2 1 S 91,9 -1*2 1 1 -6 C.T 1 3 -21 3)*6 40.4 -1 .3 1 9 66. 9 -?«2 1 1 -7 1*4 1 3 -2 2 |4* 4 20* t —c* 1 1 S 27*7 I. 1 1 1 • 6 2*1 1 1-2) 13,6 -9,| 1*0 I 9 76 .9 -C.4 1 1 3.1 1 3 -23 6 .9 9*8 -3,7 1 s 51.9 ‘ -C .) 1 1 - I f -C.2 1 3 I 71.6 9,8 7*3 1 S 73*4 -C.S I I -11 C .6 1 3 2 47*8 40,7 1*1 1 3 39*9 1.1 1 1 -12 1.3 1 3 3 86, 9 92*2 1 9 76* 9 -1*2 •1 I -13 C.4 1 3 4 44,1 -36*7 -2.0 1 9 82.9 C.S 1 1 -14 •C.4 1 1 S 77*2 -23*3 1 S ®3.2 9.3 1 1 -IS C.3 1 J 6 43. 3 42.9 C,1 1 S 6 ). 1 - o .s I 1 -16 l.S 1 3 T *1,6 44*4 - f ,3 1 9 46.4 - C .l 1 1 -IT 1 1 9 44,3 -4 d ,J —3 ,6 1 S t.S ^9*S 1 1 -1* 1 C.6 1 ) ir 34*2 3t*S -0* 6 1 9 4 4 . t r , S 1 1 -19 -C.2 1 3 11 T 3.6 7 t« ) C.4 1 S 36*4 C.S r.4 1 1 -2 f -3*3 1 3 12 14,6 -12,4 s . s 1 S I f . 9 1 1 -21 - f *2 1 1 13 19,3 -21*4 - f * 4 1 3 31*6 c . t 1 1 -1.1 1 3 IS 65*2 64,2 C .l 1 S 16*6 r .4 1 4 C .l 1 3 17 7*.6 -7 2 .) -3 *2 1 9 9. 2 7 .0 < t 1 S -1 . 1 1 ) I t 9 ,3 3*6 1 9 ( .1 1 1 6 11 3.4 1 3 19 12,4 33.3 -C.2 1 9 1 1 7 -l.ff 1 3 2C 73*4 24*4 ^ ? .l 1 6 s i . e -C.3 I 1 t -C.S 27.9 23.7 1 6 IB ,7 C.2 1 3 21 1 8,1 1 1 C.l 1 3 21 23 .r -17*6 d s 1 * -3 .7 1 1 f l l • - f .2 1 3 23 11.4 -10*3 0. ) 1 6 2 1 . S 28 l

TABLE 3 h - continued

M K t r . F t ° / r H K I Pt * / € H K L Pm F c V r 1 fr -fc | , T 1 ft -23 -1 .3 1 11 - i lt* h 19.9 f mi 1 ft -1 -7 1 . ? -*.1 1 ft 1 : .2 1 11 - t 3P.4 -V ,.P c . l I 6 - f fr.t - u * r -I* 1 1 ft 2 29,0 -C.7 1 tl -4 24*1 24.9 **1 1 b -7 -43,2 - '.f t I 6 V -r .4 1 It -fr ift.p - 2 4 .7 1 b -6 fcl*? '• 3 1 8 3 - r . t 1 11 -7 -1 * .* ~r*2 I b -4 1 3 .A 2.2 1 4 b c . t 1 It -ft 21. 2 - ? t . 9 f*5 I 6 — 1— -1 3 .7 “ .4 * 1 ft 7 < .) 1 11 -9 11.2 - I 4.4 -C .l I fr • 11 76. 3 r . 7 1 4 ft 1 It - I f 11*1 9.4 • .4 -2 3 .? c .9 1 4 5 -* , * t it -11 16.4 - | ft* 7 -16. 3 - '. 7 I ft IT c .b 1 11 -13 I9 .J lft.2 ' . 2 1 b - It 27. C - f , 8 1 ft 11 -f, •; 1 u -14 26.1 -2 9 .4 1 b — 1 5 I t . 2 * ,2 1 9 12 i *i 1 II -17 11.2 -1 1 .1 C.C “i t S. 3 -C." 1 6 13 -: . t 1 II -tft 1 4 ./ |2 ,3 P .4 | b —1T -4 5 .1 C.ft 1 ft 14 -C.S 1 U - | b 17.2 -2P.A 1 b -1 b 13.9 -: .2 I 6 19 r *b I 11 -2T 21*4 -2 4 .9 -r* b & 6 * Jf -2 3. t -c .o 1 A 1 ft : . t 1 t l -21 12*1 19*9 -T.T - 9 .9 C.7 1 ft 17 C. 2 1 It -2 ? 11*2 t b . l -1*2 j t -2 2 6.3 -:* i 1 8 2T T*l 1 II 1 31*6 -4C .4 •C .1 t b 1 -3 7 ,2 - c .3 1 ft 21 P.l 1 11 2 9 | . t -Sfc.C -T *2 1 b 2 -f,9*2 -c.ft 1 ft 22 c .3 1 11 3 b .l 4, T r , 1 1 fr 3 2 t. ft C.4 1 ft 23 ' .1 1 11 9 17.9 21.0 -r*b 1 6 < 20.7 -23*3 -C*3 1 ** P -'•.ft 1 11 b 21, ft 2 t,6 r . t 1 6 3 -87.2 -7*3 1 b -1 f *7 1 11 7 2P.2 22.4 -C .5 1 fr t 9.2 -C.3 I b -2 : .4 1 11 A b f . l -3 9 .3 » *7 1 b r ft? .f -C ,4 1 9 - 1 C.4 1 11 ft 39*2 -32*2 C,5 1 * a 76.3 - : .9 I b -4 -1 ,4 1 II IP lt.O 32,6 c .4 I b « *29. 1 • C..b 1 9 -9 ■l.l 1 tt 11 b .l -3 .9 1*1 1 6 IT -bG *6 -C.O 1 9 -6 e. 9 1 II 1? 39.7 -1 6 .4 1.9 1 b | | 17.* * - lb . b c .2 1 9 -7 16**4 -o .c 1 tt 13 11*2 9 .9 C.4 1 b 17 - I t . 3 C.ft 1 9 -4 - p .4 I 11 14 11.2 7.9 f .8 1 b I t 73.1 -r .3 1 9 -9 C .t 1 II tb 31,1 -27.9 r . t 1 b 13 -fc7*b c .l 1 9 -1C " *4 1 11 IT A.3 - t . t 1 .4 1 b 1b 17.6 c .a I 9 -11 r . 9 1 u 18 16.8 14*2 C.S 1 b IC -1*9 1 9 - I t i.p 1 a 1 9 7,3 A 1*2 1 b 7) - I b l l - 7 ,2 1 9 -13 : . 3 t 11 it d.fc -ft,3 3.1 1 b ?fr ft.l C.T t b - t b f . 2 1 12 c 10,b 34.2 -C.8 1 T C 2 i*r c .l * 1 9 -IT M , 1 12 -2 19.9 12,2 f .b 1 7 -1 -1 3 .6 - l . l l b - l b - t .b I 12 -3 f .b 1 T -2 -I *" 1 9 -21 v l 1 -C.« 1 12 -4 2 2 .C -21* 8 C.T 1 7 - 1 6fr. 7 -1,C I 9 1 -f.T 1 12 -7 ■’.» 1 7 - 4 3 6.2 1.3 1 9 7 C.2 1 12 -6 l i l t 3fri< - f * 1 1 7 -5 -7 b .b - : . z 1 9 3 C . 5 1 12 -9 11.2 - 1 1 . t f *f 1 7 -b - ftb. 6 - r . b 1 9 4 3,2 I 12 -IC 9,3 8*5 *, 2 1 7 -7 137, t U b .c - < .7 1 9 9 C.3 1 17 -13 35.8 -17*2 C* 5 1 T -8 30. 8 ftft, 7 f .b I 9 ft C .9 1 12 -14 11.2 -1 5 ,2 -1,0 I 7 -b - 3ft* 3 -C .3 1 9 7 .) 1 12 -1 9 43.4 44.C -c.l 1 7 *10 -3T ,3 9.2 I 9 ft p. 1 1 12-lb 32. t 17.5 -C .l 1 7 - 1 1 12.7 C.ft I 9 b -c .4 t 12 -21 it.b -IC.fr 3,2 1 7 *12 Ift.fc - r * l 1 9 i r -7.4 t 12 I 61. 1 -69*4 - f »fr 1 7 "1 3 22,7 - : . i 1 9 1? -r* ) 1 12 2 Ift.ft 17.4 r .3 1 7 * I t -2 7 ,6 f .3 I 9 t l 0.2 1 12 3 94,1 5 t.9 -3 4 . 27 .8 C .l 1 ft t t r . t 1 12 4 49,4 -4 6 .9 C.2 1 7 - 1 8 2 ?• ft C .l 1 9 11 c . l 1 12 9 2b *2 -2 6 .5 - t l . 9 - 0 .2 I 9 IT T .1 1 12 6 39,7 46*4 -1*1 16,3 .2 1 9 IP I.C 1 12 e 2ft.P -7 5 , 6 r . 5 1 7 - 2 2 11, 7 C.7 I b 2f - r . t 1 12 13 14,9 -16 *5 f .5 1 7 -23 12,4 - f t,3 1 9 71 1 *3 I 12 It |b ,4 -1 1 .4 r .b -17,4 .? 1 9 22 -c .c 1 12 12 11,1 6.6 l . l 1 7 1 24.1 •r* 1 1 9 24 - r ,2 1 12 13 3**9 2 9 .P T .t 1 7 7 -bft.2 -< .2 1 10 f 9.3 1 12 19 24* 3 -2 3.1 c.3 1 7 3 I.* V^t.2 1 10 -1 - r . » 1 12 U 2T.4 2P.3 r ,f 1 7 fc 2011 13,3 l .c 1 1? -2 C.2 1 12 16 9*2 -6 ,4 ,7 I 7 5 3C.I -C.l 1 10-J —1», * 1 I) - 2 24.fr 71.3 r « i 1 7 t 3b* 7 -C .l 1 K -4 -1 ,2 I 13 -4 19,2 1b*2 t 7 e — 11 ft* b - '. f t 1 1C -6 : * i 1 1) -fr 34.A — 31 ,b Tab 1 7 b .-ft ,b - : . 2 1 to -ft r . 7 1 13 -7 2b. 3 2 5 .3 1*9 1 7 |C 23.1 C .l I IC -0 ,3 1 13 -e 11.4 K.T C ,2 1 7 11 -13.4 C.3 1 10 - I f c . t 1 11 - u JC, 4 21*6 - r* i 1 7 12 -3.?* :.7 1 10 •11 l . l 1 13 •13 12*9 13,9 -r.7 1 7 13 lb* b r . t 1 10 -12 l.T t 17 -IT 16.5 -71*1 -C ,6 1 7 It lb ,2 -c.l 1 1?-13 -C .7 1 13 -19 19.C | A* ft fmC 1 7 13 b« > ?*5 t 19 -14 1*0 1 13 2 6*9 - 7 ,2 c . t 1 7 It - 2ft. ft r , 1 1 10 -14 <«t 1 13 3 14.3 15,1 -? ,2 1 7 17 -lb.9 -0.4 1 10 •17 * f. 1 1 11 9 12*4 32.4 r . r 1 7 18 -2 3 .4 -(.2 1 to - z : -%.t 1 13 fr 9,1 4 .9 r .5 1 7 i f fc.C c . l 1 10 t -C.9 1 13 T 3C.1 -IT.ft -.*.3 1 7 21 9 b .| < *7 1 19 2 C.ft t 11 a 34*2 31.1 r.fr 1 7 23 •1 7*b - c . l 1 10 * 7.1 1 13 U 16*9 11.3 1.2 1 • c. 37*3 c *9 1 IC 4 iz lo • r . r 1 13 II 15.7 -16.5 - : . i 1 • -1 ICA.9 -1*3 1 IT 4 - r . t 1 13 13 79,7 7ft, T r . 2 1 A -2 71. b - r . 7 1 10 6 1 13 14 11*4 14,2 c . t l n -3 -27.1 - 7 .9 1 10 7 c* 1 1 13 19 9 ,3 -4 ,4 ,3 1 a - t -? ft. 6 »7 .6 1 19 8 t . t 1 13 16 71.1 - 19. b 0 . J 1 b -3 • IC, b • t *3 1 to 9 C*fc 1 13 17 9,1 ' f t .4 T *9 I 8 -b -ft.3 - : . i 1 10 12 c .2 1 13 Ift / o . r 12.6 Ci. 4 1 n -8 4 4 .2 C.T 1 10 13 M 1 13 21 lb . 3 16.1 C.C k i - ic 79.9 1.1 t to 19 C.ft 1 14 - I fcT.ft 47.1 O.T 1 « - I t b l.7 ; 1 to 17 C .t 1 I t -2 74.7 21*3 f .7 1 ft -12 - ? M C.6 1 1C 1 A • ’ *4 t I t •4 I t , ' •1 1 .2 r . t 1 ft —19 - / c . l C.ft 1 10 19 0. 2 1 14 - 5 |7.<: 13 .ft T.T 1 ft - I t -23*6 ‘ .7 1 10 21 -C.r 1 14 - <• *.4 - 9 , T fcft.C » *3 1 i r 21 -C.4 14 -7 1 6 ,T 16.9 -C*o 1 , ft -23 -7 ,7 : .7 1 to 74 - C . f t t t t -A 11. J 16*3 - '. 7 I2.C •*3 1 t l -1 1.4 1 14 -IC f *7 282

TABLE jk- continued A* H K t H K I. H_K_JL 11.1. P.S 2 7 -P J1*3 il*n 1.4 IV =rr ’ ,r I Ir t ? -C .l I 11 3 - 1 4 . S f *4 2 2 - 9 61.2 -12.1 1 •) 14 *i j 4 2 2 - i r bi* 4 62, 9 14 -IS < -i 1 la -71.T -? •* -: .2 1 IB s I I . s 2 2 - 1 1 11,i JS. 2 C a 5 14 - I t 1f1.3 -4|,2 •IT C.4 1 IB u 12.4 1 *T 2 2 -12 1 *2 14 7 2 -13 M*1 - t 7, 2 0*7 14 -16 -r «s 1 IB 11 ti. C C.S 14 ,,*i I 14 17 r . i l.S 2 7-14 n*9 ia,o C.T 1 * 6I.S 16.7 14 -C.S 1 19 - I S .l -C.f 2 2 -IS *1.7 3 2 7 *16 I t . a i t . ) 4 ■ C .l 1 19 -2 I'.S r.S r . 1 14 -S - c . l 2 2 - 1 7 4 * a 5*) l . l 14 s C.S 1 19 la . 2 c*r 1 19 -7 -14*4 2 2 -18 a . to 24.2 -o .5 14 * 19.4 *19,1 -o * l N o .6 1 19 - 12 -1 3 .7 -f ,4 7 7 *27 14 7 2 - 2 1 16.2 -IJ.2 ♦ *7 14 4 r .2 1 19 7 9*9 r *b C • 7 1 19 3 - s . 4 1.2 2 2 -22 22.4 -71*1 0*2 14 If 2 2 -23 r , i ic .a - c . l 14 -3.1 1 19 S IT* 4 o. 7 11 ,5 U . 2 - r ,« 2 2 -24 2 * ,1 30.* -* .3 14 12 c .f 1 19 6 c ,« 1 14 T - l n*3 3*6 2 2 -76 11.2 -2 J.C -l*C 14 13 2 2 1 53.9 14,6 14 14 J . 1 1 19 6 -4*4 0. 3 - ,4 o. 1 1 23 -J 7.3 - c . l 2 2 2 |C4. 1 -1J5.7 •2*4 14 16 - * 14 IT - r . J 1 20 -1 7*6 c .2 2 2 3. 3H.d -4 6 ,6 • 1 .) ;« i 1 2t* -6 IS* 2 2 2 4 99*9 1 M .4 -1.1 14 IT. 49* 9 4H, 6 14 < • 2 1 73 S 10.C *2 2 2 5 14 2 2 to 34*3 -27.1 1 -c .4 1 20 t - a . 4 C.S 1.3 15 2 2 B B4.A t»5«) IS - 4 -*■.4 2 0 -4 — Iwt f c -s -1*1 2 2 9 79.) -24,2 1.0 IS -s • r , ? 2 0 “6 32.1 -31.4 7 2 10 21*6 -1 9 .C IS —to -: .s 2 0 -a l . l 2 2 II 17.4 14.a C.T IS -7 -r .3 2 C -K 146*4 1*1 2 2 13 31.0 25,9 1*0 IS -B -f .6 2 o -12 -1 .7 r.% 7 0 -14 7b.S C.S 2 2 14 21.9 2C.S l . l IS r .4 IS -14 - i . i 2 0 *17 24.9 Z ,1 2 2 16 4, b a.c 2 2 17 26.2 24.0 IS -IS r . r 2 0 *22 -7 1 .9 - c . l c.o 2 2 19 IS • l b 2 3 4 - 1 7 .S 19,7 -7 1 .a -?*s IS -17 - ' . 2 2 0 P l l . S 3.2 2 2 21 | b. 2 1 7 .) —0. 3 -C .3 IS 1 -: .i 2 0 |C -ftfc.r 0 .7 7 2 22 11*0 |6 . ) IS 2 —1*4 2 9 12 -I 7.C 2 2 24 7 .9 -IC ,9 -1,7 11*7 12.7 IS j 2.9 2 0 1* 63.4 C.2 2 2 75 -C. 2 IS 4 3 .4 2 0 16 -S B .2 C.S 2 2 26 6 .9 7.7 -**7 49.6 6 4 .| IS * r . s 2 C 1 a It..? 3 *2 2 3 C IS 6 f .9 2 ? 20 -27*7 C.a 7 3 -1 7C .7 — 9 3* C — 1.6 IS 7 l .4 2 0 22 73*4 -c *s 2 3-2 46.4 -l?6*S -1 *o IS ir r . i 2 0 24 -I o,J -C.S 2 1 - 3 21*6 I9i S' 0 .) 2 3 - 4 IS 11 -C .l 2 n 76 -1*6 C.T 5C.S 47,1 1*3 15 - % i 7 1 C ai .4 •2 .7 2 3 -5 4 :,4 -33.3 1,3 13 2 3 —6 94* 4 -9 4 .2 IS 15 -r* c 2 1 - I -7C, 4 - l . l 0*0 2 3 *7 44,2 41*2 IS I t - r .4 2 1 -7 tod.l -1*9 0 *5 15 IT -f .7 2 1 -3 le o .a M 2 3 -a 22*2 -12.5 I *■ 14 •2 -0*3 2 1 -4 n . 4 t*c 2 3 - 4 14,6 17.3 r , ) 14 -3 » <1 2 1 -S l.S 7 3 - i r 21*6 12*2 2*0 16 -4 C.o 2 1 - t —6 a, 9 1*1 2 3 -11 tl. 3 -1 4 .1 1*1 16 -S r . | 2 1 -T 1T.B r . s 2 3 *12 13.4 1.3 i , a 16 -7 7.4 2 1 -7 4 4 .a - : *4 2 1-11 14.1 22*4 -0.1 2 3 -14 34* 1 *33.1 16 -6 C. T 2 1 - o *C - 46, 6 c.a C.2 16 -IT M 2 1 -10 12*0 - 1 a 1 7 J -IS 27.9 27,6 c« i 2 3-16 42*4 -41.4 16 -11 -0*2 2 1 -11 -19.4 r . s 3.2 16 -IS r . 6 2 1 •17 lb* 6 r .4 7 3 - IB 2 6 ,9 26,) c, 1 4 3 .9 -47,5 16 1 ;*3 2 1 -11 2a . 3 C *4 2 3 -19 -C»6 16 4 - c .t 2 1 *14 71*4 C.S 2 3 -20 25. B -23.3 C.S 16 5 C.o 2 1 -IS 17. 7 1*1 2 3 -71 17*4 19, a -0 ,4 16 6 ? .s 2 1 - tb -12*2 -? *1 2 3 -72 11*4 12*4 *2 16 T r . 6 2 1 *17 -12* T -0.1 2 3 *23 10* 7 -1 2 .7 -0,4 16 I? l.o 2 1 -IB 39*1 - c . l 2 3 *74 16.4 -16*1 -0*4 16 11 0.1 2 I -19 -31.2 • * s 2 1 -26 6*1 -7 ,5 - t . l 16 12 C.2 2 1 -20 16,C -C.4 2 3 1 39,4 4 7*6 -1 . 4 lb 14 7.2 7 I -21 IT .4 -r,4 2 3 2 5*2 -6 ,4 - c .3 16 15 -C .l 2 1 -2 3 14.9 -C.9 2 3 3 21*1 -23*5 -C.4 16 16 2 1 -24 13.4 7 3 4 74,6 - ) 6 ,S -1 .6 17 ( —?*4 2 1 -2S -10.7 -0.4 2 3 5 12.1 32,3 -0.1 17 -I - r . i 2 1 1 9*6 -0*2 2 3 6 6.2 -5.9 C, 6 IT -1 c *7 2 1 7 S4*4 0 .9 2 3 T 61.1 64,3 C.2 17 -5 -C .l 2 1 3 -61 *1 —1.6 2 1 B 39*2 -35*9 Z ,4 17 -I - c .c 2 1 S 72.C 1.7 2 3 4 tol.7 -66, 4 -0.1 17 • Q 7*: I 1 6 - i t . a 1*4 2* 3 1? S2.T 4S.4 1*1 17 -II -C.T 2 1 T -2 « , C -C.C 2 1 11 45. # 44,9 c . l 17 -12 c »s 7 1 a 44.3 C.S 2 3 17 9 .0 -1 1 . C -C.S -11 -7*1 2 1 4 -26*7 0,4 2 3 13 J3*9 32.2 M K 1 C .l 7 1 lo 39.1 - f *1 2 3 14 70.2 -19.7 0,1 ir 2 C.4 2 I 11 12.7 o .a 2 3 IS 11.9 11.) C .l IT 1 -O .f 2 1 13 -16. 3 -0,4 2 3 16 26.4 -30.C -0 .) IT C .l 7 1 14 7S.6 0*1 7 3 17 41*5 -4 5 .1 -C .6 IT C.S 2 1 IS J1.7 7 3 19 32.1 33,1 •O.l IT C . 7 2 1 16 1*6 2.C 2 3 24 6*9 -7*9 1.3 17 7 C .l 2 1 IT -3 7 .1 C.o 7 * c 9«,2 |P 9,« -2 .1 2 4 - | IT 4 * *7 2 I 19 2 l . t -"•* S,"> —•#* •1,2 IT 4 -C .l 2 1 2f 7S.2 -0* f 2 4 *7 9 ,1 20,7 - I . 7 IT 12 0,1 2 1 72 -1*1 -C.9 2 4 - J 7 I .2 20.1 0.2 IT II -3.4 2 1 23 0.7 2 4 - 4 9 ,7 6*2 9.) 17 14 1.7 2 2 C 114, 1 -3.1 2 4 * 1 SI* s -17*1 -r .s 14 -c.l 2 7 -1 -n .v “I ,6 2 4 - 6 4 4 ,0 -41 0 .2 la - N C.2 2 2 -2 >*3 0.4 2 4 *7 9 ,6 - i c . a -?.J 16 - I f C.2 2 2 -3 63.2 C.% 2 4 -B 7.3 *4,S c. 7 15 o.O 2 2 -4 -6 9 ,4 -1.7 2 4 -V i s . a r.T 1.6 -II 2 4 *10 16 - r ? -0,4 2 2 -s a, a -0 ,2 6S*ft S i *7 3*4 la -ii 1.1 2 2 -6 42.6 1.6 2 4 -11 4 2 .) *4C.6 C. 3 U -14 7 .4 2 2 *7 >4,4 0.9 2 4 -17 49*4 —31*9 l.S TABLE 3^ “ c o n tin u e d 284

TABLE 34- continued JL±. Pa H K L f o P t * Y t 7 1? -4 14.9 -14 .6 r .7 2 16 -6 23.6 24.6 -r ,1 2 12 • ) j r . 2 • r.T -i* l 2 16 -A 3 I 7 14, 5 13.* r.» 7 12 .7 1.9 4.3 r , | 2 16 -11 -r .1 3 1 3 41,1 -A C .1 r .3 2 12 -3 4" .4 19.7 t *7 2 1 6 -1 3 -? .2 3 1 4 40,T -J6.7 3.T ? 17 a *5 1 !•*> -1 4, 3 7.3 2 16 -1 4 r . a 3 1 3 52,1 6**6 C.2 7 12 -11 39,'» *9.4 r . 1 2 16 - U r*2 3 1 6 37*7 4 | . 1 - r ,2 2 12 *17 1l*» li* ? -? * I 2 16 -1 7 - : * i 3 1 7 0,6 7,4 r • 3 7 17 *11 74.7 - 7u*6 -C, 6 2 16 2 7.6 3 1 B 70.9 -70,4 r ,o 7 12 -14 21 *6 C *7 2 14 3 t.i ? 1 9 13.4 -13.T c.r 2 12 -13 7%4 71.2 -r.i. 2 16 4 c.t 3 111 |4,0 lK.0 r .2 2 1? -16 11.7 11.7 -r,« 7 16 3 c.3 3 1 t* 19,4 U .4 r . 7 2 12 -1 7 16.4 n *6 —,« 2 16 6 £ .4 3 1 I t 2 3 ,J -24.6 -1.7 7 12 * 11f i i . r i i . j - r ,4 2 16 11 f • 0 3 1 IT 34.1 -> 6 .r -f* 3 7 12 -14 16.7 —14.2 ,4 7 14 12 r .0 3 1 IP 14*1 19.7 - r .3 2 12 - i r I '. e “1 4 .t *7 7 16 13 M 3 1 1 9 37*2 42,6 2 12 -21 6. ? 7.0 - r . 4 2 IT 7 C,2 3 t 2r lt.1 - n . r -r* 3 7 17 -27 a*3 6 .7 “* *r 7 IT -7 C .) 3 1 21 4.3 -7 .9 C .l 2 12 1 44.4 2 17 -1 C.l 3 1 22 7.4 6.7 r .2 2 12 3 44*1 49. 1 f * i 2 1 7 - 4 • c.t 3 2 - 1 5 1 .2 -5 6 ,1 - f *7 7 12 4 7*.T •7 6 . 1 7 .7 2 17 -3 -3.2 3 2 - 2 19,3 14.7 r .2 2 12 6 34. 1 2 9.1 C,4 2 IT -7 c. 3 31*3 29.4 C.4 2 I? 7 44.2 42. C * . 4 2 IT -P 2*« 72,9 -67.0 r ,4 7 17 4 3T.4 —3 4.6 f ,4 2 1 T -14 r .2 14,3 -IT,a -*•7 2 12 ir. 4. 4 11.2 -f *3 2 IT -13 *f. 1 3 2 - 6 17.9r -1 T,Ca r , 2 7 12 11 I2*r |4 .6 - r . 7 2 17 3 -r ,J 27*1 2P.2 t , 2 2 17 12 17.9 — 1 6.6 < *7 2 17 4 -r.l 3 2-6 20.7 -23.4 r*9 2 12 14 4. 1 6. S r,i> 2 IT 3 i.T 3 2 - 9 *4.2 -T6.1 i.r 2 12 13 14.6 19* 1 r . l 2 17 11 : *i 3 2 -10 73.6 67,1 1 *1 7 17 17 4.4 9.1 3.1 2 IT 13 -« .o 3 2-12 123.3 -129. 7 -C.4 2 12 17 14. 1 -1 6. 9 -C .l 2 17 14 r . r 3 2 -I J 29.4 2 5 .T r . 7 7 17 1 4 6 .) -4 .2 r .3 7 la r 3*2 3 2 - 1 4 10,6 9.6 ?*2 ‘ 2 13 C 14*4 1C.3 l .1 2 1 0 - 4 c.? 3 2 - I T 20*0 -7r*4 - f . o 2 1) -1 11* 9 •6 .8 1.2 2 la -6 -r .3 11.1 -13*4 -r *6 7 13 -2 9.3 *0 .2 2 l a -7 -3.5 3 2 - 2 1 21* r - 2 2 .6 - r , i 2 13 -3 2-1.2 -7 C.l C.3 2 le - a -C.4 37*7 -44*4 . - 1*2 2 11 -3 W.5 1 r.6 f , 1 2 IB -9 -C *4 1 2-23 12.4 12,3 :* i 2 13 -6 22 •"> - r . i 2 10 1 - r . o 26*3 74.4 -C.4 2 11 -* I*. 3 ( .5 2 ta 7 1.1 3 2 -74 7.4 -2 .4 1.2 2 11 •4 ir .1 9. 3 C.2 7 19 0 3 * r 3 2 -26 19.0 -16.1 -f-.l ‘ 2 13 - i r 23*7' 76.6 -7.7 2 10 ir c.i 3 2 1 2 3 ,r -27*4 - r , 9 • 2 13 - I I 17. 1 -1 1. 1 - r .2 2 10 11 -<*♦* 3 2 2 T4.3 -B *.4 -r ,a 2 11 *17 17.1 *4.9 l.T 2 19 -5 -3.4 3 2 3 9.9 -1 5 . a -1*4 7 13 -11 1.6 -9.6 *i 2 1 9 - 7 -(*? 3 7 4 74,7 74.4 - r . i 2 13 *14 2 19 -a 0*C 16,1 IC .l 1 *4 2 13 -13 K.4 11.4 -r •! 2 19 1 -I ,r 3 2 6 42.4 -42* 3 -c*c 2 13 -17 24. 1 -74. 6 -r* i 2 19 3 1.3 3 2 P S J.3 4 7 .I i *9 7 13 -16 7.4 3. 1 r . 4 2 19 6 3 *3 3 2 9 11.0 -7.5 r.i 2 11 1 1 J .4 14.6 _r ^ 2 |9 6 -I*'? 3 7 1C 04.1 -09,7 - r , 4 2 13 2 36. 2 C* 7 2 19 a r . l J 2 11 21,4 -17.0 C *5 7 11 3 14*1 1C .9 r *7 2 29 -1 : .1 3 2 13 13,1 -16.7 -0,0 2 11 4 19.4 13.2 C*4 2 2C * 3 -r.i 3 2 14 13.7 1 1 .T - r . i 2 13 t 17. 7 -1 3.1 r ,3 2 24 2 ■f *4 3 2 IS 13*3 13*1 9*1 7 13 A 17.9 - 11 r 1*1 2 20 4 3.2 3 2 16 13.2 -1 1 ,9 C .l 7 13 1 J 36*f 12*3 r .6 3 0 - 2 c*3 3 2 23 7*7 *0*7 - C ,f 2 13 13 13.1 - 2 1 .r - r . h 1 2 - 4 -3 .3 3 3 0 41*7 47.6 -C .i 2 1316 12.7 _r s j 3 0 - 6 -r.c 3 3-1 64,0 -73,7 -1*2 2 13 17 l"*4 13.7 t.O 3 0 -P r .4 3 3-2 33*3 -29*9 r.l 2 13 14 4 .3 6. 3 r . 4 3 C -1 r -3.r 3 3 - 3 10.4 12,9 -0*3 2 1) 2r- 1*4 -r.P r-*9 1 e -12 c» 2 3 3 - 4 12*5 l o . i -M 2 14 -7 72. 3 22* C r . l 1 C -14 •C.9 3 1 - 9 23*2 -72*4 0.2 7 14 -3 13*4 19. P -C .2 3 0 *16 3*4 3 3 —6 17*0 -1 1 .7 1*3 2 14 •4 r .2 -r .1 3 0 - i p T.3 3 3 —7 51*2 4 7*6 C.5 2 14 -3 39. 7 — 2 P. 0 r . 3 3 c -?r f.t 3 3 -a 53,1 32.2 :.i 2 14 -6 74.1 -72 *4 r *4 3 C -22 0*1 3 3 - 9 91*0 -4 4 .4 1.) 2 14 - 9 27.1 —26.3 - ; ,1 J r -74 -i.r 31.9 -31*9 r . i 2 14 • 11 12. 0 11.9 p. 3 3 0 4 i*r 33.0 -27,1 1*4 2 14 -1 J 31 *1 r IOC C* 7 3 3 - 1 3 10*6 -10*3 r.,n 2 14 -13 11.9 1 r. 3, r.7 3 0 9 - r . l 3 3 - 1 4 73*0 73*3 -0 *4 7 14 -17 3 " 1r 3.4 3 1-16 3®, 1 -33,6 C.6 2 14 1 64.4 -46.4 - ? . i 3 r 17 r. ? 3 3 *i a 0 7 *4 61*7 r*» 7 14 1 73.4 26,4 • n»? 3 9 14 -3*1 3 3 - 1 4 3®.6 —4|, 4 < * » 2 14 4 43*r — 44,3 C .l s o u c*i 3 1 -2C 21* T -23*2 r . l 7 14 6 69.0 43.1 r . i 3 9 22 C.l 3 3 - 2 1 29*3 74,3 -7,® 7 14 11 11.2 •19. 3 -•?* j 3 0 24 *3.7 3 3 - 2 3 19*9 « | 9, 9 - r , a 2 14 12 71.7 •2 6 .4 r , r 3 1 - 1 3 3 1 43.1 47.0 -e.F 2 14 1) 9*4 1 r ,| -r*v 1 1 -2 - r .b 3 3 3 79,1 -*2.3 *0,4 2 |4 14 14.1 1 2 .C r . 6 3 1 -3 3.3 3 3 4 13*7 13*0 r .2 2 14 13 r*9 • 4 .0 ) 1 - 4 f . 3 3 3 6 92*4 97*7 -r.3 2 13 -1 70*? 21.2 -*1* i 3 I -9 1.3 3 3 6 26.6 -14.1 1*5 7 14 J4.4 - r , 1 I 1 - t 1.1 3 3 7 70*9 -74*1 -r* 4 2 13 r . i 13.9 ■ f .i 3 1 - 7 l« t 3 3 P 36*1 -1>*3 9,5 2 13 - 9 79. ? 24, 7 - r*6 3 1 -6 -3*4 3 3 4 11*3 -3 1 .7 C* 3 2 13 1 n . 3 -7C* 7 - r .2 3 1 - 4 I*) 3 3 ir 46,1 44,0 -r .3 7 13 2 13*7 r *1 J 1 - I f t*i 3 3 16 14,3 -IH.4 7*1 2 13 3 11.9 13*6 -0*4 3 1 -II M 3 3 17 20* T -20*7 • r . r 2 13 4 7 . 4 22.4 * r „ 3 1 - 1 2 r.® 3 1 IP r . i 6 , t r*a 7 13 3 7r.O 14.9 3,7 ) 1 -13 -'“•I 3 4 r 32*6 64,6 -1.4 2 13 7 34* » - 3 4, 1 r* 3 3 1 - 14 -C*6 3 4-1 24,6 -27.7 -1*7 7 13 6 14.2 r 3 1 - I t e.i* 94*7 K 4*7 -1.0 7 13 12 4.1 - .9 1 1 - 1 7 -3.7 t4* 4 TC.2 - r ,s i 13 1) >.4 11.7 -C* 7 3 1 *l« - r . 1 3 4 - 4 43,1 — 4 | , 0 r . 6 7 13 IT t *.2 -11 *7 r .3 1 1 -79 • r *4 3 4 - 9 H .2 J3.P C *6 2 13 f 7^.7 2«‘ .9 3 1 -71 -1*1 9 4 —6 7* 4 4, | r*« 7 13 IT, | 14,2 r . 4 1 1 -74 *r. 9 14-7 21,5 -1 1 ,6 1*3 285

TABLE jk - continued r H K F* P. - V c z * F« 1 F«-_ H K 1, F» . F t J s •f' 1 ST •*,r 3.2 3 7 -A -■rtTT" ^ * 4 1 lb -rt 51 f t 9 4 *1f 74,4 7i«4 f» ? J 7 - 4 r .3 3 If - 4 >2.6 -7ft. 4 r .5 ) 4 -1 1 i n : *14." 0.3 3 7 -K 12.ft -r.4 3 n -11 47.3 45 .6 r*3 1 4 - 1 ? 14... -1 7*1 f .4 3 7 -11 • 19* 9 -e*o 3 10 •I? 21.0 21*3 t .9 3 4 - 1 4 13.2 -14.C -r.? 3 7 -12 - v , 1 r .4 1 IP -13 ??.ft - ? ! • 1 r* 1 3 4 -1 9 15.4 14.6 ?•? 3 7 - 1 * 1 15,4 r ,0 3 1; -J* ? i . 7 —2 7.7 - r ,4 3 4 - lb n . i 12*2 -t *? 3 7 -14 Ifl.T -t* 2 3 1C -15 1C, 7 9.2 r .4 24.2 21.9 '*2 3 7 -14 .? 3 17. -16 4 ft.3 47.4 C*2 1 4 - 1 4 1^*4 -:i*6 ?.i 3 7 - U -31*1 r .2 3 10 -17 1 5*1 ft.4 3.2 3 4 -?0 19* * 11* 7 r. 3 3 7 -17 - r .? 3 10 -1ft ft. 7 12. ft - 0 . ft 3 4 -2 1 P . 2 . 11*3 -<•*4 3 7 -16 5*1 3 t r -Jf 11.3 -20 .6 • r . b J * 4 -2? 4. h - U , l -C.l 3 7 -19 - 5 5* ? -C, " 1 10 -22 4. H n . 4 3 % 12*5 V4.2 -'.1 1 1 -ir f .1 3 1C-21 1.7 •17. 3 - 0 , b ln*t -16*4 *1 3 7 -21 10*4 -c*2 3 1C 1 24*6 -2 9 .7 —0 • 2 3 4 1 24,3 22.6 C.3 3 7 -2? 13.2 -( .? /■ a 3 1C 2 1C.1 - 5 .5 1*1 9 4 2 a 1 .6 - 3 - 0 31.7 -91*4 r*f 3 a r 3 11 -6 ?5.5 -2 7 .7 -0*4 91 ■9 .1 • 66**7 45 * 3.9 3 a -1 3 U -6 I7 .J r .* 3 5 -a 34*4 19*0 r, 1 3 6 - 2 31.6 - r .4 . 3 11 - a 1C. ft -4*3 1 .6 3 5 - 9 29 .4 31.1 r *7 3 8 -*1 43* 1 - l . c 1 3 It -1C 27.0 2 b .r r.% 11. ? -11.1 r.4 3 a -4 -2 7 *0 f *5 3 II - I t 20.2 14.4 3*ft 3 9 -1 1 66.7 -59. 4 c *9 3 8 - 3 c • 7 9 11 - I ? 21*5 -1 4 . 2 C.ft 3 9 -VJ 42*4 41,9 : *i 3 B -6 — 9 5 *6 C.4 3 11 •I* 21 .1 -20*4 r*Z 20. > 1 >.9 U4 3 a -7 29.? - .s 3 11 -15 12. 7 13*9 -f *9 3 3 -13 1? *r J6,7 C,4 3 ft -e ?»,1 0*3 3 tl -U 1C. 1 ' ft.7 ( .4 3 3 -1 4 21.C -19.5 '.3 3 6 - 1 1 44.0 r .2 9 11 -17 13.6 -I 6 •? -3 .6 3 . 5 - 17 25, 7 -r. f 3 ft -12 r» r 3 11 i ?ft. 7 -?&*6 0.4 9 5 -IB 35.4 3 3*1 t .4 3 4 - 1 1 — 5 7. 6 r . t 3 11 3 17.7 ( *3 3 9 - 1 ° 21. 1 -24.9 -r,3 3 ft -14 3,5 3 11 4 27.3 ?6*A ' 3.1 9 9 -?C K*4 -11*? -0 .1 3 ft -15 l?*l L»! 3 11 t 32*4 -?ft. 6 r , 6 3 5 -21 14*1 14*7 -r,i 3 6 -16 6.9 I.C 3 11 12 ?3.6 20.2 C .l 9 5 -?9 a. 0 11. r -r.T 3 ft -1 7 l?.9 -‘ .4 3 11 1? 21*4 17.9 r .p 1 5 1 26 *6 2>*l r . i 3 6 - ?f — 14. 9 • r.b 3 11 1" 4 .6 • 1 1 .? -C .4 9 9 2 53*4 -36,9 -3.5 1 ft -73 3 It 19 1?.C -Ift.C -3 .2 3 5 9 41,6 42*5 - r .l 3 ft 1 30.4 .3 3 U U 10. 6 -21.3 -f . h 3 9 4 47.3 49 .6 -r *4 3 ft 4 — ?9, ft - r. 4 3 11 10 21.9 IS.A 0 ,7 9 3 9 24* 6 2.4.4 -<*3 3 0 9 - f .? 3 1? C P . 7 0 ,4 3 9 t 21 *T -19.7 C«4 3 ft 6 -JO, ft . 3 1? -? 17.1 16.6 0*1 3 5 ® M*2 -10*9 1 *6 3 ft 7 1*1*4 r .5 9 12 -3 22,3 22*2 0 .0 9 9 11 21.6 21*2 c, 1 3 ft 9 -14*9 r *3 9 12 -4 10.0 -ft. 7 r ,» 5 9 11 4?.6 36.4 C.l 1 1 If -40. 4 0,1 3 12 -5 u . c - 1 4 .9 -1*7 1 9 IT 22*6 -21.9 :•? 1 0 11 39*4 < .5 3 1? -6 44.3 -44,0 ?.*> 3 9 19 2C.9 72*7 — C* 4 3 0 16 -11*4 -:*4 3 12 •6 24,2 ?4*8 -0* 1 3 6 3 29.1 3t *1 -<.4 3 0 10 -10* 5 -C.4 3 12 -4 41.3 — 4f *4 f *2 9 4 - 1 T.9 -7.7 -r .i 14-2 19.C C .l 3 12 •11 2 4 .4 25.9 -3,1 1 9 - 2 67.3 07.4 c *r 3 4 - 3 *»♦? r.T 3 12 •1 ? 1ft. 7 -14*7 t , 0 3 4 - 9 10* a L t *C 3 9 - 4 K . 7 u e 9 12 -13 1"»*6 •ft.1 C.4 3 4 - 4 6?* 4 -a*. 7 •C.l 3 4 - 3 —4? .6 -3.3 3 12 -1ft 4.4 -IC .3 -c .? 3 4 -3 76.> -7T.4 -r *1 3 9 - 7 24,1 -o.n 3 12 -?C 0*6 - 0 .9 - C .l 9 4 - 4 21*2 1.4 3 4 - t r 17*2 C .l 3 12 6|,4 -51*0 1*1 3 5 - 1 49*2 4f. 7 C.4 3 4 -11, 3 12 3 24. r 21.0 0,4 1 4 - 9 22*9 -21*7 C.2 3 4 -1? -ft! 1 n# 9 3 12 4 36.4 -3 4 .4 C.4 9 4 — 1C1 *7. 3 57,6 1.2 3 4 -13 9.0 C ,5 3 12 6 1 4 .C 10.9 9 6 - 1 ? 16*4 -?'*4* -c.6 3 4 - | 4 3 7.4 r.5 3 12 7 If .9 15,2 - I . r 3 6 *13 21 *f *16.4 7.6 3 4 -16 3 12 B 13.4 -7 .4 C*A 9 6 -1 9 27.5 -27*4 C.r 3 4 -IB 41*4 •3 .4 3 12 q 16. 9 -15.2 r .4 3 4 -It 11*? 6*6 r.6 1 6 - 1 9 — 14 a 2 0.3 3 1? 1? Ift.ft - lb . t C,0 3 6 -1 T 14.6 1 t,r r.3 3 9 -in -f 3 12 13 4.9 -1 C .4 -3*2 J 6 — 1? 11*4 |4*9 -C.5 3 9 *21 19*1 -* *5 1 12 14 14.3 15.4 -0 .4 19 .2 • n . i -C.2 1 ft -2? ft.C C.r 9 12 19 13.3 «.n r . 3 9 6 - ? 1 17.9 -1 »*5 t.« 3 9 -23 19.4 -C .9* 1 12 16 9.4 - K . 4 -3 .2 3 4 -?? 0.7 C.l 3 « 1 11.6 -f *1 3 1? 10 ft.r -5 .7 0 .2 3 4 1 37.4 -97*1 f .4 3 9 ? 3 13 r 11,9 14.4 -0 .0 3 6 ? 44* 3 -47.4 -r*4 3 9 4 99.1 3.6 3 13 -1 Ift.l C.5 3 6 3 43*7 41*1 -C.l 3 4 f t -4*6 r .l 3 11 *3 45.7 - 50 ,c - r . i 3 6 4 It *6 3*4 3 9 7 n . T -7.N 3 13 -5 29.2 ?r*6 r# 5 3 6 9 24.9 -24.6 r* ^ 9 4 If 14*4 '.I 3 11 - Q II.C - 11.3 - 0.1 3 6 6 11,1 92*1 3 ft I? - r . 4 3 1) -11 11.2 — 16.2 •C .2 9 6 ? 24.? ? 5* 9 r .7 3 9 11 ll.ft .2 3 13 -1ft 17.4 16. 6 3.3 3 6 4 12.6 - |«* *| C.6 9 ft 14 ? J, 2 r .l 3 11 16.6 •17, I -r.l * * *14 9 6 1? 14*7 *14*7 3 9 15 — 1 ft i 4 r , 3 3 13 1 2*,? -?l*ft ) 6 II 34*4 32.1 r.4 3 ft 16 : .1 3 13 2 IT. T • 12.0 l . t 5 6 13 14*? •3J.7 r.2 3 ft 14 19.) -r,? 3 13 4 30.4 31 *n • r . l 9 6 1? 2C.4 •11* 7 i.« 3 9 14 *.9 - r .2 J 13 6 91.& -10*2 3 ? -1 It.* 1?.' •c * 4 3 4 21 -3.4 3 13 7 13.2 -11* 7 r . i 9 ? -2 >7.) -46*6 3 1 e r t l . » -C .2 3 13 9 /2 ,k -13*7 10 0,4 3 1 * 9 91. 1 * m »*. a“ c * > 3 13 -2 r . .r 1.1 3 13 It 12.1 1ft, 6 0 .6 9 ? -4 4*.? ■•6.6 •V * 7 3 10 -1 11.9 r.4 3 13 11 17,6 17.1 C .l 9 ? -6 37*6 —1r .7 r . 6 3 If -7 >>.<• -c .r 3 13 16 17.1 -1 1 .3 r .2 286

TABLE continued

H K L F t */* H K L F* F l V r H K L j h c IM 2 U ) r .4 “T -----T ~ P ~ — r r r r -LS.t* — r r r 4 4 - 1 1 ■ Jq, ■ ' I s .J fmt _ « •* * j 14 -1 1 4 ,t •6 *7 1.1 * l -9 96. 1 92,1 r . t 4% , - 4#* * ■.*1C * ) 14 -4 20. S 2 r « 8 - r . l 16*8 0 .4 4 4 I t ) 16, * ^ .l 1 14 -3 74*7 7S.3 - r . i 4 1 -11 42,1 r . s 24. —71, li (• 9 3 14 -6 21.2 -3 0 .4 -1 .6 27.4 — 1 7, 7 1.0 4 4 - 1 9 74, - 7 0 ,) C,A 3 1* -8 14*2 IS. 7 -0 . 1 4 1 -1 S 31! ,6 -28 ,4 r *4 4 4 - 1 7 1 ) , 17 *9 - i . : 13 #5 12.4 -0 .9 4 1 -16 27*r —2 9 *2 0,4 11* 11* 3 Cm r IS. 1 39. r - r . s 3S.6 36,0 -r ,C 8 , «6 ,6 0 .4 j 14 -1 ) 21*4 -79*2 - r . i 4 1-19 2*.? -29*1 -C*8 4 4 2 12, -1 1 .2 c . l 3 14 -14 t.o -9«s -3 .7 4 1 -2C 73, 4 -72. 7 c ,t 4 4 ) 14* C.2 3 14*13 12. r I S .4 - r . s 4 1 1 37*8 18,6 - r . i 4 4 4 11 • -9*1 1*4 3 14 -111 1*8 9.7 - r . s 6 1 2 )?*C C ,9 4 4 9 43* 69* 3 - r . s 3 14 2 2C.3 -14.7 1.2 4 1 J ST. 8 - 9 ) , 9 C.b 4 4 K 1 ). -12 .0 C*3 3 14 4 21*4 •24*4 -r* 7 4 I 9 J5 *9 33.9 0 .4 4 4 11 1 ). -1.3 3 14 ft 28 .4 27.7 r .2 4 1 7 39,8 -37,8 C.) 18, -2 4 .? -1 .2 3 14 7 14, 7 14.2 C.l 4 1 8 41.9 -49*0 -0 . 3 4 6 19 12 * - r . t 3 14 4 12*0 -12*8 -C .2 4 1 U 18 .) 20.4 -0 *4 4 9 0 IT* - : . i 3 14 ir t»4 I C.4 -? ,2 4 1 11 16*2 16*3 -<*•: 4 9 - 1 94. •5 5 .4 3 |4 11 9.0 8*4 C .r 4 1 I t 12,o l.c 2*6 4 9 - 2 41. -47,4 3 14 12 13 .4 -1 2 .7 -f ,4 4 1 1 7 11.4 -1 7,4 -1 .4 4 9 - 3 13, 0.9 3 14 |3 e.o 6*4 4 1 18 1C. 7 -9.1 C.4 4 S -4 52* 92.9 - c . r 3 14 12*2 -1 2 .7 - r . i 4 I 19 18.4 74.4 -1 * 1 4 9 - 9 t : . 14,6 •1,3 3 13 C 13.1 -1 6 .3 - r . 7 4 2 C 19*3 IS*) 3*3 4 9 -b 27, r *o 3 14 *2 10. t I I . 1 -0.1 4 2 - 2 as. i 79, a C.b 4 9 - 7 * -32*6 1.2 3 13 -3 23.1 22.9 f ,0 4 2 - 3 47.0 -0 .1 4 5 - 9 14* r . s 1 IS -fr 1C.4 7* 7 :.s 4 2-4 24,4 *c»: 12. 8,2 1*0 3 IS - ? 10.3 4. 3 i* r 4 2 - t 46. 4 42.9 0,9 47, - 4 2 .) C.9 3 I* -II 17,9 •1 7 .6 r . l 4 2 - 7 41*9 -)4* 6 1*4 24* -1 6* 9 US i : . i 9,4 : .2 4 2 - 8 41.4 -31. 6 1*6 1), -1 4 .7 *0 .2 11.8 16*4 - r . f 4 2 - 9 23*7 21*2 0 .9 16* 16*7 3 13 -11 11*9 -1 4 ,6 - r . t 19>*7 IC7.9 -3 .4 21. -2 2 , 2 -o«2 3 13-13 3*. 6 32.7 - r . i 4 2 - 1 1 23*1 —1 8. 8 C* 4 13, 14,7 - r *3 3 13 -17 I t . 4 -1 9 ,0 r . l 4 2 - 1 2 2*.* — 24*4 r .2 It* 19,6 -:* 3 3 IS | -11 »S £ *3 24,3 29*3 2*2 33. - r . t 3 13 3 i s i 33*4 r .3 13*9 -1 9 .6 - c . 9 13. 1 )*C - r . s 3 IS 4 12.6 I S .2 - r . t 47.1 47.9 -0 *| 4 5 1 10, • .4 3 IS S 10.7 2*9 1.8 11*7 16*2 -1.1 4 9 2 42* — 44, C - C .l 3 is a 4,4 -4 .1 C. 1 4 2 - 2 4 21*4 72,9 -o , 1 6 9 3 39 • aJ lQ r • .l * 3 IS 13 2S.il 22.9 C.6 4 2 1 23*1 r . s 4 9 4 49* 43.6 f Is 2S.I 26,6 -0 .3 4 2 7 21, 6 - ? l . 9 -0*1 4 9 9 38* 98.6 r . o 3 1* -1 14,6 1C.J 1*0 4 2 4 10,9 11.8 • 0 ,2 4 9 6 2 ) , *10.2 0.6 1 14 -3 21.7 -2 4 , * -3 .7 4. 2 s 1 1 ,s ; «i 4 5 7 38, -1 4 ,0 0.7 3 14 - 1 20,7 -7 2 .9 - 0 .6 4 2 6 4 7.9 48, C -< *o 4 9 1 49, -4 9 .2 *o«| 3 1» -( 11.6 13.4 -0 .4 4 2 7 4J ,0 38.1 r . t 4 6 - 1 81. -91*2 -1*2 3 I* -13 9.1 -I*,'* -S .4 4 2 8 21.2 M .8 4 6 - 2 9v • 94,1 -C * 7 7 !• -14 6*8 - 9 .6 -C. 7 4 2 « 27, 4 0 .? —L. JLD — J% jIB. — * * B «1 »* •* 3 14 -IS ?*4 -11. S -1 .0 4 2 10 34*7 •3 9 .9 - r .2 4 6 - 4 46. -4 8 ,2 -C .l 3 14 1 9*9 -1.1 4 2 12 ) » ,r 98.9 -? .7 4 6 - 5 33, •32.* o ,2 3 16 2 23* 2 -2 0 ,2 1.0 4 2 13 20, 7 -o . 1 4 6 - 6 59* —34 J4 : , 2 3 14 6 14.4 1 1.4 3 .2 4 2 IS 12.7 a ls 1*0 4 6 - 7 21* 16* t 1*0 3 14 r 14* 7 -9 ,1 r*4 4 2 16 12. 1 11,0. 0,1 4 b -6 * 7 8 ,a •S' ,1 3 16 I t t . l 10*4 -C ,3 4 2 21 9,f •14.2 -1*3 4 b - 9 12, ft* 7 3 14 II 9.4 9*3 : . t 4 ) 0 U . r 16.6 -0 .1 24. 71*7 r , 6 3 17 C 11.2 -1 4 ,7 -f* 8 4 3 - 1 13. t -21*9 16. •12.9 9.7 3 1 7 - 1 t . t 7.6 r ,4 4 3 - 2 49 *c -SO 4 -C .2 13. -1 4 .3 -0*2 3 17 - ) 14,4 -2 1 .4 -0 .4 4 J - ) 62*7 £3.9 —3 * 4 4 6 - I ) 29* -2 5 .6 c .o 3 17 -4 2ft* ft 20*9 - 0 ,7 4 3 - 4 28. 1 2C* t 1,4 48. -44*9 9*1 3 17 -S 16 . 4 14.4 2 .4 4 3 *3 17 ,4 0*1 11* -16 ,8 - 1 .2 3 17 - 4 1 0 .t -1 1 .6 - r .2 4 J -6 21 .6 14.1 C«4 15, -1 6 ,3 •3*1 3 17 -A IS .3 -1 3 ,1 -<*7 4 3 - 7 4S, I 4 ). 2 Cm 3 4 6 I 49, * )i 2 r . l 3 1 7 - 4 o .r -13. J -1.3 4 3 *8 29.4 29,0 0 *1 4 6 2 36* -38 .C •0*7 3 1 1 —13 1 2 .S - I 2 , « -(• 1 4 3 *9 43, b 38.4 0,9 4 6 9 27* -2 S* * 0*4 3 17 4 4.6 a*c C .l 14,6 14,4 o. 1 •4 A 4 0U .9 .9 . f 9 —• *r * n 4 3 17 S 10,2 I t . 4 -f .2 4 3 -1 L 4? ,7 1.2 6 6 9 II. -19*9 -0*3 3 17 T |2 .o •1 1 .6 -C*4 4 3 - 1 2 46. 8 -49. 3 C.2 6 6 1C 27* -2 9 ,3 - c ,s 3 1? 6 7*1 -4*7 •r .4 4 3 - 1 3 3ft *6 49,4 0 .6 i >*t 1 C♦ * F1* i* * 4# J I I - 6 17.9 -1 9 .9 r . s 4 J - |4 36,2 34*4 r .2 4 6 14 t* 7 .7 1*4 3 I t -7 • .8 -1 0 .9 - r . s 4 3 - 1 3 30. 9 28,3 C.4 4 7 - J 39, 36.3 r*b > i t -a 4 .6 I2.S 4 3 -16 11.6 0*t * 1 9 «l —1»,_ f *r 3 I t -4 14.1 14.4 r , ) 4 3 - 1 2 29.6 " * « lf r , 3 4 7 - 7 27* 26*4 0*6 3 I t -I 6 ,7 9,9 *C .8 4 3 -29 30*4 >2.4 - r . s 4 7 - 8 42* -4 0 .2 0*4 3 I t -2 7.6 4* 4 -0 .1 4 3 1 2 > .: 24,7 0*1 4 7 - t 24, 2 0 ,b C.7 1 I t -4 7*1 6 ,7 0 .2 4 3 2 i ) . ft 32. 7 0.1 29, 24*9 r .2 3 I t - t S.? 10*8 -1*1 4 9 4 i M 29.4 3 ). • 34, 6 -ft, s 3 I t -T t . c -9 .1 - 0 ,0 6 1 9 ?r*i 71,6 -o*,2 16* •1 3*0 r . t > I t 1 12*6 -11*6 0 .2 4 ) 6 14,4 — 14. 6 -0*0 4 7 * 1 9 4). 39, 6 0,6 3 I t 4 1 1 .S 11.6 - o .r 4 9 7 3S.r *)4»4 r . i 4 7 - 1 4 24* 71,1 0 ,6 4 0 4 69,1 V\ 3 7.4 4 3 9 29,3 21*9 f .3 n . —36,9 -r. *t 4 0 *4 64,9 —66*4 -O.J 4 3 1? 13. 2 10*7 0 .4 4 7 -1 7 24, 2 "* 0 -0 .5 4 0 -4 29, 3 —71. * 1*2 4 3 1) 26,8 -0 .4 4 7 -1 i 24, * 5 ,4 -C .2 4 0 -8 40.6 -37*4 r .6 4 ) 16 -?*) 21 • —22 *9 *2 * 4 C -12 S3.4 -SS ,3 -2,3 4 1 IT l l ! t - I 7*4 - c * t 4 7 -2C 19, -2 0 ,3 - r .2 4 C -18 32.4 4 3 18 1*.4 11.1 -C.2 19* 17 *v -< .3 4 0 - 2 2 4 9 ,t -3 3 ,1 - r , ? 4 ) |9 IT. n 20*3 -r*9 4 7 2 9 ft* -5 1 .9 -% l 4 H -24 17.0 43*7 -1*2 6 4 C 17.1 o * i 4 7 3 44, 4% 7 1*7 4 0 6 34*4 -3 2 .1 <•6 4 4 - 2 71 .6 86*3 -1 *9 4 7 6 32* 39,3 ^ *6 4 0 1- 91.4 -7 0 .S r ml 4 4 - 3 4-. 4 4 9 .6 -C .b 4 7 6 12, -1 0 ,7 C.4 4 0 I t IS. 7 —J *, 4 - l . : 4 4 - 4 79.9 -74*2 r . l 4 7 11 16, 1 T.l - r . i .1 - 4 0 I.** 4 ,2 |0 .1 - r . i 4 4 - 9 39.0 -33 ,7 1*1 4 7 17 15, m• 9 f' _ , IV i * -■ 4 1 - 1 W.C 3 ,9 4 4 - 6 2S.9 - 14* t 2. 1 4 7 13 12* H* 8 r * t 4 1 - 1 19.1 - i t . i C.2 4 4 -7 4|*9 ) » ,s C .l 4 7 IT 12, -1 1 .9 ( .7 _• * 4 1 -4 34*, —ib,* - r . j 4 4 - 6 76*4 -?3*r C.3 %a Vr t| fla ■i i1 *•• —* • r 4 1 - t 33.4 74.S 1 .7 4 4 * • 18*9 — 39,6 C. 9 4 7 I t i l l 14,7 -C .2 4 1 - 7 S l . l -4 9 .S 0.7 4 6 -IT 7 * .? 71.0 o . t 4 7 li -«*) C *1 28T

TABLE 3!).- continued “/* - Y c ft H X[ *■ F» Pc M K I. H f t Lf \ * -6 I f , 6 14,6 z *3 4 0 T -•»1 4 11 -F l O " -U.J -J.* ft i 4 0 - 1 -c .c 4 12 - 9 27. 4 -25,2 r.ft ft -6 36,1 -70.0 I . r S 8 *2 4 12 -1 1 32.9 1 4 .S • l . t - 0 15,0 lft.9 • f . l 11.9 -1 7 .4 4 0 -4 -: *3 4 12 - 1 1 -? .2 ft -10 50.1 34.6 2.4 4 0 * 1 r. 1 4 12 - 4 11.4 -1 3 ,4 •C. 6 ft *11 19.0 19, 3 - r , n « 1 -9 f *3 4 12 —16 l i t 5 1ft.4 '- r .7 -13 32*5 24.9 f .6 4 ft -If t.9 4 12 2 l i t 1 - I f . f 0 ,6 ft -1 4 30.4 -2 7 .9 C.6 4 S -tl 1 * 9 4 12 4 13.* - 0 .4 l . l ft -1ft 29.1 -7 7 .6 1.7 b 4 ft -12 4 12 3 9.2 3J.6 “? ,4 -17 15,1 18.7 -3 .7 -C.4 4 12 T 12, 6 1C. 9 C.4 ft -21 2C.3 2C.4 -c* o 4 0 * 1 4 « | 4 ■ ft - n r .7 4 13 16.2 tft.l r.i ft -22 20,ft •23.7 - 0 .7 4 13 — T U . 9 16. J -ft .ft ft 1 22 • A 21.5 C *3 4 0 -14 -3.1 17.5 4 0 - I T -f* 1 4 11 - 1C 2 r ,c -r.ft ft 2 27.1 •20.3 -f.2 4 0 -23 -C.l 4 11 - t 1 14,0 -1 2 .2 T .6 4 14.7 17.6 - r .T 4 0 1 '.1 4 13 -12 11*4 -10.7 r .2 ft 7 74,0 24,7 1.1 4 ft < - C a t 4 13 -11 11.1 If, 1 C.2. ft 13 14,6 -1 4 .2 - I . r 4 0 9 4 13 -1ft 12*1 10.4 -l.ft 14 13*7 -1 .3 2 .0 4 1 1C f • 4 4 13 1 2ft. 1 -2 1 .7 C.T ft 15 19.6 11.2 1*0. 4 0 11 -f *? > 4 13 3 29.9 31*9 -C.ft ft -.1 14.1 *15.3 -C*7 4 6 0 12 —* 9 ft 4 11 24.2 26,7 . .ft -7 44.7 -<•6 ,C 0 . 3 4 0 13 — 1*4 4 11 6 26. 7 -24. 1 C.ft 9 -ft 24, ft 3 1 .5 • € .4 4 ft 13 4 14 r 2 b ,4 23.7 r .6 ft -7 5 9 .r - 9 7 .9 r .2 4 9 - 2 ft.i 4 14 -1 10.2 14.9 3.4 - 0 1 7 .9 -1 7,1 2 .1 4 4 - 4 - 1*6 4 14 10*1 - 11. r - 1 .4 - 4 5 1 ,6 4 6 .3 1.1 4 9 - 5 C . 4 4 14 22.4 72.0 •C .l ft •M 36.0 -3 3 ,1 r .f t 4 9 -ft -f «4 4 14 16. 9 -1 0,0 -r .4 ft -12 33,7 *30,2 0 .6 4 4 -ir C . l 4 14 -11 24.1 24.4 - r . i ft -1 4 7 5 ,9 - 2 0 , 7 -0 * 6 4 4 -11 t .5 4 14 -IT 9,9 12.0 -3 .9 •2ft 10.3 -1 7.4 C .l 4 9 -12 C.l 4 14 1 12.4 -1 1 .6 C.2 ft -2 3 14.4 1C. 7 -C .l 4 9 -13 -C.2 4 14 2 2 3 ,9 - 2 2 .ft r , 2 ft 2 2 4 .4 -7 C .3 I . r 4 9 -14 -1.3 4 14 9 4 .9 2.2 1.9 ft 3 14.1 -15*9 -r* 4 4 9 -If. C.2 4 |4 11 14,9 14.3 0.2 9 4 1 7 .4 i e . 1 - C .l 4 9 -23 -C .4 4 14 13 12*2 •1 3 .0 • 0 .4 ft 5 15.0 1 3 .C C.ft 4 9 1 -fl.T 4 15 C U.T -1 1 .ft 3*1 ft 6 1 ft,1 -1 6 ,6 -f t,3 4 9 3 -C* I 4 1ft 12.1 -1 3 .0 -C.ft ft 7 15.5 — 1 ft, 6 - t .C 4 9 4 • r*4 4 15 -ft 24.7 21.0 r.A 0 19,7 ‘-1 4 .3 -C*9 4 4 b 1.3 4 15 -0 U . r -10.3 - 1*1 9 n 24.3 -29.1 •T.7 4 4 0 C . 4 4 1ft 17.1 •1 9 .6 - r , 6 ft •1 5 3 .6 - 5 5 .6 •C. J 4 9 13 4 15 -1C 10,4 11*4 -C .l -2 96,1 4612 1*4 4 9 1ft -c.*i 4 13 -13 19.6 •1 7 ,4 C.4 9 -3 4ft.2 44.2 C.2 4 4 14 C . l 4 13 -1ft 20,4 22.5 - 0 .1 ft - 4 9 1 ,2 a 4 9 1ft -3.2 4 19 11,6 -13.9 *7.1 -ft 5 7 .0 -9 0 .1 O .ft 4 1C C r. 1 4 16 - | 13.1 -1 2 .2 C. 7 ft -T 1 4 .4 -1 9 .2 -C .2 4 1C -2 -f .ft 4 16 -3 10.6 9,1 C .l ft - I f ftft.T 44*0 I . r 4 1C - J 4 16 21*3 -2 1 ,4 :.3 ft -11 72*5 -?ri*9 7*3 4 If - 4 -C.ft 4 U - T 19.7 -12*0 -C .6 ft -1 2 1 9 .6 -2 1 .3 - 0 .4 4 1ft -ft 3.4 4 1ft 12.0 11,6 C .l ft -1 4 31.9 -2 0 .9 C .6 4 ir - 4 C.T 4 16 -9 9,4 0. 7 C.2 ft -1 ft 2 2 .3 -2 f t,C -C .6 4 1C -9 -r .4 4 14 -12 4 .1 -9 .2 -C*C ft -16 10,9 16.7 c .f t 4 1C - 1 C r.4 4 1ft 2 10.4 •9*7 3.2 ft •1 7 1 0 .2 -7 0 .9 - e ,» 4 1C -11 0 . 4 4 16 3 10,1 1 2 .C -0 .9 ft 1 1 3 .4 1 . ) 2.9 4 10 -12 -C.2 4 1ft ft 14.4 -14,2 C*t ft 2 2 2 .0 12.0 2*3 4 JC - 1 3 -C.2 4 IT -7 Ift.T 0.5 1.6 ft 9 14.3 -1 9 .7 -1 .2 4 i n -is C.T 4 t7 •0 7.7 -1 1 .2 -C. 9 ft 4 1 4 .9 - 1 6 ,6 - 0 .4 * |C - 1 6 r . 3 4 IT 1 9.0 -IC .4 -C.ft 11 1 5 .2 -1 *4 C .9 4 ie - 1? r.i 4 IT 1 19*1 13,6 -0*7 ft 12 1 4 ,7 2 2 .9 -1 .8 4 10 -10 - r . s 4 IT 4 7.4 0.0 -f.C 5 • 1 2 9 .7 23* 7 C.4 -24*4 4 10 - 1 9 3 . 2 ft 0 c 39,3 2.6 -6 2 6 ,7 2 0 .7 1 .2 4 10 -2r -f . 6 ft c -4 21*9 IT .t 0.9 ft - 0 31.3 -3 9 .4 • 0 ,4 4 10-21 r.ft ft c -4 22.2 -1 7 ,6 1.0 ft - t r 27,6 2 4 ,4 0 .6 4 10 2 -C.l ft 0 27.4 -2 4 .0 3.3 ft - U 14.7 —ft 6 ,8 C.ft 4 10 3 C . 4 s 0 -1C ftft.* 43.2 1.5 ft -1 2 22,7 -2 1 .9 C.2 4 10 6 -P .ft ft 0 -14 19.9 •17*. ft 0 .4 ft -1 ) 31.1 31 *t C.O 4 1C ft -0.2 9 0 • 16 41* I 46.) -C.0 ft •14 27,6 29.4 C.ft 4 10 9 - r . i ft 0 -10 * 24,4 -39.4 -1 .1 ft -1 6 30.6 - 3 7 .6 - 0 .4 4 10 If 0 .4 9 C -20 23*7 27,6 -r.0 ft -17 2 3 .6 2 2 .0 - C .l 4 If 11 - c . J ft c -22 20.6 -2 1 .2 - 0 ,1 ft -1 0 1 3 .0 1 6 .6 - r .6 4 |0 12 -3.4 ft 0 2 29.9 - 1 7 .C 2*5 ft -1 9 1ft* 4 — 19* 0 o.,o 4 10 13 -C.2 ft 0 6 30*6 23,4 1*4 ft -21 1 J .0 -1 3 .0 o .e 4 10 14 - C . 4 ft C ir 37*7 - 4 | . l •C .6 ft 5 3 5 .4 3 5 .9 - r . l 4 If 16 : «4 ft 0 12 33.6 14,0 -< .0 ft T 1 4 .2 - 2 0 ,6 . - C . l 14 14.1 4 11 r f, 0 ft c - 1 4 .C f.C ft -1 19*7 -2 2.9 O ,7 4 11-2 -c.l ft 1 17.4 17.9 r*o ft -2 19*6 23.9 -C .9 49.3 4 11 -3 3 . 6 ft 1 - 4 46*1 r.ft ft - 3 19,7 1 9 ,6 0.0 -7 4 U -ft f . r ft 1 16.1 -11.0 C* 7 ft - 6 24*4 -25*9 6*2 4 11 -6 r . S ft 1 -0 40 .9 42 ,0 1.1 ft • 7 29, 7 2 8 .9 C .l 4 11 -ft f *6 ft 1 -9 92. 6 44*9 1,7 ft -0 14.3 |4 .0 C .9 4 11 -9 C.ft ft 1 *11 X‘, t -2 4 .9 1.0 ft -1 0 31.2 28*9 S .4 4 11 -11 *i .ft ft 1 -14 32*7 JO.* 0.4 ft -1 1 3 1 .4 2 6 .5 £ .4 4 11 - 1 4 -9.1 ft 1 -2C 13.0 14,7 -0 .4 ft -14 41*7 -42* 1 *0. *1 4 1 1 - 1 3 l.ft 9 1 -71 11.9 -1 0 .1 -l.f t ft -16 28.9 28.1 4*1 4 If -10 : *2 4 1 1 24,3 21.9 0.9 ft -1 7 31*5 3 4 .5 - 0 ,6 4 || 2 - r . l ft 1 7 79.6 23.9 f,«* ft •22 11,6 -13*2 *f *6 4 11 4 i -r.ft ft 1 ft 24,1 -16*3 1.2 ft ft 3 9 .0 34. P 0*9 4 11 4 C . 6 ft 1 4 ftC,4 49*2 r . l ft 1ft 15*8 •17*6 0 .3 4 It 9 - r . l 9 1 4 >6.4 30, 3 - C .l ft 11 2 8 .6 26,2 M 4 U 11 -f .3 ft 1 T 93*3 *91.0 r .2 ft 12 10.C 2 1 ,0 - r . 4 4 11 14 •C.ft ft 1 0 i'2.4 22.2 r.f ft : 17,4 19*4 -C .3 4 11 1ft r . l 9 1 9 )«•» 72.6 -C.T ft • 1 r 27, ft -2 7 . 0 r . l 4 12 C 3.1 ft 1 tft 17.5 - 1 9 .ft -C.ft ft -3 14*6 16*7 - r * » 4 12 -| - r . l ft 2 ( 70. 7 -20.6 C.r -4 |«*T 15 ,4 - : .2 4 12 -ft C.l ft 2 -] 2> *0 2Q, I - r . 6 ft -1C 1 6 .4 34*5 r«> 4 12 - 4 ft? ft 2 • 2 71.4 03,2 -1.7 ft -13 15,9 •1 4 .4 r . t 4 12 -ft -f.l ft 2 -4 91.4 - 4ft,4 f *A ft •14 24*0 26*1 - : .ft 288 TABLS continued

H K L _ _ W.t _ .*7ar ... * 7 -19 t* .l -C.O * 7 *ltt *24.a 0.2 9 7 -19 -14.1 -2*9 * r 1 14.0 M 9 7 4 19.1 •0.1 9 T 9 tl.ft r.m 4 9 7 6 - 19*1 c .c 9 7 9 11*1 9*4 9 7 1) 12.5 C.O 9 7 15 -17*4 -0 .9 9 ft C -73.7 -2.1 9 a -1 -40, ) -1* 1 9 a -2 12*9 -C .l 9 a - J 14.1 >•1 9 a -11 -20*2 •0*2 9 a -12 12.4 0.7 9 a -IS 14*5 0*1 9 ft -14 -21*2 - r . l 9 a •19 -74.3 2*1 9 ft -17 19*9 -r, ? 9 a 2 •21*4 -0 ,4 9 a 4 17.f 9*4 9 a 1C -4,1 1.4 9 9 ; 19,6 -c.c 9 1 *2 -3i, a -C.2 9 9 -9 -17*6 - C .l 9 9 -7 14,9 5*5 9 9 -ft -49,2 -C.4 9 9 - K 11*9 3*4 9 9 •11 - I t . 7 0.9 9 9 -14 *13.ft C« 1 9 9 -IT 19,1 -C.9 9 9 I —14*2 9 9 6 -27.2 0.6 9 9 It 16*9 r .3 9 9 14 -2C.C C.2 9 19 -1 -2C.5 -1.1 9 1C -2 1 7,C * M * 9 10 -1 20. ft -0 .4 9 Ift -4 70*6 -1*1 9 10 .-9 -19**6 5.4 9 14 -6 • t tl, 9 C.2 9 1C -12 19*3 -0.1 9 10 -11 14.C C, 7 9 10 -12 - r . 7 C.9 9 10 -19 -15*3 -:.6 9 10 6 37.3 •1.6 9 10 1? -14*4 -0 .2 9 1! 0 -14.7 9 U -6 21« 4 C.2 9 11 -1? 19*7 -C.4 9 11 •11 -4,8 2,0 9 U -14 71*7 -0 .0 S 11 -17 11.9 -3.5 9 n 2 1ft. 4 •C .l 9 11 1 21*9 -o.7 9 II 4 29*7 5.3 9 11 6 -24,7 0.7 9 11 e 15.2 - o .i 9 11 it 14.C C.5 9 12 -3 34,7 -1 .4 9 12 -6 -19.6 r .a 9 12 -14.9 -C.4 9 12 -11 16.1 r .7 9 12 1 11*1 : . r 9 12 ? •7 8 ,C e.T 9 12 4 19*4 -C .l 9 1) -6 21. a -7.4 9 19 • a -24.4 -J.C 9 13 -13 -17*9 c . l 9 14 -3 11*4 0.4 9 14 -4 9. ] 0*9 9 1% -9 -16*1 -5.1 9 14 • 6 - 22. a o. a 9 14 3 • *4 t . f 9 14 3 -17.4 •0.# 9 19 - r 11*6 - r . i 9 19 -a -9.7 C .l 9 19 -4 -15.1 - f .9 9 19 1 -15. 1 - r .4 9 16 ft 9.0 -5*2 9 U - 3 11.8 -r.4 9 16 4 -1*6 9.6 289

IV. DISCUSSION OF THE STRUCTURE OF [Cu(SP(CH3 )3 )3]C104

Distances and angles in the structure are tabulated in Tables 35“

3 8 . The geometry of the anion and cation are diagrammed in Figures XLVI and XLVII respectively, and the crystal packing diagram is presented in Figure XLVIII. Root-mean-square amplitudes of vibration are given in

Table 39* Table kO contains the distances of atoms from the plane of the three sulfur atoms. The crystal structure of tris(trimethylphosphine sulfide)copper-

(i) perchlorate consists of discrete, well-separated [Cu(SP)CH3) 3 )a] cations and disordered perchlorate anions. Excluding possible hydrogen interactions, the perchlorate atoms are more than If. 0^ from a ll atoms in the cation. The shortest Cu-Cl vector (6.9a) is far too long to permit coordination of the perchlorate group whereas the closest Cu-Cu distance (6. 2A) precludes metal-metal bonding.

The crystal packing diagram (Figure XLVIII) shows that the heavy atoms in the cation (cu, P, s) roughly form planes which pack in the lattice slightly inclined (23°) to the be plane. The trimethylphosphine sulfide ligands adopt a pinwheel-like configuration about the metal in a way which would tend to minimize steric interactions between lig a n d s .

Of primary interest in the structure is the geometry about copper (Figure XLVU). Copper is bonded to three sulfur atoms to form a nearly trigonal coordination set which is planar within experimental 290

TABLE 35

DISTANCES AND ANGLES IN THE CuS3 P3 COORDINATION SPHERE

Bonded Interactions Distance (A) Angle (Degrees)

Cu-Si 2 . 2 6 l*(l*) Si-Cu-S2 1 1 7 .8C l)

Cu-S2 2 . 21* 8 (1*) Si-Cu-S3 H 9 .1 * )(l)

Cu**S3 2. 2520*) S2-Cu-S3 1 2 2 .8 (l) 'y S1-P1 2 . 0 0 1 (1*) Cu-S1-P1 107.1*(2)

s 3-p 2 1 .9 8 2 (5 ) Cu-S2-P2 1 10. 1 (2 )

S3 -P3 2 . 0 0 t*(l*) Cu-S3~P3 id * . 6 (2 )

Non-bonded Interactions

D istan c e (A) D istan ce (I)

C u-Pl 3 . 1*1*3 (i*) S2 -C4 3.1l*(2)

Cu-P2 3- ^72(1*) S2 "Cg 3 -1 0 (2 )

Cu-P3 3- 3 7 i(3 ) S2 “Cg 3 -1 7 (2 ) Si-C x 3 . 1 ^ ( 1 ) S3-C7 3 .1 5 (2 )

S i-C 2 3 . 1 8 ( 2 ) S3 “Cg 3 .1 2 (1 )

S1-C3 3 . 1 0 (2 ) S3 -C9 3 . l U 2 ) 291

TABLE 36

BOND LENGTHS AND ANGLES ABOUT PHOSPHOROUS

IN THE CCu(SP(CH3 )3 )3 ] + CATION

Bond length Bond Angles

Sl-PjL 2. OOl(lf) S 1 - P 1 - C 1 112. 2 (5 ) S i - P i - C 2 113.0 (5 ) S 1 - P 1 - C 3 109 . 9 (5 )

C jL - P l 1 .7 8 ( l) C 1 - P 1 - C 2 107. 8 ( 7 )

C2“P2 1 .7 9 (2 ) C 1 - P 1 - C 3 106. 9 (7 )

C3 -P3 1. 8 1 (2 ) C2 ~ P ~ C 3 106. 7 (7 )

S2-P2 1 .9 8 2 (5 ) S2 "*P2“^4 1 12. 3 ( 8 ) S 2 ~ P 2 "C 5 110. 0 (8 ) S2 “P2 “Cq 113. 9 ( 8 )

C 4 “ P 2 1 .7 7 (2 ) C4-P2 -C5 lOlf. 8 ( 1. 1 )

C g - P 2 1 .7 9 (2 ) C4-P2 "Cq 101. 9 ( 1. 1 )

CQ“P2 1 .8 0 (2 ) Cs-P2 -Cq 113. 1* ( 1. 1 )

S 3 - P 3 2 .0 0 7 (5 ) S 3 - P 3 - C 7 112. 2 ( 7 ) S 3 - P 3 - C 8 110. 7 ( 7 ) S 3 - P 3 “ C 9 115. 1 (7 )

C 7 - P 3 1. 81(2) C 7 “ P 3 “ C g 105. 0 ( 1 0 )

Ce-P3 1. 8 0 ( l) C 7 - P 3 - C 9 101. 2 ( 1 0 )

C s - P 3 1.75(2) C3“P3"Cg 111. 9 (1 0 ) 292

TABLE 37

BOND DISTANCES AND ANGLES IN THE DISORDERED

PERCHLORATE GROUP®

D istan ce (A) Angle(degrees)

c l - 0 3 1. 2 8 ( 2 ) 0 1 -C l-02 11M 1 )

C l-02 1 . 3 6 ( 2 ) OI-CI-O3 1 2 7 ( 2 )

C l-O l 1 .3 8 (2 ) O l-C l-05 1 0 0 ( 2 )

C l-02 1. *1-3(2) Ol-Cl-Olj. 8 7 (2 ).

C l-05 1 . ^ ( 3 ) O2 -CI-O3 1 1 5 ( 2 )

02-C1-05 1 0 3 (1 )

02-C1-0*]. 8 0 (2 )

O3 -CI-O 5 9 0 ( 2 )

03-Cl-Olj- 8 1 ( 3 )

oi).-ci - 0 5 1 7 0 ( 2 )

a ) OU and 05 have partial occupancies of .6 1 8 and .3 8 2 respectively. 293

TABLE 3 8

SELECTED INTERATOMIC DISTANCES AVERAGED OVER .THERMAL

MOTION USING THE "RIDING MODEL' *

Stationary At cm "Riding" Atom Distance (A)

Cu SI 2. 266CU

Cu S2 2.251M

Cu S3 2.258(10

51 PI 1.998(14-)

52 P2 1.980(5)

53 P3 1.996(10

ci 01 1. 1*2(2)

Cl 02 1.39(2) ci 03 1.37(2) c i oi* 1 .1 * 7 (3 ) ci 05 1.1*5(2) 29^

PI SI 107.4t2)

Cu P2

S3\ 104.6(2) S2

CARBON P3

Figure XLVII. View of fcufSPf 0^ 3 )3 )31 down the pseudo-threefold a x is . J Figure XLVIII.. Projection of the crystal structure of [cuCSPfCHs^s] C I O 4 parallel to the ''a" axis. TABLE 39

HOOT-MEAN-SQ.UARS AMPLITUDES ALONG PRINCIPAL VIBRATIONAL AXES ( a ) in [Cu(SP(CH3)3)3]C104

Atom Minimum Medium Maximum

Cu ‘ . 1 88 (8 ) .2 2 8 (3 ) .2 3 9 (4 ) SI .3 9 5 (5 ) . 2 19 (6 ) S2 . 2 0 3 (4 ) .2 0 5 (4 ) .3 0 3 (7 ) S3 .1 9 9 (5 ) .2 1 2 (4 ) .3 6 3 (8 ) PI .175(15) .2 0 4 (4 ) .2 1 8 (4 ) P2 . 2 0 3 (9 ) .2 1 2 (4 ) .2 5 9 (5 ) P5 .170(10) . 211(4) .2 1 8 (6 )

Cl . 2 0 3 ( 1 1 ) . 2 5 8 (5 ) .2 9 1 (4 ) 01 .277(20) . 3 6 6 (2 0 ) • 579(27) 02 .257(22) . 3 8 2 ( 1 9 ) .527(24) 03 .235(26) . 6 6 6 (3 8 ) .7 3 5 (1A) 04 .267(27) . 2 8 6 (3 1 ) . .484(36) 05 .226(45) .404(54) .484(57)

<8 o\ 297

error. The long Cu-Cu, Cu-Cl, and Cu-P distance preclude bonding to the metal from any potential donor atoms in the structure besides su lfu r.

The three S-Cu-S angles in the CuS3 coordination are very close to the value of 120° for' ideal trigonal planar geometry. Thus, th‘e structure represents the most nearly ideal trigonal planar geometry in a metal coordination compound yet determined by diffraction methods except for [Fe(N(Si(CH3)2)3] 1""4 and [Pt(p(CeH 5 )3)3].5 The structure of [Cu(SP(CH3)3)3]+ is also the first reported example of a monomeric three-coordinate copper(i) compound.

The th re e Cu-S d is ta n c e s i n [Cu(SP(CH3 )3 )3] + a re 2.21+8(1+),

2.252(1+), and 2. 26k(b) A, thus ranging over four estimated standard deviations. In order to test whether bond lengths of the same kind in a molecule are significantly different, the chi-square distribution test may be implemented if the estimated standard deviations of all the bond lengths are sim ilar.80 Application of the test indicates that the three Cu-S bonds are different from the mean value 2. 255A at greater than the 99$ probability level. Therefore, averaging of the Cu-S bond lengths is not justified on a statistical basis.

The copper-sulfur distances in [Cu(SP)CH3)3)3] lie toward the short end of the range of metal-sulfur distances found in related coordination compounds (Table 1+1). Thus, copper-sulfur distances in thiourea complexes range from 2 . 25A for terminal groups in 298

TABLE 1+0

DISTANCES OP AT0M3 FROM THE PLANE OF THE THREE SULFUR

ATOfcS IN THE COORDINATION SPHERE

Equation of plane through SI, S2, and S3 on Cartesian

■if* -it axes defined with x along a , y along b , and z along

.9 1 8 9h x + .39h3ly OO5U0 z + .3 1 3 8 8 = 0

atom distance from Planed)

Cu -.0 0 9

P I -.1*25

P2 .282

P3 -TMt TABLE l a

BOND LENGTHS TO SULFUR IN COMPLEXES

RELATED TO [Cu(SP(CH3 )3 )3] +

Formula M-S lengths(S) Angle at Sulfur Other Ref. (degrees)

[ cu (s c (nh 2 )2 )2 i c i 2. 26- 2 .3 1 83 , 138 (Cu-S-Cu) 16 (bridging) 2. 23, 2. 24 (term in al) rCu(SC(NH2 )2 )2]Cl2 2.323(6), 48 2. 306(6 )

rCu4(SC(NH2 )2 )a](N03 )4 2.291-2.469 69-123(Cu -S-Cu ) • 17 (bridging) rcu(sc(NH2))4]ci 2.345(5) 110. 1 (3 ) 50 [Cu(sc(NH2 )2 )31C1 2.27-2.35 1 0 5 -1 1 4 49 [Ni(sc(NH2 )2 )4Cl2] • 2.462(4) 1 1 3 .9 51 [Ni(S2P(CH3)2)21 2.24(l) 85 ( 1) P-S=2. 03j(l) 52 rNi(s2p(oc2%)2)2] 2.236(4), 95-8 P -S -L 993 (6 ), 26 2.230(4) 1. 986 (6 )

[N i(s2C2 (CN)2 )2l 2.16 103 27 rZn(sc(NH 2 )2 )2Cl2 1 2.352(5) 108.6(7) ' 46 500

Cu(sc(NH2 )2 )2Cl t o 2 .V 7A for bridging groups in [Cu^ScO^)^] (n03 )4.

Average Cu-S distances appear to be about 2. 23A for three-coordinate copper and 2 . 31A for four-coordinate copper* compared to 2. 39.1 f o r the sum of the covalent radii for tetrahedral copper and sulfur . 19

One would expect the effective radius of a three-coordinate metal to be less than that of a four-coordinate metal for electrostatic reasons

(see references 15 and 8 2 ). The copper-sulfur distances in

[C u (S P (d i3 )3 )3] +j 2 .214-8(lf), 2 . 2 5 2 (1|-), and 2 . 26l|-(l{-), th u s ap p ear norm al *> for three-coordinate copper and do not indicate any significant amount of multiple bonding in the Cu-S linkage.

The three trimethylphosphine sulfide groups are not quite equivalent in terms of internal structure of the ligand and bonding to the metal. The P-S infrared stretching frequency in [Cu(SP( 0 1 3 )3 )3 ] in fact does exhibit a slight asymmetry which could be due to non equivalent ligands (Figure XLlX). The nature of the deviation from

i d e a l C3 symmetry may be visualized as a tw isting of phosphorous atoms

one, two, and three from the CuS 3 p la n e b y M5, +. 28 , and +. 76 A,

respectively. In addition S2 has moved slightly towards SI, producing

a slight shortening in the Cu-S2 and S2-P2 bonds and closure of the

S1-CU-S2 angle. Temperature factors for carbon atoms on P2 are also

significantly higher than for those on PI and P 3 . An ex am in atio n o f

the crystal packing diagram reveals no obvious features which could

account for the apparent non-equivalence of the ligands. The differences 301

600 - i 500 CM

Figure XLIX . The P-S infrared stretching region in (—— )(CII^)^PS and ( ...... ) [cu(SP(CH3 ) 5 )5 ] CIO^. ( KBr)

probably are not connected with the disordered perchlorate group as the distortions persisted with the various anion models. Staggering of the triraethylphosphine groups above and below the coordination plane would minimize intramolecular interactions between methyl groups but a more nearly planar CuS3P3 unit might be expected to pack more 302

efficiently. The departures of the CuS3 coordination plane from ideal D3h symmetry are slight (although significant) and could "be due to crystal packing effects.

The crystal structure of the free ligand trimethylphosphine sulfide has been independently determined during the course of this work.24 It is of considerable interest to examine the effects of coordination to copper upon the structure of the ligand. Table ^2 shows that remarkably little change in the ligand has occurred. The

P-S bond length has increased by only . 03A upon coordination. This fact and the nearly tetrahedral angle about sulfur in the complex suggests that little change in the P-S bond order has occurred upon coordination and that sulfur has approximately sp3 hybridization in the complex. In principle, sulfur could s till form a multiple bond with phosphorous in the complex via backbonding from one (or both) of its * two unshared pairs of electrons. However, the sim ilarity of the P-S distances in the coordinated and uncoordinated ligands would seem to make such an interaction unlikely. Multiple P-S bonding in the complex' is also disfavored by charge considerations.

The P-S bond lengths in [Cu(SP(CH3)3)3]+ are 2. OOl(lf-), 1. 982 ( 5)9 and 2. OOlf(!}■); these are significantly different according to the chi- square test at greater than the 99$ confidence level . 00 The three values may be compared to the P-S bond lengths 1 .959 ( 2 )A in the free lig a n d , 1.9J+-1.98A in several diphosphine disulfides, and 1.95A f o r 503

t a b l e b2

STRUCTURAL EFFECTS IN TRIMETHYIPHOSPHINE SULFIDE

UPON COORDINATION3,

F u n c tio n Free Ligand Complex

p-s(A) 1 .9 5 9 (2 ) 1 . 9 8 2 - 2. 00!).

p-cU) 1.797(2), 1.799(2), 1.75 (2 )- 1. 8 1 ( 2 )

1 .7 9 9 (2 ) Avg. 1.79(2)

S-P-c(degrees) 113. 8 , 112.9, 109.9-113.9

112.9 Avg. 112.2(17)

C-P-C(degrees) 108 . 1, 10!)-. 2, 101. 2 - 113. !)■

101)-. 2 Avg. l06.6(l)-2)

a) The values in parentheses are the estimated error in the least significant digits. The values for the free ligand were estimated from standard errors in atomic coordinates, whereas those for the complex were derived from the least-squares variance-covariance m a trix . t>) Data taken from reference 2h. 30b

exocyclic "bonds in P4S (Table 30 in introduction). However, the P-S distances are 2. 0 5 ( 1 )^ in [ (CH3 )3P-S-CH3]I and 2.08-2.39A for endocyclic bonds in PS compounds. These distances would also imply that very little change in the P-S bond order has occurred upon coordination of trimethylphosphinesulfide. Thus, in the formal sense,

r3p= £ <------> r 3p + - s 3 "

I I I

r3p + - si r3p - s'. Cu Cu

III resonance forms II and III would seem to be dominant for both the coordinated and uncoordinated ligand.

The nine independent P-C distances vary from 1.75“1* 8 lA. E ig h t values lie within one estimated standard deviation of the mean (l. 79 a ) j whereas P3-Cg is shorter (l. 75a) by about two standard deviations.

These variations are neither chemically nor statistically 80 significant and thus the mean value 1. 7 9 (l)A is taken as the best estimate of the

P-C distance. These P-C values appear normal when compared to related compounds (Table 30 in introduction). Thus, P-C distances have been found to be 1.798(2) in the free ligand 24 and 1 . 8 1 - 1 .8 5 in various

RaP(s)-P(s)R2 compounds . 4 0 ,4 1 ,4 5 305

The S-P-C and C-P-C angles for trimethylphosphine sulfide are close to tetrahedral and are virtually unchanged when the ligand

is coordinated to copper. In both the free and coordinated cases,

sp3-hybridized phosphorous is indicated.

\ 306

V. CONCLUSIONS

Crystals of tris(trimethylphosphine sulfide)copper(l) 4* perchlorate have been shown to contain [Cu(SP(CH 3 )3)3] cations of very nearly regular trigonal planar geometry. An examination of the structure reveals no obvious features which would strongly disfavor addition of a fourth ligand to produce a tetrahedral copper(l) complex. In an independent but pertinent experiment, Toldan and Meek studied the tendency of the [Cu(SP(CH3)3)3] cation to add additional ligands in solution by monitoring the proton nuclear magnetic resonance signals of the methyl groups. Even at a twenty-five fold excess of ligand, only 89 the starting tris compounds could be detected.

One concludes from the above studies and investigations of copper(l) thiourea compounds that there are electronic reasons for the tendencies of copper(l) (and other metals of Group lb) to form three- coordinate compounds. Since univalent Group lb metals have the d 10 configuration, ligand field effects can play no role in determining the geometry of the complex. Thus, the complexes have structures which may be predicted on the basis of simple electrostatic considerations, viz. linear, trigonal planar, and tetrahedral for two, three, and four- coordination, respectively. 4* *f Orgel has attributed the propensity of the d 10 ions Cu , Ag , 4* ~H* Au , and Hg to form complexes of low coordination number, particularly 44" 44“ i l~f linear, whereas the related ions Zn , Cd , and T1 form predominantly 307

tetrahedrally (and higher) coordinated complexes to relatively greater d-s mixing in the hybridization for the former ions, rather than any special stability of sp hybrids75. These arguments may also be extended to explain the stability of trigonal planar coordination with *$• *4* *4* ,|.j_ Cu , Ag , Au , and Hg .

It may easily be shown that there are four permissible schemes for hybridization of pure atomic orbitals to give a trigonal planar arrangement of bonding orbitals about a central atom. Defining the z-direction as normal to the trigonal plane, the possible hybridizations are: sp^p^, sd ^^d ^ and d^d^^d^. However, because the

3d orbitals of a d 10 metal are filled, the d-orbitals used In the hybridization of Cu(l) would have to be Ud orbitals. Since the Ud orbitals lie considerably above the Us and Up orbitals in energy, the Ud orbitals would not be expected to significantly contribute to the overall hybridization scheme. On a simple basis one would therefore expect the hybridization of the metal to be primarily of the sp 2 ty p e .

However, the filled 3d orbitals are very close in energy to the vacant Us and Up levels. Contribution to the trigonal planar hybridization of copper(l) may be effected if initially the 3d 2 and Us oribtals are allowed to mix to form a filled orbital ¥ 1 and an empty orbital V*2. If extensive mixing does occur then f x should be of lower energy than the pure 3d _2 orbital. The empty if* 2 orbital possesses the z 508

required Ai symmetry and may mix with the Up and Up orbitals to x y form a set of trigonal planar hybrid orbitals which could accept electron pairs from the ligand donor atoms. Such a hybridization scheme would have two important consequences compared to a pure sp 2 hybridization scheme. First, it would permit participation of the relatively low-lying 3d 2 orbital via 'f 2 in the sigma bonding network. z Energetically, this should be a favorable situation; f 2 would have a more directional,'electronegativity 0 for ligand orbitals in the trigonal plane than a Us orbital. Secondly, the filled f 1 o r b i t a l should produce a strong electric field in the z-direction which would strongly repel incoming ligand molecules. 1 would also encourage dn(metal) -♦ d«(ligand) backbonding, although structural evidence for significant n-bonding in trigonal planar copper(l) complexes is not entirely convincing.

Finally, it should be noted that increased participation of

Up orbitals in the bonding scheme of Cu , Ag , Au , and Hg (as might occur in tetrahedrally vs. trigonally coordinated complexes) is not ++ ++ ++ +++ favored compared to the metals Zn , Cd , Wg , and T1 for electronic reasons. Since the Us-Up separation is nearly twice as great for the former group of metals , 75 hybridization of p-orbitals would be more difficult than for the latter group of metals. 309

( f t ( f ille d )

Figure L. The formation of d z os hybrid orbitals from d p z and s s atomic orbitals. The orbitals all have rotational symmetry about the a a x is.

*f* It is to be noted that the former set of metals (Cu , Ag , Au , and Hg ) form the most stable complexes with 1'soft'' ligands such as phosphines, h a lid es, and su lfu r compounds for which a sig n ific a n t amount o f covalent nature might be expected in the m etal-ligand bond.

The high polarizability of such ligands might be expected to be particul arly effective in satisfying the electrophilicity of the metal even when only a relatively small number of ligands are coordinated. 310

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PART THREE

The C rystal and M olecular Structure o f H itrosyl-1,1, l-tris(diethylphosphino)ethane- nickel Tetrafluoroborate

315 I. INTRODUCTION '

The chemistry of the coordinated nitrosyl (NO) ligand has attracted considerable attention in recent years because of the general stability of its complexes and the unusual features of the metal-NO bond,1 Three-dimensional X-ray diffraction studies have revealed three ways in which the NO group can coordinate.

1) The ligand may coordinate through nitrogen with a linear metal-N-0, - „ angle. - 36-39*54

2) The ligand may coordinate through nitrogen with a M-N-0 angle near 120°. 4,5,20133,56

3) The NO group may coordinate through nitrogen with a M-N-0 angle intermediate between 120 and 180°.3,SS Crystal structure reports for type 1 have been most numerous, with types 3 a>nd 2 occurring in decreasing frequency. The linear M-N-0 linkage is most often found in first row coordination complexes and in second row poly-carbonyl compounds; type 3 is found in complexes of soft, electron rich metals such as Ir and Rh; bonding type 2 is found with metals intermediate between those giving type 1 and 3. A fourth bonding type for the nitrosyl ligand, bridging to two different metals through nitrogen and oxygen, has been postulated in a few cases but not demonstrated by diffraction methods?

The usual approach to explaining the structural features of the coordinated nitrogen oxide group starts with consideration of the valence-bond resonance forms for the nitrosyl (N0+) cation, since this

316 517 is the most common source of the NO group in preparative procedures

(e. g. NO+BF,t ). Figure LI shows the resonance structures which are + expected to be the major contributors for the NO cation. By electro negativity considerations, resonance structures with the positive charge residing on oxygen would not be favored. Linearly N-bonded N0+ groups may be considered to arise via simple donation of the single lone pair of electrons on nitrogen to a suitable metal.

1N==0I

IN=(^ M<—N = £ M-->N o ;

A B

Figure LI. (a ) Principal valence bond representations of NO1 . (b) Simple a"^onation of the lone pair of electrons on nitrogen in NO', giving rise to a linear M-N-0 linkage. (cO Simple c -donation from a lone pair on the metal to N0% giving rise to a M-N-0 angle of 120°. 518

The nearly simultaneous discoveries that soft, electron rich m etals in coordination compounds may a ct as Lewis bases in some oxid ative addition reactions and that the M-N-0 bond angle in NO adducts of the same or similar complexes often approached 120° rapidly led to the + suggestion that the NO cation could act as a Lewis acid towards certain

- j , transition metals.5,20523,53 Considering the NO valence bond hybrids

(Figure Li), upon donation of an electron pair from the metal

/i-> / , x0) IN IN V iao° - y SI M A B

Figure m . (a) Principle valence bond representations of NO®. (b ) Simple a-donation of one lone pair of electrons on nitrogen in NO , giving an M-N-0 angle of ca. 120°.

to the N0+ ligand, then an M-N-0 angle close to 120° should arise due to resultant sp2 hybridization on nitrogen. 519

Alternatively, the 120° angle about nitrogen may be rationalized by considering the complex to form via addition of the nitrosyl (NO ) anion to the metal complex which is formally in the 2+ higher oxidation sta te (Figure LH and EIXl).13,37 +n + s + 4* ^ IN«s'OI OR \v M n + 8 + ^ — 0 .1 Figure HII. Coordination of the nitrosyl ligand to give a M-N-0 angle o f 120°.

Although the first approach treats the nitrogen oxide group as a

Lewis acid and the second as a Lewis base, both approaches used to explain the 120° M-N-0 angle observed in some nitrosyl complexes are equivalent in a molecular orbital description. Bond angles between 120° and l80° can best be described as an electronic configuration intermediate 4* *• between the limiting coordinated NO and NO cases. Thus, it is easily seen that the formal "oxidation state" of both ligand and complex in nitrosyl complexes is a loosely used device which has strict meaning only in the limiting (l and 2) M-NO bonding cases. In the non-linear cases it is necessary to describe the bonding in terms of molecular orbitals. 320

The nitrosyl complex which is described in this segment of the dissertation represents a classic case where assignment of the

11 oxidation state11 of the metal and the NO ligand could not be made on the basis of chemical and spectroscopic methods. During a study of the coordination properties of the *'umbrella-like*', potentially tridentate phosphine ligand- 1,l,l-tris(diethylphosphinomethyl)ethane, hereafter referred to as tep (Figure LIV ),

CH3 I CHf'T-CHa r v \ (C2»s>2P I P(C2 HS)2 P(C2Hs )2 tep

Figure LIV. The potentially tridentate phosphine ligand tep. 321

Berglund and Meek discovered that tep and nickel(ll) halides react in ethanol to form planar Ni(tep)x 2 complexes in which the ligand acts as a bidentate. However, the same reagents in the presence of nitrite ion form intensely colored solutions from which deep red complexes of elemental composition

NiX2 + OT3C-(CH2F(c2H5 )a)3 + NO./ > [Ni(tep)(NO)]X

X= CljBrjIjBF^BPh*

[Ni(tep)(NO)IX crystallize. The presence of the nitrosyl group was indicated by a strong infrared absorption frequency at ca. 1760 cm 1, which was assigned to a N-0 stretch. The above reaction is similar to a previously reported reaction in which nitrite ion is reduced in the presence of transition metals to form complexes containing coordinated X2j X3 NO groups; in neither study were the oxidation products characterized. Berglund and Meek found that the [Ni(tep)(N0)]X complexes were

1:1 electrolytes in nitromethane. The visible electronic spectra were invariant with respect to X, proving that the anion is not coordinated to the metal in solution. Furthermore, the electronic frequencies and bandshapes were identical in solution and in the solid state, showing that structural changes did not occur upon dissolving the [Ni(tep)(N0)]X complexes. The crystalline complexes were diamagnetic, and molecular weight determinations indicated a monomeric structure in solution. 322

Two models were proposed to fit the chai'acterization data, which strongly suggested the presence of a four-coordinate, monomeric, deeply colored, diamagnetic cation containing a coordinated nitrosyl group and three phosphine donors from a single tep ligand.

1) The [Ni(tep)(N0)]+ cation could be formulated as a planar nickel(ll) complex containing a coordinated nitrosyl (NO ) anion.

Tetrahedral geometry for the N i(ll) formulation is disfavored because of the diamagnetism of the complex.

2) The [Ni(tep)(N0)]+ cation could be formulated as a Ni(o) complex containing a coordinated nitrosy3. (N0+) moiety. In this case the four-coordinate complex would be expected to have tetrahedral geometry because of the dxo electronic configuration of the metal.

Both models 1 and 2 were proffered with reservation. The short chelate bite of the umbrella-like ligand would require either severe distortions from planar geometry or an uncomfortably close contact between planar nickel and the ' 'bridgehead'* carbon atom of the ligand if Model 1 were correct. On the other hand, it is difficult *4" to explain the intense red color of [Ni(tep)(no)] if a d 10 nickel(o) complex is present (Model 2 ), unless the visible absorption is due to charge-transfer bands originating in the nitrosyl group. 323

It was felt that a three-dimensional X-ray crystal structural determination of a [Ni(tep)(NO)]X complex was necessary to fully elucidate the structure. Models 1 and 2 should be readily discernible since 1 involves a planar complex with a coordinated NO group, and thus should have a Ni-N-0 angle close to 120°. In contrast, Model 2 requires tetrahedral geometry with coordinated nitrosyl (N0+) cations; here the Ni-N-0 angle should be close to 180°. I I . CRYSTAL SELECTION, DATA COLLECTION, AND DATA REDUCTION

A. Preparation of [Ni(tep)(NO)]I and [Ni(tep)( no)]BF4

A sample of [Ni(tep)(NO)]I was generously donated by D. Berglund

and D. W. Meek. Deep red polyhedra were obtained by slow recrystal-

lization from ethanol.

The [Ni(tep)(N0)]BF 4 complex was prepared by metathesis from

[Ni(tep)(NO)]I in the following manner, nearly identical to the method

used by Berglund and Meek . 10i 11

Sodium tetrafluoroborate (.078 g, 0.71 mmole) was dissolved in a

mixture of 2. 0 ml of water and If. 0 ml of ethanol and then filtered into

a stirred solution of [Ni(tep)(N0)]I (.17 g» O. 3 O8 mmole). After the

resulting solution had been stirred for fifteen minutes, the solvents were evaporated under a nitrogen stream to a total volume of 1 m l;

then deep red crystals separated from the intensely colored solution.

The mixture was allowed to stand overnight. The solid was collected by

filtration, extracted with a minimum quantity of dichloromethane, and

filtered. Upon addition of pentane and allowing the solution to stand

for a few hours, deep red crystals developed. These were filtered off

and washed with pentane. Crystals suitable for single-crystal X-ray

diffraction studies were obtained by dissolving the sample in ethanol

and allowing the solvent to evaporate slowly. 325

B. Crystal selection, and space group determination of fNi(teu) (uo)~[I and [Ni(tep)(N0)]BF 4

Both the iodide and tetrafluorohorate salts crystallize from ethanol as large, well-formed deep red polyhedra whose approximate shape is that of an icosahedron compressed in one direction. The twelve major faces of the tetrafluorohorate crystal were later established to be of the form { 110} by correlating precession and

Weissenberg photographs and diffractometer settings with crystal measure ments obtained on the optical goniometer. The crystals did not extinguish polarized light when viewed through crossed Nicol lenses, consistent with an isotropic crystal. However, the intense red color of the crystals may have prevented the observation of extinction in any case. Each crystal was mounted on a glass fiber with nail-polish glue with a large face perpendicular to the fiber and prelim inarily aligned with the aid of a two-circle optical goniometer. X-ray photography proved both crystals to be isomorphous and cubic. Precession photographs of the (hhj&), (hh+l^), (hOjfc), (hhjd) and

(h+ 1, h,j&) zones and Weissenberg photographs of the hkO and hkl zones of [Ni(tep)(wo)]I indicated a cubic cell withLaue symmetry mj. The observed systematic absences were hOO (h=2n+l), OkO (k=2n+l), and 00 g,

1=2n+l). For the [Ni(tep)(N0)]BF 4 compound, photographs of the hkO hkl, hk2, and hkj nets by the Weissenberg method and of the hOg hlfc, h 2jfc, 0 k£, lkX, and 2k£, layers by the precession method indicated a cell 326

of very similar dimensions with identical systematic extinction conditions. The symmetry and observed systematic absences uniquely d e fin e ( in th e c u b ic system ) th e space group P2i3**T4, No. 198 i n th e

International Tables for Crystallography. 8

This space group is isogonal with the point group T^ and is related to the common orthorhombic space group F 2 i 2 i 2 i-D 2 (No. 39) by the operation of a threefold axis.

The densities of £Ni(tep)(N 0 )]BF4 and [Ni(tep)(NO)]I were determined by the flotation method in a CCL^/hexane mixture. The solvents were added dropwise until crystals suspended in the solvent mixture neither floated nor sank. The respective experimental densities for the tetrafluorohorate and iodide salts are 1. j k + . 01 and

1 .^ 8 5 + -005 g/cm3, in good agreement with the densities calculated from cell constants obtained from the photographs, 1*339 and 1. g/cm3, under the assumption of four [Ni(tep)(N0)]X units per unit cell. With

Z=h in space group P2i3, both the anion and cation are required to occupy special positions of site symmetry 3 at (x,x,x); (l-*x,i--x,x);

(x,ltx,^-x); (i-x,x,l+x).s Three-fold symmetry is therefore required of both the [Ni(tep)(NO)] cation and the BF 4 anion. Thus, pseudotetrahedral geometry might be anticipated for the complex. 3 2 7

The mass absorption c o e ffic ie n ts (^) fo r each compound, ca lcu lated for copper and molybdenum rad iatio n , are given below.

ComPle * ______»cmov(cm' 1)______**MaK.((al' 1)

[Ni(tep)(NO)]I 129.38 22.^5

[Ni(tep)(MO)]BP4 25.6

C. Determination of Accurate Cell Constants for fNi(ten)( no)IBFa

The [Ni(tep)(wo)]BF4 crystal was mounted on a Picker four-circle diffractometer and thirteen reflections with 20 values between 16.6° and 56.?° for nickel-filtered CuKq- x-radiation were carefully aligned.

The orientation angles 20, ^ and thus obtained were used in a least squares refinement of the unit cell parameters using the locally written er . computer program CQZIS. In this refinement, 20, y, p, and the cell edge

*’a'1 were refined. The refined unit cell edge is a=13.6365 (33-

D. Intensity Data Collection

The [Hi(tep)(NO)]BF4 crystal was remounted on the Picker auto mated diffractometer and carefully centered for height in the x-ray beam by examining several equivalent forms of a number of reflections. Copper

radiation was used throughout the data collection, with monochro- maticity being obtained by inserting a . OOO5 inch nickel filter into the d iffr a c te d beam. 3 2 8

During data collection the diffractometer was under the automatic control of the Basic Asset software package of the EMR computer. The Basic Asset system is an executive program which controls the various operations of data collection, which includes sluing the diffractometer to the proper setting angles, collection of background times, and scanning the reflection. When abnormal conditions were encountered during data collection, e.g. collisions, excessive counting rates, or difficulties in reading the angular encoders, the reflections were tagged for separate measurement. Basic Asset also has the capability for time-sharing operation, although this feature was not operational at the time of data collection.

The mosaicity of the crystal was examined by the uj-scan technique; the width at half-peak height for a typical strong reflection was 0. l°, which is suitably small . 18 The takeoff angle was then adjusted to 0 . 8 °, at which point the peak intensity of a reflection was reduced to 75$ of its maximum value. The 0-29 scan technique was employed in data collection with the four-circle diffractometer operating under equatorial geometry. A symmetric 20 scan range of 1. J0 ° about the calculated peak center for Cuifoi radiation was determined to be adequately wide to give reliable backgrounds and intensities.

Stationary-counter, stationary-crystal background counts of ten second duration were collected at the extremes of each scan. Attenuation was provided for reflections whose peak counting rates exceeded 9,000 counts per second by inserting brass shims of thickness .001 inch into the diffracted beam; reflections requiring attenuation were tagged during data collection and measured separately. Of the 2O65 reflections measured, twenty eight required one attenuator, one reflection required two attenuators, and three reflections required three attenuators to reduce the counting rate to the required level. The attenuator factor 2.9Tj as previously determined in this laboratory, was used for attenuator corrections. A ll reflections collected were recorded on a strip-chart recorder operating at the rate of 0.5 inch per minute. The source to crystal and crystal to counter distances were approximately 2h and 26 cm, respectively. The pulse-height analyzer settings were chosen to give a window passing about 95$ of the radiation incident on the scintillation counter. These settings were: gain-10$, lower-level helipot-2.71 (^.05 Kev), and upper-level helipot 8. i(-0 (12.6 Kev). In order to monitor crystal and instrument stability during data collection, the 352, 35°> an{* oo1* reflections, which are medium intensity reflections occuring in diverse regions of reciprocal space, were used as standards and remeasured after every two hundred fifty reflections. The standards were constant within 1$ throughout data collection, making corrections to the data unnecessary.

A total of 2065 reflections, including systematic absences, were collected in the hkC octant. Because of the cubic symmetry of the 3 3 0

crystal, this octant actually contained approximately equal components from the equivalent forms hk£. jjhk, and k£h.

E. Data reduction

Intensities were calculated from the raw data according to the equation Ine^. ~ A(c- ^ q (Bi +B2)) where A is the attenuator factor, t is the scan time, C is the total count accumulated during the scan, and

Bi and B2 are the first and second background counts. Standard deviations (a-) for each intensity were estimated according to the fo rm u la

aa(lnet)= Aa[C-^+(pInet)2 + 0.5(tb)2(Bi+B2+l8)] where p is an adjustable weighting parameter which was arbitrarily set to . 05 and tc and tb are the total counting time and individual back ground times, respectively. The constant factors nine and eighteen are included to account for errors introduced by truncation of the last digit in measuring the backgrounds and raw counts with the Picker scalar.

The constant factors are important in the calculation of cr(lne^) only for peaks of weak intensity or background. Of the total 2065 reflections actually measured, 19 8 6 had net intensities greater than % (lnet) and were considered observed. Using the locally w ritten program PIPIC19,6S

Lorentz and polarization corrections (i^) were applied to convert the intensities to the initial set of structure factors according to

^((lnet)/LP^ For equatorial geometry, the Lp factor takes the same simple form as in zero-level Weissenberg geometry, viz.

1 1 + COB2 gQ Lp= (sin2e)( 2 )

Standard deviations on the structure factors were obtained from the fo rm u la

ct(f) = (tP)_ 1/ 2 F x a(lnet)

Application of absorption corrections and averaging of equivalent reflections were performed at an intermediate stage in the refinement of the structure. A description of these calculations is given in part III , '' Structure Solution and Refinement''. I I I . STRUCTURE SOLUTION AND REFINEMENT

A. Structure determination and in itial refinements

In itial Fourier and least squares calculations were performed in house on an Electromechanical Research Advance Model 6 1 3 O Computer using locally w ritten programs. e 0 J 6 7 The EMR 6 1 3 0 computer has l 6 K words of core storage, each word being sixteen bits in length. The computer has a cycle time of 0 . 7 5 microseconds and is equipped with one million words of auxiliary disc storage. Because of core lim itations on the EMR 6 I 3 O computer, least squares refinements involving more than ninety variables used the block diagonal approxi mation. Each block contained the positional, thermal, and occupancy parameters for one atom, except for individual blocking of the overall scale factor.

For computational convenience, in itial least squares and Fourier calculations were performed in the orthorhombic space group P 2 i 2 i 2 i , which is closely related to the true space group P2i3* (P 2 i 2 i 2 i becomes

P2i3 with the operation of the threefold axis. ) The entire (unaveraged) octant of data originally collected was used in these computations.

Least squares shifts for symmetry-related parameters were then averaged after each cycle and applied so as to maintain the threefold symmetry required by the cubic cell. While this refinement procedure is not mathematically rigorous, its use was justified by the close sim ilarity of the least squares shifts of symmetry-related parameters in the cubic

3 3 2 3 3 3

symmetry and the relatively rapid convergence of the refinements. For intermediate refinements a more rigorous treatment was afforded by using a modified least squares program w ritten by Professor 6 6 P. W. R. Corfield. This modification allows the refinement to be carried out in the orthorhombic space group but the appropriate derivative constraints and parameter resettings are automatically per formed by the program so as to maintain the threefold symmetry required by the true space group 1P2 i 3 »

The function minimized in the refinements was

w( |F obs j - |F c a lc | ) 2 where Fobs and Fcalc are the observed and calculated structure factor amplitudes and w is the relative weight assigned to the reflection

(w = i/j2 (f)). The discrepancy factors referred to in subsequent discuss ions are defined by

The structure solution was straightforward but the least squares refinements were complicated by the disorder problem. A summary of various stages in the refinement may be found in Table • With Z=k in space group P2i3, threefold symmetry is required of both the cation and anion and the following atoms are required to lie on the threefold axis: nickel, two carbons, boron, nitrogen, oxygen, and one 3311-

fluorine. Therefore a pseudotetrahedral geometry ahout the nickel

atom including a linear M-N-0 linkage was anticipated. A three-

dimensional unsharpened Patterson synthesis verified the expected

geometry and gave tria l coordinates for the nickel, phosphorous,

nitrogen, and the ’'bridgehead** carbon (Cl) atoms as well as what was

initially believed to be the fluorine atom which is required to lie on

the threefold axis. After two cycles of refinement of an overall scale

factor and positional and individual isotropic temperature factors

for each of the above atoms, the agreement factors were R= 2 8 . 5 7 and

Rw=5 lf. 3 ^ (NV=22, NO=2065). Structure factors from this refinement

were used to calculate a difference Fourier synthesis which clearly

revealed the remaining carbon atoms. The Fourier function also strongly

suggested that the atom refined as a fluorine was actually boron.

Coordinates were obtained from the difference Fourier synthesis for the two independent fluorine atoms, and one fluorine on the threefold at x= .33 (labelled F, ) and one fluorine in a general position (labelled Aon F* Even at this early stage in the refinement, however, the A off electron density in the anion region indicated either large anisotropic

thermal vibration or disorder in the anion.

Four cycles of least squares refinement of a ll the non-hydrogen

atoms in the structure converged with R=12.1* and Rw=15. 6 . Bond d is ta n c e s

and angles in the cation appeared quite reasonable but the geometry of

the anion was quite distorted from tetrahedral. Furthermore the unusual 3 3 5

isotropic temperature factors in the tetrafluoroborate group (-. 2 A2 f o r b o ro n , 1 5 . kk2 for FAoffJ and 2 2 . 3 A2 for FAon) suggested possible disorder in the anion.

A second difference Fourier synthesis gave evidence at this point for anisotropic thermal vibration for the nickel atom and also

indicated a second possible position for the fluorine atom on the three

f o ld a x is a t x=. U 6 (labelled F_ ). Accordingly the fluorine coordinates £on on the threefold at x=. 3 3 (FAon) were replaced by FBon. Three cycles

of refinement of this model, also introducing variable anisotropic

temperature factors for the metal, produced R= 1 3 . 1 and Rw=13»8 , with a predicted new Rw=l3. ^ after the final cycle of refinement.

Temperature factors for atoms in the anion remained anomalous;

B(boron)= 0.4A2, B(FBon)=25* 0A2* and B(FAof,f )=19. 8 l2. It was also evident at this early stage that there was considerable correlation between the anion model and the coordinates of the nitrogen atom, an

important feature of the structure.

A new difference Fourier synthesis was computed using structure

factors calculated from the above model without the anion. The pre

dominant feature was a broad peak of height 5 * 5 e/A3 at the boron p o s itio n (x=. lj- 0 ), extended in both directions along the threefold axis.

Electron density was 2 . 1 e/A3 at the FAon and positions but

virtually nil near F„ . The exceptional peak height near boron Bon suggested the possibility of partial isomorphous replacement of the 336

tetrafluoroborate group by iodide. Since the data crystal was prepared by raetathetical replacement of I by BF 4 and since [Ni(tep)(NO)]I and

[Ni(tep)(NO)]BF 4 are isomorphous (cell edges= 13*52 and 13.61*- A, respectively), partial replacement would not be unreasonable. Therefore, a test refinement was performed in which the BF 4 group was deleted and replaced by an iodine atom. In addition to the isotropic cation (except for nickel), the position and occupancy of iodine was refined. Near convergence was reached after two cycles of refinement with the iodine occupancy at . 107. However, the high R factors, R=l1*-. 2 and Rw=l 6 . J, indicated that although mole 10$ iodine might be present, the model with only iodine as the anion was distinctly inferior to one with tetra fluoroborate present.

Test refinements were therefore performed including both I and BF4”. In addition to individual positional and isotropic temperature factors for atoms in (BF4)A and I, and the non-hydrogen cation atoms, the occupancy of iodine was refined. After each cycle the occupancy of (BF4)a was reset so that the total anion occupancy remained unity.

Convergence of this model was reached after three cycles with R=l?4-. OT and Rw=l 6 . J*l(NO=2035, NV=Vt). The occupancy of iodine now stood at

* 0 5 9 . .

The next refinement involved to tal removal of iodine and refinement of the two BF 4 anions of equal occupancy, but with the inclusion of only one boron atom. FAons and FBon were positioned as in previous refinements, whereas was Placed as

suggested "by the preceding difference Fourier summation. Refining

the cation as before (only Ni anisotropic) and refining the two BF 4

groups isotropically and independently, the refinement converged after

five cycles with R=10.66 and Rw=12.21, a very considerable improvement in agreement. As in the single BF 4 refinements, temperature factors

remained anomalously low for boron ( 0 . 5 a) and high for fluorine (IT* 3 *

2 5 .2 , Xk. and 1 5 . T A2 for FAoff, FAon, FBoff, FBon, respectively). At this stage, F-B-F angles and B-F distances for each group ranged

from 96-121° and 1. 3 O -I.62 A, r e s p e c tiv e ly .

B. Absorption corrections and averaging of equivalent reflections

The diffraction data next were corrected for absorption of

x-rays using the locally w ritten computer program PICABS , 0 7 b ased on

Busing and Levy’s method . 1 9 An 8 x 8 x 8 Gaussian grid was used and the

total crystal volume was . O 5 2 3 mm3. The maximum and minimum corrections

on F 2 were 2. 5^ and 1. 9 Tj respectively. The correction assumed no

iodine to be present in the crystal. Refinement of the above double

BF4 model gave a slight improvement in agreement to R-10 . 5 8 and

Rw«l2.13 after application of the absorption correction to the data.

Up to this point, the entire non-unique (unaveraged) octant

of data had been used in a ll the computations. Now equivalent

reflections in the octant of data were averaged to produce the sector

of data unique for the cubic space group. At the same time all the 338

indices were converted to positive numbers. Equivalent reflections were averaged and the indices were made positive in a way such as to retain the ' 'handedness1* of the original dataset and to maintain the integrity of Friedel pairs of reflections. The averaged intensity F for each reflection was calculated according to

F = (swiFi)/£wi and

where there are N estimations of F, wi is the weight of F^, and o (f ) is the standard error in F. The weight of F is given hy 1 weight(F) = ^T fT . The average deviation of equivalent reflections from the mean value was If. 3 8 $, strongly suggesting that the crystal is indeed cubic. All subsequent least squares refinements used the averaged, unique dataset. For computational convenience on the EMR 6 I3O computer, the averaged dataset was expanded to a fu ll octant for Fourier syntheses in P2i2i2i. Refinement of the double BF 4 model after averaging only slightly improved the agreement in weighted R: R-10 . 7 3 and Rw=ll. 6 l .

C. Intermediate Refinements

At this point anisotropic thermal parameters were refined for all non-hydrogen atoms in the structure except the anion. The refine ment converged after three cycles with a highly significant improvement in agreement with the addition of thirty-six parameters: R= 8 . Olf and 5 3 9

Rw= 9- 20 (N 0 =6 8 T, NV=8^i- ). Temperature factors for atoms in the anion remained unusual: thus, isotropic B’s for the boron. F. FA , 3 A off Aon PBof f* and FBon atoms were x- 9a 20. 5, 7.1, 12.8, and 20. 5 A2. The anion geometry was also poor, especially the short B"FAon distance (0 .hi a ) . For the purpose of re-examining the anion region in detail and determining hydrogen positions, a fine grid (.2 A) difference Fourier synthesis was calculated. The map was remarkably flat. , The two highest peaks ( 0 . 5 e/A3) occurred near the boron atom and the original co ordinates for FAon(x “ *335)* The third highest peak was only 0. 5 e/A3 ) and occurred at a distance from the boron atom reasonable for a B-F bond. Hydrogen atoms were not located with confidence.

From this point in the refinement, all computations were performed on IBM 3 6 0 / 7 5 and 3 7 0 /1 6 5 computers. Full matrix least squares refinements were performed with the program NUCIS5 as, which allows refinement of a group of atoms as a rigid body.20 29 The rigid body is constrained to fixed geometry but the orientation and position of the rigid body may be refined. All subsequent Fourier summations used Zalkin1s FORDAF program. From this point on, a ll calculations were performed in the cubic space group F2i3 an£* include the six methyl ene hydrogens in periodically updated calculated positions.69

As attention returned to the difficulty in finding a suitable model for the disordered anion, a series of rigid group least squares refinements were initiated. For a rigid BF 4 group constrained to lie on the threefold axis, only one rotation angle to define the orientation about the axis and one positional parameter to describe the position of the group along the threefold axis need to be considered. Since certain atoms, including some in the anion, lay on special positions (on the threefold), the appropriate summations of derivatives and resetting of parameters had to be taken into account.

Selection of a B-F bond length for the rigid tetrahedron posed a problem.

The B-F length in tetrafluoroborate salts appears never to have been measured with very great precision because of the common.problems of disorder and high thermal motion.20 24 In fact, the BF4 group in some cases seems to be easily distorted and may exhibit genuine deviations from tetrahedral symmetry.215 22124 A B-F distance of 1 . 3 8 A was selected, this value being the approximate vaue found in the present refinements of [Ni(tep)(no)]BF4 and in previous structural deter minations. 21,22,24 However, a slightly longer B-F distance (l. 1*3 A) has been used by other workers for rigid group refinements of tetra fluoroborate compounds.23

In itial group orientation parameters for (BF4 )a and (BF4 )B were calculated with the use of computer program HBANG . 3 0 The two rigid BF4 groups were assigned equal occupancies of 0. 5 0 and a least squares refinement was attempted in which the rotational and positional para meters were refined for each group, in addition to individual isotropic temperature factors for each atom in the two groups; the anisotropic cation was refined as before . The refinement gave B=13.1 and

Rw=1 5 . 3 after the first cycle but sharply diverged in the next cycle Jll-1

with R=27» U and Rw=35.2 (NV anion=10, NV total=80, N0= 6 7 6 ). The

temperature factors for the two boron atoms clearly were highly

correlated, oscillating wildly to produce in the second cycle B(boron

A)= “8 . 3 A2 and B(boron B)= U. 1 A2. The correlation may have been due

to the coalesence of the two boron atoms during the first cycle of

refinement. Therefore, the refinement was repeated but only a single

isotropic temperature factor was refined (after the appropriate

derivative constraints were taken into account) for "corresponding 11

atoms in the two BF 4 g ro u p s. ' 1 Corresponding 1 1 atoms in this context

means the pairs BA and B^, FAon and FBon, and FAoff and FBoff* With

this condition, the refinement converged smoothly after three cycles

to g iv e R= 8 . 80 and Rw=lO. U^(NO= 6 7 6 , KV= 78). However, individual

temperature factors in the rigid EF 4 groups remained quite unreasonable.

Thus, the B 1 s were 0. 7 A2 (boronA and bororig), 3 9 . 6 A2 (FAon and FB0n^>

and l £ . 7 A2 (FAoff and FBoff^* These refinements clearly indicated that the double rigid group

model was inferior to non-rigid models. Again the presence of a small

amount of iodine was suggested by the low temperature factor on boron.

Therefore, iodine was reinserted with 556 occupancy and the BF 4

occupancies were reset to . *4-75 each. A final rigid group test refine

ment involved "tiltin g 11 the groups from the threefold axis. Such a

model would duplicate a free, dynamic precession motion or a static

11 t i l t i n g 1 1 disorder of the tetrafluoroborate groups. The results of i

3^2

these refinements also were distinctly inferior to models involving BF 4

groups which were disordered but aligned along the threefold axis. Thus,

the best refinement with a ** tiltin g 11 model gave R=8. O3 O and Rw=9. 236.

The constraints for rigidly tetrahedral geometry were next

removed and the above model was refined, with isotropic temperature

factors for f* corresponding* * atoms in the anion being constrained as before. In order to avoid matrix singularity, one boron atom of

occupancy .95 was included rather than two boron atoms. Refinement of

t h is model converged a fte r fiv e c y c le s with R=7*^27 and Rw= 8 . 213

(NO=£85, NV=83). However, the f in a l distan ce ( 0. 5^ ) was

distressingly short, a feature found in previous refinements.

A trial refinement of a model identical to the above model

except for the inclusion of anisotropic temperature factors for the

fluorine atoms failed. The refinement seemed to be near convervence

after three cycles with R=6 . 930 and Rw=7*6jOj "the refinem ent then

diverged sharply as the F. and boron atoms eventually overlapped i l W ll (N0=685, NV=97)» Thus, the anisotropic anion model, while in itially

giving lower R factors, was reluctantly discarded.

At thlB point a final difference Fourier synthesis was computed

in order to examine in detail the anion region and to search for hydrogen

atoms. Structure factors were calculated using the converged isotropic

anion model discussed in the preceding paragraph (R=7. Ij-27, Rw= 8 . 2 1 3 )*

The dominant features on this electron density map were a . 3 e/A3 peak near nickel, two . ^ e/A3 peaks in the BF 4 region, and several peaks o f ab o u t .3 e/A3 near the terminal carbon atoms (methyl groups). Only the one independent hydrogen on C 2 was located with any confidence and this atom was included (but not refined) in the final round of calculations with an isotropic temperature factor equal to that of C 2 before anisotropic refinement. No unusual features were observed in the vicinity of the nitrosyl group and the relative flatness in the tetra

fluoroborate region indicated that the main disorder effects had been accounted for.

D. Determination of the ^Handedness 11 of the Crystal and Examination

of the Weighting Scheme

In non-centric space groups, the anomalous dispersion effect

causes Friedel pairs (Fhkl and Fhkl) to have different structure factor m ag n itu d es . 6 1 Ordinarily the anomalous dispersion effect is observed

only when elements heavier than phosphorous are present in the structure. For lighter atcms the magnitude of Af1' > the imaginary component of the structure factor, is too small to give detectable differences in

]?hkl and F j^ • For nickel and phosphorous the Af * * terms are 0 . 6 7 and

0.27 electrons, respectively. The 1 * handedness 1 1 of the crystal may be

investigated by changing the signs of a ll the atomic coordinates,

reversing the signs of all the indices, or by changing the sign 1 th e

imaginary part 11 of the anomalous dispersion correction . Chang

ing the sign of Af 1 1 for nickel and phosphorous and least squares refinement of the above model gave R=T«^ 6 l and Rw=8 .255 compared to

R=7- lf-27 and Rw=8 .213 before changing Af' ’. The significantly better agreement before changing Af1’ shows that the original 1 ’handedness 1 1 of the atomic coordinates are correct as written.

Up to this point, the calculated structure factor magnitude f o r th e ( 2 , 0 , 0 ) reflection had been invariably higher than the observed value by about 25“3^* Since the ( 2 ,0,0) is a very strong, low-order reflection and the data crystal was relatively large, the disagreement could well be due to primary extinction. Therefore, this plane was dropped from a ll subsequent refinements.

In a least squares refinement, if the weights w^ for the observations are properly chosen and the disagreements between Fobs and Fcalc reflect only random errors in the diffraction data and the model, then the function w.(J|Fobsl |F c a lc |) should be relatively invariant when analyzed in any systematic fashion. The ultimate criterion for proper weights, however, is that they reflect the best estimate of the error in the original observations . 3 1 ’ 4 1 , 0 1 U sing

Corfield* s program Ranger, a weighting analysis of the data after convergence of the non-rigid, isotropic, double BF 4 refinement including

5$ iodine (R=7*^27 and Rw= 8 . 2 1 3 ) clearly showed that the function w^[||Fobs|^-|FcalcJ^|] was systematically large for strong, low-order planes. The dependence could partially be attributed to a slight under estimation of the adjustable weighting parameter p originally applied to 3!t-5

the total raw counts in calculating the original crflnetj's (see

Section an underestimation of p would produce standard errors which are too low (or weights too high) for the stronger planes. The main cause for the larger values for w^[|| Fobs |^-J Fcalc j.J |] for the

strong, low order planes seemed to he connected with the imperfect model for disorder in the anion. Since the anion contains light atoms whose scattering power decline rapidly with sin q/\s the low order planes would be affected more than higher order planes. The absence of the methyl hydrogen atoms in the refinement also would produce an effect in the same direction.

In order to test the sensitivity of the structure to the weighting scheme, refinements were carried out using several different

Cruickshank weighting formulae. A scheme which successfully produced a much flatter distribution for w^[ j jFo|^-|Fc|^] was

CT(Fobs) = (5 + .1 Fobs + .01 Fobs2)^

The main effect in the cation with the refinements using various weighting schemes was (as noted with the various anion models) a slight correlation with the nitrogen coordinates. Thus, the Ni-N and N-0 lengths were 1.60 and 1.16 A, respectively after convergence of the non- rigid, isotropic, double BF 4 model with 5$ iodine using the original weighting scheme based on counting statistics. These distances compare with the values 1.62 and 1.15 A, respectively after convergence of the same model with the above Cruickshank weighting scheme. Although the 3M5

Cruickshank scheme does give a better weighting analysis in terms of w ^[||Fobs|^-|Fcalc|^j], the original weights appeared to give more realistic estimations of the uncertainties in the original observations, and therefore, the original weights were retained.

E. Final Refinements with the Inclusion of Lagrange M ultipliers

It seemed highly desirable in the final round of calculations to refine simultaneously occupancy parameters for (BF4)A, (BF4)B, and

Iodine. However, since variables describing these occupancies would not be independent but subject to the linear constraint

occ(iodine) + occ(BF4)A + occ(BF4)B = unity the usual least squares procedure would be inappropriate. Variables related by linear constraints may be properly treated in least squares refinements by the introduction of Lagrange m ultipliers . 3 1 ,3 4 Thus, the minimization function may be w ritten

M = S W h(|Fo|-|Fc | ) 2 +j£{Qx b~ ) h where the true values of the parameters x are related to the tria l set x 0 by

x = xo + fix 0

The variables are subject to the constraints

Qx = b and Ar are t *13 Lagrange m ultipliers. Minimizing M gives

^ = 0 = -s Sw^lFol-jFop-fW- +£ ,qi where is the i column of Q, Performing the usual Taylor expansion on Fc and ignoring terms higher than the first gives

= 0 “ • ssof1^ +JZ - a which on rearrangement yields

^ 5 ^ • a = (ip°!-iF=i >+ aiTA

Upon redefining terms,

C &x = b + where C is the usual normal matrix, b is the usual right hand side of the normal equations without constraints on the variables, and £x are the parameter shifts. Thus,

6x = c"1 b + C"1^

Since all the quantities on the right hand side of the equation are known, the parameter shifts are simply obtained by performing the matrix a d d itio n 3^8

Least squares refinements were performed with the inclusion of the Lagrange condition for occupancy factors of (BF4)a, (BF 4 )g, and iodine, the necessary derivative relations being duly accounted for.

In addition to independently varied positional parameters for each non-hydrogen atom in the structure, isotropic temperature factors were refined for the anion atoms (one isotropic B for each pair of

* 1 corresponding*’ atoms) whereas anisotropic temperature factors were refined for the cation atoms. Methylene hydrogens were included in calculated positions as before and H2 was included but not refined. The values for isotropic temperature factors for hydrogen atoms were taken as those of the corresponding carbon atoms before anisotropic refinement.

Refinement of this model converged after five cycles with R=7* 0^ and

Rw=7.91 for refinement on a ll data including unobserveds (NO= 6 8 ^ , NV=

687). The refinement indicated occupancy factors of . 0 7 0 (3 ), .It 1 7 ( 8 ), and . 5 1 3 ( 7 ) for iodine, (BF4)a, and (bF4)jj respectively. Temperature factors for the fluorine atoms were s till rather high ( 2 3 A2 f o r F^Qn and Fgon, 13 A 2 for FAoff and but those for the boron and iodine atoms were reasonable (^. 8 (ll) and 4. l( 6 ) A2 respectively).

The presence of a small quantity of iodine was even more con vincingly demonstrated by an attempted refinement of a similar anion model containing only (BF4)A and (BF4)B, constraining temperature factors as described above. In addition a variable a describing the occupancy of (BF4)a and (BF4)B (1-qO was refined. This refinement diverged sharply 3 h9

as the temperature factor for the boron atoms plummeted to - 3 . 1 A2.

The negative temperature factor presumably Is an attempt by the refine ment to account for the decreased electron density at the anion center in this refinement (5*° electrons) compared to the Lagrange refinement with iodine included (If. 6 electrons from the boron atoms plus 3 . 7 electrons from iodine). The sensitivity of the ’ ’boron1' temperature factors might also reflect the different shapes of the scattering factor curves for boron and iodine.

The refinement including Lagrange m ultipliers for the tetra fluoroborate and iodine occupancies was considered to be better than for any previous models because of the low R-factors and the overall geometry of the tetrafluoroborate groups. Therefore, the refinement was terminated at this point.

The final R-factors are R=7« O3 6 and Rw=7.905 for a ll data and the error in an observation of unit weight is 3 . 5 2 . In the final refinement the maximum shifts were .25 standard deviations in the cation

(y coordinate for C 6 ) and . 39 standard deviations in the anion (x coordinate for F. ). Final structure factors are tabulated in Table Aon k-3 and the final atomic parameters are listed in Table 1*4 . A summary of results of various refinements is given in Table TABLE k3 550

FINAL STRUCTURE FACTORS FOR [Ni(tep)(NO)] BF 4 F« H K L Pi l»* r s * H K L P. 0 1 1 ?*■*> I r . i -0 .9 0 J 4 49*7 10)'* -7.9 0 4 7 *•? 1*7 1.4 0 0 t 10*9 71.1 •I. 9 0 r-4 1 40.1 ft 1 * 9 - 2.1 0 0 * 17.9 lt.l -9.1 b • « 2J.« 24.7 -2*2 V J 10 JU ft 22.* •0.9 0 « 9 *0.1 4 1.2 • l . a 0 0 U 0,0 -0.2 0 • * 21.* 2 2.9 - 1*1 0 0 1* 17.0 11*1 -9,1 0 • 7 7.2 4 .7 2*9 O i l 11.7 J4.7 •19.t 0 ft ft t*«0 Ift.ft -1*1 0 1 * 11.fr 97.9 *•0 0 ft 4 4 .2 1*4 0 .9 0 1 9 11. * 14.1 -?.* 0 ft 10 2 0 .7 2 1.4 • )*1 0 1 * )l«ft 11.* 2.9 0 ft ' II 12.4 17.0 1 .4 0 | T 1*0 t.ft l.ft 0 4 12 11.4 l?.fr -2*2 0 1 ft z*«t 77.2 •2.0 0 4 | *•« 7.1 0 1 ft 19'* 17,1 •9.2 0 9 * 1ft. 2 1 4 .) - 1 .2 0 1 to ft«ft n .o •1.1 0 4 1 l l . f t 13,4 7 .1 0 I 11 1**9 I* .9 •1.1 0 9 * 72*2 24.7 -4*7 0 t u |1*» 19.7 -9.0 0 4 4 2 J .4 7d.fr -0 .2 0 I |J l.ft 9.0 1*0 0 9 4 Jft'l 24* " 0. 7 0 1 1* ll'ft 19'f -*»ft 0 m 7 10* I 1 0 .ft - 1 .0 0 i 19 *•? 4.1 0*0 0 4 1 * >1.7 2 1 .ft -0 .1 O f t 14*7 17.7 *»• 0 9 4 ft.ft 7.4 - l . t 0 1 ? MiO ft*.l -9.7 0 9 10 4 '2 7 .0 •2 .9 a l l *S«ft 12«4 19*1 0 9 t l 7.2 ft.4 1'4 0 i * l)«* 7.7 21.) 0 4 1? * .0 2 .0 1 .7 0 1 9 11.1 lO.ft 0.9 0 10 1 17.4 19*2 4 .9 0 1 f t 91«ft 99.11 •*.1 0 10 9 O.ft T.9 1*7 0 Z 7 IT. 9 l*.t -l.ft 0 10 1 72.T 2 l.fr - 2 . ) 0 1 7 71.2 20«* ).* 0 10 * 1 4,0 )2«1 l.ft 0 t • l).ft 12.• 1.9 0 10 9 1 0 .) 10.9 •1*4 0 1 10 11.) 12. * •0*4 0 10 6 14*2 1 4.4 O.ft 0 1 II 2ft.* 77.0 -I.) u 10 7 f t.7 9*4 2 .1 0 1 11 T'ft 7.2 0.4 0 10 ft 2 ) .4 2 1 .) - 0 .9 0 2 1} 19*7 If.* -*.2 10 4 4*2 9*9 •1*0 Oil* ft.ft 11*7 -4*0 10 IQ 2 7 .7 79*7 -2 .2 0 « 1 *1*9 97.4 9.9 IQ 11 ft.7 f t.l - 0 .2 O l ? 1-7.0 41.2 •2.7 II 1 7*9 f.ft •0.2 O i l ft» .* 74.7 •9*9 11 ? 1.1 4.T -1*1 0 1 * l l . f t 91*9 -7 * 4 II ) 1 4 .0 14*9 - 4 .0 0 1 9 97*1 ft?.* -1*2 II * 2 1.0 21*9 )* • 0 1 f t «**) *7.7 1*2 1) 9 1 7 .| M . l • 4 .9 0 1 7 20* ft Ift.ft 2.7 11 4 71.9 7S.7 0.0 O i l *4.fr ftT.d 2.4 11 7 tl.o 11.4 - 0 .9 o i f t 19.7 )*.? -1*1 11 « 17* ft 14.1 • 4*7 0 1 to ll'ft I t . * •0*4 I t < 0 .0 2 .) •0 .2 0)11 11') JO.t 2*4 11 to ft.O 4*1 1*9 0 1 11 11.9 11.7 -1.1 U 1 4 .7 ft.) 0*9 Oil) 9*7 10.7 -1.9 12 7 ft.O ft.ft •1*1 O i l * 7.9 9.0 -2.1 4 .0 2*2 0 * | **.7 *0'ft ft.O 12 2 4 .4 0 * 1 *21.2 2).* -0*4 11 * D.O I d .) -0*7 *ft.* 1? 9 4 .) f . l •2 .2 0 * 1 71.0 •l.ft 17 4 9 .4 7 .4 1 .1 0 * ft 19. ft 19.1 7*2 1? 7 ft'ft 6*1 1 .0 0 ft 1 *1,0 *9.1 •1.2 12 4 ft.9 9 .4 -2*2 0 ft ft 27.9 29.9 4.4 1? 4 4 .9 J*T 0*0 0 * 7 9.1 4.0 2.1 1) 1 10.9 27.0 -2*1 0 * 7 21.9 27.7 -9*1 11 2 14.7 14.0 2*0 0 * * ll.ft 1)'* l.t 1) 1 1 0 .) 1 1 .) •2*4 0 * 10 21.1 21.9 -1.0 I ) * 9*4 10.4 -2*2 0 * 11 12.0 -4*0 1) 1 2 4.1 2 4 .9 O.ft 0 * 11 ft.* lolf -2*9 1J ft 4 .0 7 .ft 1 .0 a * n ll.ft I**? -0.9 11 7 19.7 1*0 0 * 1* 0.0 0.9 -0*0 14 1 1 .7 l.f t 1 .7 o i l *1.7 *9.4 -2*1 1* 2 10*2 10*9 - 1 .0 0 9 1 90.2 97.| . -9*1 I* 1 4 .4 ft*7 0 .9 0 1 ) **.7 44.1 -ft.l 1* * 2«ft 1.4 0*9 0 9 ft I?.* ll.ft -ft.O I* 9 4 .4 11.4 -9*2 0 9 1 )U? 19.9 •10.0 M t !? * • t)* 7 -1*1 0 9 * *1.7 *7.9 -ft.9 1 2 4 0.1 4 1 .4 -2 .9 0 9 7 ft. 7 O.ft 10.4 1 1 12*2 *9*4 1 .9 0 9 1 **.0 *4.9 -9.2 1 4 10.1 12.9 -10.4 0 9 * 21.7 27.* •9.1 1 9 79.9 19.9 •0 .4 0 9 10 14.9 19.4 •7.2 1 4 29.9 7 9.2 - 4 .9 0 9 11 71.4 20.7 2*9 1 7 2 0.4 2 J.1 Q.9 0 9 1? lu.ft 11.4 -1*7 1 • 1 4 .) 21.2 - 9 .* 0 9 1) 10.0 9.ft 0*2 1 4 4.4 ft.2 - 1 .9 0 9 1* l.ft * •9 -1*4 1 to 7 .ft f.ft •O.ft 0 ft 1 9.0 ft.2 -1*2 1 II 4. ft 9 .9 -0*2 0 ft 1 !•*» 11.9 2.4 13.1 1.9 t 1 12 10*4 0 ft ftj.ft *4.9 -1*0 1 1) 1 0 .ft 10.7 - 0 .4 0 ft * 20.7 19.7 2.2 1 1* ft.O ft.ft •O .ft 0 9 9 9ft.* ft).9 -*•9 1 19 1.4 11.3 -2*2 0 ft 9 9.11 ft.ft -2*1 2 2 rft.C 91,* -1*9 0 ft 7 II.0 JI.7 -0*4 2 1 77.4 44.4 10*4 0 ft ft *•2 4*1 0.1 2 4 1 ft.1 4J.C - 4 .4 0 9 f t 11.2 10.4 2.1 2 9 40.1 47 .ft 2*1 0 ft 10 tft.ft 17.? -1.9 2 4 4 ) .9 4 4.0 - l .f t 0 9 11 *.7 9*1 -O.ft 2 7 4 0.4 44*7 -7*2 0 ft t? ?.* t.f 0.2 2 ■ 14*9 1 4.7 0*9 0 ft 1) 9.* ft.* •1.0 2 9 1**1 1 7.7 •4 .9 0 7 1 29.9 JO.* -0.9 2 10 l*.T Jft.l 1.4 0 * 1 10.2 10.* -2.4 2 11 1 .) 1 .) • 0.0 0 7 1 F.ft ft.) -O.ft I 12 11.1 12*7 1*0 0 7 4 19.7 *1.4 -lO .f t 0 7 ? 2 11 M ,4 14.9 •0*4 21.) 7**0 -1.7 2 1* 4*1 4 .0 0 .1 0 7 f t 7.0 ft.) l.f I I 11**7 117.* 1.4 0 7 7 2ft.* 11.1 - 9 . 9 1 7 44.7 7 * . 4 9*1 ‘ 0 7 « 17.7 17.4 1.0 4ft.4 44*7 -0*4 0 7 ft 1**9 Ift.iJ 1.9 ) 4 O 7 10 1 * 14,4 2 7 .ft 4 .2 l.ft t.r -o.O 1 ft 17*1 21.1 -9*9 9 7 II ft.ft 7.7 2.9 Id . * 0.7 0 7 tl )•■ 2*2 1*0 ) T 10.4 ft ‘ 0 7 1) 1 9 19.4 !*.ft 9*9 10.7 9.4 1*9 ) • 19*4 14.4 0*9 351

TABLE hj- continued.

H K U P* “ /ft* H K t 1 % IQ l.ft ft.* •1 .2 1 » 11 11*1 1**7 •7*9 I J 17 a . 7 11.t •l.ft 1 ft II 11.0 11*4 •7 ,3 t ft I* to* * 11 a* “ l.ft 1 * 7 U i .4 «T.* 2.7 1 * » ift.t- 11.7 1.1 I 4 4 00*1 *1.0 7*9 1 » ft 2 * .I 7*.7 0*1 1 ft * 9**4 ft.ft 1 ft » 99.0 1 7 .f 0,1 1 ft 1 P . 1 12.7 r.ft 1 ft 9 14.! 1 M 1.9 I ft 1J /lift 71.7 “9.7 1 ft tl 4«; 4.4 “2.3 1 « IS tr* 7 lft.0 • 0.0 t ft t) 1 3*0 W .0 0.1 t ft U 1.1 4.2 -0 ,4 1 ft 7 *4.0 32.1 2.7 1 ft 1 'f.ft 14.1 •1*9 l i f t 11.9 47.4 •l.ft I 1 J 1ft.U M .l •0.1 ft).1 41.4 1 1 T 11.0 12.7 0.9 1 ft » Ift.ft 1’ . t 1.9 1 ft ft T.l i ,r “ 2.1 1 ft 10 11.9 I7.a 1*9 1 ft 11 ft.ft 4*1 1, 7 1 ft 1* ft.O *.7 0.9 i s n l .g 1.4 l.ft t ft i» 4.9 **1 “0.1 1 4 s 79.0 ?*.» -ft*0 i ft i *1.2 17.4 9*9 i « ft • ft.9 34.9 •D.O i - s 24*4 i t . 4 4.7 i ft ft 7.1 9.4 •9 .1 i « ft 24.1 24.7 0.2 I ft ft 2 « .1 ift.t- -0 .1 i ft • 29*11 I*.* •1*9 1 ft in 2**9 2*.« •0.1 i * a 9.7 7.7 • 1 .7 1 ft 11 l . l 13.0 •l.ft 1 ft t l 2.0 l.T 1.1 i i * *0.4 n . o 1.2 1 1 1 11.0 13.4 0.2 1 T 4 IV.t 71.1 •0,4 1 T « *•2 4.* “1,1 1 T ft 49.1 *4.4 •O.I 1 1 f 9.1 4.1 Uft 1 T 1 19.D 12.7 *,7 1 T ft 2*1 9.4 1-3 1 1 10 9.1 <•7 l.ft i » a ll.ft 17.1 7.0 1 T 12 *.9 ».? 2.7 i * n 4.9 4.7 •O .f i • i 19.4 Jft.o •0 .2 i • » 14»ft ?*•* 0.9 i ft * I ft. 2 17.0 •7 .9 i • i 2T.« 74.1 9*0 i ft #• Ift.ft 1b.1 •Q. 1 1 ft 7 tft.9 1*.7 0 .) 1 ft ft 14.2 17,1 t.ft 1 ft « 11.1 10." 0*ft t » Iff 1*.4 14.1 •o .a 1 « 11 9.9 4.2 • I. 1 1 9 12 ••0 • •9 1.9 t ft r 44.9 *7.4 •ft.ft I ft • 17.7 W .l 0.4 i « * 7*. 1 7*.* l.ft i ft ft Ift.ft H.ft •0.1 I ft ♦* 11*7 13,ft l . l 1 • » 7.7 l.ft 0*1 t ft ft 9.7 1*4 0.1 1 ft ft 22.4 21.2 1.3 1 ft la 7.1 4.9 3.9 1 ft 11 4*.* ll.ft 0*9 1 ft 12 •.ft "•ft 0.1 1 12 1 2.9 4.9 l . t 1 10 1 29.1 24.7 • l*ft 1 10 ft 4.4 O.ft 9.0 1 19 ft 27.4 29." -7 .1 1 U 4 9*9 *,ft 7.0 1 19 1 If.* 70,7 •1.1 1 13 * 9.9 *.T 1.0 1 » • It.* l/.O •O.ft 1 12 IJ i . g 9.7 •O .f 1 19 11 ft.4 l.ft 1*1 1 11 2 17.7 12.0 O.ft 1 11 9 73.0 7 »•> •l.ft 1 11 4 7.0 ft.O 0 ,2 9.4 •1*9 1 11 • 1.4 >.1 •1 .0 I 11 ft 1.1 ft.ft •1.1 1 11 * ft. 1 ♦ a •2*1 1 II " 1*.* INC -0 .9 1 II 10 7.4 : .t 1*9 t 11 2 •ft.ft 4.1 O.ft 1 17 » I4.J l».C 7*7 1 12 ft 14.0 14.7 0.0 1 12 1 17.7 l*.f •9*2 t 17 ft 14.7 14.* l.ft 1 17 7 11.4 11*4 • 1 .7 1 17 * *•1 •.0 0.2 I 12 * 4.1 4.* 1.2 I l» ? 1.4 7.fl 0.9 1 11 7 4.7 1 J.l *2.9 1 11 ft T.g .7 O.ft 1 11 • 1.7 ** 1*9 3 5 2

TABLE lfj-continued

H K L Pm F* *VCT H K L *i4r 7 n » 14*1 |7.l 3*1 i it t 4* 1 4*4 1*3 1 ii • |1»t lf«c •2*2 i n ? 2*P 4.0 •1*1 I tl Id 6# 4 4.) -1*1 1 If J 12*1 12.4 1.0 f II * 4.3 ».) 7*1 2 17 4 T*A 7*4 0*2 2 1 1 6 1.4 7.2 I I? I 4*7 4*3 4 II • 2*4 1.0 2*3 r it ’ M 4.7 -1.2 2 tJ 4 *.? 9*4 2 U 4 Il«> 17*1 -1.4 ill* 7*7 7*1 1*3 I D 1 4*2 0*4 2 1* 1 7*9 «.* -0.0 2 1 * * 2« 6 U? o.r 2 14 9 t.l 4*0 -4*3 1 1 ) 44*4 (•4*1 0*2 ) 1 * 2).7 2)*? -0.9 1 ) 9 4?*4 6)*? 4*4 ■ 1 6 42,2 49.7 1 ) 1 14*4 14*7 ) 5 ' 44. 1 *4 .6 1 ) 6 26. t 26*7 1 1 10 U,J 12*1 ill ) J 11 20*9 71.7 3 ’? II ti n n.« 0*4 ) 1 D 4*4 7.4 ) 1 1* .11*1 11.1 o!i 1 4 * 2 7.4 74.6 4*9 ) * 97*1 Jo.*. 1*1 9 4 * 72*9 24.4 9 4 ? 90.7 24*6 ill J 4 I*.? 1**3 -3*1 1 4 * 14.4 16*2 l.t 27.) J 4 11 14.2 l4«0 ’ 0*9 1 4 12 11*7 11*2 1*2 ) 4 u 17.? II.? 1*4 1 4 D I.P ».* -0.3 3 4 * 21.4 72*4 1*1 1 4 4 41.4 44*3 3*0 1 9 4 14.1 )4*7 4.0 13.1 11.4 -1*4 1 4 * 74.0 7**6 1.1 1 1 4 10.7 n*4 •0*3 1 4 10 U.6 • 2*1 1 4 It U.J ) 9 12 7*2 T.T -o n ) 9 1) 6.3 1*4 1*1 ) * 4 4 76.4 74.4 9*9 1 4 4 16*0 1I.U 4*1 1 k 1 13*9 |4.9 -1*1 3 6 ? 4.4 4.0 l.l 1 6 4 10.1 10*4 •0*9 3 4 6 32*0 2**0 •* 0 9 6 10 4*1 4 .) -0.* 1 111 11.* 2t*<* > 6 11 A. 7 6*7 0*0 4 4 n 7*6 4*4 1.4 1 T 4 49*1 47,9 0,? 1 1 9 24.9 33*1 •0.9 I t * 23*2 J * ▼ ) ? ? w!t ».T 4.9 ) 7 * 12.2 11*1 •2.3 1 7 6 4*0 6.7 0*9 I T 10 1*.T 17.6 1*0 ) 7 11 6.1 1*1 0.9 1 ? tl 10*1 4.3 0.9 1 T tl 6.0 4*4 0.2 29*6 2*4 1 9 * 24.2 ... 1 1 9 46. 6 6)« 1 7* If 1 4 * 19.6 13*1 1.3 1 1 ? I7*« 72*7 0.9 t • « 4*0 3.1 0*9 1 4 • 13.0 14*1 -1.6 3 * 10 1.4 1*0 0.6 3 * 11 13*4 14*» -1.* 3 9 12 I*? 3*6 2*4 1 6 4 71*4 21*0 •3.2 3 4 9 6.7 6*3 4.6 1 9 4 7*1 0.1 1 4 T *■•7 tl? -1.9 w ~ — 4.2 4*1 0.2 3 4 4 r.t 7.4 O.f » 4 10 4*6 1*1 I * 11 7*7 «*2 -2.1 ) 10 * 17*1 3.4 1 10 4 t i l l 17*3 2.4 i n * 1.4 7*9 1.4 1 10 7 27.4 22.) 1*0 ) 13 • 6*7 f*> • l . l 1 10 4 17*0 17.4 0*2 1 13 10 4*1 4.1 •0*1 111* n .4 It #4 •2.0 1 U 1 11*7 U.9 2.4 i* 11tl 6& 1*1 1*2 1 II » f i t 7*4 •7*1 1 11 • 0*4 ) 11 * «#V * .* •1*0 1 12 * * 1 3.0 tl *7 ? 12 4 4*“ I.* • i l l 3 II * 4.2 4*4 •1*0 1 12 ? 1U) 11*4 -0*0 3 12 « 4*» 3*7 1*1 V ^ * U.o , 7*1 1*2 3 5 3 TABLE ^ c o n tin u e d

■ f f K L »». F. * /< r to t 1 2*1 I I . 1 2 .4 ft 10 t M l . f t 2 *0 ft 10 • • » t * 0 .4 ■ 10 10 " * ft 4 .2 1 *4 • I t ft ft. 5 1 0 .1 * 1 . 4 ft II 7 4*1 4 .4 7 .4 ft II ft 11*4 1 1 .7 • 2 . 4 ft I t ft ft* 1 '• 1 0 *0 * 1? ft 4 *7 ft.ft ■ 0 .4 * ft ft 1 4 *4 1 .4 * ft T 4 ,7 i j . » * 4 * 0 1 ft * 2 4 . * 7 4 .0 4 ft 4 ft* i 4 ft 10 • * I 4*1 o i l 4 ft 11 * « f 4 *2 0 .0 » ft I f 4 .T *» ft ! • ■ ft T 7 W . l 1 7 *4 1 *2 ft T • :?** If t. f t ft.ft ft T • I2 « ft 1 7 . 1 1 .4 ft T 13 1 7 .2 1 7 .4 0 .0 A t 11 ft* f 7 .4 1 ,1 ft AT IJ.OIJ.) ■ 0 *4 ft 1 4 2 4 .4 2% .ft 1 *2 ft ft ft r.fc ft.ft l . f t ft ft 10 t i « ) l l . f t * 0 . 4 ft • 11 ft.O r . f t 4 .1 ft ft r ft.O • ■ ft l . f t ft ft ft ft.O i* , f 0 * 0 ft ft ft ft.ft f . f t O .ft ft « 10 7 . ) * * ft 1 .0 ft 13 1 1 0 .4 la . f t • 0 * ft ft ta • 1 0 .1 1 ,* 7 *2 ft 13 ft 4*1 4 * 0 4 .1 ft 11 t 4 *4 f t * t O .ft ft 11 ft 2 *7 l. O 1 *4 ft I f ft 1 .1 ft.ft 0 .7 7 7 T ll* « 2 7 . t 1 .4 7 t ft 1 1 .7 Id** O . f 7 7 4 1 ll. f t Ift.ft - 0 . 0 7 7 in ft.ft 4 * 2 9 .2 T 7 11 ft.2 b .r - 1 . 0 t r ft l l . f t I * . I 1 .4 T ft • 4 .6 T#Q 1 .4 ? • I J 10.4 4 *7 l.ft 7 ft ft l?*l 1 7 *4 4 .4 7 ft • 1 7 *4 1 2 *1 0.1 ? 10 • ft.O 4 * 0 0 ,2 t ■ ft 2 1 .4 2 4 *4 •4 * 0 ft t 4 ft.O 7 .4 4 .0

*K). 4*4 «!¥• nr TABLE

FINAL POSITIONAL AND THERMAL PARAMETERS FOR [Ni(tep){NO)]BF* B,bjC

Atom P n or B pancym- 022 033 012 013 023

Ni .01^57(1) X X 1 .00650(8) 011 011 .00007(8) 013 012 N .1126(6) X X 1 ,0080(!*) 011 011 -.0016(5) 012 012 0 .2618(7) X 1 . 0138 (6 ) 011 011 -. 0017(7) Pla, ^ 0 !2 , . P .0969(a) *.0171(2) -.0957(2) 1 . 0070( 1 ) . 0070(2 ) .0070(2) .0006(1) . 0013(1 ) -.0002(1 ) Cl -.0969(7) X X 1 . 00711( 5 ) . 011 011 -.0002(6) 012 0 1 2 C2 -.161*8 9) X X 1 . 0105(7 ) 011 011 -. OOlUtT) 012. , 0 1 2 . C5 .0022(9) -. 0938 ( 1 0 ) -.11*93(9) 1 . 0107(8 ). 0097 (8 ) .0096(8) 00ih(8) .0017(7) -. 0028(7) Cl* • . 1326(9 ) . 0721(8 ) -.1877(7) 1 . 0115(9 ) . 0096 (8 ) .0069(6) -. 0001(7 ) .0027(6) . 0002(6 ) C5 .1770(13) . 031*9 (1 1 ) -. 2 8 6 7 (1 0 ) 1 . 0192 (1 6 ) . 0122(1 1 ) . 0118 (1 0 ) 0023(1 2 ) 0069(1) -.0010(l0) C6 . 2030(9 ) -. 09101 ( 1 0 ) -. 0918 (9 ) 1 . 0113(9 ) . 0125(1 0 ) . 0091 (8 ) . 0038 (9 ) .0019(8) .0002(9) C7 .2935(10) -. 0380 (1 6 ) -. 0563(1 3 ) 1 . 0090 (9 ) • 022!*(20) . 0182 (1 6 ) . 0039 (1 2 ) ,0017(11) -.0051(18 )

I .40»f(l) X X . 07 0 (9 ) l*. 0(6) B . . 3 8 9 (2 ) X X .930 1*. 8(10) F1A . 3 5 7 (5 ) X X .1*17(21*) 23-0(20) F2A . 3 5 6 (2 ) . 1* 10 (3 ) . 1*8 0 (2 ) .1*17 13. **(5) FIB . 1*14.7 (1*) X X .513(21) 23*0 F2B . 3^6 (2 ). 31* 1 (2 ) • ldSl*(2) .513 13. ^ 1 0

ro 7-0 H2 -.171 - .1 3 5 V* 1 (not refined^ Calculated Methylene hy H31 .0287 -,1 6 2 1 -.1516 1 8 .1 H32 -.0089 -. 0696 -.2176 1 8.1 HUl .1827 .1159 -. 1569 1 6.8 tf*2 .0T2T .1 1 1 1 -.201*1 1 6.8 H6l .2151 -. 1 2 1 0 -.1592 1 8.5 H62 .1899 1500 -.01*57 1 8.5

The numbers in parentheses refer to the estimated standard deviations in the least significant digits as derived from the variance - covariance matrix. The temperature factor is of the form expf-tPijh2 + +• 033i2 + 20iahk + 20i3h£ + 2023^)]. Calculated assuming H-C-H= 109*7° and C-H= 1.0a and Csv local symmetry at carbon. The isotropic temperature factors are approximately the same as those of the corresponding carbon atoms before anisotropic refinement. TABLE 45

VARIOUS STAGES IN THE REFINEMENT OP [N i(tep)(N O )]BF 4

NC NO NV R Rw RwPre Comments

2 2 0 6 5 2 2 28.37 34.34 Atoms from Patterson solution. Includes Ni, N, 0, Cl, P, and B.

4 1 9 0 8 1 0 0 12.4 1 5 .6 (BF4)A as anion. Only planes with F 2 > 2 ^(F2) used. 3 2 0 6 5 1 0 1 1 3 . 1 1 3 .8 13.4 Only Ni aniso, axial fluorine FR(x= .46) substituted for Fa(x= . 3 3 ).

2 2065 46 14.9 19.0 18.9 BF4 group replaced by iodine. Occ(l)= .107.

2 2 0 3 5 47 14.07 1 6 .4 1 Both (bf4)a and iodine included. Cfccupancy (iodine) re fin e d to . O5 9 . Isotropic B for boron = 1.99 A2. 5 1925 50 1 0 .6 6 1 2 .2 1 No iodine included. Both (BFa)a and (BF^L refined (but only one boron atom). Only planes with F2 > 0. 5 cr(P2 ) used. 2 1925 5 0 1 0 .5 8 12.13 Preceding model after absorption correction. 3 599 5 0 10.73 1 1 .6 1 Preceding model after averaging equivalent reflections. Only p la n e s G. T. 1 .4 t* 687 84 8 . 0 4 9 . 2 0 All non-hydrogen and non-anion atoms refined anisotropically. 3 6 7 6 78 8 .8 0 3 10.44 Two r ig id EF4 groups of fixed occupancy 0. 50. No iodine. Constrained temperature factors for 1 'equivalent' anion atoms. 5 6 8 5 83 7.427 8 .2 1 3 Non rigid isotropic refinement of equal quantities of ; (BF4 )a and (BF4)g with 5$ iodine. TABLE lj-5 ~ continued

NC NO NV R Rw RwPre Comments

3 685 82 8 . O3O 9.236 Rigid dynamically disordered isotropic BF 4 groups ( ” t ilt e d model11 )s with 5$ iodine. k 681+ 87 7.O36 7.905 Isotrop ic refinement o f anion with the Lagrange condition for occupancy factors. .

Vrt \_n 0\ IV. DISCUSSION OP THE STRUCTURE OF N l[(tep)(N O )]B F 4

A. Crystal packing

The crystal packing diagram is presented in Figure XLJCV.

[Ni(tep)(NO)]BF 4 crystallizes as discrete, we11-separated [Ni(tep)(NO)] cations and disordered BF 4 anions. In the present data crystal, partial isomorphous replacement of the tetrafluoroborate group by iodide ion . was also found. The large nearly spherical cation is centered very close to the origin of the unit cell and the smaller, symmetric anion lies near (l/2, l/2 , 1/ 2 ). As may be seen by comparison of the packing diagram with Figure LVI, this arrangement very loosely approximates the sodium chloride face-centered lattice, with the cations occupying the corners and faces of the cube and the anion lying at the center and half-way along the edges of the cube.

OCati on

® Anion

Figure LVI . The sodium chloride lattice.

The sodium chloride structure normally occurs in binary ionic crystals when the radius ratio of the cation and anion lies between .Ij-llf and

35T Figure LV. The Crystal Packing Diagram for [Ni(tep)(NO)]BF4 . Dashed lines indicate threefold axes inclined at k5°. 3 5 9

• 732. 5 9 Assuming an approximate 1'ionic radius*' for the cation as

5 . 0 A (about half the distance between the carbon 2 and oxygen atoms) and a radius for the tetrafluoroborate anion as about 2.0 A (about

2.5 A for iodine), the cation:anion radius ratio is seen to be in the required range. Since the ions are not hard spheres, however, there is somewhat more unoccupied space than in simple binary salts. This factor could favor the observed disorder in the anion.

The cations and anions appear to be separated by normal

Van der Waals forces (Table ^ 6 ). Thus, the shortest interatomic distance between different cations is 2.88 A (H2 - H^2), whereas the closest cation-anion contact is 2. k6($)h (F^^-Hte). There are no vectors less than 0 a between atoms in different anions.

B. The geometry in the fNi(tep)NO)l+ cation

Interatomic distances and angles for the [Ni(tep)(NO)] cation are presented in Table kj . Perspective views of the cation are found in Figures LVH and LVHL Root-mean-square amplitudes of vibration are found in Table k9 ■ All the atoms in the Ni-N-0 linkage are required by space-group symmetry to lie on the threefold axis (site symmetry 3 ). Therefore, the

Ni-N-0 linkage is crystallographically required to be linear. The possibility of dynamic disordering of the nitrosyl group 3 3 was seriously considered since the thermal vibration of the oxygen atom is somewhat 360

TABLE U6

INTERMOLECULAR DISTANCES LESS THAN 3 . 7A BETWEEN THE

[N i(te p )(N 0 )]+ CATION AND THE DISORDERED ANION1

D ista n c e D ista n c e A

2. 5 l(k ) I-Hll-2 3*573(3) FA off"H52 I-H 32 3 .6 o i (^) FA off-H52 2 .7 7 (3 ) 3 .1 1 (3 ) B-H31 3*3^(2) ^ o f f ' 1* 2 B-H62 3*5^(3) 3*28(3) B-rfj-2 3*5 5 ( l) w 1* 2 B-H32 3 . 6 7 ( 1 ) W 0? 3 .^ 5 0 0 3*50(3) 3 . 0 8 (3 ) FA o ff"G5 3*6l(ij.) FA off"H62 W 1852 3 -1 8 (5 ) F. -H 6l 3 -3 7 (1 0 ) FA o ff“C3 3*67(3) Aon 3*69(3) F a -Ift.2 3 . 6 3 (3 ) FA off"H62 Aon 3 . 6 0 ( 1 ) FBon“H52

. FB o ff”H^2 2. ^6 (3 ) 2. 51(2) FB o ff-H51 2 .6 6 (3 ) FB o ff"H62 2. 8 2 (2) FB off~H2 W ^ 2 3*05(2) W* 3*30 (3) 3*37(2) FB o ff"H51 FB o ff“C5 3**H(3) FBoiT‘ C2 3*1«-8(3) FB o ff-C5 3*50(2) FB o ff-C6 3* 52(3) FB o ff"H61 3* 5M 3) 3*69(2) FB o ff"C2 a) Excluding possible vectors to methyl hydrogen atoms on C5 and C7* 361

TABLE l|-7

INTRAMOLECULAR DISTANCES AND ANGLES IN THE [N i(te p )(N O )]+ CATION

D ista n c e Angle A Depcrees Ni-N 1 .5 8 2 (ill-) N i-N -0 1 8 0 . 0 0 N i-P 2 .2 2 3 (3 ) N-Ni-P 1 2 2 . 8 ( 1 ) N-0 1.1 6 2 (1 7 ) P -N i-P 93- M l) P-C3 1 .8 1 ( l ) Ni-P-C3 1 1 0 . M ^) p-cit 1 .8 1 ( l ) N i-P-C^ 115- 2 (4 ) P-C5 1.79 ( l ) N1-P-C6 1 1 7 .1 (4 ) C1-C2 1.56 (3) C3-P-dt- 102. 7 (5 ) C1-C3 1 .5 ^ ( l ) C3 -P-C6 1 0 6 .9 (5 ) Ck-C5 1.56 ( 2 ) C4-P-C6 101. 5 (6 ) C6-C7 1.59 ( 2 ) C2-C1-C3 1 0 6 .5 (7 ) C1-C3-P 118 . 8 (9 ) C3-C1-C3 112-3(7) p-cii--C5 106. l(lf) P-C6-C7 115. 2 ( 8 )

Atom A______Atom B______A

Ni N 1.591 1^) Ni P 2.25 (3) N 0 1. 1 6 3 ( 1 9 ) P 03 1.82 ( l ) P. <& 1.82 ( l ) P c6 1.80 ( l ) Cl C2 1.56 ( 3 ) C* C5 1.5.7 (2) C6 C7 1.61 ( 2 )

a) Distances corrected for 1 * riding’' motion. Atom B rides on atom A. 362

112*3(7) t* 54(l)jfc| 03 102*7(5) I08*S(5> 07 (0) iie^jC 115-2(4) l*8((l) 117*1(4) 0 6 101*5 (S) 07

C4 ;*223(3) C6 04 1*56 C2) 07 C5

06 04 106*1(4) 05

Figure T.yTT. View of the [Ni(tep)(N0)]+ cation normal to threefold axis. 36? C5

C 3

C 3 07 C 4

06 0 3 05

04 06

05 07

i Figure LVIII. View of [Ni(tep)No] down the threefold axis. TABLE U8 INTERATOMIC DISTANCES LESS THAN k.OA BETWEEN ATOtE IN DIFFERENT [N i(te p )(N O )]+ CATIONS

D istan c e A D istan c e A

0-H61 3 . 0 1 ( 1 ) H31-H62 3-38l|- 0-C5 3 . 5^ ( 2 ) H3 1 -H^2 3-917 H31-H61 3.9U8

H2"H^2 2 .8 7 7 H32-H62 3 .8 1 8 H2-Hlt-1 3 .2 1 2 H3 2 -C7 3 .8 9 0 H2-C5 3 . 30^ H2-C1+ 3 .3 1 1 H^l-C5 3.305 H2-H62 3 .6 3 1 H ifl-H la 3.3 5 6 H2-H1J-1 3 .7 3 6 H la-C2 3 .8 6 3 H2-H1J-2 3 .8 2 3 H^2-C2 3* T57 Hlt2 -H31 3-917

H61-H61 3 .8 1 6 h 6 i - o 3 .9 0 0 9

a) There are no interatomic distances less than k. Oa between atoms in different anions. b) Excluding possible vectors to methyl hydrogen atoms on C5 and C7« 365

TABLE k-9 SELECTED NONBONDED INTERATOMIC DISTANCES WITHIN

THE [Ni(tep)(NO)]+ CATIONS^

Intramolecular Vectors Intramolecular Vectors O D ista n c e A D ista n c e A

NI-C3 3 0 2 ( l ) Cl*-C 6 2 .7 9 (2 ) N i-C l 3 . ^ 1 ( 2 ) C^-C7 3 .2 5 (2 ) N i-0 2 . 7^ ( 2 ) Ni-(& 3 - li-l(l) C5-Hlfl 2 .0 9 (1 ) N i-c6 3- ^ 3 ( l) C5-H61 2 .7 9 (2 ) C5-C6 3 .2 1 (2 ) P-H61 2. 313(3) C5-C7 3 .6 9 (2 ) P-H ^l 2- 31^(3 P-H31 2 .3 1^(3) C6 -H3 I 2 .6 8 (1 ) P-C7 2 . 8 2 ( 1 ) P -C l 2 .8 9 ( l) C7-H61 2 . 1 3 (2 ) P-C5 2 . 9 l ( l ) C7-H62 2 . 1 3 (2 ) P-P 3 .2 3 5 (5 ) P-N 3- 3 5 ( l) H2-H2 1 . 6 1 1 P-C3 3-3T 1 P-C3 3. ^ 3 ( l) H31-H32 2 . ^ 8 0 , I .6 3 3 H31-H61 2.605 C1-H31 2 . 0 7 0 H31-H62 2 . 6 3 ^ C1-H2 2.101* H3 2 “H^ 2 2 .7 1 0 C2-H1J-2 3 .7 6 ( l) C2-C3 2 .14-8(2) H^2-H62 2 . 076

C3 -C3 2 . 5 6 (2 C3-H2 2.65(1), 2.67(l) C3 -H3 I 2 .6 9 ( l) C3-H32 2.7^(1) C3 -C6 2 . 8 5 ( 2 ) C3 -C»f 2 .9 2 (2 ) C3 -C5 3 .5 0 (2 ) a) There are no intermolecular anlon-anion vectors less than k*QA. b) Excluding possible vectors to methyl hydrogen atoms on C5 and C7» 366

TABLE 50

R00T-MEAN-SQUAR3 AMPLITUDES OP VIBRATION FOR [N i(te p )(N O )]*

Atom Component along principal axesa (A) Minimum3 Medium Maximum0

Ni . 2* 6 (2 ) - . 2 5 0 (11.)

N . 2 1 (2 ) ** . 3 0 ( 1 )

0 0 . 3 1 (2 ) - . 3 8 ( 1 )

P . 2 2 8 (3 ) . 2 6 0 (3 ) . 2 8 1 (3 )

C l . 2 6 (3 ) - . 2 7 ( 1 )

C2 . 2 7 (3 ) - . 3 3 (2 )

C3 . 2 5 ( 1 ) . 2 9 ( 1 ) . 3 6 ( 1 )

c* . 2 3 ( 1 ) . 3 0 ( 1 ) . 3 5 ( 1 )

C5 . 2 7 ( 1 ) • 5 3 (2 ) . 11.7 (2 )

c6 . 2 6 (2 ) . 3 0 (2 ) . 3 9 (2 )

07 . 2 7 ( 1 ) . 3 9 (2 ) . 11-9 (2 )

a) Only non-hydrogen atoms in the cation were anisotropic. Symmetry restricts the vibrational ellipsoids of atoms on the threefold axis to be ellipsoids of revolution. b) In all cases this gave the component -parallel to the threefold axis for symmetry-constrained atoms. c) In all cases this gave the component normal to the threefold axis for symmetry-constrained atoms. higher than that of the coordinated nitrogen atom. This type of disorder would take the form of a bent Ni-N-0 linkage undergoing free or hindered rotation about the threefold axis. However, the magnitude of a possible ''bending*' of the Ni-N-0 linkage was considered minor for the following reasons, l) Electron-density maps at various stages in the refinement revealed no features which would suggest a dynamically disordered nitrosyl group (e.g. a doughnut-shaped ring of residual electron density centered about the threefold axis in the vicinity of the nitrosyl group). 2 ) The root-mean square amplitudes of vibration for N (.JO(i)a) and 0 ( . 3 8 ( 1 )!) normal to the threefold axis are reasonable for N-bonded nitrosyl groups. A value for a possible bent

Ni-N-0 bond was calculated by fixing the nitrogen on the threefold and permitting oxygen its maximum amplitude of vibration normal to the threefold axis, the value obtained being only about 18°. This should be a very pessimistic estimate of the deviations from linearity however, since it is more likely that N and 0 would vibrate in concert in the same direction normal to the threefold axis. With the latter assumption the maximum bending of the M-N-0 angle would be about I)-0.

The disordered anion unfortunately seemed to show some correlation with the coordinates of the nitrogen, thus, diminishing the accuracy of the bonds to nitrogen. Since the Ni-N and N-0 distances varied between 1. 58 - 1 .6 3 ° and 1. l4-l. 18 A with the various anion and weighting models, the standard deviations on the Ni-N and N-0 distances 368

may be somewhat underestimated. Even w ith th is q u a lific a tio n , the

Ni-NO d istan ce, 1. 58(l)A , i s very short when compared to other f i r s t -

row metal-nitrosyl distances, which usually fa ll in the range 1.70-

1. 8Qa.5,3S Short M-NO distances include 1.686(?) in the pseudo-tetra hedral [Ni(N3)(N0)(P(CeH5)3)2] ,3 1.68(2) in [ n-(CsHs)Ni(N0)],7 1.63(2)

in [ n-CCsHs)Cr(N0)Ntfe2] 2 and 1.66 in [ ( Jt-C5H5)Cr(N0)sCQHs] 2. 62 The

shortest metal-nitrosyl distance thus far reported is 1.57 A in

Cs[Fe4(N0)7S3]*H20.5 The shortness of the Ni-NO bond in [Ni(tep)(N0)]+

is consistent with a large amount of multiple bond character in the Ni-

NO linkage and is indicative of a formally N0+ ligand. 1,39,04

The N-0 distance found in the present study, 1.l£2(l7)A, lies

in the range 1. lk-l. 18 A usually found for coordinated nitrosyl g ro u p s . 5 ’ 38 The N-0 length however, does not appear to be a very good

indication of the oxidation state of the ligand. 3 ,5 ,3 0 ,5 8 I n o th e r

nickel complexes N-0 distances have been found to be 1. l 6lf-(8 )A i n

[N i(N 3 )(NO)(p(ceHs )3 )2 ] 3 and 1. 1 8 (2 ) i n [ ( it-C5Hs )N i(N 0 ) ] . 7 The normalcy

of the N-0 bond is further evidence that disorder of the nitrosyl group

is not an important feature of the structure, since the apparent N-0

distance would be quite sensitive to bending of the Ni-N-0 linkage.

The geometry about nickel is best described as distorted tetra

hedral, as the N-Ni-P angle is 122. 8 l ( 8 ) and the P-Ni-P angle is

93. ^(l)« The deviations from tetrahedral angles at the metal appear to derive from strain within the ligand when a ll three phosphorous donors 369

are coordinated. With only one methylene group between the apical carbon atom Cl and the phosphorous atoms, coordination of a ll three donors to tetrahedral nickel with normal Ni-P distances would require an unreasonable opening of the C1-C3”P angle. Indeed, the observed

C1-C3-P angle is 118. 8(9 ) ° 5 much greater than the usual tetrahedral angle about tetra-substituted carbon. The C 3 -CI-C 3 , 112.3(7)° is also slightly greater than the ideal value of 109 . 5°*

It is interesting to note, however, that the observed angles at nickel would be nearly ideal for maximum overlap of vacant phosphorous d-orbitals with filled metal d-orbitals or lobes of the Ni-P bonding

(or anti-bonding) orbitals, if nickel uses nearly pure p-orbitals in its sigma-bonds with phosphorous (Figure IHX). In terms of the orient ation of the bonds with respect to filled metal d-orbitals, the angles at nickel would also be favorable for backbonding from nickel to n# orbitals on the nitrosyl group. The N-Ni-P angle of 122. 8 (l)° maybe compared to the angle between the edges and the diagonal of a cube

(125.27) and the P-Nl-P angle of 93.4(l)° may be compared to the right angle between pure p-orbitals. The pseudotetrahedral geometry at nickel, coupled with the diamagnetism of the complex, strongly favor the formu lation of the metal as Ni(o) and the nitrosyl group as N0+.

The nickel-phosphorous distance in [Ni(tep)(N 0 )]+, 2.211(4) A> is reasonable when compared to sim ilar distances in other alkyl phosphine complexes. Thus, Ni-P distances have been found to be 2. 3 1 5 ( 8 ) A in O p

t / i dxe.

Figure LIX. Approximate orbital orientation about the metal in [Ni(tep)(NO)]+. 3T1

trans-[M i(P(c 2H5 )3 )aBr2 ] , 53 2 . 2 6 5 (5 ) and 2.275(5) A in trans-fNl-

(p (c QH5 )(CH3 )2 )2Bra ] , 54 2.206(8) A in [Ni(TAP)CN]+ (TAP= P(CH 2 CH2 CH2-

As(CH3)2)3),ss and 2.19 A (equatorial P) and 2.15 A (axial P) in the • trigonal bipyramidal [Ni(p(0CH 3 )(CH2)2)5]2+. Other Ni-P distances include 2.225 A in [N i(P(caHs) (CH3 )2 )3 (CN)2 ] , 54 2.120(9) A in

[Ni(DSP)l2] (DSP=(o-C 6H4SCH3 )2P(C6H5 )2 i SB 2. 115( 7 ) A i n [Ni(TSP)ci]+

(TSP= (o-CsH4SCH3 )3P ) , 60 2 .2 8 9 , 2. 205, and 2.189 A in [NifPCCeHs)-

(0C2H5 )2 )3 (CN)2] ,6;L 2.177(5) in [Ni(SeP)2] (SeP=o-SeCsH 4P (cQH5 )2 ), and

2.257(2) and 2.506(2) A in [Ni(N 3 )(N0 ) (p ( c QH5 )3 )]. The stun o f th e co valent radii for nickel and phosphorous is 2.28A ,.33 The Ni-P distance in the [Ni(tep)(N0)] cation is only slightly shorter than this sum and thus, a large amount of Ni-P multiple bonding is not indicated.

Perhaps one might have expected a somewhat longer N i(o)-P bond in the present case than for the N i(ll)-P bonds mentioned above because of the charge on the metal. However, no apparent difference was found for the N i(ll)-P distance (2.251(3)) A'and the N i(lll)-P distances (2. 265(5 ) and 2.273(3) A) in [NiBr 3 (p (c aH5 )(CH3)2)2] • 0. 5[N iB r2 (p (c 6H5 )(CH3 )2 )23 , which contains nickel atoms in both the 2 + and 5 + oxidation state . 54

The three independent P-C distances.are not significantly different from their mean length 1.80(l) A and agree well with previous

P-C determinations. For example, phosphorous-alkyl carbon distances have 372

been found to be 1.800-1. 826 A i n [N iB r 3 (p (c 6H5 )(CH3 )2 )2;]* 0. 5[NiBr2-

(p(CqHs)(cH 3 ) 2 ) 2 ] , 44 1. 7 86 - 1. 82 & in [Ni(p(CeH 5 ) (ch 3 )2 )2 (c n ) 2 ] , 47 and

1 .8 1 5 -1 .819A i n c is - [ P d (P ( c 6H5 )(CH3 )2 )2Cl2 ] . 35

The angles at phosphorous in [Ni(tep)(no)]+ are consistent with a steric repulsion by ethyl groups on adjacent phosphorous atoms, resulting in a bending back of ethyl groups on each of the phosphorous atoms. Thus, the Ni-P-C4 and Ni-P-c 6 angles are 115- 2(^)° and 117. l(*f)° respectively. In contrast the C&-F-C3, C 6 -P-C3, and Cl|--P-C 6 angles are compressed from a tetrahedral angle to 1 02. 7 ( 5 ) °, 106. 9 ( 5 )°> and

1 0 1 .5 (6 )°, respectively. Despite the apparent steric strain in the small bicyclic cage (as implied by the distorted bond angles at Ni, Cl, and 03)9 the value of the Ni-P-C 3 angle is surprisingly close to tetra hedral (llO.4(lj.)0). The range of bond angles at phosphorous, 101.5(6)° t o 117. l(^)°, is comparable to that found in other phosphine com plexes . 35 ’ 443 47 The Ni-P-C3-Cl sequence of atoms is nearly planar. Thus, the dihedral angle between the plane containing Ni, P, Cl and the plane

containing Ni, C3, Cl is only 2.7(5 )°* The near-planarity of the

Ni-F-C3-Cl fragment is consistent with steric strain caused by a combination of the small size of the bicyclic cage and the geometric requirements of the metal atom. 373

The four independent carbon-carbon distances range from

1. 5l+(l) for C1-C3 to 1. 59 (2 ) for C6-CT. The individual vaines are not significantly different from their mean value 1. 56^ ( 2 0 ), which is a normal distance for carbon-carbon single bonds.01 The bond angles at

C& and c6, 106. l(l |-) 0 and 115* 2 ( 8 )°, respectively do differ significantly from an ideal tetrahedral angle but the amount of distortion is not major. As may be seen in Figures LVIEand LV3II, the ethyl groups are staggered in a way which would minimize ethy 1-ethyl. steric interaction.

C. The geometry in the disordered anion

The anion appeared to exhibit both occupational disorder between the tetrafluoroborate and iodine ions and a static disorder involving two orientations of the tetrafluoroborate group (Figure IX ). The geometry of the fluorine atoms about iodine and the 7$ occupancy factor for iodine would logically suggest that this atom is in fact boron.

However, extensive refinements using the iodine scattering factor curve and 5-10^ occupancy for this atom were definitely superior to refine ments using the boron scattering factor curve and half* or fu ll occupancy for the atom (see Section III). It should be noted that inclusion of iodine for boron also involved a corresponding removal of fluorine atoms and thus the effect of exchanging I for B would not be restricted to the center of the'anion. 3 7 h

95(2)117(2)

.96(3)

Figure LX . The disordered anion viewed normal and parallel to the threefold axis. 375

TABLE 51

INTRAMOLECULAR DISTANCES AND ANGLES IN THE DISORDERED ANION8,

D istance k Angle Degrees

B-Fa 0 .7 6 (1 2 ) Aon FAon "B~FAoff 117(2)

l.l+ 0 (9 ) 101(3) . B- FBon FAoff"B“FAoff

1 .3 5 (4 ) B"FAoff FBon "B~FBoff 9 5 (2 )

B“FBoff 1 .3 4 (3 ) FBoff"B“FBoff 1 1 9 .3 (7 )

B-I 0. 3 6 ( 5 ) FAoff“I~FAoff

l . l ( l ) Aon W ^ A o f f 102(2)

I-F 1. 0 3 ( 8 ) 1 1 6 (2 ) x Bon FAoff"I_FAoff

I-F 1 .2 3 (4 ) A off FBoff~I’FBoff 110(2)

I-F 1 .4 2 (3 ) B off FBoff“I”FBoff 109(2) a) The occupancies of (BF4)a, (BF*)^, and I are .1+12(8), . 517(7)j

and . 0 7 1 (3 ), respectively. 3*76

Elemental analysis on the gross sample from which the data crystal was selected indicated h 2 mole $ presence of the iodide ion as the anion. This measurement, however, gives no check as to whether co-crystallization with iodine and tetrafluorohorate anions occurred in individual crystals (including the data crystal). A check upon the iodine composition in the data crystal independent of the X-ray results would have to be performed by a m icro-analytical technique (such as flame-ionization spectroscopy or nephelometry) on the actual data crystal.

The two tetrafluoroborate groups differ by the orientation of the 1'axial'' fluorine atom along the threefold axis. The two BP. 4 groups are twisted relative to each other by a 2 8 (2 )° rotation about the threefold axis so that the closest intermolecular P-F distance i s . 9 6 (3 ) A- With the exception of all the B-F distances and

F-B-F angles are comparable to previous determinations of the tetra fluoroborate anion geometry.20 24 The short distance was a persistent anomaly throughout the structure refinement and undoubtedly is related to the overall anion disorder.

In short, the disorder in the anion has not been completely described by the final model. Of the numerous models examined, however, it is believed that the final model is the most descriptive of the true disorder. The relatively low R-factors and the flatness of the final difference electron density map indicate that the main disorder features have been accounted for. Since the anion was of interest * f

377

in the structure only in its effects upon the accuracy of geometry in the cation, the refinement was terminated with this model.

o 0

V. CONCLUSIONS

Three features of the structure of the [Ni(tep)(N0)]+ cation distinctly suggest that the metal should be considered as zero valent

-j and the nitrosyl ligand as NO . These features are l) the pseudotetrahedral geometry about nickel, 2.) the linear Ni-N-0 linkage, and

3 ) the short Ni-N distance. Thus, the Intense red color of the cation may be assigned to charge transfer transitions of the nitrosyl-metal ty p e .

Manoharan and Gray ®0 have presented molecular orbital calculations which indicate that metal 3^ orbitals and the rr and n# • orbitals of a nitrosyl group are very close in energy. Mingos and

I b e rs 4,a9 have applied these observations in a qualitative manner to predict that a m etal-nitrosyl moiety is favored (in the formal sense) 11+ + as M - NO when the metal is in a high oxidation state or when there is extensive n-bonding between the metal and the nitrosyl ligand. The case of [Ni (tep) (NO) ]+ would seem to fit the latter category. It should, also be noted that the sim ilarity in the energies of the metal and nitrosyl ji-orbitals would certainly facilitate charge-transfer inter a c tio n s .

Enemark on the other hand has emphasized symmetry arguments in explaining the linearity and non-linearity of coordinated nitrosyl g ro u p s . 3 According to his arguments, a non-linear M-N-0 linkage w ill result whenever the gross symmetry of the complex is less than C 3 and

578 rc-interactions "between the metal and ligand are significant. In this case the two orbitals of the nitrosyl group are no longer degenerate and interact with the metal d-orbitals differently, resulting in a * *bent* * M-N-0 linkage. Enemarkrs arguments would seem to apply to the case of [Ni(tep)(NO)]+ since both the free tep ligand and the complex possess C3 symmetry. At least one previous case has been described in which a nickel complex is deeply colored even though the metal is probably best described as zerovalent.65 Thus,

Gosser and Tolman have synthesized and chemically characterized a deep red presumably three-coordinate phosphite complex of composition

{Ni[P(o-0CeH4CH3)3]3}. The analogous U:1 complex with the same ligand is 1' off-white* ’ in color. VI. REFERENCES

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If2. J . A .J. J a r v i s , R.H. B. M ais, and P. G. O uston, J . Chem. Soc. (a ), 1473 (1968).

4 3 . V. Scatturin and A. Turco, J. Inorg. Nucl. Chem., 8, 447 (1957)*

44. J.K. Stalick and J.A. Ibers, Inorg. Chem., 2 j ^53 (l970)*

45. D. L. Stevenson and L. P. Dahl, J. Am. Chem. Soc. ,82, 3424 ( 1 9 6 7 )*

46. E. F. ELedel, J. G. Verkade, and R. A. Jacobson, Abstracts of the American Crystallographic Association Meeting, Minneapolis, Minn., 0967, No. P -10.

47. J.K. S ta lic k and J.A. Ibers, Inorg. Chem., 8, 1090 ( 1969).

48. D.W. Meek and J.A. Ibers, Inorg. Chem., 8, 1915 (1969)*

49* G. R. D avies, R. H. B. M ais, and P. G. Owston, J . Chem. Soc. (a ), 1750 (1967).

30. L.P. Hangen and R. Eiseriberg, Inorg. Chem., 8 , 1072 (1 9 6 9 ).

51. J.K . Stalick and J.A . Ibers, Inorg. Chem., 8 , 1084 (1969).

52. R. Curran, J. Cunningham, and R. Eisenberg, Inorg. Chem., % 2749 (0970).

53. L. Pauling, *1The Nature of the Chemical Bond1*, 3rd Ed., Cornell University Press, Ithaca, N. Y., i 960 , Chapter 7.

54. C. G. Pierpont, A. Pucci, and R. Eiseriberg, J. Am. Chem. Soc., 2i» 3 O5O (1 9 7 1 ).

55* C.E. S tro u s e and B .I . Swanson, Chem. Comm., 55 ( i9 7 l) . 383

56. D. J. Hodgson, N. C. Payne, J.A. MeGinnety, R. G. Pearson, and J . A. I b e r s , J . Am. Chem. S o c ., £0, Mi-86 (1968).

57- J .P . Collm an, N.W. Hoffman, and D.E. M o rris, J . Am. Chem. S o c ., 23* 5659 (1969).

58 . M.A. Bush and G.A. Sim ., J . Chem. Soc. ( a ) , 6 05, 6ll(l970).

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66. The following programs were w ritten for the EMR 6 I 3 O computer "by Professor P. W. R. Corfield: conversion of raw data to structure factors PIPIC; structure factor-least square refinement (SFIS1, SFIS2, SFIS3, and SFI Sk); F o u rie r summation (FOUR and FHPHNT)j averaging of equivalent reflections (MERGE); bond distances-bond a n g le s (GEOM).

6 7 . The following programs were w ritten for the EMR 613O computer by Dr. G. J. Gainsford and Professor P. W. R. Corfield: The cell refinement routine Q0Z1S; the four circle diffractometer absorption program P1CABS.

6 8 . J. S. Rollett, '' Computing Methods in Crystallography'', Pergamon, O xford, 1965 , p . 50.

69* Computer program F1NDH, K. N. Raymond, Northwestern U niversity, ca. 1966.