@prefix vivo: . @prefix edm: . @prefix ns0: . @prefix dcterms: . @prefix skos: . vivo:departmentOrSchool "Science, Faculty of"@en, "Chemistry, Department of"@en ; edm:dataProvider "DSpace"@en ; ns0:degreeCampus "UBCV"@en ; dcterms:creator "Tsai, James Hwa-San"@en ; dcterms:issued "2011-09-26T23:40:03Z"@en, "1965"@en ; vivo:relatedDegree "Doctor of Philosophy - PhD"@en ; ns0:degreeGrantor "University of British Columbia"@en ; dcterms:description """Current interest in metal-metal bonded systems has been largely confined to the synthesis of such compounds, and little is known of the chemical behaviour of the metal-metal bonds. One of the simplest systems to study was the tin-tin bond, and thus the additions of fluoro-olefins to hexamethylditin were examined. Such additions were found to occur readily under ultraviolet irradiation which suggests that the formation of (CH₃)₃Sn radicals is an important feature of the reaction mechanism. The formation of adducts such as (CH₃)₃Sn(CF₂CF₂)nSn(CH₃)₃ (n = 1 or 2) , (CH₃)₃SnCF₂CF(CF₃)Sn(CH₃)₃, (CH₃)₃Sn(CFHCF₂)nSn(CH₃) ₃ (n = 1 or 2), and (CH₃) ₃Sn(CH₂CF₂)nSn(CH₃)₃(n = 1 or 2) , as well as the occurrence of secondary reactions leading to products of the type (CH₃)₃Sn(CF₂CF₂)nH (n = 1,2, or 3), (CH₃) ₃SnCF₂CF(CF₃)H, and other analogous compounds are discussed. The (CH₃)₃Sn radical was found to have nucleophilic character, and to attack exclusively on the group marked with an asterisk in the following olefins: [ Formulas omitted ]. The factors responsible for the orientation of such unsymmetric olefins with respect to the (CH₃)₃Sn radical are considered. The compound (CH₃)₃Sn-Mn(CO)₅, containing a mixed metal-metal bond, was also shown to be very reactive, but to behave differently toward a variety of olefins. A two-carbon insertion into the tin-manganese bond was readily achieved by the reaction with tetrafluoroethylene at 50° under ultraviolet irradiation, which again might suggest that a free-radical mechanism is involved. Two interesting dimers, i.e., the "boat and chair" forms of [CF₂=CFMn(CO) ₄] ₂, containing both σ- and π-bonds were formed, presumably through the decomposition of the adduct (CH₃)₃SnCF₂CF₂Mn(CO)₅. With trifluoroethylene, neither adduct nor dimer is obtained but the novel fluorovinyl-transition metal compounds cis- and trans-(CFH=CF)Mn(CO)₅ were formed. When reacted with trifluorochloroethylene, CF₂=CFCOMn(CO)₅ was predominantly obtained, as well as cis- and trans-(CFCl=CF)Mn(CO)₅ in small yields. The reaction with ethylene caused the cleavage of the manganese-carbonyl bond rather than the tin-manganese bond, forming (CH₃) ₃Sn-Mn(CO) ₄(π-C₂H₄) . The catalytic activity of (CH₃) ₃Sn-Mn(CO) ₅ in the hydrogenation of ethylene was also examined. Detailed spectroscopic studies were made for the products obtained in the pure state."""@en ; edm:aggregatedCHO "https://circle.library.ubc.ca/rest/handle/2429/37632?expand=metadata"@en ; skos:note "The U n i v e r s i t y of B r i t i s h Columbia FACULTY OF GRADUATE STUDIES PROGRAMME OF THE FINAL ORAL EXAMINATION FOR THE DEGREE OF DOCTOR OF PHILOSOPHY of JAMES HWA-SAN TSAI M.Sc. Fresno State College, Fresno, C a l i f o r n i a 1962 TUESDAY, OCTOBER 26, 1965 AT 3:00 P.M. IN ROOM 261, CHEMISTRY BUILDING COMMITTEE IN CHARGE Chairman; K, C. Mann Wo Jo Co Ro Cullen Po Kutney A= McDowell L„ Wo Reeves Ro Co Thompson Jo Trotter Eo Peters Research Supervisor Ho C. Clark External Examiner. R. S= Nyholm Department of Chemistry Un i v e r s i t y College, London, England. SOME REACTIONS OF METAL-METAL BONDS WITH FLUORO-OLEFINS ABSTRACT Current in t e r e s t i n metal-metal bonded systems has been l a r g e l y confined to the synthesis of such compoundsj and l i t t l e i s known of the chemical behaviour of the metal-metal bonds. One of the simplest systems to study was the t i n - t i n bond, and thus the additions of f l u o r o -o l e f i n s to hexamethylditin were examined. Such additions were found to occur r e a d i l y under u l t r a v i o l e t i r r a d i a t i o n which suggest that the formation of (CH 3) 3Sn ra d i c a l s i s an important feature of the reaction mechanism. The formation of adducts such as (CH 3)3Sn(CF2CF2) nSn(CH 3)3 (n = 1 or 2), (CH 3)3SnCF2CF(CF3)Sn(CH3) 3, (CH3)3Sn(CFHCF 2) nSn(CH 3)3 (n = 1 or 2), and (CH 3) 3Sn(CH 2CF 2) nSn(CH 3) 3 (n = 1 or 2), as well as the occurence of secondary reactions leading to products of the type (CH3)3Sn(CF2CF2)nH (n = l s 2, or 3 ) 3 (CH3)3SnCF2CF(CF3)H, and other analogous compounds are discussed. The (CH3)3S*n r a d i c a l was found to have nu c l e o p h i l i c character, and to attack e x c l u s i v e l y on the group marked with an a s t e r i s k i n the following o l e f i n s : CF2=CFCF3S CF2=CFH, CF2=CH2S and CF2=CFC1„ The factors responsible for the o r i e n t a t i o n of such unsymmetric o l e f i n s with respect to the (CH 3) 3Sn r a d i c a l are considered. The compound (CH3)3Sn-Mn(CO)5, containing a mixed metal-metal bond., was also shown to be very r e a c t i v e , but to behave d i f f e r e n t l y toward a v a r i e t y of olefins« A two-carbon i n s e r t i o n into the tin-manganese bond was r e a d i l y achieved by the reaction with tetrafluoroethylene at 50° under u l t r a v i o l e t i r r a d i a t i o n 3 which again might suggest that a f r e e - r a d i c a l mechanism i s involved,, Two i n t e r e s t i n g dimers, i . e . , the \"boat and c h a i r \" forms of (CF2=CFMn(CO)4)2, containing both 3Sn-Mn(CG)4('' r -C2H4) 0 The c a t a l y t i c a c t i v i t y of (CH3)3Sn=Mn(CO)5 i n the hydrogenation of ethylene was also examined. Detailed spectroscopic studies were \"made for the products obtained i n the pure state. GRADUATE STUDIES F i e l d of Study: Chemistry Topics i n Physical Chemistry A. Bree J. R. Coope Seminar i n Chemistry S. A. Bryce Topics i n Inorganic Chemistry N. B a r t l e t t . H. C. Clark W. R.. Cullen Advanced Inorganic Chemistry W. R. Cullen H. C. Clark Spectroscopy and Molecular Structure A. Bree K„ B. Harvey L„ Wo Reeves C r y s t a l Structures S. Melzak J. T r o t t er The Chemistry of Grganometallic Compounds H. Co Clark Topics i n Organic Chemistry J. P. Kutney F . McCapra A= I. Scott PUBLICATIONS H.C. Clark, J.D. Cotton, and J„H. T s a i REACTIONS OF METAL-METAL BONDS. PART I s STUDIES WITH THE Sn-Sn BOND Inorg. Chem., i n press. H.C. Clark and J.H. T s a i REACTIONS OF METAL-METAL BONDS. PART I I s THE Sn-Mn BOND Inorg. Chem., i n press. H.C. Clark, N.N. Cyr 3 and J.H. T s a i N.M.R, SPECTRA OF TIN COMPOUNDS, PART IV 5 1H and 19F.N.M.,R. SPECTRA OF A TRIMETHYLTIN DERIVATIVE CONTAINING AN ASYMMETRIC CARBON ATOM Can, J. Chem., i n press. H.C. Clark and J.H. Ts a i A TWO-CARBON ATOM INSERTION INTO A METAL-METAL BOND Chem. Comm.,, I l l (1965) H.C. Clark, J.H. T s a i s and W.S. Tsang FLUOROVINYL DERIVATIVES OF TRANSITION METALS Chem, Comm., 171 (1965) G.B, Kauffman, J.H. T s a i , R.C. Fay and C.K. Jorgensen THE CONFIGURATIONS OF YELLOW AND RED TRICHLOROTRIS (DIETHYLSULFIDE) IRIDIUM ( I I I ) Inorg, Chem., 2, 1233 (1963). G - B , Kauffman,. and J.H. T s a i TETRAAMMINEPALLADIUM(II) TETRACHLOROPALLADATE(II) AND TRANSDICHLORODIAMMINEPALLADIUM(II) Inorg, Syntheses, Vol. VIII (Accepted on July 23 s1963 G,B, Kauffman and J.H. Ts a i SODIUM HEXACHLORORHODATE(III) DIHYDRATE AND POTASSIUM HEXACHLORORHODATE(II) MONOHYDRATE Inorg. Syntheses,Vol,VIII (Accepted on July 23,1963). G.B. Kauffman and J.H,, Ts a i CIS- AND TRANS-TETRACHLOROBIS = (DIETHYL SULFIDE) PLATINUM(IV). Inorg. Syntheses,Vol.VIII(Accepted on February 20,19 G,B. Kauffman and J.H. Ts a i A HIGH-YIELD CONVERSION OF RHODIUM TO SODIUM HEXACHLO RORHODATE(III), J. Less-Common Metals, 4, 519 (1962). J.H, T s a i PREPARATION OF AMMONIUM SULFATE BY GAS PHASE REACTION Current Reports of Chinese Council on Science Development, (June s 1960). SOME REACTIONS OF METAL-METAL BONDS WITH FLUORO-OLEFINS by JAMES HWA-SAN TSAI B.Sc, Cheng-Kung University, 1955 M.Sc, Fresno State College, 1962 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY i n the Department of Chemistry We accept t h i s thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA September, 1965 In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f the r e q u i r e m e n t s f o r an advanced degree a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , I a g r e e t h a t t h e L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and s t u d y . I f u r t h e r a g r e e t h a t p e r -m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y p u r p o s e s may be g r a n t e d by the Head o f my Department o r by h i s representatives„ I t i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i -c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . Department o f C h e m i s t r y The U n i v e r s i t y o f B r i t i s h Columbia Vancouver 8, Canada Date October 26, 1965 i i ABSTRACT Current i n t e r e s t i n metal-metal bonded systems has been l a r g e l y confined to the synthesis of such compounds, and l i t t l e i s known of the chemical behaviour of the metal-metal bonds. One of the simplest systems to study was the t i n - t i n bond, and thus the additions of f l u o r o -o l e f i n s to hexamethylditin were examined. Such additions were found to occur r e a d i l y under u l t r a v i o l e t i r r a d i a t i o n which suggests that the * formation of ( C H 3 ) 3 S n r a d i c a l s i s an important feature of the reaction mechanism. The formation of adducts such as ( C H 3) 3Sn(CF 2CF 2) nSn(CH 3 ) 3 (n = 1 or 2) , (CH 3 ) 3 S n C F 2CF(CF 3)Sn ( C H 3 ) 3 , (CH 3) 3Sn(CFHCF 2) nSn(CH 3) 3 (n = 1 or 2 ) , and (CH 3) 3Sn(CH 2CF 2) nSn(CH 3) 3 (n = 1 or 2) , as well as the occurrence of secondary reactions leading to products of the type (CH 3) 3Sn(CF 2CF 2) nH (n = 1 , \" 2 , or 3), (CH 3) 3SnCF 2CF(CF 3)H, and other analogous compounds are discussed. The (CH 3)3 S n r a d i c a l was found to have n u c l e o p h i l i c character, and to attack e x c l u s i v e l y on the group marked with an a s t e r i s k i n the following o l e f i n s : CF 2=CFCF 3, CF2=CFH, CF 2=CH 2, and CF 2 = C F C 1 . The factors responsible f o r the o r i e n t a t i o n of such unsymmetric o l e f i n s with respect to the (CH 3)3 S n r a d i c a l are considered. The compound (CH3)3Sn-Mn(C0)5, containing a mixed metal-metal bond, was also shown to be very r e a c t i v e , but to behave d i f f e r e n t l y toward a v a r i e t y of o l e f i n s . A two-carbon i n s e r t i o n into the tin-manganese bond was r e a d i l y achieved by the reaction with tetrafluoroethylene at 50° under u l t r a v i o l e t i r r a d i a t i o n , which again might suggest that a f r e e - r a d i c a l mechanism i s involved. Two i n t e r e s t i n g dimers, i . e . , the \"boat and cha i r \" forms of [CF2=CFMn(C0) i+] 2 j containing both a- and -rr-bonds were formed, presumably through the decomposition of the adduct (CH 3)3SnGF 2CF 2Mn(C0) 5. With t r i f l u o r o e t h y l e n e , neither adduct nor dimer i s obtained but the novel f l u o r o v i n y l - t r a n s i t i o n metal compounds c i s - and trans-(CFH=CF)Mn(CO) 5 were formed. When reacted with t r i f l u o r o c h l o r o e t h y l e n e , CF2=CFC0Mn(C0)5 was predominantly obtained, as well as c i s - and trans-(CFCl=CF)Mn(CO)5 i n small y i e l d s . The reaction with ethylene caused the cleavage of the manganese-carbonyl bond rather than the tin-manganese bond, forming (CH 3) 3Sn-Mn(CO) i t ( T T-C 2H l t) . The c a t a l y t i c a c t i v i t y of (CH 3) 3Sn-Mn(CO) 5 i n the hydrogenation of ethylene was also examined. Detailed spectroscopic studies were made f o r the products obtained i n the pure state. i v TABLE OF CONTENTS Page ABSTRACT i i TABLE OF CONTENTS i v LIST OF TABLES v i i i LIST OF FIGURES * ACKNOWLEDGEMENTS x i I. GENERAL INTRODUCTION 1 II . REACTIONS OF HEXAMETHYLDITIN WITH FLUORO-OLEFINS 6 A. Introduction 6 B. Results and Discussion 11 1. Reaction with tetrafluoroethylene 11 2. Reaction with hexaf luoropropene '. 1 8 3. Reaction with t r i f l u o r o e t h y l e n e and with 1,1-difluoroethylene 23 4. Reaction with t r i f l u o r o c h l o r o -and trifluorobromoethylene 30 5. Reaction with ethylene 34 I I I . REACTIONS OF TRIMETHYLTIN-PENTACARBONYLMANGANESE WITH FLUORO-OLEFINS 35 A. Introduction 35 B. Results and Discussion 37 1. Preparation and ch a r a c t e r i z a t i o n of (CH 3) 3Sn-Mn(CO) 5 37 V Page 2. Reaction with tetrafluoroethylene 39 3. Reaction with t r i f l u o r o e t h y l e n e 47 4. Reaction with t r i f l u o r o c h l o r o e t h y l e n e 50 5. Reaction with ethylene 55 IV. SPECTROSCOPIC STUDIES 58 A. The Infrared Spectra of Fluorocarbon Derivatives of Tri m e t h y l t i n 58 1. Introduction to the i n f r a r e d bands associated with the t r i m e t h y l t i n group 58 2. Introduction to the i n f r a r e d bands associated with fluorocarbon groups 59 3. Discussion 63 B. The N.M.R. Spectra of Fluorocarbon Derivatives of T r i m e t h y l t i n 70 C. The Infrared Spectra of Fluorocarbon Derivatives of Pentacarbonylmanganese 90 1. Infrared spectroscopy of manganese carbonyls 90 2. Discussion 96 a. Infrared bands associated with the (CH 3) 3Sn group 96 b. The carbonyl stretching frequencies (fOcO) 98 c. The manganese-carbonyl deformation bands (SMnCO) 104 d. The manganese-carbon stretching modes (\\)Mn-C0) 105 e. Infrared bands associated with C-F absorptions 106 v i Page f. The C=C stretching frequencies 109 D. The N.M.R. Spectra of Fluorocarbon Derivatives of Pentacarbonylmanganese 113 V. CONCLUSION 132 VI. EXPERIMENTAL 136 A. General Techniques 136 1. Vacuum l i n e 136 2. Reaction apparatus 136 3. Analyses of products 136 B. Special Techniques 139 1. Preparative chromatograph 139 2. Vacuum d i s t i l l a t i o n and sublimation 140 3. Liquid-phase chromatograph !142_ C. Spectroscopic Techniques 145 1. Infrared spectra 145 2. N.M.R. spectra 145 D. Reactions of Hexamethylditin with F l u o r o - o l e f i n s 146 1. Preparation of hexamethylditin 146 2. Reactions with tetrafluoroethylene 147 3. Reactions with hexafluoropropene 152 4. Reactions with t r i f l u o r o e t h y l e n e 154 5. Reactions with 1,1-difluoroethylene 157 6. Reactions with t r i f l u o r o c h l o r o e t h y l e n e 161 7. Reactions with trifluorobromoethylene 163 8. Reaction with ethylene 165 v i i Page E. Reactions of Trimethyltin-pentacarbonylmanganese with Fluoro-olefins 167 1. Preparation of trimethyltin-pentacarbonyl-manganese 167 2. Decomposition of trimethyltin-pentacarbonyl-manganese 168 a. Pyrolysis 168 b. Photolysis 168 3. Reactions with tetrafluoroethylene 169 4. Reactions with t r i f l u o r o e t h y l e n e 173 5. Reaction with t r i f l u o r o c h l o r o e t h y l e n e 175 6. Reactions with ethylene 178 a. Reaction with ethylene at 1G atm. 178 b. Reaction with ethylene at 1 atm. in the presence of hydrogen gas 179 BIBLIOGRAPHY 181 v i i i LIST OF TABLES Page 1. Reaction Results of (C H 3 ) 6 S n 2 and CF 2= CF 2 12 2. Reaction Results of (CH 3) 6Sn 2; and CF 2=CFCF 3 19 3. Radical Addition to CF 2=CFCF 3 22 4. Reaction Results of (C H 3 ) 6 S n 2 and CF2=CFH 24 5. Reaction Results of (CH 3) 3Sn-Mn(C0) 5 and CF 2= CF 2 40 6. Physical Properties of Some Carbonylmanganese Derivatives 43 7. C-F Absorption Bands (cm. *) i n the IR Spectra of Some Polyfluoro-alkanes 60 8. C-F Absorption Bands (cm. i n the IR Spectra of Perfluoroalkyl-metal Compounds 61 9. C-F Absorption Bands (cm.-''') i n the IR Spectra of Polyfluoroalkyl-metal Compounds 62 10. Infrared Bands of the Reaction Products Containing (CH 3)3 Sn Group 64 11. Infrared Bands of the Reaction Products Containing P o l y f l u o r o a l k y l Group 65 12. Chemical S h i f t s and Coupling Constants f o r Some Organometallie Compounds Containing HCF 2CF 2-Group 71 13. XH N.M.R. Data of (CH 3) 3SnCF 2(CF 2) 2CF 2H and Some Polyfluoroalkanes 75 14. lH and 1 9 F Data of (CH 3) 3SnCF 2CFHCF 3 and (CH 3) 3SnCF 2CF(CF 3)Sn(CH; 3) 3 78 15. Some Coupling Constants of Unsymmetrically Substituted Polyfluoroalkanes 79 i x LIST OF TABLES (continued) 16. Infrared Bands of the Reaction Products Containing Carbonylmanganese Group 17. Infrared Bands of the Reaction Products Containing Carbonylmanganese Group (continued) 18. Observed ^ CO Modes (cm. - 1) for Some LMn(CO) 5 Compounds 19. Assignment of C-F Absorptions (cm. *) Due to CF2=CFX Group 20. The C=C Stretching Frequencies of Some Fluoro v i n y l Groups 21. N.M.R. Data of (CH 3) 3Sn-Mn(C0) 5 and Its Derivatives. 22. N.M.R. Data of Some Fluorovinyl-Mn(CO) 5 Complexes 23. Chemical S h i f t s (c.p.s.) and Coupling Constants (c.p.s.) of Some Tri m e t h y l t i n Derivatives 24. The Spin-spin Coupling Constants (c.p.s.) ( i n Some Fl u o r o - o l e f i n s and Their Derivatives 25. The F-F Coupling Constants (c.p.s.) i n Some Per f l u o r o v i n y l Derivatives: CF2=CFX 26. 1 9 F Chemical S h i f t s of CF2=CFX Groups 27. 1H N.M.R. Data of Some V i n y l Compounds 28. Cold Baths 29. A n a l y t i c a l Data f o r the Reaction of (CH 3) 3Sn-Mn(C0) 5 and CF 2=CF 2 X LIST OF FIGURES 1. The Boat and Chair Forms of [CF 2=CFMn(C0) h] 2 2. 'H N.M.R. Spectrum of (CH 3) 3SnCF 2CFHCF 3 3. 1 9 F N.M.R. Spectrum of (CH 3) 3CF 2CFHCF 3 4. 1 9 F N.M.R. Spectrum of the B-CF Group i n (CH 3) 3SnCF 2CFHCF 3 5. 1 9 F N.M.R. Spectrum of the y-CF 3 Group i n (CH 3) 3SnCF 2CFHCF 3 6. Rotational Isomers of (CH 3) 3SnCF 2CFHCF 3 7. 1 9 F N.M.R. Spectrum of the a-CF 2 Group i n (CH 3) 3SnCF 2CFHCF 3 8. Possible Configuration of (CH 3) 3SnCF 2CFHCF 3 9. ir-bonding Isomer of (cis-CFH=CF)Mn(CO) 510. J 1 1 9Sn-CH 3 vs. Vsn-C f o r Some Methyltin Compounds 11. J 1 1 9Sn-CH 3 vs. J 1 3C-H 3 f o r Some Trimethyltin Compounds 12. § C H 3 vs. J 1 1 9Sn-CH 3 and J 1 3C-H 3 f o r Some Trim e t h y l t i n Compounds 13. § C H 3 vs. Radius of X i n ( C H 3 ) 3 SnX Compounds 14. Sample C o l l e c t i o n C e l l s f o r the Gas Chromatograph 15. High Vacuum D i s t i l l a t i o n Apparatus 16. Vacuum Sublimation Apparatus 17. Liquid^phase Chromatograph Column 18. VCO Band I n t e n s i t i e s vs. E l u t i o n Volumes x i ACKNOWLEDGEMENTS I wish to express my sincere appreciation to Professor Howard C. Clark who suggested t h i s research t o p i c , and who has provided constant guidance during t h i s work. Many thanks are extended to Dr. John D. Cotton f o r many valuable discussions, e s p e c i a l l y during the preparation of th i s manuscript. I am also indebted to Mrs. Nancy N. Cyr for recording the 1 9 F N.M.R. spectra and for the discussions on the N.M.R. spectra of (CH 3) jSnCFgCFHCF 3. The f i n a n c i a l assistance of the Univ e r s i t y of B r i t i s h Columbia, who awarded me a U.B.C. Graduate Fellowship (1964-1965), i s also acknowledged. Last, but not l e a s t , I would l i k e to express my h e a r t f e l t appreciation to my wife f o r her patient understanding and encouragement throughout the years of study. Sec. I 1 1. GENERAL INTRODUCTION. As long ago as 1869 Ladenburg (1) found that the vapour density of an e t h y l t i n compound at 225° corresponded to the formula (C 2H 5)gSn 2. This was the f i r s t instance of an organometallic compound containing a metal-metal bond being recognized. The existence of the mercury-mercury bond i n the mercurous ion and i n mercurous c h l o r i d e , Cl-Hg-Hg-Cl, has also been known for a long time (2). However, i n t e r e s t i n compounds possessing two or more metals d i r e c t l y linked to each other has developed r a p i d l y only i n recent years. This i s a t t r i b u t a b l e to the unusual problems, both t h e o r e t i c a l and experimental, which such compounds present. From the t h e o r e t i c a l point of view, descriptions have been given, i n molecular o r b i t a l terms, of the metal-metal bonding i n the metal k+ o -c l u s t e r s of complex halide species such as MogClg and R e 3 C l 1 2 , by Cotton and Hass (3). Nyholm and coworkers (4) have c l a s s i f i e d substances containing metal-metal bonds into four main classes ( i . e . , metals i n the condensed state, concentrated metal compounds, compounds containing single covalent metal-metal bonds, and metal donor complexes), and have considered the r o l e played by the electron configuration and e l e c t r o -n e g a t i v i t y of the metal atom i n the formation of covalent metal-metal bonds. A very recent review (5) s u b s t a n t i a l l y covers the metal-metal i n t e r a c t i o n i n t r a n s i t i o n metal complexes. On the experimental side, a t t e n t i o n has been l a r g e l y paid to the syntheses and characterizations of new metal-metal bonded compounds (4 - 16), most of which are organometallic i n nature. That compounds having bonding Sec. I ' sequences involving three (7, 8) or f i v e (9) metal atoms, of three d i f f e r e n t elements, have now been described i l l u s t r a t e s t h e i r possible complexity, e.g., y\\ \\ ,QQ O C - M Q ^CO OC CO CH 3 CO CO CO OC Mn Sn — — Mo / \\ I / \\ OC CO CH 3 OC CO CO <3_Fe Sn F e - £ > o c x oc C O Mo—CO 6 A large number of such mixed metal complexes can be obtained according to the general equation (6, 17) Na ML + CI M'L » LM-M'L + NaCl where M and M' are metals and L i s an appropriate s t a b l i z i n g ligand. In sharp contrast to the large number of newly prepared metal-metal bonded compounds, only l i t t l e e f f o r t has been devoted to the study of the chemical properties of metal-metal bonds. Some representative reactions so f a r reported i n connection with metal-metal bonds are summarized as follows. (a) Cleavage of the metal metal bonds with a v a r i e t y of reagents. Several metal-metal bonds were found to be r e a d i l y cleaved by a va r i e t y of reagents. Of the - b i m e t a l l i c compounds containing Group IV metals, ( C g H 5 ) 3 S i - S i ( C g H 5 ) 3 (18) i s e a s i l y cleaved by m e t a l l i c l i t h i u m , which i s so re a c t i v e that even a very st a b l e , s i x membered r i n g s i l i c o n compound [ ( C g H 5 ) 2 S i ] g can be cleaved (12). Other examples are the cleavage of the silicon-germanium bond i n (C 2H 5) 3Si-Ge(CgHg) 3 by li t h i u m (19) and the t i n - t i n bond i n hexamethylditin by oxygen, chlorine (20), Sec. I 3 and by CF 3I (21 - 24). Compounds containing bond(s) between a Group IV metal and a t r a n s i t i o n metal were also examined. [ ( C 2 H 5 ) 3 P ] 2 P t [ G e ( C g H 5 ) 3 ] 2 has been shown (25) to be very re a c t i v e toward hydrogen ch l o r i d e , to cleave the two platinum-germanium bonds i n the molecule, whereas the i r o n - t i n bond was found (26) to be very r e s i s t a n t to f i s s i o n by the same reagent. Treatment of (CO)^FetPb(CgH 5) 3] 2 with mercuric chloride causes breakage of the i r o n -lead bonds, giving (CgH 5) 3PbCl and a polymeric compound [HgFe(CO) ^ ^ ( 2 7 ) . The study was also extended to compounds containing two Group V atoms d i r e c t l y bonded; e.g., the arsenic-arsenic bond (28) and the phosphorus-phosphorus bond (29) were found to be cleaved by CF 3I. (b) Cleavage of bonds other than the metal-metal bond. The t i n - i r o n bond i n (CgH 5) 3Sn-Fe (CO) 2 (TT-C 5H 5) (26) i s so stable that the carbon-tin bond rather than the t i n - i r o n bond i s cleaved by hydrogen c h l o r i d e , forming compounds such as Cl 3Sn-Fe(C0) 2 ( I T - C 5H 5) . Similar s t a b i l i t y of the tin-manganese bond was also observed i n (CgH 5) 3Sn-Mn(C0) 5 (26). Treatment of t h i s complex with triphenylphosphine causes displacement of carbon monoxide, while with chlorine CI 3Sn-Mn(C0) 5 i s obtained. (c) Cleavage of metal-metal bonds with heat. The yellow-white compound (CH3Hg) 2Fe(C0) l+ (30) i s very unstable. On heating to ~80°, or even on standing for a short period, t h i s compound undergoes disproportionation to give the stable polymeric d e r i v a t i v e [HgFe(CO) J n . The molybdenum-iron bond i n (TT-C 5H 5) (CO) 3Mo-Fe(C0) 2(IT-C 5H 5) (31) i s r e l a t i v e l y stable to heat, but i t may decompose under more vigorous conditions, leading to the cleavage of the molybdenum-iron bond. Sec. I 4 (c) Carbon i n s e r t i o n s into the metal-metal bonds. It has been shown, f i r s t by Beg and Clark, that the carbon-carbon unit i n s e r t s into the t i n - t i n bond (32), a s i m i l a r reaction to those of compounds containing phosphorus-phosphorus bonds, with acetylene (33) and tetrafluoroethylene (34). Later, t h i s type of reactions was extended to compounds containing arsenic-arsenic bonds (35, 36). While the chemical behaviour of many metal-metal bonded compounds has yet to be examined i n d e t a i l , important i n d u s t r i a l applications are already being developed. A platinum-tin complex, which i s prepared by t r e a t i n g stannous chloride s o l u t i o n with c h l o r o p l a t i n i c acid, has been shown to be a very e f f e c t i v e c a t a l y s t i n the f a c i l e homogeneous hydro-genation of ethylene-and acetylene (37), and i n the isomerization of pent-l-ene to a mixture of c i s - and trans-pent-2-ene (38). Cramer et a l . (37) have suggested that t h i s behaviour i s a t t r i b u t a b l e to the coordination of the o l e f i n s through ir-bonding to platinum atom which i n turn i s promoted by stannous c h l o r i d e . Cross and Glockling (25) have reported that the platinum-germanium bond i n [ ( C 2 H 5 ) 3 P ] 2 P t [ G e ( C g H s ) 3 ] 2 has the unique property of cleavage d i r e c t l y by molecular hydrogen.at atmospheric pressure and room temperature without added c a t a l y s t , giving both platinum-hydrogen and germanium-hydrogen bonds. In addition to the extensive applications of Co 2(CO) 8 as a c a t a l y s t i n hydroformylation (39), Calderazzo (40) has recently found that M n 2 ( C 0 ) 1 0 also catalyzes the carbonylation of primary a l i p h a t i c amines almost e x c l u s i v e l y to 1,3-dialkylureas. More recently, a cobalt-containing Ziegler-type system ( i . e . , products from treatment of cobalt stearate with triethylaluminum) was shown (41) to react at room temperature with carbon monoxide, y i e l d i n g acylcobalt carbonyl d e r i v a t i v e s . Sec. I 5 The high chemical r e a c t i v i t y , p a r t i c u l a r l y towards such important i n d u s t r i a l s t a r t i n g materials as the o l e f i n s etc., of metal-metal bonds i s a t t r a c t i n g considerable attention and appears to have great p o t e n t i a l . A systematic i n v e s t i g a t i o n of some of t h e i r reactions with a s e r i e s of o l e f i n s was therefore undertaken i n the hope that t h i s would provide basic information on the chemistry of metal-metal bonds, and also throw some l i g h t on t h e i r c a t a l y t i c a c t i v i t y . The f i r s t compound studied i s one of the simplest metal-metal compounds', and has two t i n atoms d i r e c t l y bonded, namely hexamethylditin ( C H 3 ) 3 S n - S n ( C H 3 ) 3 . In Section II of t h i s t h e s i s , the reactions of t h i s compound with a number of f l u o r o - o l e f i n s of general type CF2=CFX, where X = F, C F 3 , H, CI, or Br, and as well as with 1,1-difluoroethylene and ethylene, are described. Fluorinated o l e f i n s were chosen, f i r s t l y since the presence of the f l u o r i n e atoms allows a d d i t i o n a l p h y s i c a l methods to be used i n determining the course of the reactions, and secondly because of the current i n t e r e s t i n , and high s t a b i l i t y of, fIuorocarbons and t h e i r d e r i v a t i v e s (42). This work was extended to the reactions of t r i m e t h y l t i n -pentacarbonylmanganese, (CH 3)3Sn-Mn(CO) 5, with the same se r i e s of f l u o r o - o l e f i n s , as described i n Section I I I . This compound was chosen as the second reactant f o r several reasons: f i r s t l y , i t has only one metal-metal bond;, secondly., i t i s c l o s e l y r e l a t e d to hexamethylditin; t h i r d l y , i t would provide new compounds containing the methyltin group which i s of current i n t e r e s t i n connection with spectroscopic studies. In the course of these i n v e s t i g a t i o n s , many new compounds were prepared. As these also showed i n t e r e s t i n g features i n t h e i r i n f r a r e d and N.M.R. spectra, Section IV i s devoted to a discussion of t h e i r spectroscopic properties. Sec. II-A 6 I I . REACTIONS OF HEXAMETHYLDITIN WITH FLUORO-OLEFINS. A. Introduction. Hexamethylditin, obtained from the reduction of t r i m e t h y l t i n halides with m e t a l l i c sodium i n l i q u i d ammonia s o l u t i o n , was f i r s t reported on the basis of cryoscopic molecular weight measurements i n d i l u t e s o l u t i o n as a \"free t r i m e t h y l t i n group\" by Kraus and Sessions i n 1925 (20). Following the synthesis of t h i s compound, these workers performed a serie s of studies concerning i t s simple chemical properties. In l i q u i d ammonia, the \"free t r i m e t h y l t i n group\" reacts with sodium as follows: (CH 3) 3Sn + Na (CH 3) 3SnNa. When the \" t r i m e t h y l t i n \" i s allowed to come i n contact with a i r , oxidation takes place according to the equation: 2(CH 3) 3Sn + 1 0 2 ^ (CH 3) 3SnOSn(CH 3) 3 2 It reacts r e a d i l y with the halogens at room temperature. Reactions were also found to occur between t h i s compound and m e t a l l i c h a l i d e s . With mercuric chloride i n ether, a rapid reaction occurs to y i e l d t r i m e t h y l t i n chloride and mercury, i n d i c a t i n g that \" t r i m e t h y l t i n \" i s s u f f i c i e n t l y e l e c t r o p o s i t i v e to reduce mercury from i t s c h l o r i d e . In 1941, Morris and Selwood (43) reported that, i n view of the magnetic measurement r e s u l t s , the t r i m e t h y l t i n group does not e x i s t as the monomer i n d i l u t e benzene s o l u t i o n , and suggested that the r e l a t i v e l y large s i z e of the t i n atom greatly reduced the s t a b i l i t y Sec. II-A 7 of (CH q),Sn f r e e - r a d i c a l as compared with carbon f r e e - r a d i c a l s . This 3 3 suggestion i s consistent with the r e s u l t found by Ladenburg (1) as long ago as 1869 that the vapour density of hexaethylditin at 225° corresponded to the formula (C2H 5) 6Sn 2. Recently, i t was discovered independently by two groups of workers (21, 22, 23) that the t i n - t i n bond of hexamethylditin can be cleaved by trifluoroiodomethane according to the equation: Heat (CH3) 3Sn-Sn(CH 3)3 + CF 3I * (CH 3) 3SnCF 3 + (CH 3) 3SnI. 80° It was stated (23) that a f r e e - r a d i c a l mechanism i n i t i a t e d by homolytic cleavage of the t i n - t i n bond i n the above reaction i s u n l i k e l y , since there i s no evidence that such d i s s o c i a t i o n occurs on heating, and instead a molecular mechanism (or four-centred system) was postulated, CF 3I (CH 3) 3Sn-Sn(CH 3) 3 C F 3 - f - I I ' I I I • I , I ( C H 3 ) 3 S n - 7 ^ S n ( C H 3 ) 3 I (CH 3) 3SnCF 3 + (CH 3) 3SnI. Later, a rapid reaction was achieved by u l t r a v i o l e t i r r a d i a t i o n of the s i m i l a r reaction mixture at 25° for s i x hours (24). These conditions were much more mild than those usually required for f r e e - r a d i c a l formation from trifluoroiodomethane, and hence i t was suggested that a r a d i c a l - c h a i n mechanism might be operating, probably i n v o l v i n g homolytic f i s s i o n of the t i n - t i n bond as the f i r s t step, Sec. II-A 8 U.V. (CH 3) 3Sn-Sn(CH 3) 3 ^ 2(CH 3 ) 3 S n (CH 3) 3Sn + CF 3I 3 . (CH 3) 3SnCF 3 + I i + (CH 3) 3Sn-Sn(CH 3) 3 s» ( C H 3 ) 3 S n I + (CH 3) 3Sn, etc. A l k y l t i n compounds are reactive toward Lewis acids. For example, R 4Sn compounds react with t i n tetrahalides to give a l k y l t i n halides (44). Boron t r i c h l o r i d e exchanges chlorine atoms for a C H 2 = CH- or a C F 2 = CF-group from t i n (45). S i m i l a r l y , BF 3 attacks (CH 3) 3SnCF 3 to afford (CH 3) 3Sn(CF 3BF 3), leading to s a l t s of the ( C F 3 B F 3 ) ~ ion (46). Thus the low y i e l d of hexamethylditin from the reaction of (CH 3) 3SnNa with boron t r i f l u o r i d e i n d i e t h y l ether was a t t r i b u t e d to the c a t a l y t i c disproportion-ation of hexamethylditin with the Lewis a c i d , producing yellow coloured dimethyltin polymers and tetramethyltin, and then the l a t t e r i n turn reacts with boron t r i f l u o r i d e to give CH 3BF2 and (CH 3 ) 3 SnBFi+ (47). ( CH 3) 3Sn - S n(CH 3) 3 ^ (CH 3) 4Sn + l [ S n ( C H 3 ) 2 ] n n (CH3)i+Sn + 2 B F 3 » (CH 3 ) 3 S n B F i + + CH 3BF 2. Similar disproportionation of hexaethylditin also occurs under mild conditions in the presence of c a t a l y s t s , such as anhydrous aluminum chlo r i d e , to give the intensely coloured organotin polymers (48). Photolysis of h e x a e t h y l d i t i n also a f f o r d s , i n addition to gaseous hydrocarbons, the coloured t i n polymers (49). Thus under u l t r a -v i o l e t l i g h t at room temperature for 80 hours, the colour of hexaethylditin changed gradually from yellow to red, and f i n a l l y to an intense cherry-red. The coloured s o l i d residue was shown, on the basis of the products from the i n t e r a c t i o n with benzoyl peroxide, to be a polymeric organotin Sec. II-A 9 containing long chains of tin atoms (49). (C 2H 5) 3Sn-Sn(C 2H 5) 3 ~ * 2(C 2H 5) 3Sn (C 2 H 5 ) 3 S n + (C 2H 5)3Sn-Sn(C 2H 5)3 ^ ( C 2 H 5 K S n + (C 2 H 5 ) 3 S n - S n ( C 2 H 5 ) 2 (C 2H 5) 3Sn-Sn(C 2H 5) 2 + (C 2H 5) 3Sn-Sn(C 2H 5) 3 ( C 2 H 5 ) 3 Sn-Sn(C 2H 5) 2-Sn(C 2H 5) 3 + (C 2H 5) 3Sn, etc. A l t e r n a t i v e l y , rupture of the Sn-C bond may occur, followed by formation of the Sn-Sn bond (C 2H 5)3Sn-Sn(C 2H 5)3 ^ (C 2H 5)3Sn-§n(C 2H 5) 2 + C 2H 5 (C 2H 5) 3Sn-Sn(C 2H 5) 2 + (C 2H 5) 3Sn-Sn(C 2H 5) 3 & (C 2H 5) 3Sn-Sn(C 2H 5) 2-Sn(C 2H 5) 2-Sn(C 2H 5) 3 + C 2H 5, etc. The subject of t h i s section was o r i g i n a l l y i n i t i a t e d by the work of Beg and Clark (32). These workers studied the reaction of hexamethylditin with tetrafluoroethylene under u l t r a v i o l e t i r r a d i a t i o n , but f a i l e d to pu r i f y the reaction product (an o i l ) s a t i s f a c t o r i l y and, consequently, no information regarding the ch a r a c t e r i z a t i o n of the product was provided. In the present work, t h i s r e a ctipn was repeated and the products were c a r e f u l l y separated and characterized unambiguously. This was done by the usual methods of vacuum f r a c t i o n a t i o n , d i s t i l l a t i o n , and sublimation, and by the extensive use of gas chromatography i n conjunction with i n f r a r e d , *H and W F N.M.R. spectroscopic studies of the various f r a c t i o n s . The work was further extended by the study of reactions Sec. II-A with some unsymmetrical f l u o r o - o l e f i n s of the type CF2=CXY. It was hoped that t h i s might throw some l i g h t on the question of o r i e n t a t i o n the o l e f i n during the reactions, and hence help to elucidate the behaviour of the t i n - t i n bond under such reaction conditions, v i z . , formation of f r e e - r a d i c a l s or four-centred systems. Sec. II-B-1 11 B. Results and Discussion. 1. Reaction with tetrafluoroethylene. In a t y p i c a l reaction, equimolar quantities of hexamethylditln and tetrafluoroethylene i n a s i l i c a tube were i r r a d i a t e d with a 200-watt Hanovia u l t r a v i o l e t lamp at 75° for four hours. The r e s u l t s are summarized i n TABLE 1. C l e a r l y , under these conditions, reaction was about 60% complete, based on the recovered hexamethylditin. Of the amount of the d i t i n consumed, 13% of the reactant appeared as decomposition products, mainly tetramethyltin which must r e s u l t from the photochemical decomposition of . hexamethylditin (49). That t h i s decomposition i s one of the secondary reactions i s confirmed by the formation of a deeply coloured i n v o l a t i l e residue, which was i n turn shown spect r o s c o p i c a l l y to be polymeric organotin compounds. The other decomposition product, produced i n con-siderably large quantity, was t r i m e t h y l t i n f l u o r i d e , which c e r t a i n l y arose from an a - f l u o r i n e atom elimination from fluorocarbon-tin compounds (23, 50). Two d i s t i n c t types of products, a l l colourless l i q u i d s , were formed during the reaction, namely, the adducts, a [ l , 2 - b i s ( t r i m e t h y l t i n ) t e t r a f l u o r o e t h a n e , (CH 3)3SnCF2CF 2Sn(CH 3) 3, and 1,4-bis(trimethyltin)octafluorobutane, (CH 3) 3SnCF2(CF2)2CF 2Sn(CH 3) 3], and the hydrogen abstraction products [ ( p o l y f l u o r o a l k y l ) t r i m e t h y l t i n , (a) For b r e v i t y , compounds w i l l be named c o r r e c t l y at t h e i r f i r s t i ntroduction i n the text, and w i l l thereafter be represented by t h e i r chemical formulas. Sec. II-B-1 12 TABLE 1 REACTION RESULTS OF (CH 3) 6Sn 2 AND. CF 2=CF 2 > Exp. 1 Exp. 2 Exp. 3 Exp. 4 gram (mmole) gram (mmole) gram (mmore) gram (mmole) S t a r t i n g Material ( CH 3) 6Sn 2 6.1 (18.3) 6.8 (20.8) 7.17 (21.9) 7.0 (21.4) CF 2=CF 2 1.85 (18.5) 2.2 (21.7) 2.2 (22.0) 2.2 (22.0) Reaction Conditions Carius tube Temperature Time (hour) Pyrex 25° 17 Pyrex 25° 60 S i l i c a 25° 31 S i l i c a 75° 4 gram (%) gram (%) gram (%) gram (%) Recovery (CH 3) 6Sn 2 4.7 (77.0) 3.8 (56.0) 4.5 (63.0) 2.6 (37.0) CF 2=CF 2 0.80 (43.0) 0.78 (35.0) 0.11 (5.0) Trace Continue to next page TABLE 1 (continued) Exp. 1 Exp. 2 Exp. 3 Exp. 4 gram gram gram gram I (mmole) (mmole (mmole) (mmole) J CF2=CF-CF=GF2 (0.1) trace (0.15) Alkane -2 F6 C 3 F 8 Trace (0.05) Other o l e f i n s CF 2=CFCF 3 CF 2=CFCF 3 (0.1) (1.10) (CH 3) L.Sn 0.03 (0.18) 0.16 (0.91) 0.3 (1.70) (CH 3) 3SnCF 2CF 2H 0.19 (0.72) 0.05 (0.19) 0.05 (0.19) 0.12 (0.45) Pro- (CH 3) 3SnCF 2(CF 2) 2CF 2H 0.31 (0.85) 0.1 (0.27) 0.1 (0.27) 0.08 (0.22) duct (CHg^SnCF^CFzKCFJH* (CH 3) 3SnCF 2CF 2Sn(CH 3) 3 S (CH 3) 3SnCF 2(CF 2) 2CF aSn(CH 3) 3 a 0.2 (0.43) Trace 0.2 (0.43) Q.1 (0.23) 0.6 (1.30) 0.3 (0.70) 0.3 (0.55) ( C H 3 ) 3 S n C F 2 ( C F 2 ) 1 2 C F 2 S n ( C H 3 ) 3 0.3 (0.29) 0.5 (0.49) 0.1 ('ca. 0.1) (CH 3) 3SnF 0.08 (0.44) 1 )1 g-1.3 (7.1) 9* poly. CF 2=CF 2 0.05 0.35 Blackish brown o i l b b b 0.8 C M e t a l l i c t i n formed None None None None (a) Quantities of these compounds were estimated from i n f r a r e d , N.M.R. and gas chromatographic data of t h e i r mixture. (b) Y i e l d was not recorded. (c) Recovered as a sublimation residue. Sec. II-B-1 14 (CH3)3Sn(CF 2CF 2)nH > where n = 1, 2, or 3]. The two adducts and (CH 3) 3Sn(CF 2CF 2) 3H were so s i m i l a r i n the v o l a t i l i t i e s that t h e i r separation could not be achieved by d i s t i l l a t i o n . Despite t h i s d i f f i c u l t y , evidence for the presence of these compounds i n the mixture was obtained by examination of the i n f r a r e d , 1H and 1 9 F N.M.R. spectra, by gas chromatographic analyses, and from the elemental analyses (see Sec. VI-D-2). The compounds, (CH 3) 3Sn(CF 2CF 2) nH, n = 1 and 2, were i s o l a t e d chromatographically i n a pure state, and t h e i r structures were established by spectroscopic data (Sec. IV-A, B) which are consistent with those of the analogous compounds (CH 3) 2SnH(CF 2CF 2H) and (CH 3) 2Sn(CF 2CF 2H) 2 (51). The formation of these p o l y f l u o r o a l k y l d e r i v a t i v e s was rather s u r p r i s i n g , because they require abstraction of hydrogen, presumably from CH 3groups. A serie s of experiments was performed under d i f f e r e n t experimental conditions to determine some of the factors i n f l u e n c i n g the rate of reaction,- and the y i e l d s . The conditions, together with the r e s u l t s , are summarized i n TABLE 1. F i r s t l y , the e f f e c t of the wavelength of the i r r a d i a t i n g l i g h t was investigated. It immediately became c l e a r that the ratf?. of reaction at the same temperature i s almost twice as fast i n a s i l i c a tube (transparent o to l i g h t of wavelength >2200 A) than i n a Pyrex tube (transparent to l i g h t of wavelength >3000A) (Exp. 2 and 3 i n TABLE 1). Secondly, the e f f e c t of temperature was determined. When the temperature was increased from 25° to 75° (Exp. 3 and 4), the reaction under i r r a d i a t i o n (> 2200A) proceeded much f a s t e r , i n d i c a t i n g the important influence of temperature on the reaction rate, although another reaction afforded no products when carr i e d out at 100° without i r r a d i a t i o n (see Sec. II-B-3). I t should be Sec.II-B-1 15 noted that, at the higher temperature, 75°, the y i e l d s of (CH3) 3S11CF2CF2H and the 1:1 adduct were improved markedly. At 25°, the r e l a t i v e abundance of adducts containing several C2F4 units was much increased, although the o v e r a l l reaction was much less complete. The e f f e c t of the wavelength of l i g h t i s understandable i n terms of the absorption maxima of the u l t r a v i o l e t spectra of d i t i n d e r i v a t i v e s . Van der Kerk and coworkers (52) have observed an absorption maximum for hexaphenylditin at 247 mu which was ascribed to the t i n - t i n bond system. They also noted the corresponding maximum for hexabutylditin, which i s s h i f t e d to shorter wavelength and apparently l i e s below 215 mu. In the present study, the absorption maximum for hexamethylditin was observed below 210 mu. Formation of f r e e - r a d i c a l s (013)3 Sn i s thus l i k e l y under u l t r a v i o l e t l i g h t . A d e f i n i t e explanation for the e f f e c t of temperature cannot be given, but two suggestions may be made. At room temperature, the- extent of reaction i n the gas phase may be low due to the high b o i l i n g point of hexamethylditin ( c . f . , b.p., 182°). At higher temperatures, the vapour pressure of the hexamethylditin w i l l be higher leading to a homogeneous reaction i n the gas phase. The formation of (CH3)3Sn(CF2CF2)nH does not involve the formation of the free r a d i c a l H C F 2 - C F 2 as the f i r s t step, since there i s no evidence for the existence of atomic or molecular hydrogen i n the photo-decomposition of hexamethylditin (49). Also, there i s no report of f r e e -r a d i c a l attack of f l u o r o - o l e f i n s on the carbon-hydrogen bond, so that the abstraction of hydrogen from CH3 groups by tetrafluoroethylene i t s e l f i s u n l i k e l y . The p o s s i b i l i t y that the adducts decompose, followed by hydrogen abstraction, i . e . , Sec. II-B-1 16 ( C H 3 ) 3 S n C F 2(CF 2CF 2)nCF 2Sn(CH 3)3 ^ |(CH 3) 3SnCF 2(CF 2CF 2)nCF ; + FSn(CH 3)3 F atom migration \\|/ H atoms abstraction (CH 3)3SnCF 2 (CF2C.F2 )n-!CF 2CF=CF 2 (CH 3) 3SnCF 2 (CF 2CF 2)nCFH 2 V could also be eliminated because products from such a route should contain a -CF=CF2 or CF 2-CFH 2 group. The formation of the above products, as well as the adducts, obviously suggested that two p r i n c i p a l reactions must occur,1 both involving the r a d i c a l (CH 3) 3SnCF 2CF 2. I t i s thus reasonable to assume at t h i s stage that t h i s species i s formed by the attack of (CH 3) 3Sn r a d i c a l s on CF 2=CF 2. This r a d i c a l then either p a r t i c i p a t e s i n hydrogen ab-s t r a c t i o n , presumably from the CH3 group, leading to the formation of ( t e t r a f l u o r o e t h y l ) t r i m e t h y l t i n , or attacks another hexamethylditin molecule giving the 1:1 adduct and another (CH 3) 3Sn r a d i c a l . Both of these steps may a l t e r n a t i v e l y be preceded by combination of ( C H 3 ) 3SnCF 2CF 2 with one or more tetrafluoroethylene molecules giving higher molecular weight d e r i v a t i v e s . The o v e r a l l reactions by these two routes can be described i n terms of the following equations, (CH 3)3Sn-Sn(CH 3) 3 2 (CH 3) 3Sn I n i t i a t i o n : (CH 3)3Sn + CF2=CF2 * (CH 3) 3SnCF 2CF 2 Propagation: (CH 3) 3 S n C F 2 C F 2 + CF2=CF2 » (CH 3) 3SnCF 2 C F 2 C F 2 C F 2 , etc. Chain t r a n s f e r : (a) (CH 3) 3 S n ( C F 2 C F 2 V + (CH 3) 3Sn-Sn(CH 3) 3 * (CH 3) 3Sn(CF 2CF 2) nSn(CH 3) 3 + (CH 3) 3Sn, etc. or (b) (CH 3) 3Sn(CF 2CF 2) n- + -C-H * (CH 3) 3Sn(CF 2CF 2) nH + ^C, etc. Sec. II-B-1 17 As can be seen from the above equations, the propagation step w i l l be favoured by carrying out the reaction at room temperature because of the higher proportion of tetrafluoroethylene i n gas phase, where most of the reaction takes place, leading to an increase i n the values of n. At higher temperatures, the vapour pressure of hexamethylditin w i l l be increased which favours the chain transfer reactions, thus y i e l d i n g the products with lower number of n. This argument i s i n accord with the experimental r e s u l t s . S i m i l a r l y , i n the photochemical addition of t r i c h l o r o s i l a n e to tetrafluoroethylene (53), the reaction was c o n t r o l l e d by f i x i n g the r a t i o of the reactants to give mainly the compound SiCl3[CF 2CF 2]nH with n = 1. I t i s possible for the present reaction, that at the b o i l i n g point of the d i t i n (180°) with u l t r a v i o l e t i r r a d i a -t i o n , the compounds with n = 1 might be formed almost e x c l u s i v e l y with none of the longer carbon chain products. However, i t i s also l i k e l y that under these more vigorous conditions, decomposition to t r i m e t h y l t i n f l u o r i d e and fluorocarbons would be quite extensive. Although the present r e s u l t s have shown that u l t r a v i o l e t i r r a d i a t i o n markedly a f f e c t s the course of the reaction, there i s s t i l l no d e f i n i t e evidence to exclude a molecular, four-centred type of mechanism. - Furthermore, the problem of the mechanism of t h i s addition involving the d i r e c t i o n of r a d i c a l - a t t a c k i s also a matter of uncertainty. Q u a l i t a t i v e information might r e s u l t from an i n v e s t i g a t i o n of the addition of hexamethylditin to unsymmetrical f l u o r o - o l e f i n s , since any polar influence of the o l e f i n , as well as any s t e r i c e f f e c t , may then become apparent. Sec. II-B-2 18 2. Reaction with hexafluoropropene. Four experiments were performed under d i f f e r e n t conditions and the r e s u l t s are summarized i n TABLE 2. I t i s apparent that the most favourable conditions are those of Exp, 1 i n which the two p r i n c i p a l products (CH 3) 3Sn(C 3F 6)nH and (CH 3) 3Sn(C 3F 6)nSn(CH 3) 3 where n=l were formed almost e x c l u s i v e l y . At 90° (Exp. 2) the y i e l d of the 1:1 adduct was decreased markedly due to decomposition, while at 25° (Exp. 4) the formation of the 1:1 adduct was almost n e g l i g i b l e . That decompositions occurred more r a p i d l y i n Exp; 2 i s confirmed by the increasing y i e l d of tetramethyltin and by the decreasing y i e l d of (CH 3) 3Sn(C 3Fg)H. The reaction c a r r i e d out i n the Pyrex tube (Exp. 3) afforded only a trace of adducts. This obviously indicates the important e f f e c t of u l t r a v i o l e t l i g h t and heat on the reaction of hexamethylditin with hexafluoropropene. (1,1,2,3,3,3-Hexaf luoropropyl) t r i m e t h y l t i n j(CH 3) 3SnCF 2CF (CF 3)H t and 1,2-bis(trimethyltinhexafluoropropane, (CH 3) 3SnCF 2CF(CF 3)Sn(CH 3) 3, both colourless l i q u i d s and f a i r l y stable i n a i r , were p u r i f i e d by gas chromatography and vacuum d i s t i l l a t i o n , r e s p e c t i v e l y . These two products were r e a d i l y characterized s p e c t r o s c o p i c a l l y as w i l l be described i n f u l l d e t a i l i n Sec. IV-A,B. The compound, (CH 3) 3Sn(C 3Fe)H, may have two possible isomers, based on the structure of the reactant CF 2=CFCF 3, namely (CH 3) 3SnCF 2CF(CF 3)H (I) and HCF 2CF(CF 3)Sn(CH 3) 3 (II) Sec. II-B-2 19 TABLE 2 REACTION RESULTS OF (CH 3) 6Sn 2 AND C F 2 = C F C F 3 > - Exp. 1 Exp. 2 Exp. 3 Exp. 4 gram (mmole) gram (mmole) gram (mmole) gram (mmole) St a r t i n g ( CH 3) 6Sn 2 7.2 (22.0) 7.1 (21.7) 7.2 (22.0) 7.2 (22.0) Material CF 2=CFCF 3 3.84 (25.6) 3.84 (25.6) 3.3 (22.0) 3.45 (23.0) Reaction Conditions Carius tube Temperature Time (hour) S i l i c a 70° 8 S i l i c a 90° 4 Pyrex 25° 130 S i l i c a 25° 36 gram (%) gram (%) gram (%) gram (%) Recovery (CH 3) 6Sn 2 CF 2=CFCF 3 0.7 a ( ? ) 1.45 (38.0) 0.4 a ( ? ) 2.38 (62.0) 4.7 (65.0) 2.3 (69.5) 3.4 a ( ? ) 2.15 (62.0) Continue to next page, (a) Recovered i n part i n the 0° trap. Sec. II-B-2 20 TABLE 2 (continued.) Exp. 1 Exp. 2 Exp. 3 Exp. 4 gram (mmole) gram (mmole) gram (mmole) gram (mmole) CF 2=CHCF 3 trace (ca. 0.1) — — CF3CFHCF3 (0.1) (0.3) b Trace — (CH 3) 4Sn 0.75 (4.2) 1.1 (6.2) 0.44 (2.5) 0.19 (1.0) (CH 3) 3SnCF 2CFHCF 3 1.2 (3.8) 0.59 (1.9) 0.70 (2.2) 0.76 (2.4) Pro-duct (CH 3) 3SnCF 2CF(CF 3)Sn(CH 3) 3 Higher M.W. adducts 1.2 (2.5) Trace 0.3 Trace 0.1 M e t a l l i c t i n formed None Yes None None c Black gum 1.0 1.5 0.85 0.4 (CH 3) 3SnF and polymeric C-F compounds — — 1.30 — Mixture of [(CH 3) 3Sn] 20,(CH 3) 3SnF, and polymeric C-F compounds d 3.7 d 2.7 — d No record (b) Only detectable by the i n f r a r e d spectra. (c) Recovered as residues from sublimation. The figures are approximate values. (d) Since the c h i e f part of the unreacted (CH 3)gSn 2 remained i n the i n v o l a t i l e residue, the unreacted material was removed from the products by means of Oxidation with oxygen, converting i t to a s o l i d (oxide) which, as well as (CH 3) 3SnF, was then centrifuged o f f . The recoveries of ( C H 3) 6Sn 2 and (CH 3) 3ShF were not determined i n d i v i d u a l l y . Sec. II-B-2 21 Only compound (1) was obtained throughout the four experiments. As described e a r l i e r , compound (1) could be formed neither from decom-p o s i t i o n of the 1:1 adduct nor by hydrogen abstraction by the o l e f i n to give CF 2-CF(CF 3)H as the f i r s t step. I t i s thus reasonable to assume that the (CH 3) 3Sn r a d i c a l attacks CF 2=CFCF 3, probably e x c l u s i v e l y on the CF 2 group. Thus the reactions may be: (CH 3) 3Sn-Sn(CH 3) 3 - M i 2(CH 3) 3Sn I n i t i a t i o n : (CH 3) 3Sn + CF 2=CFCF 3 s» (CH 3) 3SnCF 2CF(CF 3) Propagation: (CH 3) 3SnCF 2CF(CF 3) + CF 2=CFCF 3 =. (CH 3) 3SnCF 2CF(CF 3)CF 2CF(CF 3), etc. Chain t r a n s f e r : (a) (CH 3) 3SnCF 2CF(CF 3) + -HC-H »» (CH 3) 3SnCF 2CF(CF 3)H + -C, etc. or (b) (CH 3) 3SnCF 2CF(CF 3) + (CH 3) 3Sn-Sn(CH 3) 3 > (CH 3) 3SnCF 2CF(CF 3)Sn(CH 3) 3 + (CH 3) 3Sn, etc. The d i r e c t i o n of addition of r a d i c a l s to unsymmetrical o l e f i n s may be considered from two rel a t e d aspects: ( i ) the r e a c t i v i t y of the attacking f r e e - r a d i c a l ( i . e . , the extent to whcih d e r e a l i z a t i o n of the lone electron occurs); and ( i i ) the n u c l e o p h i l i c or e l e c t r o p h i l i c character of the attacking r a d i c a l , i n conjunction with the s u s c e p t i b i l i t y toward n u c l e o p h i l i c or e l e c t r o p h i l i c attack of the o l e f i n . These two e f f e c t s may be assessed by inspecting TABLE 3. Sec. II-B-2 22 TABLE 3 RADICAL ADDITION TO CF 2=CFCF 3. Fre e - r a d i c a l attacking Attack (%) on the carbon atom with a s t e r i s k . * CF 2=CFCF 3 CF 2=CFCF 3 Reference (CH 3) 3Sn Exc l u s i v e l y Not detected This work (CH 3) 3 S i 96 4 (54) (CH 3) 2SiH 95 5 (54) (CH 3) 2S 91 9 (55) CF 3 80 20 (54) (CH 3)SiH 2 76 24 (54) CF 3CH 2S 70 30 (55) PH 2 66 34 (54) S i H 3 60 40 (54) SF 5 50 50 (56) CF 3S 45 55 (55) Sec. II-B-3 23 Considering ( i ) , one would expect that the more reactive r a d i c a l would lead to l e s s d i s c r i m i n a t i o n i n the p o s i t i o n of attack on an o l e f i n . Examination of the table where the more rea c t i v e r a d i c a l s • • • • include CF 3S,CH 3S, H 3 S i , and ( C H 3 ) 3 S i , f a i l s to support t h i s p r e d i c t i o n . R e a c t i v i t y thus may have i t s e f f e c t mainly on the rate of reaction. Regarding ( i i ) , the r a d i c a l most reactive towards an o l e f i n which i s susceptible to n u c l e o p h i l i c attack, should be the one bearing the most powerful electron-releasing substituents, e.g., ( C H 3 ) 3 S i > (CH 3) 2SiH > (CH 3)SiH 2; or CH3S > CF 3CH 2S > CF 3S. Consequently, the reverse trend should also be true for attack on an o l e f i n which i s susceptible to. e l e c t r o p h i l i c attack. TABLE 3 i l l u s -t rates c l e a r l y that hexafluoropropene i s very s e n s i t i v e to n u c l e o p h i l i c r a d i c a l s which attack e x c l u s i v e l y on the CF 2 group of CF 2=CFCF 3. The (CH 3) 3Sn r a d i c a l i s thus, i n t h i s sequence, nearly as s p e c i f i c as the ( C H 3 ) 3 S i r a d i c a l towards hexafluoropropene, and possesses a high degree of n u c l e o p h i l i c character. 3. Reactions with t r i f l u o r o e t h y l e n e and with 1,1-difluoroethylene. As a t h i r d i l l u s t r a t i o n of olefin addition to the t i n - t i n bond, the reactions with some polyfluoroethylenes have been studied. The r e s u l t s of the reaction of hexamethylditin with t r i f l u o r o e t h y l e n e are summarized i n TABLE 4. The best conditions, as shown i n the table, required a temperature of 85-105° with u l t r a v i o l e t i r r a d i a t i o n of the Sec. II-B-3 24 TABLE 4 REACTION RESULTS OF (CH 3) 6Sn 2 AND CF 2=CFH. Exp. 1 Exp. 2 Exp. 3 Exp. 4 gram (mmole) gram (mmole) gram (mmole gram (mmole) St a r t i n g ( C H 3 ) 6 S n 2 7.85 (24.0) 21.0 (64.2)a 6.73 (20.5) 7.0 (21.4) Material CF2=CFH 1.96 (24.0) 3.8 (46.0) 1.8 (22.0) 1.7 (21.1) Reaction Conditions Carius tube Temperature Time (hour) S i l i c a 85° 4 S i l i c a 95° 8 S i l i c a 105° 14 S i l i c a 45° 20 gram (%) gram (%) gram (%) gram (%) Recovery ,-( C H 3 ) 6 S n 2 CF2=CFH 2.7 (35.0) 0.43 (22.0) 11.0 (33.4) C 0.68 (18.0) 0.7 b 0.54 (30.0) 6.7 (96.0) Not recorded Continue to next page (a) 40% i n excess (18.3 mmole i n excess). (b) Recovered i n part i n the 0° trap. (c) Recovery: 11 g. = 33.6 mmole, 18 mmole i n excess, % recovery = 3 3 ^ _ z J L 8 x 1 0 Q = 3 3 - 4 % _ Sec. II-B-3 25 TABLE, 4 (continued.) Exp. 1 Exp. 2 Exp. 3 Exp. 4 gram (mmole) gram (mmole) gram (mmole) gram (mmole) C-F gas condensed at -126° Trace Trace (0.21) None ( C H a U S n 0.35 (1.95) 0.51 (2.85) 0.57 (3.2) None (CH 3) 3SnCFHCF 2H and (CH 3) 3Sn(CFHCF 2) 2 H 0.15 0.9 0.08 None (CH 3) 3SnCFHCF 2Sn(CH 3) 3 — 1.2 d — None Pro-duct (CH 3) 3Sn(CFHCF 2) 2Sn(CH 3) : 1.1 1 (2.2) 0.7 d (1.4) 1.7 (3.5) Not iden-t i f i e d Uncondensable gas (0.12) (0.20) (0.47) None M e t a l l i c t i n formed Trace Trace ca. 0.3 None Blackish brown o i l 1.0 4.2 0.8 Trace S o l i d part Not recorded 3.2 f 3.2 g (CH 3) 3SnF 0.15 (0.8) (d) The d i s t r i b u t i o n was estimated from proton N.M.R spectrum where peaks due to methyl group were integrated. (e) Recovered from vacuum d i s t i l l a t i o n . (f) (CH 3) 3SnF and polymeric C-F compounds. (g) Mixture of (CH 3) 3SnF, [ (CH 3) 2 S n ] 2 0 , polymeric C-F compounds. Sec. II-B-3 26 s i l i c a reaction tube 0 The two series of products (CH 3) 3Sn(C 2F3H)nH and (CH 3)3Sn(C2F3H)nSn(CH3)3 again must r e s u l t from e i t h e r hydrogen abstraction or by i n s e r t i o n into t h e . t i n - t i n bond,, At 85° with four-hour i r r a d i a t i o n , ( 1 , 2 , 2 - t r i f l u o r o e t h y l ) t r i m e t h y l t i n , (CH 3)3SnCFHCF 2H, and (1,2,2,3,4,4-hexafluorobuty1)trimethyltin, (CH 3)3SnCFHCF 2CFHCF 2H, were formed. The evidence for these two products, both colourless l i q u i d s , was obtained by 1H N.M„R* spectroscopic study (see Sec. VI-D-4), although they could not be i s o l a t e d i n a.pure state. Under the same conditions, the adduct was formed with n=2 ex c l u s i v e l y ; 1,4-bis(trimethyltin)1,1,2,3,3,4-hexafluorobutane, (CH 3)3SnCF 2CFHCF 2CFHSn(CH 3) 3, an a i r stable, pale yellow o i l , obtained as an about 95% pure product, 1 1 9 was characterized by means of both H and F N.M.R. and i n f r a r e d spectra (See Sec. VI-D-4). Formation of these two se r i e s of products containing two units of - C F 2 C F H - evidently indicates that the f r e e - r a d i c a l mechanism involves propagation as a second step, U.V, (GH 3)3Sn-Sn(CH 3)3 2(CH 3) 3Sn (CH 3) 3Sn + CF2=CFH (CH 3) 3SnCFHCF 2 (CH3 ) 3SnCFHCF 2 + CF2=CFH (CH 3) 3 SnCFHCF2 CFHCF 2, etc. \\ (CH3) 3Sn(CFHCF 2)nCFHCF 2 + ~C-H or (GH 3) 3Sn(CFHCF 2)nCFHCF 2H + -C (CH 3) 3Sn(CFHCF 2)nCFHCF 2 + (CH3 ) 3 Sn-Sn(CH3 ) 3 (CH 3)3Sn(CFHCF 2) n + 1Sn(CH3) 3 i+ (CH 3) 3Sn, etc. (n=0 or 1). Sec. II-B-3 27 The presence i n the hydrogen abstraction products of terminal -CF 2H groups rather than - C F H 2 groups strongly suggests that the addition of (CH 3) 3Sn r a d i c a l i s predominantly to the CFH group of t r i f l u o r o e t h y l e n e . This i s i n accord with other r a d i c a l additions, e.g., of CF^ (57) and C l 3 S i (58). According to the above equation, one would predict that the propa-gation reaction may be reduced by an increase i n concentration of the chain transfer reagent, hexamethylditin. Thus when hexamethylditin i n 40% excess was treated with t r i f l u o r o e t h y l e n e under u l t r a v i o l e t i r r a d i a t i o n at 90° for eight hours, a mixture of the 1:1 adduct, 1,2-b i s ( t r i m e t h y l t i n ) t r i f l u o r o e t h a n e [(CH 3) 3SnCFHCF 2Sn(CH 3) 3], and the 1:2 adduct was obtained i n the approximate r a t i o of 2:1. To lend further support to the f r e e - r a d i c a l concept, a heat-only experiment was performed. Neither the 1:1 adduct nor the 1:2 adduct was detected from the r e a c t i o n of hexamethylditin with t r i f l u o r o e t h y l e n e at 100° i n the dark for more than 10 hours. At such high temperature, however, the reduction of hexamethylditin seemed quite extensive. Thus thermal decomposition of hexamethylditin i n the presence of t r i f l u o r o e t h y l e n e gave m e t a l l i c t i n , tetramethyltin, and uncondensable gas, probably hydrogen. M e t a l l i c t i n was also formed extensively i n Exp. 3 where the temperature was 105°. The reaction between equimolar amounts of hexamethylditin and 1,1-difluoroethylene likewise occurred at 75° with six-hours i r r a d i a t i o n to give the hydrogen.abstraction products [ ( 2 , 2 - d i f l u o r o e t h y l ) t r i m e t h y l t i n , (CH 3) 3 5 n C H 2CF 2H, and (2,2,4,4-tetrafluorobutyl)trimethyltin, (CH 3) 3SnCH 2CF 2CH 2 C F 2 H ] and the adducts [1,2-bis(trimethyltin)-2,2-difluoroethane, ( C H 3 ) 3SnCH 2CF 2Sn(CH 3) 3, and 1,4-bis(trimethyltin)-2,2, 4,4-tetrafluprobutane, (CH 3) 3SnCH 2CF 2CH 2CF 2Sn(CH 3) 3]. However, with Sec. II-B-3 28 40% of excess hexamethylditin under u l t r a v i o l e t i r r a d i a t i o n at 92° for seven hours, i n addition to the products (CH 3) 3Sn(CFHCF 2)nH with n=l and 2, and the 1:1 adduct was e x c l u s i v e l y formed. This again c l e a r l y demonstrates the f r e e - r a d i c a l mechanism inv o l v i n g r a d i c a l attack e x c l u s i v e l y on the CH2 group of 1,1-difluoroethylene for the i n i t i a t i n g step, as was found for the r a d i c a l attack by CF 3(59), Br (60) or PH 2 (54). The factors responsible for the o r i e n t a t i o n of these two o l e f i n s with respect to the (CH 3) 3Sn r a d i c a l i n the i n i t i a t i n g step now must be considered. Since i n the e a r l i e r reaction with hexafluoropropene, the (CH 3) 3Sn r a d i c a l has been found to possess a high degree of n u c l e o p h i l i c character, one would expect (CH 3) 3SnCF 2CH 2 and (CH 3) 3SnCF 2CFH as the S- £+ S-r e s u l t s of the o l e f i n p o l a r i z a t i o n s CF2=CFH and CF 2=CH 2, re s p e c t i v e l y (60). Radical attack i n the reverse d i r e c t i o n , i n the present study, reveals that the n u c l e o p h i l i c character may not play too important a r o l e i n the reaction with t r i f l u o r o e t h y l e n e and 1,1-difluoroethylene as far as t h e i r orientations are concerned. It has been pointed out (61) that the order of f r e e - r a d i c a l s t a b i l i t y i s , i n general, « • » primary (-CH2) < secondary (=CH) < T e r t i a r y (=C) where the terms primary, secondary, and t e r t i a r y r e f e r not to the carbon skeleton but to the number of atoms or groups other than hydrogen attached to the carbon atom on which the lone electron i s located. By using t h i s simple r u l e an explanation can be given for the d i r e c t i o n of addition of the (CH 3) 3Sn r a d i c a l to these polyfluoroethylenes. Sec. II-B-3 29 Two sets of f r e e - r a d i c a l s (CH 3) 3SnCFHCF 2, (CH 3) 3SnCF 2CFH; and (I) (I') (CH 3) 3SnCH 2CF 2, (CH 3) 3SnCF 2CH 2 ( I D (II') may a r i s e from f r e e - r a d i c a l additions. From a comparison of t h e i r s t a b i l i t y using the above r u l e , (I) and (II) are expected to predominate over (I') and ( I I ' ) , and this i s as seen experimentally. Consequently, the homopolymers of fluoroethylenes r e s u l t i n g from the propagation step may also contain e x c l u s i v e l y t a i l to head u n i t s . The hexafluoropropene reaction may also be reconsidered i n t h i s connection. The two r a d i c a l s (CH 3) 3SnCF 2CFCF 3 and (CH 3) : 3SnCF(CF 3)CF 2 might be expected. Both r a d i c a l s have a t e r t i a r y carbon atom possessing the lone, ele c t r o n , and thus would have an approximately equal s t a b i l i t y . In t h i s case, therefore, the n u c l e o p h i l i c character of the (CH 3) 3Sn r a d i c a l might become important i n determining the p o s i t i o n of attack. An attempt by gas chromatrograph to p u r i f y (CH 3) 3SnCFHCF 2H and (CH 3) 3SnCH 2CF 2H was unsuccessful because they decomposed on the column under the conditions where pure (CH 3) 3SnCF 2CF 2H and (CH 3). 3SnCF 2CF(CF 3)H were i s o l a t e d . Thermal decomposition of (CH 3) 3SnCH 2CF 2H gave monofluoroethylene, CFH=CH2. I t should be noted that t h i s o l e f i n cannot be derived from (CH 3) 3SnCF 2CH 3 because the migration of g-hydrogen i s u n l i k e l y , further supporting the proposed formulation. The thermal i n s t a b i l i t y of -CFHCF2H and -CH 2CF 2H groups was also found (51) i n the analogous compounds (CH 3) 2SnH(CFHCF 2H) and 1 (CH 3) 2SnH(CH 2CF 2H)j, which y i e l d CFH=CFH and CH2=CFH, re s p e c t i v e l y . Haszeldine et a l . (58) have reported that i n the hydrolysis of polyfluorocarbon derivatives of Sec. II-B-4 30 t r i c h l o r o s i l a n e , loss of 6-fluorine occurred when the (3-group i s CF 2H with CFH as the a-group, but not when 3-group i s CF 2H with CF 2 as the a-group. The dif f e r e n c e i n s t a b i l i t y of -CFHCF2H and -CH 2CF 2H groups, compared with -CF 2CF 2H might be att r i b u t e d to the differ e n c e i n s t a b i l i t y of the -CH2-, -CFH-, and -CF 2- groups which i n turn may be accounted for by thermochemical data (62). For the se r i e s of ethanol, monofluoroethanol, and difl u o r o e t h a n o l , the data f o r heat of f l u o r i n a t i o n show that nine Kca l more heat i s l i b e r a t e d when a second hydrogen i s replaced by a f l u o r i n e atom than during the f i r s t f l u o r i n a t i o n step (62). 4. Reaction with t r i f l u o r o c h l o r o - and trifluorobromoethylenes. T r i f l u o r o c h l o r o e t h y l e n e , reacted with hexamethylditin at 90° with four-hour i r r a d i a t i o n , afforded e x c l u s i v e l y the hydrogen abstraction product, ( 1 ; 1 , 2 - t r i f l u o r o - 2 - c h l o r o e t h y l ) t r i m e t h y l t i n , (CH3)3SnCF2CFHCl, and secondary reaction products such as tetramethyltin, t r i m e t h y l t i n chloride and t r i m e t h y l t i n f l u o r i d e . Unexpectedly, no adduct was detected by a c a r e f u l spectroscopic examination on the reaction mixture. A f r a c t i o n , o r i g i n a l l y a colourless l i q u i d which condensed i n a 0° trap on the vacuum l i n e , changed i n colour to yellow, orange, and f i n a l l y became a brown s o l i d , giving tetramethyltin. This was the f i r s t time t h i s phenomenon..was observed i n the present study, and apparently, from the colour changes and the consequent formation of tetramethyltin, c a t a l y t i c polymerization (49) of hexamethyltin has taken place. Sec. II-B-4 31 When a s i m i l a r reaction with an equimolar r a t i o of reactants was c a r r i e d out i n n-pentane at 25° under 30-hour i r r a d i a t i o n , again adduct was not detected from the r e s u l t i n g mixture. Under such mild conditions, the products were (CH 3) 3SnCF 2CFHCl, (CH 3) 3SnCl, (CH 3) 3SnF. The c a t a l y t i c polymerization of hexamethylditin also occurred during the vacuum f r a c t i o n a t i o n of the v o l a t i l e products. C l e a r l y , the r a d i c a l (CH 3)3SnCF 2CFCl was formed as the r e s u l t of r a d i c a l attack of (CH 3) 3Sn predominantly on the CF 2 group of tr i f l u o r o c h l o r o e t h y l e n e , followed by hydrogen abstraction.to y i e l d (CH 3) 3SnCF2CFHCl. The or i e n t a t i o n of t h i s addition i s i n good • • • * agreement with many other reactions, e.g., CF 3, CC1 3 (63), Br (64), S i C l 3 (58), and VU2 (54) , where i n a l l cases the influence of the d i r e c t i o n of r a d i c a l attack was at t r i b u t e d mainly to the differe n c e i n s t a b i l i t y of the r a d i c a l s , RCF 2CFC1 > RCFC1CF 2. This i s understood i n terms of t h e - s t a b i l i z i n g e f f e c t (57). The two terminal groups -CFC1 and -CF 2 could be regarded as t e r t i a r y r a d i c a l s (61), but the dif f e r e n c e i n s t a b i l i t y may a r i s e from the fact that the former contains the chlorine atom which has a powerful s t a b i l i z i n g e f f e c t on the r a d i c a l , whereas the l a t t e r possesses only f l u o r i n e atoms which have a r e l a t i v e l y weak s t a b i l i z i n g e f f e c t (57.). The experimental r e s u l t s did not d i s c l o s e whether or not the adduct has been formed i n the photochemical reaction. The presence of t r i m e t h y l t i n c h l o r i d e , as well as t r i m e t h y l t i n f l u o r i d e i s a strong evidence for the following reactions, Sec. II-B-4 32 (CH 3) 3SnCF 2CFCl + (CH 3) 3Sn-Sn(CH 3) 3 1 |(CH 3) 3SnCF 2CF(Cl)Sn(CH 3) 3 ; + (CH3) 3Sn ! (CH 3) 3SnCF 2-CCl j + •FSn(CH3;)3 ClSn(CH 3) 3 (CH3)3SnCF=CFCl (CH3)3SnCF=CF2. This may not be the case because there was no (CH 3) 3SnCF=CFCl or (CH 3) 3SnCF=CF 2 i n the reaction mixture. Furthermore, t r i m e t h y l t i n f l u o r i d e and chloride might w e l l r e s u l t from thermal decomposition of (CH 3) 3SnCF 2CFHCl, Nevertheless, the fact that adducts could not be obtained from th i s reaction cannot be c l e a r l y explained without further study, but a s t e r i c e f f e c t (60) may be t e n t a t i v e l y suggested to account for the present r e s u l t . Hexamethylditin reacts i n a s l i g h t l y d i f f e r e n t manner with t r i -fluorobromoethylene. When a mixture of the reactants i n a 1:1 r a t i o was subjected to u l t r a v i o l e t i r r a d i a t i o n at room temperature, the products were ( p e r f l u o r o v i n y l ) t r i m e t h y l t i n , (CH 3) 3SnCF=CF 2.tetramethyltin, t r i m e t h y l t i n bromide, and t r i m e t h y l t i n f l u o r i d e . I t was s u r p r i s i n g that neither a hydrogen abstraction product nor adducts could be detected even under such mild conditions. These r e s u l t s i n conjunction with the concept of f r e e - r a d i c a l s t a b i l i t y i n d i c a t e that the following reactions may have taken place, Sec. II-B-4 33 (CH 3) 3Sn-Sn(CH 3) 3 U' V' 2 (CH 3) 3Sn (CH 3) 3Sn + CF 2=CFBr ^ ; (CH 3) 3SnCF 2CFBr (CH 3) 3SnCF=CF 2 + Br Br + (CH 3) 3Sn-Sn(CH 3) 3 3 - (CH 3) 3SnBr + (CH 3) 3Sn, etc. This i s consistent with the ease of formation of the reactive Br r a d i c a l under i r r a d i a t i o n (54, 57, 61 and 64). However, an a l t e r n a t i v e route to these products cannot be eliminated, (CH 3) 3Sn-Sn(CH 3)3 + CF 2=CFBr I (CH 3) 3SnCF 2CFBrSn (CH 3) 3 ;' (CH 3) 3SnCF=CF 2 + (CH 3) 3SnBr. A s i m i l a r reaction has been reported (35) (CH 3) 2As-As(CH 3) 2 + CF 2=CFBr (CH3) 2AsCF 2CFBrAs (CH3) 2 *• (CH 3) 2AsCF=CF 2 + (CH 3) 2AsBr It i s i n t e r e s t i n g to note that a large amount of brown s o l i d had formed on the inside wall of the reaction tube by the end of the i r r a d i a t i o n . In the reaction of hexamethylditin with t r i f l u o r o c h l o r o -ethylene, t h i s brown s o l i d was also observed, not at the end of i r r a d i a t i o n , but during vacuum f r a c t i o n a t i o n . Apparently more extensive polymerization of hexamethylditin has occurred i n the reaction with trifluorobromoethylene. This might indicate that some species produced i n the reactions of hexamethylditin with t r i f l u o r o c h l o r o - and t r i f l u o r o -bromoethylenes act as powerful c a t a l y s t s for the polymerization of methyItin. Sec. II-B-5 34 5. Reaction with ethylene. In view of the successful addition of acetylenes to organotin hydrides to give compounds of the type R 3 S n C H 2 C H 2 S n R 3(65), i t was hoped that ( C H 3 ) 3 S n C H 2CH 2Sn(CH 3) 3 might be formed by the attack of the (CH3)3Sn r a d i c a l on ethylene. When an equimolar r a t i o of hexamethylditin and ethylene was radiated at 25° for one week, more than 90% of reactants were recovered. The only suspected product was a clear l i q u i d which condensed at -76° and which was shown chromatographically to consist of f i v e components including tetramethyltin, but no adducts could be detected. This i s i n sharp contrast to the sequence for the ease of r a d i c a l attack given by Haszeldine et a l . (60), i . e . , C 2H t + ^ CH2=CHCH3 ^ CH3CH=CHCH3 > CH 2=CF 2> CF 2=CF 2 > CF2=CHC1 > CF2=CFC1 > CF 2=CHCF 3 > CF 2=CFCF 3. This contradiction may be t e n t a t i v e l y explained i n terms of nucleo-p h i l i c or e l e c t r o p h i l i c character of the attacking r a d i c a l s . The above order was established by employing Br and CFg r a d i c a l s which are m anticipated to behave more as e l e c t r o p h i l e s than would the (CH3)3Sn r a d i c a l . Hence the ease of f r e e - r a d i c a l attack on the e l e c t r o n - r i c h carbon atoms of ethylene i s favoured with Br and CF3 r a d i c a l s , and the opposite trend might be true that the more n u c l e o p h i l i c (CH3)3Sn r a d i c a l more r e a d i l y attacks the electron-poor carbon atoms of tetrafluoroethylene. Sec. III-A 35 I I I . REACTIONS OF TRIMETHYLTIN-PENTACARBONYLMANGANESE WITH FLUORO-OLEFINS. A. Introduction The preparation of a non-ionic organometallic compound containing a t r a n s i t i o n metal and a Group IV metal was f i r s t reported by Hein et a l . (66) i n 1941. Compounds of t h i s type having a tin-manganese bond were recently synthesized by Gorsich (26) according to the following general reaction. R 4_ nSnCln + nNaMn(CO)5 — R 4. nSn[Mn(CO) 5]n + hNaCl. The tin-manganese compounds were described (26) as being thermally more stable than the analogous lead-manganese compounds. In compounds of the type (CgH 5) 3M-Mn(C0) 5 where M i s a Group IV metal, the oxidative s t a b i l i t y appears to increase i n the series S i < Pb < Ge < Sn (6). Several i n t e r e s t i n g reactions have been c a r r i e d out with the t r i p h e n y l t i n d e r i v a t i v e , (CgH 5) 3Sn-Mn(C0) 5 (26). Heating of t h i s compound with triphenylphospine or triphenylarsine causes the replacement of one mole of carbon monoxide, (C 6H 5) 3Sn-Mn(CO) 5 + L ( C 6 H 5 ) 3 -(C 6H 5) 3Sn~Mn(CO) 4L(C 6H 5) 3 + CO (L = P or As). Treatment of (Cg Hg) 3Sn-Mn(CO) 5 with tetraphenylcyclopenta-dienone at 190° causes the replacement of two moles of carbon monoxide to form the a i r s e n s i t i v e n-complex (Cg Hg ) 3 Sn-Mn(C0)3 [ tr - C 5 (C & )^ 0] , the Sec. III-A 36 structure of which i s proposed to be Of p a r t i c u l a r i n t e r e s t i s the reaction between (CgH 5) 3Sn-Mn(CO) 5 and chlorine, where the carbon-tin bond rather than the tin-manganese bond i s cleaved, { — (C 6H 5) 3Sn-Mn(CO)5 + 3C12 3 3 CI3Sn-Mn(CO) 5 + 3 C 6 H 5 C I . This i s i n agreement with recent work which demonstrates the s t a b i l i t y of bonds between t i n and other t r a n s i t i o n metals such as platinum (37, 67), rhodium, and i r i d i u m (67). In another cleavage reaction, the dip h e n y l t i n d e r i v a t i v e (C 6H 5) 2Sn[Mn(CO)5]2 (26) undergoes a two-step reaction with c h l o r i n e , probably f i r s t i n v o l v i n g rupture of the carbon-tin bond, followed by attack of the tin-manganese bond by ch l o r i n e , (C 6H 5) 2Sn[Mn(CO ) 5 ] 2 + 2 C 1 2 * Cl 2Sn[Mn(CO)5]2 + 2C6H5CI C l 3 S n-Mn ( C 0 ) 5 + ClMn(CO) 5. Hydrogen chloride i s considerably more s e l e c t i v e . I t cleaves only the carbon-tin bonds of ( C ^ ) 2 S n [ M n ( C 0 ) 5 ] 2 to give Cl 2Sn[Mn(CO) 5] 2 and benzene. I t i s c l e a r that the tin-manganese bond behaves d i f f e r e n t l y towards a v a r i e t y of reagents, but i t s chemical r e a c t i v i t y with respect to f l u o r o - o l e f i n s was unknown. In view of the easy i n s e r t i o n under s u i t -able conditions (such as u l t r a v i o l e t i r r a d i a t i o n etc.) of the o l e f i n s into the t i n - t i n bond, adducts containing a Sn-C-C-Mn skeleton are anticipated from s i m i l a r reactions of tin-manganese complexes with o l e f i n s , Sec. III-B-1 37 B. Results and Discussion. 1. Preparation and characterization of (CH3)3Sn-Mn(CO)5. This mixed-metal compound was prepared by treating trimethyltin bromide with an equimolar amount of sodium pentacarbonylmanganate(-I), according to the method described by Gorsich (26). (CH 3) 3SnBr + NaMn(CO)5 > (CH3)3Sn-Mn(CO)5 + NaBr. The reaction proceeded smoothly in tetrahydrofuran and the product -3 was purified by d i s t i l l a t i o n at A7°/10 cm. Hg, giving a 74% yield. Trimethyltin pentacarbonylmanganese, a white solid which melts at 29.5° to give a pale yellow liquid, is f a i r l y stable in a i r , in contrast to the hexaalkylditin compound, which form t i n oxides [e.g., (CH 3) 3Sn-0-Sn(CH 3) 3] on standing in air for brief periods. Either on heating at 130° for prolonged periods, or under ultraviolet irradiation for briefer periods, decomposition i s negligible, although under the latter condition an intense purple colour formed. (CH3)3Sn-Mn(CO)5 is readily soluble in most organic solvents, but decomposes,in some of them, e.g., i t yields a brown solid on prolonged standing in carbon tetrachloride solution. The infrared spectrum in the carbonyl stretching region of (CH3)3Sn-Mn(C0)5 shows three principal bands with the (2A^ +E) pattern, which evidently arise from the C symmetry of the Mn(C0)5 group (68j 69). This, and the locations of these bands, are characteristic of pentacarbonylmanganese complexes containing the Mn-M bond, e.g., M = Mn, Re (70) or Au (71). In the far infrared region, there are two absorptions attributable to the Sn-C asymmetric and symmetric modes Sec. III-B-1 38 c h a r a c t e r i s t i c of the (CH 3) 3Sn-M' group [M' = Sn (72)] . This c l e a r l y indicates that the t r i m e t h y l t i n group i s associated with pentacarbonyl-manganese through a tin-manganese linkage. The presence of the t i n -manganese bond i n (CH 3) 3Sn-Mn(CO) 5 i s confirmed by a N.M.R. spectroscopic 119 study. The value of the Sn-CH3 coupling constant, i n conjunction with the Sn-C stretching frequencies, i n d i c a t e s that the s-character of the t i n o r b i t a l s used i n the tin-manganese bond i s very s i m i l a r i n magnitude to those i n t i n - t i n (72), tin-molybdenum, and t i n - i r o n (8) bonds i n the corresponding t r i m e t h y l t i n d e r i v a t i v e s . Furthermore, the charge separation i n the tin-manganese bond i n (CH 3) 3Sn-Mn(CO) 5 i s apparently v i r t u a l l y n e g l i g i b l e . Abel (17) has stated that one of the strongest a f f e c t s upon the stretching frequencies of the terminal carbonyl groups i s the presence of a charge on the species. P o s i t i v e charges are found to r a i s e the carbonyl stretching -1 - l frequencies by roughly 100 cm. (from 2000 cm. where the terminal carbonyl groups i n neutral binary metal carbonyls absorb), while negative charges tend to lower them also,by about 100 cm. 1 , e.g., . ~1 , ' [Mn(C0) 6r, 2090 cm. ; [Mn^O^]\", i 8 9 5 and 1863 cm. . The present tin-manganese complex shows the average carbonyl absorptions, at about 2030 cm.\"1 , and hence i t i s anticipated to have a nearly neutral manganese atom. Discussion regarding the spectroscopic study of (CH 3) 3Sn-Mn(C0) 5 w i l l be given i n Section IV„ Sec. III-B-2 39 2. Reaction with tetrafluoroethylene. A series of reactions of (CH 3) 3Sn-Mn(CO 5 with te.traf luoroethylene was performed under d i f f e r e n t conditions, and the re s u l t s are summarized i n TABLE 5. As c l e a r l y seen i n the table, the reaction occurred r e a d i l y i n pentane solution-under u l t r a v i o l e t i r r a d i a t i o n at 50°, with about 70% consumption of the tin-manganese reactant a f t e r s i x hours,- Inter e s t i n g l y the intense purple colour which was observed i n the photolysis of (CH 3) 3Sn-Mn(C0) 5 alone, did not appear throughout the i r r a d i a t i o n periods of these experiments (and was also absent i n the reactions with other o l e f i n s ) . The p r i n c i p a l products were t r i m e t h y l t i n f l u o r i d e , obtained i n approximately 55% y i e l d , plus f i v e other compounds containing carbonyl-manganese groups. The 1:1 adduct, l-trimethyltin-2-pentacarbonylmanganesetetrafluoroethane, (CH 3) 3SnCF 2CF 2Mn(C0) 5 ( I I I ) a , was obtained as a white c r y s t a l l i n e s o l i d i n 14% y i e l d . In s l i g h t l y greater y i e l d (21%), a component which was shown on the basis of the a n a l y t i c a l r e s u l t s to have the composition C-(QFgMn05, was i s o l a t e d chromatographically. The in f r a r e d spectrum (Sec. IV-C) shows that t h i s component contains an Mn(CO) 5 group of nearly C^ v symmetry and a perfluorocarbon group with a terminal C=C bond. XH N.M.R. spectrum i 9 i n d i c a t e s the complete absence of hydrogen atoms, while i t s F N.M.R* spectrum consists of f i v e groups of absorptions centred at +110.0, (a) Compounds appearing i n th i s section w i l l be numbered i n accordance with the sequence used i n Section IV-C,D. Sec. III-B-2 . 40 TABLE 5 REACTION RESULTS OF (CH3),Sn-Mn(CO) AND CF 2=CF 2. Exp. 1 Exp. 2 Exp. 3 Exp. 4 gram (mmole) gram (mmole) gram (mmole) gram (mmole) Starting M aterial (CH 3) 3Sn-Mn(CO) 5 CF 2=CF 2 3.3 (9.2) 3.3 (32.8) 3.2 (8.9) 2.3 (22.7) 2.4 (6.8) 1.1 (11.3) 1.7 (4.7) 1.6 (16.2) Solvent Pentane (6 ml.) Pentane (10 ml.) None Pentane (2 ml.) Reaction U.V. l i g h t Yes Yes Yes None Conditions Carius tube S i l i c a S i l i c a S i l i c a Pyrex Temperature 50° 80° 70° 65° Time 6 hrs. 4 hrs. 4 hrs. 10 days Resulting reaction mixture Pale yellow l i q u i d with white s o l i d Orange l i q u i d with white s o l i d Orange l i q u i d with white s o l i d Colour-les s l i q u i d with white s o l i d gram (%) gram (%) gram (%) gram (%) (CH 3) 3Sn-Mn(CO) 5 1.0 (30). 1.1 (34) <1.0 (42) 1.5 (88) Recovery CF 2=CF 2 1.9 (58) 1.4 (61) 0.4 (36) 1.5 (93) Continue to next page Sec.III-B-2 41 TABLE 5 (continued). Exp. 1 Exp. 2 Exp. 3 Exp. 4 gram gram gram gram (mmole) (mmole) (mmole) (mmole) Uncondensable CO CO CO None gas (0.51) (0.05) (0.11) CF 2=CFC0Mn(C0) 5 0.4 0.3 Trace None (1.3) (1.0) C 5F 9Mn(CO) 5 0.8 0.5 ~0.2 None (1.9) (1.2) (~0.5) (CH 3) 3 SnCF 2CF 2Mn(CO) 5 0.6 0.3 Trace None (1.3) (0.7) -Pro- Dimer 1* 0.4 0.3 0.5 None Duct (0.8) (0.6) (1.0) Dimer 2* 0.2 0.1 Trace None (0.4) . (0.2) (CH 3) 3SnF 0.9 0.5 ~0.5 Trace (5.0) (2.7) (~2.7) Polymerized C 2 F^ None Trace -0.3 0.1 ( d . l ) Residue (gum) 0.1 Yes Yes None (No record) i (No record) (*) Isomers of [CF 2 =CFMn(C0)Lt ) 2 Sec. III-B-2 42 +33.4, +30.8, +17.5, and -14.2 p.p.m. ( r e l a t i v e to t r i f l u o r o a c e t i c a c i d ) , i n d i c a t i n g the presence of at lea s t f i v e kinds of f l u o r i n e atoms i n chemically nonequivalent environments. Unfortunately, an attempt to obtain a hyperfine structure for each absorption was unsuccessful, and hence an assignment of the 1 9 F N.M.R. spectrum could not be achieved. Accordingly, t h i s component can only be formulated as C5FgMn(CO)5 (IV), The other three products containing p e r f l u o r o v i n y l groups are perfluoroacryloylpentacarbonylmanganese, CF 2=CFC0Mn(C0) 5 (VII), and the two isomers of dimeric perfluorovinyltetracarbonylmanganese, [CF 2=CFMn(C0) 1 +] 2 [(VIII) and (IX)]. A l l of these carbonylmanganese complexes are f a i r l y stable i n a i r for prolonged periods. Some of t h e i r p h y s i c a l properties are l i s t e d i n TABLE 6. The structures of ( I I I ) , (VII), (VIII), and (IX) are r e a d i l y established s p e c t r o s c o p i c a l l y (Sec. IV-C, D). However, the l a s t two compounds could not be distinguished with respect to the s p e c i f i c stereo-isomers of the dimeric perfluorovinyltetracarbonylmanganese because t h e i r s o l u b i l i t i e s were too low to prevent a study of t h e i r 19 F N.M.R. spectra. Nevertheless, the a n a l y t i c a l data and the observed molecular weights of both (VIII) and (IX) are consistent with the formulation [CF 2 =CFMn(C0) 1 +] 2 , which can be regarded as a \"boat\" or \" c h a i r \" form of the dimeric r i n g structure, as shown i n Figure 1. Sec. III-B-2 43 TABLE 6 PHYSICAL PROPERTIES OF SOME CARBONYLMANGANESE DERIVATIVES. m.p. Colour S o l u b i l i t y (CH3) 3SnCF 2CF 2Mn(CO) 5 (III) 57.5° White v.s. i n a l l organic solvents. CgFgMnCCO) 5 . (IV) b Pale Yellow v.s. i n a l l organic solvents. CF2=CFCOMn(CO)5 (VII) 41.0° White c v.s. i n a l l organic solvents. [CF 2=CFMn(CO) i + ] 2 Dimer I (VIII) >150 o d White s. i n acetone, s.s. i n chloroform. Dimer II (IX) >150 o d White s. i n acetone. (a) v.s. = very soluble, s. = soluble, s.s. = s l i g h t l y soluble. (b) L i q u i d at room temperature. (c) Very v o l a t i l e s o l i d . (d) Decomposed without melting and did not sublime at 90°/10 cm. Hg. Sec. III-B-2 44 Figure 1. The boat and chair forms of [CF 2=CFMn(C0) 1 +] 2. It was shown i n TABLE 5 that, under the same i r r a d i a t i o n con-d i t i o n s , an increase i n temperature had no e f f e c t on the formation of the products, and t h i s became even more obvious when the reactants were heated i n the dark for 10 days, when no reaction occurred except some polymerization of the o l e f i n . It i s thus most s i g n i f i c a n t that u l t r a -v i o l e t i r r a d i a t i o n should cause such ready reaction and t h i s again indicates that a f r e e - r a d i c a l mechanism may be involved. It was also noted that the absence of solvent not only causes more rapid decomposition but also prevents the formation of the 1:1 adduct. This may well be due to the f a c t , as suggested e a r l i e r , that a f a c i l e one-phase reaction may take place i n the so l u t i o n due to the ready s o l u b i l i t y of tetrafluoroethylene i n n-pentane. Compound ( I I I ) , (CH 3) 3SnCF 2CF 2Mn(C0) 5, i s the f i r s t example of Sec. III-B-2 45 the I n s e r t i o n of an organic group into a mixed metal-metal bond, p a r t i c u l a r l y into the bond between a Group IV metal and a t r a n s i t i o n metal. An i n s e r t i o n of the tetrafluoroethylene molecule into the •transition m e t a l - t r a n s i t i o n metal bond has been reported (73). Treatment of octacarbonyldicobalt with tetrafluoroethylene at room temperature gives an orange c r y s t a l l i n e compound (CO) l tCoCF 2CF 2Co (CO) ^. A s i m i l a r compound (CO)5MnCF 2CF 2CF 2Mn(C0)5 has been prepared (74) by decarbonylation of the p e r f l u o r o g l u t a r y l d e r i v a t i v e (CO) 5MnC0(CF 2) 3C0Mn(C0)5. The three compounds containing p e r f l u o r o v i n y l groups, i . e . , (VII), (VIII), and (IX), are believed to form from compound (III) by an elimination of t r i m e t h y l t i n f l u o r i d e . The o v e r a l l reaction of (CH 3) 3Sn-Mn(C0) 5 with tetrafluoroethylene may be shown as follows: (i) U.V. (CH 3) 3Sn-Mn(CO) 5 + CF 2=CF 2 -» (CH 3) 3SnCF 2CF 2Mn(CO) 5 ( i i ) (CH 3) 3SnCF 2CF 2Mn(CO) 5 1 f CF2=CFMn(CO) «.] + (CH q) ^ SnF Dimerization 2C0 CF, / CF\\ / '* (CO)^Mn MntCO)^ \\ / \\ .CF / CF 0 5j ^\"3J 3\" Carbonylation + CO CF2=CFCOMn(CO)5 (\"boat and \" c h a i r \" forms) Sec. III-B-2 46 Since the structure of compound (IV), C 5FgMn(C0) 5, i s s t i l l uncertain, any suggestion as to the route of formation i s impossible. However, two possible ways of achieving t h i s compound are t e n t a t i v e l y proposed on the basis of the apparent molecular formula: ( i i i ) (CH 3) 3SnCF 2CF 2Mn(CO) 5 s» (CH 3) 3SnF + C 2F 3Mn(CO) 5 C 2F 3Mn(CO) 5 + C 3 F 6 C 5FgMn(CO) 5, or (iv) (CH 3) 3Sn(C 3F 6)Mn(CO) 5 — - ^ (CH 3) 3SnF + C 3F 5Mn(CO) 5 C 3F 5Mn(CO) 5 + C2Fk ^ C 5F 9Mn(CO) 5. The C F units must a r i s e from hexafluoropropene present as an impurity i n the tetrafluoroethylene. The t o t a l amount of hexafluoro-propene could well be considerable i n the great excess of o l e f i n employed i n the reaction. In f a c t , reactions ( i i i ) and (iv) may be proved by carrying out the reaction with a mixture of o l e f i n s containing a higher r a t i o of hexafluoropropene. It i s i n t e r e s t i n g to note that Stone et a l . (95) have encountered a s i m i l a r case. A compound of unknown structure, formulated as CH 3(C^F g)Re(CO) 5, was obtained from the reaction of CH 3Re(C0) s with tetrafluoroethylene ( i n 3:80 mole r a t i o ) at 130° for 19 four hours. This product gave an F N.M.R. spectrum showing two groups of peaks, and was described as having a fluorocarbon side chain. Although the 1:1 adduct (CH 3) 3SnCF 2CF 2Mn(C0) 5 i s formed under favourable conditions for f r e e - r a d i c a l addition ( i . e . , u l t r a v i o l e t i r r a d i a t i o n ) , a number of puzzling questions remain. F i r s t l y , i f f r e e -r a d i c a l attack occurred i n v o l v i n g the homolytic f i s s i o n of the t i n -manganese bond, a r a d i c a l (CH 3) 3SnCF 2CF 2 should be formed. Why then could no hydrogen abstraction product, e.g., (CH 3) 3SnCF 2CF 2H, be isolated? Sec. III-B-3 47 Secondly, why i s there no evidence for the propagation step of the .reaction, which would form compounds having more than one molecule of tetrafluoroethylene? The factors responsible for the above observations may become clear by extending i n v e s t i g a t i o n to the reactions with a v a r i e t y of unsymmetrical o l e f i n s . 3. Reaction with t r i f l u o r o e t h y l e n e . The reaction of (CH 3) 3Sn-Mn(CO) 5 with t r i f l u o r o e t h y l e n e also proceeds r e a d i l y under the same conditions i n which the -CF 2CF 2- unit was smoothly inserted into the metal-metal bond. Fewer secondary products were obtained and the reaction i s easier to follow. The main product was again t r i m e t h y l t i n f l u o r i d e i n almost quantitative y i e l d based on the recovery of the tin-manganese reactant. In addition, the c i s - and trans-isomers of ( l , 2 - d i f l u o r o v i n y l ) p e n t a -carbonylmanganese [(cis-CFH=CF)Mn(CO) 5 (V) and (trans-CFH=CF)Mn(C0) 5 (VI)], were also i s o l a t e d . These isomers e x i s t as a i r stable monomers, unlike the analogous, possibly intermediate, compound CF 2=CFMn(CO) 5 which eliminates carbonyl groups immediately to form the dimers. S u r p r i s i n g l y , no evidence could be found for the adduct, (CH 3) 3Sn(C 2F 3H)Mn(CO) 5, nor for hydrogen abstraction products. Compound (V), p u r i f i e d by r e c r y s t a l l i z a t i o n from cyclohexane s o l u t i o n , was obtained as f a i r l y v o l a t i l e , w h i t e needle-like c r y s t a l s , m.p., 78°. Its formulation as C 2F 2HMn(CO) 5 i s supported by elemental analyses and molecular weight measurements. Spectroscopic studies i n d i c a t e two possible structures for (V), which are shown as follows. A f u l l discussion of the d e r i v a t i o n of these structures i s given i n Section IV-C, D. Sec. III-B-3 48 OO 0=C 1-—C=0 8 V A V B The formation of structure (VB) would not be su r p r i s i n g because an analogous structure has been proposed (76) for C 2H3COCo(CO) 3, which was prepared according to the following reaction: CH2=CHC0C1 + NaCo(CO), Et 20_ /-.CO C H ^ C o — C O + CO X \"^CO 0 The coordination of the double bond to the cobalt atom i n C 2H 3C0Co(C0) 3 was shown by the in f r a r e d spectrum and by chemical evidence (76). In contrast to the carbonyl linkage i n a simple acylcobalt compound which -1 -1 . absorbs at 1720 cm. , t h i s complex has an ac y l carbonyl peak at 1850 cm. , i n d i c a t i v e of a highly strained system. Addition of iodine to the reaction mixture l i b e r a t e d three moles of carbon monoxide. Treatment of t h i s complex with triphenylphosphine gives no evolution of gas, but the 1850 cm. 1 peak disappeared from the r e s u l t i n g s o l u t i o n , and instead two new peaks were observed at 1670 and 1635 cm. These r e s u l t s were at t r i b u t e d to a displacement of the double bond rather than a terminal carbonyl group by triphenylphosphine, and the two new peaks were accounted for by the uncoordinated double bond and the ac y l Sec. III-B-3 49 group i n CH 2 = C H C 0 C o(CO) 3P(CgH 5) 3 , r e s p e c t i v e l y . In an attempt to i d e n t i f y structure (VB), the above method was employed. Compound (V) was refluxed with triphenylphosphine ( i n s l i g h t excess) i n an ether s o l u t i o n . Infrared examination of both the r e s u l t i n g s o l u t i o n and the solvent-free reaction mixture showed only the o r i g i n a l peak and no new peak a t t r i b u t a b l e to the double bond and acyl group. It thus appears that the correct configuration of compound (V) can only be deduced by an X-ray c r y s t a l l o g r a p h i c study which has been undertaken i n t h i s department under the supervision of Dr. J . T r o t t e r . Compound (VI), p u r i f i e d on a F l o r i s i l column, was obtained as a white s o l i d which i s more v o l a t i l e than i t s cis-isomer. Spectroscopic studies (Sec. IV C, D) c l e a r l y show (VI) to have the structure H F > = < F Mn(C0) 5 I t should be noted that t h i s compound and the dimers of [CF 2 =CFMn(CO)1+.] are among the few t r a n s i t i o n metal complexes containing a-bonded f l u o r o -v i n y l groups (77). The only other compounds having t h i s type of group are CF 2=CFRe(CO) 5 and CF 2=CFFe ( C 0 ) 2 ( i r-C 5H 5)., which were reported (78) while this work was i n progress. It i s concluded from the above r e s u l t s , that the o v e r a l l reaction of (CH3) 3Sn-Mn(C0)5 with t r i f l u o r o e t h y l e n e can be represented by the following equations: Sec. III-B-4 50 (CH 3) 3Sn-Mn(C0) 5 + CF2=CFH s> !fCH 3) 3SnCFHCF 2Mn(C0) 5| (CH 3) 3SnF (CFH=CF)Mn(C0)5 ( c i s and trans) It should be noted that the d i r e c t i o n of addition i s i n accord with that i n the reaction of t h i s o l e f i n with hexamethylditin, i . e . , the t i n atom i s linked with the -CFH group. An a l t e r n a t i v e o r i e n t a t i o n would give r i s e to the decomposition product CF2=CHMn(C0)5, which was not observed. 4. Reaction with t r i f l u o r o c h l o r o e t h y l e n e . Under the same conditions as i n the previous reactions, the reaction of (CH 3) 3Sn-Mn(C0)5 with t r i f l u o r o c h l o r o e t h y l e n e again gave t r i m e t h y l t i n f l u o r i d e but i n much smaller y i e l d (about 9%). In contrast, carbon monoxide ( i n very large amount compared with the •reactions with other o l e f i n s ) , as well as t r i m e t h y l t i n chloride i n considerable y i e l d (about 45%), were obtained. Again, no adduct con-taini n g the Sn-C-C-Mn group could be i s o l a t e d . Instead, the p r i n c i p a l product containing carbonylmanganese, was compound (VII), i . e . , CF 2=CFG0Mn(C0)5, obtained i n more than 60% y i e l d . Other products also having-an Mn(CO)5 group, were the c i s - and trans-isomers of (1,2-difluoro-2-chlorovinyl)penta-carbonylmanganese [(cis-CFCl=CF)Mn(C0)5 1 9 and (trans-CFCl=CF)Mn(C0)5]. These isomers were detected by the F N.M.R. spectra (Sec. VI-E-5), although they could not be i s o l a t e d i n the pure state because of the small y i e l d s . Sec. III-B-4 51 The formation of these three products indicates that the reaction might proceed as follows: (CH 3) 3Sn-Mn(CO) 5 + CF2=GFC1 ; (CH 3) 3SnCtFClCF2Mn(C0) 5] a-chlorine e l i m i n a t i o n a - f l u o r i n e elimination (CH 3) 3SnCl + [CFCF2M.n(CO) 5 ! CF2=CFMn(C0)5 (CH 3) 3SnF + ^CClCF2Mn(CO) 5 j Dimerization , + CO T CFCl=CFMn(CO) 5 C c i s and t r a n s ) CF2=CFC0Mn(C0)5 An a l t e r n a t i v e route to form (CFCl=CF)Mn(C0) 5 by migration of a chlorine atom may also be considered. Pyrolyses of the compounds CHFClCF 2SiCl 3 and C F C l C F 2 S i C l 3 (7 9) mainly gave the following decom-p o s i t i o n products CHFClCF 2SiCl 3 C F C l 2 C F 2 S i C l 3 250' * CHF=CFC1 +FS1CI3 -> CFC1=CFC1 + F S i C l 3 , i n a ddition to very small amounts of the o l e f i n s CHC1=CF2 and CC1 2=CF 2, . res p e c t i v e l y , which would be formed by release of f l u o r i n e atoms from the p-position with respect to s i l i c o n atom. Consequently, the mechanism was described (79) such that the i n i t i a l step i n the p y r o l y s i s involves i n t e r n a l n u c l e o p h i l i c attack on a s i l i c o n atom by a a - f l u o r i n e atom, followed by migration of an atom other than f l u o r i n e from the 8-po s i t i o n , Sec. III-B-4 52 Thus the o v e r a l l reaction of (CH3)3Sh-Mn(CO)5 with t r i f l u o r o c h l o r o e t h y l e n e may be revised i n the following way: (CH 3) 3Sn-Mn(CO) 5 + CF2=CFC1 U - V \" 0(1 1 (CH 3) 3SnCF 2CFClMn(CO)5 B-Cl elimination a-F elimination K + CO (CH 3) 3SnF + I^CFCFClMn(CO) 5} 3-C1 ^ migration (CH 3) 3SnCl + CF2=CFCOMn(CO)5 CFCl=CFMn(CO) 5 I t i s then clear that t h i s reaction provides no information regarding the d i r e c t i o n of addition, but gives r i s e to the questions: (a) Why was there no c h l o r i n e - a b s t r a c t i o n by manganese atom? !(CH3) 3Sn(C 2F 3Cl)Mn(CO) 5\"! (CH 3) 3SnCF=CF 2 + ClMn(C0) 5 r i 1 lclMn(CO)J 2 + 2CO. r T (b) Why does dimerization of jCF 2=CFMn(C0) 5; not occur? ». J 2 |CF2=CFMn(C0) 5 j e- |cF2=CFMn(C0) 4] 2 + 2C0 (boat and chair forms). These compounds [(CH 3) 3SnCF=CF 2, and the dimers] were not detected i n t h i s experiment, although ClMn(C0) 5 and [ClHn(C0) 1 +] 2 might well have been present i n the reaction residue which was not investigated further. A more d e t a i l e d r e i n v e s t i g a t i o n of the above reaction and a k i n e t i c study are required to provide answers to these questions. A tentative explanation of the c h l o r i n e - a b s t r a c t i o n by a s p e c i f i c metal atom could be given, however, i n terms of bond energy. The manganese-chlorine bond -1 energy i s 69 Kcal mole (80), smaller than that of the t i n - c h l o r i n e Sec. III-B-4 53 -1 bond (76 Kcal mole ), so that i n competition for bond formations, the l a t t e r bond i s probably favoured over the former. In view of the high y i e l d of CF 2=CFC0Mn(C0) 5, i t i s s i g n i f i c a n t to consider here the factors responsible for the ease of carbonylation of CF 2=eFMn(CO) 5. Certain aspects of the decarbonylation of acylpentacarbonylmanganese de r i v a t i v e s have been studied i n great d e t a i l . Studies with l a b e l l e d carbon monoxide have demonstrated (81) that the carbon monoxide molecule which i s l o s t does not come from the ac y l carbonyl group, but instead from one of the terminal carbonyl groups. This decarbonylation reaction i s therefore not to be regarded as the \"popping out\" of the acyl carbonyl group, as may have been suspected o r i g i n a l l y . Instead, i t appears to be due to-migration of the organic group, which was attached to the ac y l carbonyl group- o r i g i n a l l y , to the metal atom with simultaneous d i s p l a c e -ment of one of the terminal carbonyl groups. Therefore, the ease of decarbonylation w i l l depend on the bond strength between the organic group and the metal atom compared with that of M-CO bond. The carbonylation of pentacarbonylmanganese d e r i v a t i v e s has been observed i n many cases. For example, methylpentacarbonylmanganese reacts with carbon monoxide under pressure at 25° to give CH3C0Mn(C0)5 i n good y i e l d (82). Cotton et a l . (83a) have demonstrated that this carbonylation reaction i s f i r s t order with respect to both CH3Mn(CO)5 and carbon monoxide. In a further study they have deteirmined (83b) the dependence of the equilibrium constants ki and k 2 for the carbonylation and decarbonylation reactions on the nature of the organic group. kl RMn(CO)5 + CO RCOMn(CO) 5 Sec. III-B-4 . 54 The constant k 1 ? representing the rate of the carbonylation, was found (83b) to decrease i n the serie s R = n-C3H7 > C 2H 5 > C 6H 5 > CH3 » C 6H 5CH 2 % CF 3. I t thus appears that electronegative groups favour the decarbonylation reaction over the carbonylation reac t i o n . This may a r i s e from the tendency for such substituents on the a c y l group to withdraw electrons to a greater extent from the metal atom, leaving a lower electron density on the metal atom to p a r t i c i p a t e i n p a r t i a l double-bonding with the terminal carbonyl groups. Thus the bonding between ttie manganese atom and the terminal carbonyl groups i s weakened (42), leading to f a c i l e decarbonylation, since, as mentioned above, the carbon monoxide which i s l o s t , comes from one of the terminal carbonyl groups. Therefore, i t seems that the CF2=CF- group may be regarded, i n t h i s respect, as a les s electronegative group than other p e r f l u o r o a l k y l groups, and hence i n the reaction of (CH3)3Sn-Mn(CO)5 with t r i f l u o r o -chlproethylene, the carbonylation was so f a c i l e that carbon monoxide l i b e r a t e d during the decomposition of some of the pentacarbonylmanganese compounds i s able to carbonylate ^CF2=CFMn(C0)5| to give CF 2=CFC0Mn(C0) 5, ,-;:r- r - y o^c tt CF . CF i r — J C F OO i o=c^ . C S O T \\ O=C Mn >| Mn I ^ M n ' I \" O O I O H C ' ^ \" O O I O B C ' I I u J .00 CO This assumption i s consistent with the observations of other workers. A compound obtained from Na[Mri(C0) 5] and ethyl iodide, and o r i g i n a l l y thought to be C 2H 5Mn(C0) 5 (84), was l a t e r demonstrated to be the Sec. III-B-6 55 propibnyl d e r i v a t i v e C 2H 5COMn(CO) 5 (85). On the other hand, C o f f i e l d et a l . (81) reported that the trifluoromethyl d e r i v a t i v e CF 3Mn(CO) 5 could not be carbonylated to CF 3COMn(CO) 5. Furthermore, the y i e l d of carbon monoxide i n the present reaction i s much greater than that i n the reaction with tetrafluproethylene. This i s consistent with the r e l a t i v e y i e l d s of CF2=CFC0Mn(C0)5 i n these two reactions. 5. Reaction with ethylene. • • • • The f i n a l o l e f i n reacted with (CH 3) 3Sn-Mn(C0)5 was ethylene. These reactants were i r r a d i a t e d i n pentane at 50° for four hours, and then at 80° for 20 hours. The reaction product was again not an adduct but, unexpectedly, an ethylene-?-bonded complex, tr i m e t h y l t i n - t e t r a c a r b o n y l -( T T-ethylene)manganese [ (CH 3) 3Sn-Mn(CO)4 (Tr-C^H^) ( I I ) ] , was i s o l a t e d i n 43% y i e l d , together with i t s corresponding amount of carbon monoxide. The reaction was shown on the basis of the carbon monoxide obtained, to be almost 65% complete at the end of the f i r s t four-hour i r r a d i a t i o n period. Compound ( I I ) , a pale yellow o i l , was separated by vacuum sublimation and decomposes slowly to give a dark brown s o l i d when i t i s allowed to stand i i i a i r . An attempt to p u r i f y (II) on a F l o r i s i l column was not successful because of decomposition. However, the sublimed product was shown by elemental analyses, a molecular weight measurement, and spectroscopic studies (Sec. IV-C, D) to be a pure compound, and i t i s proposed that' i t has the -following structure: (a) The term \"sublimation 1 1 used here means that a d i s t i l l a t i o n of t h i s o i l was performed using the same technique as the sublimation of s o l i d s (see Sec. VT^-B). Sec. III-B-5 56 CO CO \\ / CH 2 (CH 3) 3Sn M n ^ — | (II) / \\ CH 2 CO CO Assuming that t h i s molecule has an octahedral configuration about the manganese atom, then c i s - and trans-isomers are expected. On the basis of the i n f r a r e d spectrum, compound (II) i s expected to be a cis-isomer rather than a trans-isomer because there i s more' than one absorption i n the carbonyl region (Sec. IV-C). A trans-isomer would have only one absorption. The H N.M.R. spectrum of ( I I ) , however, shows only a sing l e peak at -2.65 p.p.m. (with respect to tetramethylsilane) which could only a r i s e from a trans-isomer. This disagreement between the i n f r a r e d arid N.M.R. spectroscopic r e s u l t s i i s t e n t a t i v e l y a t t r i b u t e d to an extremely rapid exchange between coordinated and free ethylene molecules which would give r i s e to a sin g l e peak i n the N.M.R. spectrum. This may be compared with the corresponding s i n g l e peak observed for? the Sn-Pt\"*- ( , n-C 2 Hi + ) complex (37). The formation of (II) through the reaction (CH 3) 3Sn-Mn(C0) 5 + CH 2 = CH 2 U.V.^ (CH 3) 3Sn-Mn(CQ) h(TT-C^) + CO i s not s u r p r i s i n g because several s i m i l a r complexes i n addition to the formation of (06%) 3Sn-Mn(C0) 3 [ 7 r r - C 5 ( C 6 H 5 ) ^ 0] (26), have b een reported. An ethylene complex ( T r-C 5H5)Mn(C0) 2 ( T T — C 2 H i + ) was prepared by the r e a c t i o n of ( i T-C5H5)Mn(CO) 3 and ethylene under u l t r a v i o l e t i r r a d i a t i o n (86). Later, an ethylene complex cation [Mn (CO) 5 (TT-C 2H[ + ) ]\"*\" was also synthesized i n the same manner (87). Sec. I l l 5 The f a c t t h a t e t h y l e n e denotes a p a i r o f i T - e l e c t r o n s t o t h e t r a n s i t i o n m e t a l i n s t e a d o f i n s e r t i n g i n t o t h e tin-manganese bond prompted a s t u d y o f t h e c a t a l y t i c b e h a v i o u r , o f (CH 3)3 S n-Mn ( C 0 ) 5. A m i x t u r e o f (CH3)3Sn-Mn(C0)5 i n p e n t a n e , e x c e s s e t h y l e n e , and e x c e s s h y d r o g e n gas (1 atmosphere) was a l l o w e d t o r e a c t under u l t r a v i o l e t i r r a d i a t i o n f o r . f o u r h o u r s . The r e a c t i o n p r o d u c t s were (CH3) 3Sn-Mn(CO) 4 (ir - C 2 H i t ) and, u n e x p e c t e d l y , o n l y a t r a c e o f ethane w h i c h might w e l l be formed s i m p l y t h r o u g h u l t r a v i o l e t i r r a d i a t i o n . I n c o n t r a s t t o t h e p r e s e n t r e s u l t s , a f a c i l e homogeneous h y d r o g e n a t i o n o f e t h y l e n e o v e r a p l a t i n u m - t i n bonded c a t a l y s t has been r e p o r t e d ( 3 7 a ) . T h i s c a t a l y t i c complex was shown by X - r a y s t u d i e s (37b) t o be a f i v e - c o o r d i n a t e d p l a t i n u m ( I I ) s p e c i e s c o n t a i n i n g ( S n C l 3 ) l i g a n d s a t t a c h e d t h r o u g h t h e p l a t i n u m - t i n bonds. The d i f f e r e n c e i n c a t a l y t i c a c t i v i t i e s o f t h e above two t y p e s o f m e t a l -3 m e t a l bonded complexes, (CH 3) 3Sn-Mn(CO)5 and [ ( C l 3 S n ) 5 P t ] , may be a t t r i b u t e d t o t h e s t r o n g t r a n s - a c t i v a t i n g e f f e c t o f t h e S n C l 3 ~ group w h i c h f a c i l i t a t e s l i g a n d - e x c h a n g e r e a c t i o n s (37b) . Sec. IV-A-1 58 IV. SPECTROSCOPIC STUDIES A. The Infrared Spectra of the Fluorocarbon Derivatives of Trim e t h y l t i n . 1. Introduction to the i n f r a r e d bands associated with the t r i m e t h y l t i n group. As the positions of the fundamental v i b r a t i o n s . f o r the organotin compounds possessing a four-co-ordinate, tetrahedral configuration have, been thoroughly established by many workers (88), the assignments of the in f r a r e d spectra f o r the compounds containing ( C H 3 ) 3Sn group can be r e a d i l y made. Most of t r i m e t h y l t i n derivatives e x h i b i t i n the 4000-600 cm. region the c h a r a c t e r i s t i c frequencies which are given below. _1 Frequencies (cm. ) Assignments * 3000 - 2900 C-H asym. and sym. s t r . 1450 - 1400 CH 3 asym. def.. 1220 - 1200 CH 3 sym. def. 790 - 760 CH3-Sn rocking * asym, asymmetric; sym., symmetric; s t r . , s t r e t c h i n g ; def., deformation. The i n f r a r e d bands associated with tin-carbon s t r e t c h i n g modes i n the f a r i n f r a r e d region are more variable i n t h e i r frequencies, and .are very c h a r a c t e r i s t i c f o r each of the following types of the methyltin compounds: (CH 3) 3SnX where X i s CI, Br, or fluorocarbon; t r i m e t h y l t i n f l u o r i d e which i s known. (89) to contain e s s e n t i a l l y five-co-orojinate t i n atom surrounded by three carbon atoms on a t r i g o n a l plane; t e t r a -Sec. IV-A-2 59 methyltin; and t r i m e t h y l t i n compounds containing a t i n - t i n bond. These c h a r a c t e r i s t i c frequencies, which are l i s t e d as follows, w i l l be important i n i d e n t i f y i n g the products of ..this study. type of _1 compound Frequency (cm. ) Reference Sn-C asym. s t r . Sn-C sym. s t r . (CH 3) 3SnX 550-54G 530-510 (88) (CH 3) 3SnF 553 ; i n f r a r e d i n a c t i v e (90) (CHgJ^Sn 524(liquid) i n f r a r e d i n a c t i v e (91) 529(gas) Sn-Sn 520-510 500-495 (72) compounds 2. Introduction to the i n f r a r e d bands associated with fluorocarbon groups... U n t i l recently l i t t l e has been published: on^the subjOct o f ' v i b r a -t i o n a l spectra of perfluoro-organometallie compounds (92,93,94), and band assignments are s t i l l d i f f i c u l t to make because no d e t a i l e d corre-l a t i o n rules have been formulated f o r fluorocarbon frequencies. Never-theless, fluorocarbon groups show very strong absorptions associated with fluorine-carbon vibration.modes i n the 1400-1000 cm. region of the spectrum. This property has been extremely useful i n the i d e n t i -f i c a t i o n of fluorocarbon-metal d e r i v a t i v e s . By examining:; the i n f r a r e d spectrum of the reaction products, i t i s possible to e s t a b l i s h how f a r the synthesis of a fluorocarbon d e r i v a t i v e of a metal has proceeded. Even though the desired compound i s d i l u t e d considerably by mixing with non-fluorine-containing substances, the strong fluorine-carbon absorptions Sec. IV-A-2 60 are s t i l l obvious. Carbon-fluorine absorption frequencies, of several series of fluoro-carbon compounds are l i s t e d i n TABLES 7, 8 and 9 accordingly. TABLE 7 _1 * C-F,ABSORPTION BANDS (cm. ) IN THE IR SPECTRA OF SOME POLYFLUORO-ALKANES CH3-CH2F CH3-CHF2 CH3-CF3 CC13-CF3 Cl 2CFrCF 3 C1CF2-CF3 CF 3-CF 3 CF 3. s t r . 1280 1233 1255 1227 1295 1232 1351 1241 1315 1250 1115 CF2 s t r . 1171 1143 1185 1133 CF s t r . 1171 1108 1110 C-C s t r 880 868 830 909 943 982 810 CF3 def. 541 561 490-590 648 715 620 Ref. (95) • (95) (95) (96) (96) (96) (96) (*) A l l bands are strong to very strong i n i n t e n s i t y . The i n f r a r e d bands l i s t e d i n Table 7 were assigned by Nielson et a l . on a t h e o r e t i c a l basis (95.96). Stone.et a l . (94,22,97) assigned those i n f r a r e d bands shown i n TABLE 8 by comparing the spectra of the per-. fluoroalkyl-metal compounds with those of polyfluoroalkanes^,, Detailed assignments of the i n f r a r e d bands a s s o c i a t e d ^ i t h the C-F absorptions of polyfluoroalkyl-metal d e r i v a t i v e s , as shown i n TABLE 9, have not yet been made. Such assignments, however, can be achieved i n the same empirical fashion as used by Stone et a l . (94). Sec. IV-A-2 61 TABLE 8 - 1 a C-F ABSORPTION BANDS (cm. $ IN THE IR SPECTRA OF PERFLUOROALKYL-METAL COMPOUNDS Assignment CF 3-M b CF 3CF 2-M C CF 3CF 2CF 2-M d CF 3 s t r . . 1160-1150 1075-1070 1350-1300 1220-1185 1195-1175 1355-1315 1230-1215 -J 1205-1190 3-CF s t r . 1160-1150 1100-1085 a-CF 2 s t r . 1070-1030 1020-1000 1040- 990 C-C s t r . 930- 905 815- 810 CF 3 def. 725- 724 735-720 725- 715 C-F def. j 670- 660 (a) „ A l l bands are medium to strong i n i n t e n s i t y . (b) For (CH 3) 3SnCF 3 and (CH 3) 2SnCF 3Cl (23). (c) For (CH 3) 3PbC 2F 5, (CH 3) 3SnC 2F 5 (22),. C 2F 5Fe(CO) 5I, C 2F 5Mn(C0) 5, C 2F 5Re(QO) 5, C 2F 5C0Mn(C0) 5, C 2F 5C0Re(C0) 5(94), and C 2F 5C0Ni(ir-C 5H5) (97) . (d) For ( C H 3 ) 2 S n ( n - C 3 F 7 ) 2 (98). C 3F 7Fe(00)^1, C 3F 7Mn(C0) 5, C 3F 7Re(C0) 5 (94), and C 3F 7CONi ( T T-C 5H 5) (97). Sec. IV-A-2 62 TABLE 9 - 1 a C-F ABSORPTION BANDS (cm. ) IN THE IR SPECTRA OF POLYFLUOROALKYL-METAL COMPOUNDS Assignment HCF 2CF 2-M b CH 3CF 2CF 2-M C C 6H 5CF 2CF2-M d 1 (B-CF 2 str..) 1370-1350 1385-1380 1275-1265 1272 1205-1200 1180-1160 6 1160-1155 1177 1100-1080 2 (a-CF 2 s t r . ) 1075-1035 1058 1045-1000 1031-1000 1025 1009 3 (C-C s t r . ) 990- 975 , 980- 975 953 845- 835 808 4 640- 635 6 (a) A l l bands are medium to strong i n intensity. (b) For (CH 3) 2Sn(CF 2CF 2H) 2, (CH 3) 2SnH(CF 2CF 2H), (CH 3) 2SnCl(CF 2CF 2H) (51), HCF 2CF 2Mn(C0) 5 (99), HCF 2CF 2Re(CO) 5 (75), and HCF 2CF 2Mo(C0) 3U-C 5H 5) , HCF 2CF2W(C0) 3 ( T T ^ H S ) (100). (c) For CH 3CF 2CF 2Mn(CO) 5(101), and CH 3CF 2CF 2Re(CO)5(99). (d) For C 6H 5CF 2CF 2Mn(CO)s(lOl). (e) These bands do not appear f o r a l l compounds l i s t e d . Sec. IV-A-3 63 A l l three types of organometallic compounds, i . e . , HCF2CF2-M,_ C H 3 C F 2 C F 2 - M , and C 6H 5CF 2CF 2-M, l i s t e d i n TABLE 9 give r i s e to C-F absorptions, f a l l i n g i n four d i s t i n c t regions. By comparison of TABLES 8 and 9, i t i s c l e a r that the frequencies i n the regions 2 and 3 are cl o s e l y r e l a t e d to the frequencies associated with the stretching v i b r a -tions ,of a-CF2 and C-C groups (94), re s p e c t i v e l y . It may-thus be possible to assign the bands i n the regions 2 and 3 to the C-F s t r e t c h i n g modes of the a-CF 2 group and C-C s t r e t c h i n g mode, r e s p e c t i v e l y . The absorptions l i s t e d i n region 1 are more va r i a b l e depending on the type of compound. This may be a t t r i b u t a b l e to the d i f f e r e n t atom or groups ( i . e . , H, CH 3, C eH 5) attached to the 3-carbon atom. It i s reason-able to assume that the locations of absorptions a r i s i n g from the g-CF 2 groups are more affected by the substituents than that for the a-CF 2 groups. Therefore, i t seems that the absorptions i n region 1 are pro-bably due to the C-F absorptions associated with the 3-CF 2 group I It should be noted that the bands i n the 1385-1350 cm. 1 region are only present i n the spectra of HCF 2CF 2-M and CH 3CF 2CF 2-M d e r i v a t i v e s , but are not observed f o r C 6H5CF 2CF 2-M compounds. An assignment of ;the frequen-c i e s i n region 4 was not attempted because these absorptions are absent i n the spectra of the l a s t two types of compounds. 3. Discussion. The r e s u l t s of the i n f r a r e d examinations of the products of the present study are l i s t e d i n TABLES 10 and 11. The assignments as shown i n the table, f o r those i n f r a r e d bands associated with (CH 3) 3Sn group of the products can be made. Sec. IV-A-3 64 TABLE 10 INFRARED BANDS OF THE REACTION PRODUCTS CONTAINING (CH 3) 3Sn GROUP. (CH 3) 3Sn-Sn(CH 3) 3 I (CH 3) i+Sn I I (CH 3) 3SnCF 2CF(CF 3) Sn(CH 3) 3 T T T Assignment I * II * III C-H asym. s t r . 2978 s 2982 s 3020 m C-H sym. s t r . 2908 s 2914 s 2955 m 2349 m 2363 m 2395 vw 1945 m 1962 w 1717 m 1692 w 1697 m 1695 w.b CH 3 asym. def. 1455 m.b 1445 s 1430 w.b 1386 m 1348 m 1360 m 1281 s 1242 m 1200 vs .b CH 3 sym. def. 1192 m 1190 s 1160 vs 1186 sh 1136 sh 1068 m 1026 vw 1029 w 1050 m 1014 •vw 995 w 931 w 910 w CH3-Sn rocking 759 vvs .b 764 vvs 778 vs .b 700 m 721 sh 680 m 614 s.b 538 s Sri-C asym. s t r . 520 s 524 s 526 s Sn-C sym. s t r . 499 m 504 Raman 512 m 505 m 469 m.b s, strong; m, medium; w, weak; sh, shoulder; v, very; b, broad. (*) Data were taken from r e f . (72). Sec. IV-A-3 65 TABLE 11 INFRARED BANDS OF THE REACTION PRODUCTS CONTAINING POLYFLUOROALKYL GROUP (CH 3) 3SnCF 2CF 2H .... . IV (CH 3) 3SnCF 2(CF 2) 2CF 2H V (CH 3) 3SnCF 2CFHCF 3 VI Assignment IV V VI C-H asym. s t r . 3000 m 2995 m .3005 m C-H sym. s t r . 2940 m 2910 m 2940 m 2390 w 2355 w 2352 vw 1720 W 1695 w 1590 w 1653 w CH 3 asym. def. 1425 w.b 1429 w.b 1420 sh 1398 m 1372 vs r 1355 s 1355 w 1360 sh 1333 sh 1310 m 1280 w 1280 m 1280 s ,b 1205 s 1200 vs ,b j 1191 sh C-F s t r . \\ 1180 s 1162 vs 1163 vs 1137 s 1150 sh 1090 vs .b 1088 s 1090 ' s 1059 s ,b 1029 vs 1030 s 1005 s ,b V 977 m 971 m 990' sh 905 w 910 m 881 s ,b 838 s 835 m CH3-Sn rocking 787 vvs ,b 788 vvs,b 788 vs,b 730 m,b 715 m 735 m 717 m 631 m 622 w 668 m 555 sh 572 w 578 w,b Sn-C asym. s t r . 539 vs 542 vs 539 vs 527 sh Sn-C sym. s t r . 513 s 523 s 513 m,b Sec. IV-A-3 66 The C-H asymmetric and symmetric stretching vibrations give r i s e _1 to the pealcs at 3020-3000 and 2960-2900 cm. ^ r e s p e c t i v e l y . The CH 3 asymmetric deformation mode always appears as a weak, broad band at _ l 1430-1420 cm. , while the absorption d,ue to the CH 3 symmetric deforma-t i o n mode i s . d i f f i c u l t to i d e n t i f y since i t occurs i n the region (1200-_ 1 1190 cm. ,) where the strong C-F absorptions are expected. _ l The strong and broad band i n 790-760 cm. region was assigned to. the CH3-Sn rocking mode. The Sn-C assymmetric and symmetric s t r e t c h i n g _1 vibrations were found at 553-538 and 530-513 cm. , r e s p e c t i v e l y , i n good agreement with the frequencies associated with a (CH 3) 3Sn group a-bonded to fluorocarbon (51). It i s i n t e r e s t i n g to note that the CH3-Sn rocking frequencies of the compounds prepared increased with an increase i n the frequencies of Sn-C asymmetric s t r e t c h i n g v i b r a t i o n s . Brown et a l . (72) have observed that the CH3-Sn rocking frequencies i n the s e r i e s of methyltin compounds also increase with increasing values of the Sn-CH3 coupling constant. The r e l a t i o n s h i p i s , however, not l i n e a r . A l l Compounds but two, i . e . (CH 3)gSn 2 and (CH 3 )i +Sn, l i s t e d i n _1 TABLES 10 and 11 possess intense bands between 1400 and 1000 cm. due _ l to C-F absorptions, and medium to strong bands between 900-800 cm. due C-C s t r e t c h i n g v i b r a t i o n s . . The spectra i n 1400-800 cm. 1 region are discussed i n d i v i d u a l l y as follows. (CH 3)3SnCF ?CF 2H: The i n f r a r e d spectrum of t h i s compound shows f i v e strong bands i n _1 the C-F absorption region. The bands at 1355 cm. (sharp and strong), _ 1 _1 1180 cm. (strong and broad), and 1090 cm. (very strong and broad) are assigned on the basis of TABLE 9 to the HCF 2- group. The character-_1 i s t i c broadness (half band width 50 cm. ) of the t h i r d band was also Sec. IV-A-3 67 observed i n the i n f r a r e d spectrum of (CH 3) 2Sn(CF 2CF 2H) 2 (51). The _1 -1 absorptions at 1029 cm. (strong and s l i g h t l y broad) and 997 cm. (medium) were assigned to the C-F stretching v i b r a t i o n of the a-CF 2 group and the C-C s t r e t c h mode, re s p e c t i v e l y . The medium band:at _1 631 cm. was t e n t a t i v e l y assigned to the C-F ;deformation mode. (CH 3) 3SnCF 2(CF P) ?CF ?H This spectrum shows a strong, poorly resolved t r i p l e t centred at _1 _1 1162 cm. and several bands (weak to medium) i n 1000-800 cm. region. The fact that a l l strong absorptions occurred i n a close region i n d i -cates a considerable overlap of C-F s t r e t c h i n g frequencies. No attempt was thus made for a d e t a i l assignment because of the-overlapping. By comparing the i n f r a r e d spectra of (CF 3) 3CH, C F 3 ( C F 2 ) 2 C F 2 H (102), and (CH 3) 3SnCF 2(CF 2) 2CF 2H, i t was noted that the l a s t two spectra are very s i m i l a r , i n d i c a t i n g the presence of a fluorocarbon group with a s t r a i g h t chain i n the l a s t compound. In contrast to t h i s , a reaction product of CF 2=CF 2, i . e . , CH 3 (CF 2) i+Re (CO) 5, was shown by Stone et a l . (75) to have a side chain fluorocarbon group whose i n f r a r e d spectrum i s s i m i l a r to that of (CF 3) 3CH. (CH 3) 3SnCF 2CFHCF 3 Despite the lack of information concerning the analysis of the spectra of CF 3CFHCF 2-X groups, a review of the spectra of CF 3CFHCF 2OR (102), where R i s CH 3, C 2H5, or C 3Hy, and of the n-perfluoropropyl-metal compounds (TABLE 8), permitted a tentative assignment f o r the ten i n f r a r e d bands associated with the C-F absorptions of (CH 3) 3SnCF 2CFHCF 3. _1 The band at 1372 cm. i s probably due to the CF 3 group. The _ l strong bands i n the region 1300-1150 cm. may be assigned to C-F Sec. IV-A-3 68 _1 s t r e t c h i n g frequencies of the CF3 group. The shoulder at 1150 cm. _1 and the sharp peak at 1090 cm. may be due to the 6-CFH group, while _ l the broad bands at 1039 and 1005 cm. are possibly associated with the cx-CF2 group. _ l The medium to strong bands i n the 1000 to 800 cm. region a r i s e from C-C s t r e t c h i n g v i b r a t i o n s . The CF3 deformation modes give r i s e . _ l to a doublet of medium i n t e n s i t i e s centred at 726 cm. , while the absorption p o s s i b l y due to a-CF 2 deformation was observed at 668 cm. (CH 3J3SnCF2CF(CF 3)Sn(GH3)a The C-F absorptions of t h i s compound were observed as a group of _ l strong multiple peaks i n the 13000-1100 cm. region. In view p f the well separated i n f r a r e d bands of (CH 3) 3SnCF 2CFHCF3, i t appears that replacement of the hydrogen atom of the g-CHF group by a ( Q ^ ^ S n group has caused a lesser number of C-F absorptions which may be.interpreted i n terms of uncoupled C-F s t r e t c h i n g modes due to the mass e f f e c t (103) of the c e n t r a l atom of the s u b s t i t u t e n t . As the mass of the central atom i s increased, i . e . , from H to Sn, vibrations of the -CF 2CFCF 3 group become purer because the heavier Sn atom moves less than H atom during the t r a n s i t i o n s , and less coupling i s thus expected. Further assignment of these bands was not attempted due to the lack of band separation. Other products Apart from the compounds discussed above,the presence of the other fluorocarbon derivatives of t r i m e t h y l t i n , which could not be i s o l a t e d i n a pure state, was. established by the cross examinations of t h e i r i n f r a r e d spectra, I 9 F and -^H N.M.R. spectra, and gas Sec. IV-A-3 69 chromatographic analyses. The details of these identifications w i l l be discussed in the experimental section. Sec. IV-B 70 B. The N.M.R. Spectra of Fluorocarbon Derivatives of Trimethyltin. The magnetic n u c l e i i n the reaction products concerned are 1 H , 1 9 F , 1 3 C , 1 1 7 S n , and 1 1 9 S n ; of t h e s e a n d 1 9 F have been observed d i r e c t l y in these studies. A l l the n u c l e i mentioned above have spin 1/2. The natural abundances of the isotopes 1 3 C , 1 1 7 S n , and 1 1 9 S n are 1.108, 7.67, and 8.68%, re s p e c t i v e l y (104). Deuterium (present to a small extent i n hydrogen) and 1 1 5 S n (0.35% abundant, and with a spin 1/2) did not a f f e c t the N.M.R. spectra noticeably. (CHCJ) .SnCFoCFoH (a) * H N.M.R. spectrum The main features of the proton resonance spectrum of t h i s compound are l i s t e d i n TABLE 12. For comparison, the chemical s h i f t s and coupling constants of some analogous compounds, i . e . , ( C H 3 ) 2 S n ( C F 2 C F 2 H ) 2 (105), HCF 2 C F 2C0Mn(C0) 5, and HCF 2CF 3 (99), are also included i n the table. The sharp, si n g l e peak 0.36 p.p.m. down-field from the i n t e r n a l tetramethylsilane (TMS) reference i s due to the resonance of the protons of methyl groups attached to t i n . The sh i e l d i n g of these protons i s greater than i n the corresponding protons of ( C H 3 ) 2 S n ( C F 2 C F 2 H ) 2 . This i s i n accord with the observation (106, 107) that upon successive replacement of methyl groups by more electronegative atoms or groups i n methyl t i n compounds the sh i e l d i n g decreases. The t r i p l e t e d t r i p l e t ( i n t e n s i t y r a t i o 1:2:1) centred at -5.51 p.p.m. with respect to i n t e r n a l TMS reference must a r i s e from the hydrogen atom geminal to two f l u o r i n e atoms (Hg), The f i r s t 57.5 c.p.s. s p l i t t i n g i s due to spin-spin i n t e r a c t i o n of the Hg and Fg, arid each peak i s Sec. IV-B 71 TABLE 12 CHEMICAL SHIFTS AND COUPLING CONSTANTS FOR SOME ORGANOMETALLIC COMPOUNDS CONTAINING HCF 2CF 2 - GROUP Compound (CH3)3SnCF2CF2Ha .(CH3)2Sn(CF 2CF 2H) 2 a (CO)5MnC0CF2CF2Hb CF 3CF 2H b Reference This work (105) (99) (99) S c H 3 -0.36 - 0.63 - • -- 5.51 - 5.63 - 5.86 -SF a +40.8 +37.9 +41.0 + 9.5C SF 3 +51.1 +51.2 +63.2 +62.0 T d J 1 1 9Sn-CH 3 57.8*0.2 64.5*0.5 J l l 7Sn-CH 3 55.4*0.2 61.5*0.5 J » C - H 9 130.0*0.5 137.3*0.5 J 1 1 9 S n - F „ a J l 7 S n - F a 249.5*1.0 237.6*1.0 J 274.0*10.0 J l ^ S n P g J 1 ? S n F e • • 10.0*2.0 8.0±i.0 JttgF0 57.S*D.5 56.5*0.2 52.0 53.0 JH0F o 5.5*0.1 5-1*0.1 6.7 3.0 Not resolved. Not resolved. 9.2 3.0 (a) Chemical s h i f t , \"6\", i s expressed i n p.p.m. with respect to tetramethylsilane (TMS) internal standardfor protons, and an external trifludroacetic acid (TFA) was used for the standard of fluorine resonance positions ( scale). (b) HexaaethyldisilOxahe internal standard was used for proton chemical s h i f t . Fluorine chemical shift was converted to the cj): scale. (c) Chemical shift for CF 3 group. (d) C o u p l i n g c o n s t a n t s a r e i n c.p.s. Sec. IV-B 7 2 further s p l i t into., a t r i p l e t (coupling constant 5.5 c.p.s., area r a t i o 1:2:1) due to the coupling of Hg with F a . The values 57;5 and 5.5 c.p.s. are consistent with the magnitudes expected f o r J^H-^F of a pol y f l u o r o -carbon compound where hydrogen and f l u o r i n e atoms are separated by one and two carbon atoms, re s p e c t i v e l y (99, 105). Integration of the peak area of Hg and CH 3 groups gave the r a t i o 1:8.5 (calc. 1:9). The Hg spectrum i s thus i n good agreement with the formulation of the -CF 2CF 2H group. In addition to the main peaks, subsidiary peaks appeared i n the v i c i n i t y of the CH3 peak because of detectable amounts of the following: (CH 3) 3 1 1 7Sn(CF 2CF 2H) ( I ) ; ( C H 3 ) 3 1 1 9Sn(CF 2CF 2H) ( I I ) ; ( 1 3CH 3) (CH 3) 2Sn(CF 2CF 2H)|. . .. ( I I I ) . The spin-spin coupling between the magnetically active Sn n u c l e i i n molecules (I) and (II) and the protons.of the methyl groups was observed as two poorly resolved doublets, one on each side of CH 3 peak. As the coupling constant between two n u c l e i i s proportional to the product of the gyro-magnetic r a t i o s of the two n u c l e i concerned (104), i t then follows that the r a t i o of J\" 1 1 9Sn-CH 3 to J\" 1 1 7Sn-CH 3 i s equal to the r a t i o of the gyro-magnetic r a t i o of 1 1 9 S n to that of 1 1 7 S n , which i s 1.046. Therefore, the larger the coupling constant observed must be J 1 1 9Sn-CH 3, and the smaller coupling constant the J~ 1 1 7Sn-CH 3. The recorded coupling constant r a t i o was 57.8/55.4 or 1.044. The i n t e n s i t y r a t i o of appropriate Sn side bands was also i n accord with the i s o t o p i c abundance r a t i o of the two Sn n u c l e i , i . e . , 8.68 to 7.77% (104). The side bands a r i s i n g from the i n t e r a c t i o n of 1 3 C and^H of methyl groups i n the molecule (III) (130.0 c.p.s.), were observed as small peaks at each side of the methyl peak. J 1 3Cg-Hg was not detected because of i t s low i n t e n s i t y . Sec. IV-B 73 (b) 1 9 F spectrum of (CH 3) 3SnCF 2CF 2H The chemical s h i f t s and coupling constants of the 1 9 F spectrum of (CH 3) 3SnCF 2CF 2H are l i s t e d i n TABLE 12. This spectrum consists of two doublets of equal i n t e n s i t y . The doublet at higher f i e l d was s p l i t by 58 c.p.s., i n accord with the value of as shown i n the , spectrum of t h i s compound. The doublet at lower f i e l d was s p l i t by 5.5 c.p.s., corresponding to the magnitude of j H g F w . Thus the resonance at +51.1 p.p.m. was assigned to the f l u o r i n e atoms of B-CF 2H group, and,the resonance at,+40.8 p.p.m. was at t r i b u t e d to a-fluorine atoms. This assignment was further supported by the occurrence of t i n side bands at both sides of the +40.8 p.p.m. doublet. Each side band was observed as a t r i p l e t (approximate.ratio 1:2:1), apparently an over-lapping of two doublets a r i s i n g from x^ 9Sn and 1 1 7 S n n u c l e i . The values of J 1 1 9 S n F a and >J117SnFa were measured as 249.5 and 237.6 c.p.s., r e s p e c t i v e l y , whose,ratio i s 1.049 (calc. 1.046). Four shoulders appear-ing at each side of each component of the +51.1 p.p.m. doublet were due to couplings of 1 1 9 S n (and 1 1 7 S n ) with Fg. The coupling constant i s about 10 c.p.s. Further s p l i t t i n g due to the spin-spin i n t e r a c t i o n between F a and Fg n u c l e i was not found even i n the widely expanded spectra of each component. This i s also true for many other cases (99, 105, 108). Abraham and C a v a l l i (108) have suggested that the \" p e c u l i a r l y small v i c i n a l F-F couplings r e s u l t from the consequence of the highly electro-negative character of the f l u o r i n e atom combined with the r e l a t i v e ease of obtaining p e r f l u o r i n a t e d ethane.\", although the s i g n i f i c a n c e of the l a t t e r clause i s not explained by these authors. Sec; IV-B 74 (CH 3) 3SnCF 2(CF 2) 2CF 2H The proton chemical s h i f t s and coupling constants f o r t h i s compound, as well as those of some polyfluoroalkanes (109, 110), are l i s t e d i n TABLE 13. The resonance associated with methyl groups was observed at -0.45 p.p.m. (TMS). The t r i p l e t e d t r i p l e t centred at -5.97 p.p.m. was due to the resonance of the hydrogen atom of the fluorocarbon group. The f i r s t s p l i t t i n g was due to coupling with two geminal f l u o r i n e atoms, and then s p l i t again because of another coupling with two v i c i n a l f l u o r i n e atoms. No further coupling was observed. Coupling between 1H and 1 9 F n u c l e i separated by three carbon atoms has not been observed in/the system HCF 2CF 2CF 2 ... CF 3 (110). It was noted that the resonance of the methyl group appears at lower f i e l d than that of (CH 3) 3SnCF 2CF 2H, and that the chemical s h i f t of the proton of -CF 2(CF 2) 2CF 2H group occurred 0.46 p.p.m. lower than that of corresponding proton of (CH 3) 3SnCF 2CF 2H. In the series of fluoroalkanes of general formula HCF 2(CF 2) nCF 2H,when n increases from zero to two, the proton resonance s h i f t s down f i e l d by 0.43 p.p.m., while n increases from zero to three, the s h i f t i s 0.53 p.p.m. i n the same d i r e c t i o n (see TABLE 13). It was also noted that the value of J 1 3C-H 3 f o r t h i s compound i s larger than that of (CH 3) 3SnCF 2CF 2H, whereas the magnitutes of J\" 1 1 7Sn-CH 3 and J~ 1 1 9Sn-CH 3 remained almost unchanged i n both compounds. Sec. IV-B 75 TABLE 13 H N.M.R. DATA OF (CH 3) 3SnCF 2(CF 2) 2CF 2H AND SOME POLYFLUQROALKANES. Compound (CH 3) 3SnCF 2(CF 2) 2CF 2H HCF 2CF 2H HCF 2(CF 2) 2CF 2H HCF 2(CF 2) 3CF 2H Reference This work (109) (110) (110) 8cH 3 -0.41 SH -5.97 -5.08 -5.51 -5.61 J 1 1 9Sn-CH 3 58.0±0.2 J 1 1 7Sn-CH 3 56.0±0.2 J 3 C - H 3 130.4*0.5 J HFg * 52.0±0.-5 52.0'±1.0 52.7±0.4 52.1 ±0.4 J H F V 5.9±0.1 5.16±0.6 5.34±0.2 j H F t Not resolved. (*) Fluorine atoms geminal to H are. designated as Fg, and v i c i n i c a l to H are F v. Ft i s the f l u o r i n e atom separated from H by three carbon atoms. Sec. IV-B 76 (CH 3) 3SnCF ?CFHCF 3 (a) *H N.M.R. spectrum The proton magnetic resonance spectrum of t h i s compound i s shown i n Figure 2a. The chemical s h i f t s and coupling constants are l i s t e d i n TABLE 14. The resonance a s s o c i a t e d w i t h the CH 3 groups attached to the t i n atom, together w i t h the s i d e bands a r i s i n g from couplings with 1 3 C , 1 1 7 S n , and 1 1 9 S n n u c l e i ( l a s t two were not resolved) were observed. The resonance of the proton of the -CFHCF3 group (Hg) appeared as .a m u l t i - , p l e t at lower f i e l d , and i n expanded form i s the subject of Figure 2b.. In the spectrum of Hg the l a r g e s t s p l i t t i n g was a doublet due t o Hg-Fg cou p l i n g (45.9 c.p.s.). Each component was f u r t h e r s p l i t i n t o a doublet due to coupling between Hg and one of the two f l u o r i n e atoms on the adjacent a-CF 2 group ( J H g - F ' a = 13.9 c.p.s.), and s p l i t i n t o doublets again because of f u r t h e r i n t e r a c t i o n with the other f l u o r i n e atoms of the a-CF 2 group ( j H g - F ' ' a = 11.3 c.p.s.). The l a s t s p l i t t i n g occurred v i a coupling w i t h the three f l u o r i n e atoms of the Y _ C F 3 group ( J H g - F Y = 6.5 c.p.s.) . Nonequivalent coupling constants r e s u l t i n g from couplings between an alkane proton and the two f l u o r i n e n u c l e i on the v i c i n a l CF 2 group have p r e v i o u s l y been seen i n a number of compounds, as shown i n TABLE 15. The occurrence of nonequivalent c o u p l i n g constants may be i n t e r p r e t e d i n terms of \" r e s t r i c t e d r o t a t i o n \" about a s i n g l e bond between two carbon atoms. Hindered r o t a t i o n about a carbon-carbon s i n g l e bond i n s a t u r a t e d compounds has been i n v e s t i g a t e d (104) by a v a r i e t y of p h y s i c a l , t e c h n i q u e s i n c l u d i n g Raman and i n f r a r e d spectroscopy, microwave Sec. IV-B 77 Sec. IV-B 78 TABLE 14 JH AND 1 9 F DATA OF (CH 3) 3SnCF 2CFHCF 3 AND (CH 3) 3SnCF 2CF(CF 3)Sn(CH 3) 3 a 3 Y CH 3) 3SnCF 2CFHGF 3 !(CH3) 3SnCF 2CF(CF 3)Sn(CH 3)' 3 S C H 3 S c H 3 - 0.35 - 4.61 + 30.71 + 37.11 +127.1 - -3.19 - 0.38 -0.42 +34.8 -4.4 J 1 1 9 S n - C H 3 J 1 1 7 S n - C H 3 J 1 1 9Sn-CH' 3 J 1 1 7Sn-CH' 3 J 1 3 C - H 3 • J 1 3 C - H 3 58.6 ±0.2 56.2 ±0;2 a a 131.0 ±0.5 a r 53.0±2.0 j H g F g j H g F g j H g F b j H g F Y J E B F ' § j F g F b j F y F b v J F a F a 45.9 ±6.4 13.9 ±0.3 11.3 ±0.3 6.5 ±0.1 7.1 ±0.2 6.5 ±0:.2 11.75*0.1 6,5 ±0.2 11.0 ±0.2 340.0 ±1.0 J H 9 S n - F j b J H 7 S n - F ^ b J 1 3 C - F Y 222.0 ±1.0 302.0 ±1.0 (a) Not i d e n t i f i e d . (b) Observed as a mult i p l e t centred at +30.8 p.p.m.(TFA). Sec. IV-B 79 TABLE 15 SOME COUPLING CONSTANTS OF UNSYMMETRICALLY SUBSTITUTED POLYFLUOROALKANES. cu B Compound RCF2-CHPQ T F U -J a J F ' - F \" B J a a Reference (CH 3) 3SnCF 2-CHFCF 3 13.9 11 3 340 This work BrCF2-CHBrC6H5 15 6 152 (Ul) BrCF 2-CHBrCl 10 7 154 ( H I ) C1CF 2-CHC1C 6H 5 9 6 158 (111) BrCF 2-CHFCl 6.3 3 5 177 (112) BrCF 2-CHFSi(C 2H 5) 3 22 10 168 (113) (CO) 5MnCF 2-CFHCl 12.4 . 5 7 (99) (a) Appeared as doublet. Coupling constant i n c.p.s. * (b) Appeared as quartet. Coupling constant i n c.p.s. spectroscopy, and electron d i f f r a c t i o n and dipole moment measurements. In these compounds the b a r r i e r to i n t e r n a l r o t a t i o n i s usually consider-ably lower than f o r compounds having double bond character. Drysdale and P h i l l i p s (111) f i r s t applied N.M.R. techniques to the i n v e s t i g a t i o n of hindered r o t a t i o n i n substituted polyfluoroethanes. They found that the lH N.M.R. spectrum i n compounds of the type RCF2-CHPQ consists of two doublets (see TABLE 15), and that the 1 9 F spectrum of the corres-ponding compound also shows two doublets. The complete spectrum i s , therefore, of the ABX pattern. I f the two f l u o r i n e n u c l e i were equi-valent, i t would be of A 2X type, and the proton spectrum would appear as a t r i p l e t . It i s now understood that the ABX pattern r e s u l t s from Sec. IV-B 8U the -CHPQ group i n which three d i f f e r e n t substituents are bonded to the carbon atom, leading to chemical non-equivalence for the two f l u o r i n e atoms of the adjacent CF 2 group. Since the spin-spin couplings between Hg, F a , Fg, and Fy nuc l e i i n the present compound are very small compared to the chemical s h i f t d i f f e r e n c e between them i . e . , |^F-5H/JFH | » 1 , |>jFgF Y \\jFgFa ~ jFgF^, was made on the basis of a f i r s t order (CH ) S n C F C F H C F •ww 2 3 J F _ F b = 6.5 cps - 0 F Fa=7.l • J F _ F = 11.75 -J F / r H =46 .o -~ H X J p y _ H = 6.53 cps \" d F _0 =6.53 y a Jp _ Fb=II.O cIpLp =11.7 1 9 F N.M.R. spectrum of the g-CF group i n (CH 3) 3SnCF 2CFHCF 3. Figure 5 . 1 9 F N.M.R. spectrum of the y-CF 3 group i n (CH 3) 3SnCF 2CFHCF 3. Sec. IV-B 84 approximation. The seven peaks associated with the y-CF3 group (Figure 5) r e s u l t from four couplings, Fy-Fg, Fy-F^, Fy-F^, and F Y-Hg, i n which each gives r i s e to a doublet. The spectrum has a symmetrical arrangement of peaks around a strong central peak, i n d i c a t i n g an overlap of two doublets, with equivalent, or nearly equivalent, coupling constants. The f i r s t order l i n e s , as shown i n Figure 5, were superimposed c l o s e l y on the observed spectrum. It was noted that the magnitude of j F y F a , which was found to be 11c.p.s. according to the above assignments, i s rather too large f o r a coupling between two f l u o r i n e atoms through four bonds (114) . The un-usually large coupling constant i s interpreted i n terms of the space coupling mechanism proposed by Ng and Sederholm (115). They suggested that t h i s mechanism i s operative when two f l u o r i n e atoms are s u f f i c i e n t l y close i n space f o r there to be appreciable overlap of t h e i r e l e c t r o n i c clouds. The f i n d i n g of a space coupling, f o r t h i s compound led to an attempt to predict the r o t a t i o n a l configuration, which would d i s t i n g u i s h the two fl u o r i n e atoms of the 01-CF2 group. This compound i s expected to have three probable r o t a t i o n a l isomers as shown i n Figure 6, with an assumption that \"staggered\" configurations are more stable than \" e c l i p s e d \" bnes because of the s t e r i c e f f e c t s . There may, however, be another three o p t i c a l isomers corresponding to the above three isomers. However, these enantiomorphic pairs are ind i s t i n g u i s h a b l e by N.M.R. spectroscopy. I f two or a l l three of the r o t a t i o n a l isomers of t h i s compound were populated, the lH N.M.R. spectrum (Figure 2b) would consist not Sec. IV-B 85 (I) (II) ( H I ) Figure 6 . Rotational Isomers of (CH3)3SnCF 2CFHCF3. of the observed 32 resonances, but of 64 or 96 l i n e s , r e s p e c t i v e l y , or perhaps somewhat less because of accidental coincidences. The same argument i s also true for the 1 9 F N.M.R. spectrum. The fact that bath xH.and 1 9 F N.M.R. spectra recorded were found to have the peaks a r i s i n g from no more than one isomer, permitted a conclusion that only one of the three possible r o t a t i o n a l configurations i s populated a t . 2 5 % at which temperature i t s spectrum was recorded. As has been noted before (116), the magnitudes of coupling constants appear to be s e n s i t i v e to bond angles and hybridzation of the o r b i t a l s . In isomer (I) ,' the-'Y-CF3 group i s symmetrically situated with, respect to the two a-flu o r i n e atoms. The values of J F Y - F | J and J F Y - F £ would be expected to be very nearly equal while the coupling constants, J F ^ F ^ andvjH^Fi would d i f f e r considerably from jF'gFy and . :.• vJrlgF^, r e s p e c t i v e l y . Isomer ( I ) , which was expected to be the most stable configuration from the s t e r i c point of view, may thus be eliminated because of the c o n t r a d i c t i o n between predicted and observed values. (TABLE 14 on page 7 8 ) . Isomer (II) may also be discarded on the same grounds, leaving the s t e r i c a l l y unfavourable isomer (III) as the most probable, si n g l e populated r o t a t i o n a l configuration of Sec. IV-B 86 (CH 3) 3SnCF 2CFHCF 3. I f t h i s i s the case, i t appears that the p r e d i c t i o n of the f i r s t -order spectra f o r the two a-fluorine atoms can be made. In isomer (III) a b the a - f l u o r i n e atom at l e f t i s designated as F a , and at r i g h t , as F a . As shown i n Figure 7c, l i n e s , p o s i t i o n s , and i n t e n s i t i e s f o r the f i r s t a b order e f f e c t of F a and F a were predicted according to the following parameters which were previously assigned i n Figures 2,4 and 5. a b F a spectrum F a spectrum J F a F a = 340 c.p.s. jF^Hg = 13.9 c.p.s JFaHg = 11.3 c.p.s. J F ^ F 6 = 7.1 c.p.s. J F a F B = 6 ' 5 C.p.s. J F Q F Y = 6.5 c;p.s. j F a F y = 11.0 c.p.s. The quartet i n Figure 3 i s repeated i n Figure 7a as a s l i g h t l y resolved form. The components designated as A and B appear as the same f i n e structure, while component C i s i d e n t i c a l with D. Since the i n t e n s i t i e s of components A and D are too weak, only the components B and C are expanded and are the subject of Figure 7b. From both Figures 7b and 7c, i t was noted that F| arid F^ f i r s t -order l i n e s f i t the spectra of B and C, r e s p e c t i v e l y . Therefore, the 3. l o w - f i e l d doublet, i . e . , components A and B, was assigned to F a atom, and the u p - f i e l d doublet (component C and D), to.F^ atoms. The agreement between predicted and observed 1 9 F N.M.R. spectra a b of F a and F a atoms further confirms the assignments made i n Figures 2, 4, and 5. It therefore can be concluded that isomer (III) i s the only populated configuration f o r (CH 3) 3SnCF2CFHCF 3. It should be noted that other a l t e r n a t i v e coupling constants were also assigned to each nucleus Figure 7. 1 9 F N.M.R. spectrum of the a-CF 2 group i n (CH 3) 3SnCF 2CFHCF 3. Sec. IV-B 88 of t h i s compound, and the f i r s t order spectra were made, but none of them agreed with the observed spectra. Isomer ( I I I ) , however, may not be a symmetrically staggered form. The facts that the magnitudes of JFgF^ and J F ^ F ^ are not equal (7.1 and 6.5 c.p.s.), that the difference between=0 / I / I VI VI' In structure VI', electrons on the metal atom are less available f o r n-bonding with the carbonyl groups. Hence, for the metal-carbon bond i n the metal-carbonyl linkage, the resonance hybrid Mn=C = 0 < • Mn +- C=0 Sec. IV-C-2 101 on the r i g h t side of the above equation w i l l be favoured, leading, to an increase i n the C-0 order, and a lowering i n the Mn-C bond order. This proposal i s supported by the fact that the observed M-CO frequencies are lower for compound (VI) than for ( I I I ) , i n accord with the above suggestion of changes i n bond order. This suggestion i s also consistent with a s i m i l a r proposal for RfC0Mn(C0) 5 (94, 120). It i s worth mentioning that, although the p r i n c i p a l UQQ, frequen-b a cies of CF2=CFC0Mn(C0)5 are e s s e n t i a l l y of the A : + E + A : pattern, a weak shoulder at 2080 cm. 1 and broadness of the E band were observed, i n d i c a t i n g a lack of a x i a l symmetry of the molecule which i s responsible for the s p l i t t i n g of the E t r a n s i t i o n and the simultaneous appearance of the Bi mode with low i n t e n s i t y (68). Stone et a l . (120) reported that a l l acyl metal carbonyls e x h i b i t t h i s s p l i t t i n g of the E mode, as high as 12 cm. \\accompanied by the appearance of the weak Bj band. For the present compound a greater r e s o l u t i o n of the UQQ bands might be achieved i f i t were recorded on P.E. 421 spectrometer. Unfort-unately, only the P.E. 21 spectrometer was a v a i l a b l e at the time of t h i s study. Compound (V), (cis-CFH=CF)Mn(CO) 5, shows f i v e bands with the r e l a t i v e i n t e n s i t i e s as follows: 2143, 2085, 2050, 2025, 1987. (4%) (8%) (55%) (30%) (2%) Three p o s s i b i l i t i e s can be suggested which may be responsible for t h i s complexity of the UQQ bands: (i) presence of impurities; ( i i ) lack of a x i a l symmetry (along C=C-M axis) causing i n f r a r e d a c t i v i t y f or a l l four fundamental vibrations (2ki + Bj + E), as predicted Sec. IV-C-2 102 by theory (68); ( i i i ) formation of s t r u c t u r a l isomer (VB) rather than (VA). H' F 0=C. F. VA VB Figure 9. 7r-bonding isomer of (cis-CFH=CF)Mn(CO) 5 The v a l i d i t y of each of these three p o s s i b i l i t i e s can be assessed as follows. (i) i s unacceptable because the a n a l y t i c a l data and 1 9 F and :H N.M.R. spectra showed an absence of impurities, ( i i ) i s very u n l i k e l y because the simultaneous appearance of the B± v i b r a t i o n , which would correspond to the 2085 cm. 1 band, must be accompanied by s p l i t t i n g of the E mode (120, 123) which was not observed i n t h i s case. Further-more, the i n t e n s i t y of the 2085 cm. 1 band i s f a r greater than expected (68, 120) . ( i i i ) may be po s s i b l e because the observed VQQ frequencies agree with the pattern ( i n t e n s i t y and band separation) expected to arise from a molecule haying C s symmetry, i . e . cis-[LL'M(CO) i+] . I f t h i s were the case, i t follows that one would expect to see two peaks associated (1) with the coordinated C=C s t r e t c h i n g v i b r a t i o n i n the region of 1600-1400 cm. 1 (124) and (2) with the ketonic s t r e t c h i n g frequency i n the region of 1660-1640 cm. 1 (94) . In the 1800-1400 cm. 1 region, however,, compound (V) shows only one sharp peak at 1630 cm. 1 . The presence of only one peak could possibly be explained i n terms of an accidental over-lapping of C=C and ketonic s t r e t c h i n g frequencies, which i s most u n l i k e l y (see discussion section on the VN_R frequencies). Theory also predicts Sec. IV-C-2 103 (69) t h a t t h e t e r m i n a l c a r b o n y l s t r e t c h i n g f o r c e c o n s t a n t s s h o u l d d e c r e a s e s t e a d i l y as t h e t e r m i n a l CO groups a re s u c c e s s i v e l y r e p l a c e d by o t h e r l i g a n d s w h i c h make l e s s demand f o r m e t a l d u e l e c t r o n s . T h i s p r e d i c t i o n a f f o r d s o n l y v e r y l i t t l e i n f o r m a t i o n f o r d i s t i n g u i s h i n g between s t r u c t u r e s (VA) and (VB) s i n c e t h e C=C bond i n f l u o r o - o l e f i n s has a s t r o n g i r-bonding c h a r a c t e r (42) and hence i t may compensate f o r t h i s demand. D e s p i t e t h e f a c t t h a t an analogous s t r u c t u r e CH 2=CHC0Co(C0)3 (76) has been p r o p o s e d on t h e b a s i s o f c h e m i c a l and t h e i n f r a r e d s p e c t r o -s c o p i c e v i d e n c e , t h e c o r r e c t c o n f i g u r a t i o n o f compound ( V ) , e i t h e r CFH=CFMn(CO)5 o r CFH=CFC0Mn(C0) h, cannot be deduced w i t h c e r t a i n t y from t h e p r e s e n t i n f o r m a t i o n . To s o l v e t h i s p r o b l e m an X - r a y c r y s t a l l p g r a p h i c s t u d y f o r t h i s compound ?as me n t i o n e d e a r l i e r , i s now u n d e r t a k e n i n t h i s d e p artment. I t i s r e a s o n a b l e t o assume t h a t t h e s t r u c t u r e o f compound ( I I ) , (CH3) 3Sn-Mn(CO) ^ ( 7 7 - 0 2 ! ! ^ ) , i s bas e d on an o c t a h e d r a l arrangement o f t h e l i g a n d s around t h e Mn atom. T h i s Would g i v e r i s e t o t h e p o s s i b i l i t y o f c i s - and t r a n s - i s o m e r i s m . A c c o r d i n g t o t h e o r y , t h e c i s - i s o m e r w i t h C s symmetry s h o u l d have f o u r i n f r a r e d a c t i v e UQQ modes ( 2 A i + B i + B 2 ) w h e r e a s t h e more s y m m e t r i c a l t r a n s - i s o m e r (C i^ symmetry assuming t h e two s u b s t i t -u e n t s f r e e l y r o t a t e a l o n g t h e a x i a l a x i s ) s h o u l d show two bands c o r r e s -p o n d i n g t o A b and E. I n v i e w o f t h e s t r o n g n-bonding c h a r a c t e r o f the C=C bond i n e t h y l e n e ( 1 2 4 ) , f r e e r o t a t i o n o f t h e e t h y l e n e m o l e c u l e i n t h e complex i s u n l i k e l y , l e a d i n g t o l o w e r i n g o f t h e symmetry o f the com-p l e x , p r o b a b l y C 2 V J and hence an i n c r e a s e i n t h e number o f UQQ bands. I t i s c l e a r t h e n t h a t t h e d e t e r m i n a t i o n o f t h e c o n f i g u r a t i o n o f ( I I ) depend-i n g m e r e l y on t h e UQQ v i b r a t i o n s i s u n l i k e l y t o p r o v i d e a c l e a r answer. Sec. IV-C-2 104 In f a c t , compound ( I I ) , i n t h i s s e r i e s o f compounds, shows t h e most p o o r l y r e s o l v e d VQQ bands, a medium band a t 2072 cm. - 1 and a v e r y s t r o n g and b r o a d band c e n t r e d a t 1987 cm. 1 w h i c h i s accompanied by two s h o u l d e r s at 1994 and 1970 cm. - 1. T h i s s p e c t r u m i n d i c a t e s t h a t t h e c i s - i s o m e r must be p r e s e n t , a l t h o u g h t h e p r e s e n c e o f t h e t r a n s - i s o m e r cannot o e r u l e d o u t . I t i s n o t e w o r t h y t h a t t h e c o o r d i n a t e d e t h y l e n e o f (TI) a c c e p t s l e s s r r - e l e c t r o n d e n s i t y from t h e m e t a l t h a n does t h e c a r b o n y l group. T h i s i s i n d i c a t e d by t h e l o w e r i n g o f t h e average VQQ f r e q u e n c y o f ( I I ) , as t h e r e s u l t o f g r e a t e r t r a n s f e r o f i r - e l e c t r o n s from t h e m e t a l i n t o t h e f o u r c a r b o n y l groups ( 1 2 1 ) . The s o l u b i l i t i e s o f compounds ( V I I I ) and ( I X ) , t h e d i m e r s , i n n o n p o l a r s o l v e n t s a r e s m a l l , and c a r b o n y l a b s o r p t i o n s a r e c o n s e q u e n t l y weak and d i f f i c u l t t o a s s i g n . A l t h o u g h t h e s o l u b i l i t y can be impro v e d i n a c e t o n e o r c h l o r o f o r m t h e i n t e r p r e t a t i o n o f t h e VQQ f r e q u e n c i e s on t h e b a s i s o f t h e s p e c t r a o b t a i n e d i n t h e s e p o l a r s o l v e n t s i s n o t r e l i a b l e , s i n c e many w o r k e r s (120, 125, 126) have r e p o r t e d t h e o c c u r -r e n c e o f s o l u t e - - s o l v e n t i n t e r a c t i o n s i n such s o l u t i o n s . T h i s r e s u l t s i n s h i f t s o f t h e VQQ f r e q u e n c i e s . No a s s i g n m e n t s o f t h e VQQ bands were th u s made f o r t h e s e two compounds. c. The manganese-carbonyl d e f o r m a t i o n bands ( §MnC0) . A s t r o n g and b r o a d band was o b s e r v e d f o r each compound l i s t e d i n TABLES 16 and 17, i n t h e v e r y c o n s t a n t r e g i o n o f 642-665 cm. T h i s band s h o u l d be a s s i g n e d t o the manganese-carbonyl d e f o r m a t i o n mode. F l i t c r q f t e t a l . (70) fo u n d t h a t t h e l o c a t i o n o f t h e m e t a l - c a r b o n y l d e f o r m a t i o n band i s m a i n l y a f f e c t e d by t h e c e n t r a l m e t a l atom o f c a r b o -n y l complexes and l e s s , o r even n o t a t a l l , by t h e s u b s t i t u e n t s . One Sec. IV-C-2 105 i n t e r e s t i n g f e a t u r e h e r e i s t h a t t h i s band i s r e s o l v e d i n t o a d o u b l e t , w i t h a s e p a r a t i o n o f about 10 c m. - 1, i n compounds ( I ) , ( I I ) , ( I V ) , ( V I I ) , ( V I I I ) , and ( I X ) , b u t t h e s p l i t t i n g i s n o t o b s e r v e d i n compounds ( I I I ) , ( V ) , and (VI) (see TABLES 16 and 17 on p a g e ) . S p l i t t i n g s - o f t h e SMC0 bands were a l s o o b s e r v e d i n t h e v i c i n i t y o f 600 cm. 1 f o r (CO) 5M-L2Rt+-M(CO) 5 , where L 2 R i f - i s P 2 ( C H 3 ) ^ , P 2 ( C 2 H 5 ) i t , or' A s 2 (CH 3) k, and M i s Mo o r W ( 1 1 8 ) . d. The manganese-carbon s t r e t c h i n g modes ( ^ Mn-CO-) ' A medium and b r o a d band p l u s a weak band were o b s e r v e d i n t h e 483-412 cm; r e g i o n . Of t h e e x p e c t e d Lfa-Qo modes i n t h i s r e g i o n a c c o r d i n g t o E d g e l l ' s s u g g e s t i o n ( 1 1 9 ) , one e x p e c t s t h a t t h e most i n t e n s e band may be due p r i n c i p a l l y t o t h e r a d i a l m e t a l - c a r b o n s t r e t c h -i n g v i b r a t i o n s . C o n s e q u e n t l y , t h e most i n t e n s e bands i n t h e 483-440 cm. 1 r e g i o n a r e t e n t a t i v e l y a s s i g n e d t o t h e ^ n - C O m o ^ e * A d d i t i o n a l s u p p o r t o f t h i s a s s i g n m e n t i s a v a i l a b l e from t h e s p e c t r a o f d i m e t a l d e c a c a r b o n y l s and p e n t a c a r b o n y l h a l i d e s ( 7 0 ) . A band was o b s e r v e d f o r (CO) 5Mn-Mn(C0) 5 a t 470 cm. 1 w h i c h i s l o c a t e d a t h i g h e r f r e q u e n c y t h a n t h e analogous band a t 429 cm. 1 i n t h e c o r r e s p o n d i n g compound M n ( C Q ) 5 I . I t s h o u l d be n o t e d t h a t t h e g e n e r a l t r e n d o f QQ band p o s i t i o n s i s e x a c t l y t h e o p p o s i t e t o t h e UQQ mode o f t h e same s p e c i e s , i n good a g r e e -ment w i t h t h e o b s e r v a t i o n f o r (CO) 5Mn-Mn(C0) 5 and M n ( C 0 ) 5 I ( 7 0 ) . T h i s i n v e r s e r e l a t i o n s h i p o f t h e e f f e c t o f s u b s t i t u e n t s on t h e UQQ and ^ - C O f r e q u e n c i e s i s u n d e r s t o o d i n terms o f e l e c t r o n i c i n t e r a c t i o n s i n t h e i T - s y s t e m s . A f a c t o r w h i c h i s r e s p o n s i b l e f o r an i n c r e a s e o f t h e CO bond o r d e r , w i l l cause a d e c r e a s e i n t h e M-CO bond o r d e r , as e x p l a i n e d by Sec. IV-C-2 106 means o f r e s o n a n c e mechanisms i n a p r e v i o u s s e c t i o n (Sec. I V - C - 2 - b ) . In a d d i t i o n t o t h e V^QQ mode mentioned above, one w o u l d e x p e c t two weaker bands i n t h e same r e g i o n , a s s o c i a t e d w i t h t h e modes s i m i l a r t o t h e A a and A b t r a n s i t i o n s o f t h e VQQ v i b r a t i o n s . However, a t h e o r e -t i c a l t r e a t m e n t o f t h e s e v i b r a t i o n s i s n o t a v a i l a b l e at p r e s e n t ( 7 0 ) . e. I n f r a r e d bands a s s o c i a t e d w i t h C-F a b s o r p t i o n s . ( C H 3 ) 3 S n C F 2 C F 2 M n ( C O ) 5 ( H I ) The s p e c t r u m o f ( I I I ) i n t h e C-F a b s o r p t i o n r e g i o n (TABLE 16) shows f o u r s t r o n g bands a t 1065, 1020, 1000, and 975 c m. - 1, o f w h i c h t h e l a s t t h r e e were o b s e r v e d as a p a r t i a l l y r e s o l v e d t r i p l e t . These f o u r bands a r e a s s i g n e d on t h e b a s i s o f t h e argument made i n Sec. IV-A-2, t o C-F s t r e t c h i n g modes o f t h e - C F 2 - C F 2 - group. F u r t h e r a s s i g n m e n t s may n o t be r e l i a b l e because o f o v e r l a p p i n g o f t h e s e bands. An o b s e r -v a t i o n drawn from c o m p a r i s o n o f C-F a b s o r p t i o n s o f ( I I I ) and i t s c l o s e l y c o r r e s p o n d i n g compounds l i s t e d i n TABLE 9 on page 6 2 , i . e . , H - C F 2CF 2Mn(CO) 5 and C H 3 - C F 2 C F 2 M n ( C 0 ) 5 , i s t h a t i n c r e a s i n g t h e mass o f t h e c e n t r a l atom o f t h e t e r m i n a l s u b s t i t u e n t e.g. from H t o C t o Sn, a p p e a r e d t o d e c r e a s e t h e number o f t h e C-F a b s o r p t i o n bands, i n a c c o r d w i t h t h e t r e n d shown by t h e i n f r a r e d s p e c t r a o f ( C H 3 ) 3 S n C F 2 C F H C F 3 and ( C H 3 ) 3 S n C F 2 C F ( C F 3 ) S n ( C H 3 ) 3 (Sec. I V - A - 3 ) . T h i s was i n t e r p r e t e d i n terms o f t h e u n c o u p l i n g o f t h e C-F s t r e t c h i n g modes ( 1 0 3 ) . C5FqMn(C0) 5 (IV) T h i s compound shows seven v e r y s t r o n g and w e l l r e s o l v e d i n f r a r e d bands i n t h e C-F a b s o r p t i o n r e g i o n (TABLE 1 6 ) . A s s i g n m e n t s f o r i n d i -v i d u a l bands cannot be made w i t h c e r t a i n t y because o f t h e c o m p l e x i t y Sec. IV-C-2 1 0 7 o f t h e s p e c t r a . F l u o r o v i n y l d e r i v a t i v e s ( V ) , ( V I ) , ( V I I ) , ( V H I ) , and ( I X ) . These compounds show a s t r o n g t o medium peak i n t h e 1750-1600 cm. r e g i o n and s e v e r a l s t r o n g bands i n t h e r e g i o n 1400-700 cm. 1 (TABLE 17 on page 9 2 ) . S t o n e , e t a l . (92) r e p o r t e d t h a t when a CF 2=CF-M group, where M i s B, Sn,Ge, S i , A s , o r Hg, i s p r e s e n t i n t h e m o l e c u l e , a v e r y d i s t i n c t i v e s e r i e s o f s t o n g a b s o r p t i o n s o c c u r s i n t h e range 1800-900 cm. 1, and t h a t t h e band w h i c h appears i n t h e r e g i o n 1792-1695 cm. 1 i s due t o t h e C=C s t r e t c h i n g mode o f t h e p e r f l u o r o v i n y l group. I t i s t h u s r e a s o n a b l e t o a s s i g n t h o s e bands i n t h e 1400^-700 cm. 1 r e g i o n o b s e r v e d f o r (V) t o ( I X ) , t o t h e C-F s t r e t c h i n g v i b r a t i o n s ; and t h e , p e a k i n t h e _ l range 1750-1600 cm. a r i s e s from C=C s t r e t c h i n g v i b r a t i o n w h i c h w i l l be d i s c u s s e d i n t h e f o l l o w i n g s e c t i o n . A c o n s i d e r a t i o n o f t h e l i t e r a t u r e r e l a t e d t o a n a l y s e s o f t h e s p e c t r a o f t h e ,CF2=CFM group (92) and t r i f l u o r o e t h y l e n e s (127, 128) p e r m i t s an e m p i r i c a l , a s s i g n m e n t (see TABLE 19) f o r t h e t h r e e s t r o n g bands i n t h e 1400-800 cm. 1 r e g i o n o f t h e s p e c t r u m o f ( V I I ) . I t s h o u l d be n o t e d t h a t t h e C-F bond v i c i n a l t o t h e a c y l group o f ( V I I ) g i v e s r i s e t o a s t r e t c h i n g f r e q u e n c y w h i c h o c c u r s at much l o w e r energy t h a n t h e c o r r e s p o n d i n g peaks o f t h e compounds l i s t e d i n TABLE 19, and t h a t t h e o t h e r two f r e q u e n c i e s ( C F 2 asym. and sym.) f a l l i n t h e e x p e c t e d , f a i r l y c o n s t a n t r e g i o n s . A l t h o u g h t h i s s h i f t may be a t t r i b u t e d t o i n t e r a c t i o n w i t h t h e a c y l group ( 9 4 ) , t h e r e i s no adequate t h e o r e t i c a l t r e a t m e n t a v a i l a b l e and t h e e x a c t e f f e c t i n t h i s case can-n o t be deduced w i t h c e r t a i n t y . The C-F a b s o r p t i o n s p e c t r a o f (cis-CFH=CF)Mn(CO) 5, ( V ) , and Sec. IV-C-2 108 TABLE 19 _1 . ASSIGNMENT OF C-F ABSORPTIONS (cm. ) DUE TO CF 2=CF-X GROUP. Compound CF 2= (asym.) =CF- CF 2= (sym.) R e f e r e n c e CF 2= CFCOMn(CO) 5 ( V I I ) 1240 1042 960 T h i s work CF 2=CFH 1326 1264 929 (128) CF 2=CFD 1323 1200 855 (128) CF 2=CFC1 1336 1215 1058 (127) CF 2=CFBr 1330 1203 1027 (127) CF 2=CFM* 1327- 1178- 1049- (92) 1274 1121 1004 (*) M i s B, As, Hg, S i , Ge, o r Sn. (trans-CFH=CF)Mn ( C O ) 5 , ( V I ) , a r e v e r y s i m i l a r (TABLE 1 7 ) . No attempt t o a s s i g n t h e s e bands was made because t h e r e i s v e r y l i t t l e i n f o r m a t i o n on comparable compounds. The two d i m e r s , ( V I I I ) and ( I X ) , a l s o show s i m i l a r C-F a b s o r p t i o n s p e c t r a . However, t h e s e s p e c t r a a r e u n e x p e c t e d l y much more complex t h a n t h o s e o f t h e ana l o g u e s such as CF 2=CFC0Mn(C0) 5 o r CF 2=CFM compounds ( 9 2 ) . T h i s i s i n c o n t r a s t t o t h e f a c t . t h a t t h e number o f CF 2=GF- groups i n t h e same m o l e c u l e has no e f f e c t on t h e C-F a b s o r p t i o n p a t t e r n , as shown by t h e s i m i l a r i t y i n t h e s p e c t r a o f ( C H 3 ) 2 S n ( C F = C F 2 ) 2 and Sn(CF=CF 2)i l ( 9 2 ) . The c o m p l e x i t i e s o f t h e s p e c t r a o f ( V I I I ) and (IX) may be u n d e r s t o o d i n terms o f t h e symmetry o f t h e CF 2=CF- groups.. The di m e r ' s CF 2=CF- groups no l o n g e r p o s s e s s t h e same symmetry as i n monomeric CF 2=CF-M group due Sec. IV-C-2 109 t o complex f o r m a t i o n o f t h e CF 2=CF- groups t h r o u g h t h e i r d o u b l e bonds, and t h e i r c o n s e q u e n t l y l o w e r e d symmetry may l e a d t o a more complex sp e c t r u m . f, The C=C s t r e t c h i n g f r e q u e n c i e s . The C=C s t r e t c h i n g bands due t o t h e f l u o r o v i n y l groups o f t h e carbonylmanganese compounds a r e more\" v a r i a b l e (TABLES 16 and 1 7 ) . These bands a r e r e p r o d u c e d i n TABLE 20 t o g e t h e r w i t h t h o s e o f some o t h e r f l u o r o v i n y l compounds f o r c o m p a r i s o n . The C=C s t r e t c h i n g f r e q u e n c i e s o f p e r f l u o r o v i n y l m e t a l l i c compounds have been used t o d e t e r m i n e the n a t u r e o f t h e n-system o f t h e compounds ( 9 2 ) . I n a s e r i e s o f p e r f l u o r o v i n y l b o r o n d e r i v a t i v e s , an a p p a r e n t l o w e r i n g o f t h e C=C s t r e t c h i n g f r e q u e n c y , which was accompanied by an i n c r e a s e i n t h e B-C s t r e t c h i n g f r e q u e n c y , Was o b s e r v e d . T h i s o b s e r v a -t i o n has been i n t e r p r e t e d i n terms o f i n t e r a c t i o n between t h e n - e l e c t r o n s o f . t h e CF2=CF- group and t h e empty p ^ - o r b i t a l o f a b o r o n atom, l e a d i n g t o a d e c r e a s e and an i n c r e a s e i n C=C and C-B bond o r d e r s , r e s p e c t i v e l y . The e f f e c t o f c o n j u g a t i o n oh t h e C=C s t r e t c h i n g f r e q u e n c i e s i s a l s o known i n c o n j u g a t e d d i e n e systems ( 1 3 1 ) . F o r example, t h e C=C s t r e t c h i n g v i b r a t i o n o f 1 ,,3-butadiene moves from about 1660 cm. 1 i n t h e o r d i n a r y h y d r o c a r b o n o l e f i n s t o 1600 cm. C o n j u g a t i o n o f t h e C=C bond w i t h t h e C=0 bond l e a d s t o a s i m i l a r d i s p l a c e m e n t o f t h e band o f about 35 cm. 1 ( 1 3 1 ) . I t i s c o n s i d e r e d t h a t & s i m i l a r e f f e c t e x i s t s i n ( V ) , ( V I ) , ( V I I ) . , ( V I I I ) , and ( I X ) . Assuming t h e c o n f i g u r a t i o n o f (V) t o be F. F H N M n ( C 0 ) 5 , t h e n b o t h (V) and (VI) would haye t h e same Sec. IV-C-2 110 TABLE 20 THE C=C STRETCHING FREQUENCIES OF SOME FLUOROVINYL GROUPS. Compound C=C (cm. - 1) Reference C 5F 9Mn(CO) 5.. (IV) 1789 s This work CF 2=CF-C0-Mn(C0) 5 (VII) 1712 s* (trans-CFH=CF)Mn(CO) 5 (IV) 1670 w (cis-CFH^=CF)Mn(CO) 5 (V) 1630 s [CF 2=CFMn(C0) k] 2 Dimer 1 (VIII) 1620 m Dimer 2 (IX) 1617 m CF2=CFX (X=CF3, C 2 F 5 , or H) 1800 s (129) CF2=CFM (M=Ge, Sn, or Hg) 1739- (92) 1719 s CF 3CF=CFM'(CO) 5 (M'=Mn or Fe) 1647-1645 s (94) (*) (VII) shows a strong absorption at .1712 cm. 1 with a shoulder at 1685 cm. . Since the C=C st r e t c h i n g frequencies associated with CF2=CFM d e r i v a t i v e s , as shown i n t h i s table, are located at 1740-1720 cm. l, and because the acyl carbonyl s t r e t c h i n g vibrations were reported to occur i n the,region 1660-1640 cm. 1 (94, 130), the 1712 and 1685 cm.\" bands were assigned to VC_C A N D VQ=0 frequencies, r e s p e c t i v e l y . conjugated system ® \\ C-) (+) {S^C-^n— C=0 ^ y :C—C=Mn—C=0 which has been postulated i n Section IV-C-2-b, whereas (VII) may have two conjugated systems Sec. IV-C - 2 111 C = C — C — M n — C=Q ' I 0 v I (+) C = C — C — M n — C = 0 0 (-) C = C — C—Mn<— C = 0 (-) 0 V) I C — C = C — M n — C = 0 ' ic-) \\-) I : C — C = C — M n — C = 0 By c o m p a r i s o n o f t h e above r e s o n a n c e s , one would e x p e c t t h a t t h e p r o -b a b i l i t y o f (T) i s h i g h e r t h a n (T) because t h e l a t t e r s h a r e s i t w i t h ( 3 ) . Hence, t h e l o w e r i n g o f f r e q u e n c y i s l i k e l y t o be g r e a t e r i n (V) and (VI) t h a n i n ( V I I ) . I n a d d i t i o n t o t h e c o n j u g a t e d e f f e c t , t h e CF 2=CF- groups o f ( V I I I ) and (IX) c o n t r i b u t e t h e i r i r - e l e c t r o n s o f t h e C=C bond i n i r - b o n d i n g , so t h a t t h e C=C s t r e t c h i n g f r e q u e n c i e s o f ( V I I I ) and ( I X ) s h o u l d be much l o w e r t h a n i n t h e above, t h r e e compounds. (IV) c o n t a i n s an u n c o n j u g a t e d C=C bond and thus t h e VQ=Q f r e q u e n c y i s e x p e c t e d t o be t h e h i g h e s t one. Sec. IV-C-2 112 The r e s u l t s , as shown in.TABLE 20, a r e i n good agreement w i t h t h e above arguments e x c e p t f o r t h e band due t o ( V ) . The d i f f e r e n c e o f t h e f r e q u e n c i e s between (V) and (VI) i s f a r g r e a t e r t h a n t h e r e p o r t e d d i f -f e r e n c e f o r c i s - and t r a n s - i s o m e r s . The c i s - and t r a n s - i s o m e r s o f (CH 3CH=CH) 3As (132) show t h e C=C s t r e t c h i n g v i b r a t i o n s a t 1610 and 1620 cm. - 1, r e s p e c t i v e l y . C u l l e n e t a l . (133) r e p o r t e d 1622 and 1642 cm. f o r t h e C=C bands o f t h e c o r r e s p o n d i n g i s o m e r s o f (CF 3CH=CH)As(CH 3) 2 • T h i s l a r g e d i f f e r e n c e i n f r e q u e n c i e s may be a t t r i b u t e d t o t h e ir-bond f o r m a t i o n o f t h e CFH=CF- group i n . ( V ) , as the s t r u c t u r e (VB) i n F i g u r e 9 on page 102 , w h i c h was s u g g e s t e d on t h e b a s i s o f o b s e r v e d UQQ f r e -q u e n c i e s . The C=C s t r e t c h i n g v i b r a t i o n a r i s i n g f rom t h e ir-complexed e t h y l e n e o f (CH 3) 3Sn-Mn(CO) i+ (-n-C2iik}> ( H ) , was o b s e r v e d as a weak and s h a r p band a t 1440 cm. - 1. The c o r r e s p o n d i n g bands o f TT-C 5H 5Mn(CO) 2(ir-C 2Hi +) (86) and ( C 2 H i + P t C l 2 ) 2 (124) were o b s e r v e d a t 1499 and 1506 cm. - 1, r e s p e c t i v e l y . I t s h o u l d be m e n t i o n e d t h a t ( I I ) a l s o g i v e s r i s e t o a weak and b r o a d band i n t h e n e i g h b o u r h o o d o f 1400 cm. 1 a s s o c i a t e d w i t h t h e CH 3 asym-m e t r i c d e f o r m a t i o n mode. F o r t u n a t e l y , t h e 1440 cm. 1 peak ( UQ_Q of H-C2HI+) c o u l d , be i d e n t i f i e d because o f i t s s h a r p n e s s . Sec. IV-D D. The N.M.R. S p e c t r a o f F l u o r o c a r b o n D e r i v a t i v e s o f Pentacarbonylmanganese. 113 H and 9 F N.M.R. d a t a o f compounds p r e p a r e d i n t h i s s t u d y a r e l i s t e d i n TABLES 21 and 22. The is o m e r s o f [ C F 2 = C F M n ( C O ) 4 ] 2 were n o t examined owing t o t h e i r low s o l u b i l i t y . Each compound p r e s e n t e d i n TABLES 21 and 22 i s d i s c u s s e d i n d e t a i l i n d i v i d u a l l y as f o l l o w s . (CHQ c,Sn-Mn(CO) s , ( I ) , and (CHQ ^ Sn-MnCCOJufTr-CpHtJ, ( I I ) . The lH N.M.R. s p e c t r a o f ( I ) and ( I I ) a r e v e r y s i m i l a r . -They c o n s i s t o f CH 3 r e s o n a n c e s i n t h e r e g i o n -0.46 t o -0.48 p.p.m. (TMS) i n a d d i t i o n t o s i d e bands i n t h e v i c i n i t y o f t h e CH 3 peak due t o c o u p l i n g w i t h 1 1 9 S n , 1 1 ? S n , and 1 3 C [ J 1 3 C - H 3 was n o t o b s e r v e d f o r ( I I ) ] . I t i s o f i n t e r e s t t h a t t h e CH 3 r e s o n a n c e s o f ( I ) and ( I I ) o c c u r a t much l o w e r f i e l d t h a n t h o s e o f h e x a m e t h y l d i t i n (-0.2 p.p.m.) (134) and t e t r a m e t h y l t i n (-0.01) ( 1 3 5 ) b u t a t h i g h e r f i e l d t h a n t h o s e o f ( C H 3 ) 3 S n C l (-0.62 p.p.m.) (136) and ( C H 3 ) 3 SnBr (-0.74) ( 1 3 5 ) . On t h e o t h e r hand, t h e v a l u e s o f J Sn-CH 3, J ? S n - C H 3 , and J C-H 3 f o r ( I ) and ( I I ) a r e s i m i l a r t o t h o s e o f t h e c o r r e s p o n d i n g c o u p l i n g c o n s t a n t s o f Sn-Sn compounds (72, 134) . The c h e m i c a l s h i f t s o f m e t h y l t i n group p r o t o n s and t h e s p i n -s p i n i n t e r a c t i o n s o f m e t h y l p r o t o n s w i t h 1 1 9 S n , 1 1 ? S n , and 1 3 C n u c l e i have been o f c o n s i d e r a b l e c u r r e n t i n t e r e s t i n c o n n e c t i o n w i t h t h e n a t u r e o f t h e b o n d i n g i n m e t h y l t i n compounds. The s h i e l d i n g o f t h e m e t h y l p r o t o n s o f Group IVA compounds was f i r s t c o r r e l a t e d w i t h t h e e l e c t r o n e g a t i v i t y o f t h e c e n t r a l atoms ( 1 0 6 ) . Brown and Webster (107) found l a t e r t h a t e l e c t r o n e g a t i v i t y i s n o t t h e o n l y f a c t o r r e s p o n s i b l e f o r t h e u n s h i e l d i n g o f t h e p r o t o n s . H y p e r c o n j u g a t i o n , d^-p^-bonding e f f e c t ( 1 3 7 ) , a n i s o t r o p y o r d i s p e r s i o n e f f e c t o f t h e s u b s t i t u e n t (136) Sec. IV-D 114 TABLE 21 N.M.R. DATA OF (CH 3) 3Sn-Mn(.C0) 5 AND ITS DERIVATIVES. (CH 3) 3Sn-Mn(C0) 5 I (CH 3) sSn-MnCCOKCTT^HO . . . I I (CH 3) 3Snc:F2CF 2Mn(C0) 5 . . . . I l l Assignment I I I I I I S c H 3 a -0.46*0.01 -0 48±0.01 -0.32±0 01 6c2HH -2 65*0.01 b c -26.0±0 . 2 b S F B +22.5*0 2 b J 1 1 9 S n - C H 3 d 48.8*0.2 58.0*0 .5 J 1 1 7 S n - C H 3 >46 0*1.0 46.3*0.2 / 56.0*0 .5 J 1 3 C - H 3 128.8*0.5 ? 6 e (a) T e t r a m e t h y l s i l a n e i n t e r n a l standard (p.p.m.). (b) S i n g l e t . (c) T r i f l u o r o a c e t i c a c i d e x t e r n a l standard (p.p.m.). (d) Coupling constant i n c.p.s. (e) Absent. Sec. IV-D 115 TABLE 22 N.M.R. DATA OF SOME FLUOROVINYL-Mn(CO)5 COMPLEXES (Dp F ( 3> ( D H F ( 3 ) ( i ) F F ( 3 ) \\ = c / X c = c / \\ = c ( ( 2 V N M n ( C O ) 5 ( 2 V X M n ( C 0 ) 5 F ' C - M n ( C O ) 5 V VI V I I 0 Assignment V VI V I I I S H 1 a -8. 1*0 05 S H 2 - 5.7*0 05 S F 1 b +50.1*0 2 + 7.4*0.1 S F 2 - c +51.0*0.1 S F 3 +14.2*0 .2 - c +64.9*0.1 J H ^ 2 d 86. 5*0 .1 J H ^ 3 10. 2*0 .1 J H 2 F ! (= F ^ 2 ) 80.0*0 .1 J H 2 F 3 ( = F 3 H 2 ) 25.0*0 .1 J F * F 2 (= F 2 F 1 ) 92.5*1 j F l p 3 ( = F 3 p l ) = 2.4 40.6*1 J F 2 F 3 ( p3p2) - c 111.5*1 (a) TMS i n t e r n a l s t a n d a r d (p.p.m.). Each r e s o n a n c e was o b s e r v e d as a d o u b l e t e d d o u b l e t . (b) TFA e x t e r n a l s t a n d a r d (p.p.m.). Each r e s o n a n c e was o b s e r v e d as a d o u b l e t e d d o u b l e t . (c) Not measured. (d) C o u p l i n g c o n s t a n t ( c . p . s . ) . Sec. IV-D 116 have been s u g g e s t e d as some o f t h e o t h e r f a c t o r s i n v o l v e d . I t has been shown (138) t h a t t h e F e r m i c o n t a c t c o n t r i b u t i o n t o t h e s p i n - s p i n c o u p l i n g c o n s t a n t between two n u c l e i i s d i r e c t l y p r o p o r t i o n a l t o t h e p r o d u c t P ( 0 ) N x P ( 0 ) ^ where P(°)^ and P ( 0 ) ^ a r e t h e e l e c t r o n d e n s i t i e s o f t h e ; two b o n d i n g o r b i t a l s . F o r c o v a l e n t l y bonded h y d r o g e n , P ( 0 ) H u s u a l l y i s c o n s i d e r e d t o be t h e same as f o r t h e hydrogen atom i n t h e I s s t a t e ( 1 3 9 ) . F o r o t h e r atoms a s i m p l e LCAO t r e a t m e n t p r e d i c t s t h a t P ( 0 ) ^ r i s p r o p o r t i o n a l t o t h e p e r c e n t a g e s - c h a r a c t e r i n t h e h y b r i d i z e d a t o m i c o r b i t a l used i n t h e b o n d i n g . T h i s r e l a t i o n s h i p was f i r s t a p p l i e d t o measure q u a n t i t a t i v e l y t h e s - c h a r a c t e r o f t h e Sn-C-H b o n d i n g i n t h e s e r i e s o f m e t h y l t i n c h l o r i d e s from t h e o b s e r v e d t i n -119. p r o t o n c o u p l i n g c o n s t a n t s ( 1 3 9 ) . R e c e n t l y , t h e Sn-CH^ c o u p l i n g c o n s t a n t s were found t o have a l i n e a r r e l a t i o n s h i p w i t h Sn-C asymmetric and symmetric s t r e t c h i n g f r e q u e n c i e s ( 7 2 ) . I t i s i n t e r e s t i n g , on t h e b a s i s o f t h e above t y p e o f d i s c u s s i o n , t o examine t h e bond t y p e o f t h e Sn-C bond, and, t e n t a t i v e l y , o f ,the Sn-Mn bond, i n (CH 3) 3Sn-Mn(CO) 5 and (CH 3). 3SnMri(CO ) i + ( i r-C 2 H i + ) , by comparing t h e i r N.M.R. d a t a w i t h t h e r e p o r t e d v a l u e s f o r o t h e r m e t h y l t i n compounds. Jl 1 9 Sn-CH 3 and Sn-C asymmetric and sym m e t r i c modes o f o r g a n o t i n compounds a r e w e l l i l l u s t r a t e d i n F i g u r e 10, where t h e compounds c o n t a i n i n g a Sn-Sn o r Sn-Mn bond obey t h e r e l a t i o n s h i p c l o s e l y . I t has been p o i n t e d out (72) t h a t b o t h t h e f o r c e TI 1 9 c o n s t a n t o f t h e Sn-C bond and J Sn-CH 3 v a l u e s r e f l e c t t h e s - c h a r a c t e r o f t h e Sn-C bond. I t t h e n f o l l o w s t h a t t h e o r b i t a l s engaged i n b o n d i n g t o t h e Mn atom a r e s i m i l a r t o t h o s e i n t h e Sn-Sn bond o f h e x a m e t h y l d i t i n b ecause t h e i r v a l u e s f a l l c l o s e l y i n t h e same r e g i o n , as shown i n F i g u r e 10. Assuming t h e s - c h a r a c t e r o f Sn-C bonds t o be 25% i n Jl 1 9 .._ _ _ . , , Sn-CH 3 v a l u e o f 54 c.p.s. Sec. IV-D 117 J ^ S n - C H g ( c . p . s . ) — F i g u r e 10. J 1 1 9 S n - C H 3 v s . l^Sn-C f o r some m e t h y l t i n compounds. 1. ( C H 3 ) 3 S n L i ; 2. [ ( C H 3 ) 2 S n ] 6 ; 3. ( C H 3 ) 6 S n 2 ; 4. ( C H 3 ) l t S n ; 5. ( C H 3 ) 3 S n B r ; 6. ( C H 3 ) 3 S n C l ; 7. ( C H 3 ) 2 S n C l 2 ; 8. ( C H 3 ) 3 S n C l ( a q u e o u s ) ; 9. (CH 3) 3Sn-Mn(CO)5; i u - C 2 H 4 ) 10. (CH 3) 3Sn-Mn (CO), From 1 - 8 , d a t a were t a k e n from r e f . (72) From 9 - 1 0 , t h i s work. T l 19 ( 1 3 9 ) , t h e o b s e r v e d j Sn-CH 3 v a l u e s (46 - 48 c.p.s.) r e v e a l t h a t t h e f o r m a t i o n o f t h e m e t a l - m e t a l bond i n o r g a n o t i n compounds i n f l u e n c e s t h e Sn-C-H b o n d i n g system. T h i s r e s u l t s i n a r e d u c t i o n o f t h e s - c h a r a c t e r i n t h e Sn-C bond, and i n c r e a s e s t h e s - c h a r a c t e r i n t h e Sn-Sn o r Sn-Mn bond t o more t h a n 25%. The anomaly o f t h e Sn-C bond i n h e x a m e t h y l -T 1 3 d i t i n has been shown p r e v i o u s l y by p l o t s o f t h e v a l u e s o f J C-H 3 v e r s u s 1 3 c h e m i c a l s h i f t o f t h e m e t h y l p r o t o n s ( 1 3 4 ) , and t h e v a l u e s o f J C-H 3 a g a i n s t J 1 1 9 S n - C H 3 ( 1 3 5 ) . These methods a r e r e p r o d u c e d i n F i g u r e s 11 and 12, r e s p e c t i v e l y , and a com p a r i s o n o f h e x a m e t h y l d i t i n w i t h Sn-Mn Sec. IV-D 118 Sec. IV-D 119 TABLE 23 CHEMICAL SHIFTS ( c . p . s . ) AND COUPLING CONSTANTS ( c . p . s . ) OF SOME TRIMETHYLTIN DERIVATIVES. No. Compound SCH3 J13C-H3 J 1 1 9 S n - C H 3 Ref. 1 ( C H 3 ) 3 S n C l -37.6 133 58.5 2 -Br -44.2 134 58.4 3 - I -53.0 134 58.0 >(136) 4 [ ( C H 3 ) 3 S n ] 2 0 -14.2 129 56.0 5 -S -23:8 131 56.3 6 -Se -34.5 132 56.0 ) 7 ( C H 3 ) 3 S n H - 4.8 129 56.9 \\ W l 3 5 ) 8 -CH 3 - 4.2 127 54.0 J 9 -C2F i|H -21.5 130 57.8 10 - C 3 F 6 H -21.0 131 58.6 T h i s 11 -C 2F l tMn(C0) 5 -19.2 - 58.0 > work 12 -Mn(CO) 5 -27.3 129 48.8 13 -Mn(C0) H(Tr-C2H 4) -28.6 - 46.0 14 - S n ( C H 3 ) 3 -12.0 129 49.6 (134) 15 - S n ( C 2 H 5 ) 3 -18.9 130 48.8 (135) 16 - M O ( C O ) 3 ( T T - C 5 H 5 ) -26.4 - 48.5 (8) Sec. IV-D 120 bonded compounds r e g a r d i n g t h e c h e m i c a l s h i f t s and c o u p l i n g c o n s t a n t s has now been made. The compounds p r e s e n t e d i n F i g u r e 11 a l l c o n t a i n t h e ( C H 3 ) 3 Sn group. The r e s u l t , i n agreement w i t h t h a t o b s e r v e d by C l a r k e t a l . ( 1 3 5 ) , c l e a r l y i n d i c a t e s t h e anomalous n a t u r e o f a l l m e t a l - m e t a l bonded t r i -m e t h y l t i n compounds. I t s h o u l d be n o t e d t h a t t h e anomalous b e h a v i o u r of h e x a m e t h y l d i t i n and ( C H 3 ) 3 S n - M n ( C 0 ) 5 a r e v e r y s i m i l a r i n t h i s r e s p e c t , i . e . , J i 3 C - H 3 v e r s u s J U 9 S n - C H 3 . I n F i g u r e 12, where t h e c h e m i c a l s h i f t c o n s i d e r a t i o n i s i n v o l v e d , t h e two compounds c o n c e r n e d do n o t f a l l i n t h e same r e g i o n , a l t h o u g h b o t h t h e i r v a l u e s a re f a r a p a r t from t h o s e o f o t h e r o r g a n o t i n compounds. The d i f f e r e n t and anomalous b e h a v i o u r o f t h e s e two m e t a l - m e t a l compounds becomes more c l e a r when t h e c h e m i c a l s h i f t s o f t h e m e t h y l p r o t o n s a r e p l o t t e d a g a i n s t t h e c o v a l e n t r a d i i o f t h e c e n t r a l atoms o f t h e s u b s t i t u e n t groups X i n ( C H 3 ) 3 S n X compounds, as shown i n F i g u r e 13. I t i s o b v i o u s , t h e r e f o r e , t h a t t h e f a c t o r s w h i c h d e t e r m i n e t h e Jl 1 9 Sn-CH 3 do n o t make I m p o r t a n t c o n t r i b u t i o n s t o t h e c h e m i c a l s h i f t s o f m e t h y l p r o t o n s . The ir — e l e c t r o n a c c e p t o r power o f t h e ( C H 3 ) 3 -Sn group i n ( C H 3 ) 3 S n - M n ( C 0 ) 5 was shown on t h e b a s i s o f t h e VCO f r e -quency s t u d y t o be alm o s t n e g l i g i b l e , so t h a t t h e u n s h i e l d i n g o f t h e m e t h y l p r o t o n s can.no l o n g e r be i n t e r p r e t e d i n terms o f h y p e r c o n j u g a t i o n o r i r - b o n d i n g , and, as shown i n F i g u r e 13, i t i s a l s o u n l i k e l y t o be due t o t h e a n i s o t r o p y o r d i s p e r s i o n e f f e c t o f t h e Mn(CO) 5 group. I t i s n o t y e t p o s s i b l e t o e s t i m a t e t h e e s s e n t i a l c o n t r i b u t i o n s r e s p o n s i b l e f o r t h e o b s e r v e d N.M.R. d a t a , and f u r t h e r i n v e s t i g a t i o n s o f o r g a n o m e t a l l i e compounds c o n t a i n i n g m e t a l - m e t a l bonds a r e r e q u i r e d t o answer t h i s q u e s t i o n . Sec. IV-D 121 0 < ccS OS F i g u r e 13. S c H , v s . r a d i u s o f X i n ( C H 3 ) 3 S n X compounds. -60 Element CI B r I 0 S Se C o v a l e n t ^ R a d i u s (A) 0.99 1.14 1.33 0.66 1.04 1.17 Ref. }(140) Element C Sn Mn Mo C o v a l e n t R a d i u s (A) 0.70 1.40 . 1.31 1.33 Ref. >(140) (141) (142) Sec. IV-D 122 N e v e r t h e l e s s , N.M.R. d a t a i n c o n j u n c t i o n w i t h i n f r a r e d s p e c t r a a r e th e e s s e n t i a l t o o l s i n d e t e r m i n i n g whether t h e m e t a l - m e t a l bond i s r e -t a i n e d , o r has been b r o k e n , i n a new r e a c t i o n p r o d u c t . F o r example, by f o l l o w i n g from F i g u r e 10 t h r o u g h F i g u r e 13, i t becomes c l e a r i m m e d i a t e l y t h a t t h e Sn-Mn bond i n (CH 3) 3Sn-Mn(C0)4(TT— C0H4). i s r e t a i n e d because i t s J * 1 9 S n - C H 3 , andScH 3 v a l u e s f o l l o w c l o s e l y t h o s e o f t h e p a r e n t compound, w h i l e t h e a d d u c t , ( C H 3 ) 3 S n C F 2 C F 2 M n ( C O ) 5 , g i v e s N.M.R. d a t a v e r y s i m i l a r t o t h o s e o f t r i m e t h y l t i n f l u o r o c a r b o n d e r i v a t i v e s . (CH 3) 3SnCFoCFoMnCCO) s ( i l l ) The *H N.M.R. sp e c t r u m o f t h i s compound shows a m e t h y l a b s o r p t i o n a t -0.32 p.p.m. (TMS) and t h e s i d e bands due t o c o u p l i n g o f t h e m e t h y l 119 117 p r o t o n s w i t h Sn and Sn i s o t o p e s , i n t h e v i c i n i t y o f t h e m e t h y l 1 3 peak. The C-H 3 c o u p l i n g was n o t o b s e r v e d . The o b s e r v e d v a l u e s o f S c H 3 , J 1 1 Sn-CH 3 and U Sn-CH 3 a r i s i n g from ( I I I ) a r e c o n s i s t e n t w i t h t h o s e found f o r t r i m e t h y l t i n f l u o r o c a r b o n d e r i v a t i v e s (see TABLES 12, 13 and 14, and F i g u r e 10 and 12) ? s u p p o r t i n g t h e f o r m u l a t i o n o f t h i s compound, as me n t i o n e d e a r l i e r . The f o r m u l a t i o n i s f u r t h e r s u p p o r t e d 19 by t h e F N.M.R. d a t a . 19 The F N.M.R. s p e c t r u m o f ( I I I ) c o n s i s t s o f two r e s o n a n c e s a t -26.0 and +22.5 p.p.m. (TFA). I n many f l u o r o c a r b o n - t r a n s i t i o n m e t a l d e r i v a t i v e s , t h e r e s o n a n c e s o f t h e f l u o r i n e atoms o f t h e a-CF 2 groups ( t h e group d i r e c t l y bonded t o t h e t r a n s i t i o n m e t a l ) have been f o u n d t o o c c u r i n t h e r e g i o n -15 t o -20 p.p.m. (TFA) (74, 14 3 ) , w h i c h i s about 50 p.p.m. t o l o w e r f i e l d t h a n t h e u s u a l r e g i o n f o r t h e CF 2 group d i r e c t l y bonded t o a Group IVA atom ( 1 4 3 ) . T h i s u n s h i e l d i n g o f t h e f l u o r i n e atoms has been i n t e r p r e t e d i n terms o f t h e f a c t t h a t , i n t h e F-C-M (M = t r a n s i t i o n m e t a l ) s y s t e m , t h e p a r a m a g n e t i c c o n t r i b u t i o n t o Sec. IV-D ' 123 t h e s c r e e n i n g c o n s t a n t o f t h e f l u o r i n e n u c l e i i s more s i g n i f i c a n t t h a n t h e d i a m a g n e t i c c o n t r i b u t i o n ( 1 4 3 ) . The -26.0 p.p.m. r e s o n a n c e a r i s i n g from ( I I I ) was thus a s s i g n e d t o t h e f l u o r i n e atoms o f t h e C F 2 group d i r e c t l y l i n k e d t o t h e Mn atom, which i s i n good agreement w i t h the r e p o r t e d v a l u e f o r t h e c o r r e s p o n d i n g f l u o r i n e atoms i n (CO)5MnCF2CF 2CF2Mn(C0)5 ( 7 4 ) . The +22.5 p.p.m. peak was c o n s e q u e n t l y a s s i g n e d t o t h e f l u o r i n e atoms geminal t o t h e Sn atom. No f i n e s t r u c t u r e c o u l d be o b s e r v e d f o r t h e s e two r e s o n a n c e s . ( c is-CFH=CF)Mn(CO) s, ( V ) , and (trans-CFH=CF)Mn(CO) s, ( V I ) . A compound w i t h t h e c h e m i c a l f o r m u l a C 2 F 2 H M n ( C p ) 5 may have t h r e e p o s s i b l e s t r u c t u r e s F \\ / F H \\ / F F \\ / H / C = c x > = c v c = c x H M n ( C 0 ) 5 F M n ( C 0 ) 5 F M n ( C 0 ) 5 (P) (Q) (R) i n a d d i t i o n t o t h e n-bonding i s o m e r s analogous t o s t r u c t u r e (VB) i n F i g u r e 9. The n-bonding i s o m e r s w i l l n o t be c o n s i d e r e d a t p r e s e n t . The r e p o r t e d H-F c o u p l i n g c o n s t a n t s i n s e v e r a l f l u o r o - o l e f i n s and t h e i r o r g a n o m e t a l l i e d e r i v a t i v e s a n alogous t o t h e above t h r e e s t r u c -t u r e s a r e r e p r o d u c e d i n TABLE 24. I n s p e c t i o n o f TABLE 24 r e v e a l s t h a t i n each cas e J H F ( g e m i n a l ) > j H F ( t r a n s ) > j H F ( c i s ) , and t h e i r v a l u e s a r e i n t h e range o f j H F ( g e m i n a l ) = 7 2 - 8 1 c.p.s. J H F ( t r a n s ) = 12 - 34 c.p.s. j H F ( c i s ) = 1 ~ 8 c.p.s. T h i s f i n d i n g s u g g e s t s t h a t t h e J H F v a l u e s a s s o c i a t e d w i t h s t r u c t u r e (P) would be 82 - 81 and 12 ~ 34 c.p.s. w h i l e s t r u c t u r e (Q) may g i v e r i s e Sec. IV-D 124 TABLE 24 THE SPIN-SPIN COUPLING CONSTANTS ( c . p . s . ) IN SOME FLUORO-OLEFINS AND THEIR DERIVATIVES Compound J H F J F F Ref. t r a n s gem. c i s t r a n s gem. c i s HFC=CC1 2 - 81 - - - - d44) HFC=CF 2 12 72 <3 119 87 33 (144) H 2C=CFC1 - - 8 - - - (144) HC1C=CF 2 13 - <3 - 41 - (144) H 2C=CF 2 34 - ~1 - 37 - (144) cis-HFC=CFH 20.1 71.9 - - - 18.6 (145) Cis-FC1C=CC1F ; - - - - - 37.5 (146) t r a n s - F C l C = C C l F - - - 129.6 - - (146) ( CF 3)C1C=CF 2 - - - a 16.6 a (147) (CF 3)FC=CFX b - - - 127 - - (93) (CF 3)FC=CFX' b - - - 131 - - (93) Compound (V) 25 80 - - - 2.4 c Compound (VI) - 86,5 10.2 d d d c (a) j F - C F 3 ( t r a n s ) = 9.2 c. p . s . , j F - C F 3 ( c i s ) = 23.8 c.p.s. (b) X i s Mn(CO) 5 and X 1 i s Fe (CO) 2 (TT-C 5H 5) . Both compounds have \" t r a n s \" c o n f i g u r a t i o n s . (c) T h i s work. Compound ( V ) , (d) Not measured. C = C H / X M n ( C O ) 5 ; Compound (VI) /C=C. F Mn(CO), Sec. IV-D 1 2 5 t o J H F v a l u e s o f 7 2 ~ 8 1 and 1 ~ 8 c.p.s. The J H F v a l u e s a r i s i n g from (R) would n o t t h e n be h i g h e r t h a n 4 0 c.p.s. By com p a r i s o n o f t h e s e d a t a and t h e o b s e r v e d *H N.M.R. s p e c t r a o f (V) and ( V I ) , i t i s r e a s o n a b l e t o a s s i g n t o (V) t h e s t r u c t u r e ( P ) , ( i . e . , a \" c i s \" f o r m ) , and t o (VI) t h e s t r u c t u r e (Q), ( i . e . , a \" t r a n s \" c o n f i g u r a t i o n ) . The 1 9 F N.M.R. s p e c t r u m o f (V) c o n s i s t s o f two s e t s o f d o u b l e t s a t + 1 4 . 2 p.p.m. [ J t 1 ) , 2 5 . 4 c.p.s.; J ( 2 ) , = 2 c.p.s.] and a t + 5 0 . 1 p.p.m. [ J ( 3 ) , 7 9 . 6 c.p.s.; J * - 4 - * , 2 . 4 c . p . s . ] , r e s p e c t i v e l y . The j C 1 ) and JT3) v a l u e s a r e i n e x c e l l e n t agreement w i t h t h o s e o b s e r v e d i n t h e *H N.M.R. s p e c t r u m o f ( V ) , and hence t h e s e two r e s o n a n c e s a r e r e a d i l y a s s i g n e d t o t h e f l u o r i n e atoms \" t r a n s \" and \" g e m i n a l \" t o t h e v i c i n a l p r o t o n , r e s p e c t i v e l y . Each component o f t h e s e two d o u b l e t s i s f u r t h e r s p l i t i n t o a d o u b l e t [ J12) and ] due t o t h e F-F i n t e r a c t i o n . I n a l l t h e p o l y f l u o r o - and p e r f l u o r p - o l e f i n s and t h e i r o r g a n o m e t a l -l i e d e r i v a t i v e s , s o f a r s t u d i e d , as r e p r o d u c e d i n TABLES 2 4 and 2 5 , t h e \" t r a n s \" F-F c o u p l i n g c o n s t a n t s f a l l i n t h e v e r y c o n s t a n t range 1 1 0 - 1 3 0 c . p . s . , c o n s i d e r a b l y g r e a t e r t h a n t h e c o u p l i n g s o f \" g e m i n a l \" o r \" c i s \" f l u o r i n e atoms. The o b s e r v e d v a l u e o f J J F F i n (V) at l e a s t i n d i c a t e d t h a t t h e two f l u o r i n e atoms o f (V) a r e not \" t r a n s \" t o each o t h e r . How-e v e r , i t s h o u l d be n o t e d t h a t J F F v a l u e i n (V) i s t o o s m a l l f o r j F F ( c i s ) v a l u e s , a l t h o u g h t h e ( J F F ( c i s ) v a l u e s v a r y m a r k e d l y i n d i f f e r e n t com-pounds. The s t r u c t u r a l s i g n i f i c a n c e o f t h i s a b n o r m a l l y s m a l l v a l u e i s not known. I t w i l l be remembered (page 101) t h a t s i m i l a r d i f f i c u l t i e s a r o s e i n t h e i n t e r p r e t a t i o n o f t h e i n f r a r e d s p e c t r u m o f (V) i n t h e UQQ r e g i o n . These d i f f i c u l t i e s , a g a i n , j u s t i f y an X- r a y d e t e r m i n a t i o n o f t h e m o l e c u l a r s t r u c t u r e . Sec. IV-D 126 TABLE 25 THE F-F COUPLING CONSTANTS ( c. p. s i ) IN SOME PERFLUORO-VINYL DERIVATIVES: CF 2= CFX Compound (X) J F F J F F Ref. t r a n s gem, c i s t r a n s gem. C I S - ( C F 3 ) 120 57 40 8 13 21 (147) - ( CF 2C1) 118 56 39 6 19 31 (93) - ( C I ) , - ( B r ) 115, 124 78, 75 58, 57 - - - (144) -(H) 119 87 33 12 72 <3 (144) -(X'R4_ n) 110-118 62-79 26-34 - - - (148) - [ X , ( C 2 H 5 ) 3 ] * 113-115 70-81 26-34 - - - (113) -[COMn(CO) 5] 111. 5 92.5 40.5 - - - T h i s work (*) X* i s S i , Ge, o r Sn. Sec. IV-D 127 The 1 9 F N.M.R. spect r u m o f (VI) i s n o t d i s c u s s e d because (VI) decomposed b e f o r e i t s s p e c t r u m c o u l d be o b t a i n e d . CF?=CFCOMn(CO) s ( V I I ) I f t h e c h e m i c a l s h i f t s o f t h e t h r e e f l u o r i n e n u c l e i i n ; a p e r f l u o r o -v i n y l group a r e l a r g e i n co m p a r i s o n w i t h t h e c o u p l i n g c o n s t a n t s , between them, t h e N.M.R. s p e c t r u m o f t h i s group may be t r e a t e d as an ABC s y s t e m f o r w h i c h a t w e l v e - l i n e s p e c t r u m i s e x p e c t e d . The 1 9 F N.M.R. sp e c t r u m o f t h i s compound c o n s i s t e d o f t h r e e s e t s o f q u a r t e t s (each w i t h r e l a t i v e i n t e n s i t y r a t i o 1:1:1:1) c e n t r e d at +7.4, +51.0, and +64.9 p.p.m. (TFA) , r e s p e c t i v e l y , a t y p i c a l s p e c t r u m o f an ABC system. Assignment o f each r e s o n a n c e t o a. s p e c i f i c f l u o r i n e atom may be made on t h e b a s i s o f comp a r i s o n o f i t s c h e m i c a l s h i f t and c o u p l i n g c o n s t a n t s w i t h t h o s e o f o t h e r analogous m o l e c u l e s . F o r a r i g o r o u s a s s i g n m e n t , a c o n s i d e r a t i o n o f t h e e f f e c t o f t h e s u b s t i t u e n t s on t h e s e p a r a m e t e r s o f t h e t h r e e f l u o r i n e n u c l e i must be made. I t was n o t e d , from TABLE 26, t h a t t h e f l u o r i n e c h e m i c a l s h i f t s i n a l l c a s e s f o l l o w t h e t r e n d S i < §2 < S 3 . I t was a l s o n o t e d , however, t h a t an anomalous c h e m i c a l s h i f t a r i s e s when one o f t h e c a r b o n atoms i n t h e v i n y l group i s d i r e c t l y a t t a c h e d t o a t r a n s i t i o n m e t a l . (2) I n t h e p e r f l u o r o - v i n y l s e r i e s t h e F v atom becomes u n s h i e l d e d as th e atom i s r e p l a c e d by a t r a n s i t i o n m e t a l c a r b o n y l group. T h i s i s i l l u s t r a t e d i n t h e f o l l o w i n g compounds ( 1 4 7 ) , (CO) 5Mn^ (3) ( C 5 H 5 ) ( C 0 ) 2 F e x C 2 ) F / ' •C=C :c=c t F 3 v \"CF3 (+29.5 p.p.m.) (+18.5 p.p.m.) (+9.5 p.p.m.) Sec. IV-D 128 TABLE 26 1 9 F CHEMICAL SHIFTS OF CF 2= CFX GROUPS (Dp F(3) C h e m i c a l S h i f t * X p(2) F ( 3 ) Ref. -C1,-H,-C 6H 5 25 5 - 2 8 5 44.5 - 56 5 68 5 - 116 5 (148) -CF 3,-CF 2C1 16 5 - 1 8 5 29.5 30 5 108 5 - 115 5 (93) -MR^-n b 3 6 - 11 6 36.2 46 8 116 2 - 123 2 (148) - M ( C 2 H 5 ) 3 C 24 5 - 2 5 6 53.7 60 6 130 .1 - 135 1 (10 3) -COMn(CO) 5 7.4 51.0 64.9 T h i s work (a) I n p.p.m. w i t h r e s p e c t t o TFA, u n l e s s d e n o t e d o t h e r w i s e . (b) R e p r e s e n t a t i v e o f f o r m u l a ( C F 2 = C F ) N M R 4 _ N > where M i s S i , Ge, o r Sn. (c) M i s S i , Ge, o r Sn. C h e m i c a l s h i f t r e l a t e d t o b e n z o t r i f l u o r i d e . Sec. IV-D 129 T h i s u n s h i e l d i n g e f f e c t a r i s i n g from t h e i n f l u e n c e o f a t r a n s i t i o n m e t a l on t h e g e m i n a l f l u o r i n e atom o f t h e p e r f l u o r o v i n y l group has been i n t e r p r e t e d i n terms o f t h e i m p o r t a n c e o f t h e p a r a m a g n e t i c c o n t r i b u t i o n t o t h e s c r e e n i n g c o n s t a n t o f f l u o r i n e atoms ( 9 3 ) . The u n s h i e l d i n g e f f e c t o f a t r a n s i t i o n m e t a l has been a l s o observed, i n - v i n y l - t r a n s i t i o n m e t a l compounds ( 1 3 0 ) , b u t not on t h e c o r r e s p o n d i n g n u c l e u s o f t h e above s e r i e s (TABLE 27) t h e c h e m i c a l s h i f t i n c r e a s e s i n TABLE 27 XH N.M.R. DATA OF SOME VINYL COMPOUNDS. (1) H (3) (21 / C — C \\ L ^ H M J l 2 - Jgem J i 3 = J c i s J 2 3 = J t r a n s M C h e m i c a l s h i f t (p.p.m.) C o u p l i n g c o n s t a n t ( c . p . s . ) Ref. S s & 8. Jgem J c i s J t r a n s -COW(CO) 3C 5H 5 a -6.4 -5.4 -5.1 2 10 17 - C O F e ( C O ) 2 C 5 H 5 -6.5 -5.2 -4.8 2 10 17 K130) - F E ( C 0 ) 2 C 5 H 5 -6.9 -5.3 -5.8 - b 8 17 - C 6 H 5 C -1.4 -0.4 0.1 1.2 10.6 17.2 (104) (a) C h e m i c a l s h i f t r e l a t e d t o i n t e r n a l s t a n d a r d o f h e x a m e t h y l d i s i l o z a n e (p.p.m.) (b) A b s e n t . (c) C h e m i c a l s h i f t r e l a t e d t o w a t e r (p.p.m.) the order J F F ( g e m ) > J F F ( c i s ) and j H H ( t r a n s ) > j H H ( c i s ) > jHH(gem) f o r a l l t h e i r d e r i v a t i v e s . The s u b s t i t u e n t s thus appear t o have l i t t l e , o r no e f f e c t , on t h e c o u p l i n g c o n s t a n t sequences.. T h e r e f o r e , i t i s r e a s o n a b l e t o a s s i g n t h e t h r e e q u a r t e t s t o t h e f l u o r i n e atoms o f ( V I I ) on t h e b a s i s o f t h e c o u p l i n g c o n s t a n t v a l u e s . S(D; «*• \\ ( 3 ) 93 cps. \\ rA r T — r 7c p s II 0 The two +51 p.p.m. and +65 p.p.m. q u a r t e t s a r e r e a d i l y a s s i g n e d t o t h e two f l u o r i n e atoms \" t r a n s \" t o each o t h e r because t h e i r f i r s t s p l i t -t i n g s a r e 111.5 c. p . s . , t h e c h a r a c t e r i s t i c v a l u e f o r J F F ( t r a n s ) . The sec o n d s p l i t t i n g s o f t h e s e two r e s o n a n c e s due t o f u r t h e r i n t e r a c t i o n w i t h F ^ a r e 93 and 40.7 c. p . s . , r e s p e c t i v e l y . A c c o r d i n g t o t h e t r e n d i n c o u p l i n g c o n s t a n t s o f t h e p e r f l u o r o v i n y l group ( i . e . , J t r a n s > vJgem > J c i s ) , t h e +51 p.p.m. q u a r t e t i s a s s i g n e d t o t h e f l u o r i n e atom \" g e m i n a l \" t o F^ 1 - '. i . e . , F ^ 2 - ' , and t h e +65 p.p.m. q u a r t e t , t o t h e F ^ atom. f 21 The +7.4 p.p.m. r e s o n a n c e was s p l i t by F w i t h 92.5 c.p.s. and f 3) f u r t h e r s p l i t by F^ J w i t h 40.6 c. p . s . , i n good agreement w i t h t h e v a l u e s o b t a i n e d from F^ J and F^ 1 . T h e r e f o r e t h i s l o w e s t f i e l d q u a r t e t was a s s i g n e d t o t h e F ^ atom. The sequence o f t h e c h e m i c a l s h i f t o b t a i n e d from t h e above a s s i g n m e n t s i s F 3 > F 2 > F 1 ? f u r t h e r s u p p o r t i n g t h e f o r m u l a t i o n o f V I I , as s u g g e s t e d by t h e i n f r a r e d s p e c t r o s c o p i c s t u d y , Sec. IV-D 131 i . e . , t h e p e r f l u o r o v i n y l group i s d i r e c t l y bonded t o t h e a c y l group r a t h e r t h a n t o t h e Mn atom (page 1 1 1 ) . Sec. V 132 V. CONCLUSION The i m p o r t a n c e o f t h e p r e s e n t work l i e s i n t h e f a c t t h a t i t e s t a b l i s h e s (a) t h a t s i m p l e o l e f i n s can be i n s e r t e d d i r e c t l y a c r o s s t h e t i n - t i n and t h e tin-manganese bonds, (b) t h a t such a d d i t i o n w i t h t h e Sn-Sn bond p r o b a b l y i n v o l v e s f r e e - r a d i c a l s y s t e m s , and (c) t h a t , t h e t i n - t i n bond and t h e tin-manganese bond a r e v e r y r e a c t i v e b u t behave i n a d i f f e r e n t manner. The f o r m a t i o n o f compounds ( C H 3 ) 3 S n C F 2 ( C F 2 C F 2 ) n C F 2 H (n = 0 , 1, and 2) and ( C H 3 ) 3 S n C F 2 ( C F 2 C F 2 ) m C F 2 S n ( C H 3 ) 3 (m = 0, 1, and 2 ) , from t h e r e a c t i o n o f h e x a m e t h y l d i t i n and t e t r a f l u o r o e t h y l e n e was c l e a r l y t h e r e s u l t o f two p r i n c i p a l r e a c t i o n s b o t h o f w h i c h i n v o l v e t h e f r e e -r a d i c a l (CH 3) 3SnCF 2CF 2.. T h i s s p e c i e s i s b e l i e v e d t o form by a h o m o l y t i c f i s s i o n o f t h e t i n - t i n bond, f o l l o w e d . b y t h e a t t a c k o f t h e r a d i c a l ( C H 3 ) 3 S n on t h e t e t r a f l u o r o e t h y l e n e m o l e c u l e as t h e i n i t i a t i o n s t e p . The r a d i c a l ( C H 3 ) 3 S n C F 2 C F 2 t h e n e i t h e r p a r t i c i p a t e s i n h y d r o g e n a b s t r a c -t i o n , p r e s u m a b l y from CH 3 g r o u p s , l e a d i n g t o t h e f o r m a t i o n o f ( C H 3 ) 3 S n C F 2 C F 2 H , o r a t t a c k s a n o t h e r h e x a m e t h y l d i t i n m o l e c u l e g i v i n g t h e 1:1 adduct and a n o t h e r r a d i c a l ( C H 3 ) 3 S n . P r o p a g a t i o n can o c c u r i n b o t h c a s e s , g i v i n g p r o d u c t s c o n t a i n i n g more t h a n one u n i t o f C 2 F 4 . H e x a m e t h y l d i t i n a l s o r e a c t e d w i t h h e x a f l u o r o p r o p e n e , t r i f l u o r o -e t h y l e n e , 1 , 1 - d i f l u o r o e t h y l e n e , and t r i f l u o r o c h l o r o e t h y l e n e i n t h e same f a s h i o n as w i t h t e t r a f l u o r o e t h y l e n e . The r a d i c a l s formed i n t h e i n i t i a t i o n s t e p were: Sec. V 133 ( C H 3 ) 3 S n C F 2 C F ( C F 3 ) r a t h e r t h a n ( C H 3 ) 3 S n C F ( C F 3 ) C F 2 ; ( G H 3 ) 3 S n C H F C F 2 r a t h e r t h a n ( C H 3 ) 3 S n C F 2 C H F ; ( C H 3 ) 3 S n C H 2 C F 2 r a t h e r t h a n ( C H 3 ) 3 S n C F 2 C H 2 ; and ( C H 3 ) 3 S n C F 2 C C l F r a t h e r t h a n ' ( C H 3 ) 3 S n C C l F G F 2 . These d i r e c t i o n s o f a t t a c k a r e c o n s i s t e n t w i t h t h o s e o f o t h e r • • • a-f r e e - r a d i c a l s , e.g., B r , C F 3 , S i C l 3 , and P H 2 , and t h i s i s f u r t h e r e v i d e n c e t o e l i m i n a t e t h e f o u r - c e n t r e d mechanism. The f a c t o r r e s p o n s i b l e f o r t h e o r i e n t a t i o n o f a d d i t i o n s i s b e l i e v e d t o be t h e s t a b i l i t y o f t h e i n t e r m e d i a t e r a d i c a l [ e . g . , ( C H 3 ) 3 S n C H F C F 2 i s more s t a b l e t h a n ( C H 3 ) 3 S n C F 2 C H F e t c . ] , and t h e n a t u r e o f t h e i n i t i a t i o n r a d i c a l ( s u c h as n u c l e o p h i l i c o r e l e c t r o p h i l i c ) becomes i m p o r t a n t when t h e i n t e r m e d i a t e r a d i c a l s have n e a r l y e q u a l s t a b i l i t y [ e . g . , ( C H 3 ) 3 S n C F ( C F 3 ) C F 2 and ( C H 3 ) 3 S n C F 2 G F ( C F 3 ) ] . I n t h e p r e s e n t c a s e , t h e r a d i c a l ( C H 3 ) 3 S n was f o u n d t o have a degree o f n u c l e o p h i l i c c h a r a c t e r as h i g h as t h e ( C H 3 ) 3 S i r a d i c a l ( 5 4 ) . That t h e ( C H 3 ) 3 S n r a d i c a l i s n u c l e o p h i l i c i n b e h a v i o u r was f u r t h e r c o n f i r m e d by t h e r e s i s t a n c e o f h e x a m e t h y l d i t i n t o e t h y l e n e . R e a c t i o n o f h e x a m e t h y l d i t i n w i t h t r i f l u o r o b r o m o e t h y l e n e y i e l d e d no h y d r o g e n a b s t r a c t i o n p r o d u c t , i n s t e a d ( C H 3 ) 3 S n C F = C F 2 was formed. T h i s was a t t r i b u t e d t o t h e ease o f f o r m a t i o n o f B r r a d i c a l s i n t h e c o u r s e o f i r r a d i a t i o n . The f o r m a t i o n o f ( C H 3 ) 3 S n C F 2 C F 2 M n ( C O ) 5 from ( C H 3 ) 3 S n - M n ( C O ) 5 and t e t r a f l u o r o e t h y l e n e i n d i c a t e s t h a t t h e C 2 F t t m o l e c u l e can a l s o be i n s e r t e d r e a d i l y i n t o t h e tin-manganese bond under f r e e - r a d i c a l c o n d i t i o n s , b u t t h e 1:1 a d d u c t s undergoes s e c o n d a r y r e a c t i o n s t o g i v e s e v e r a l new p r o d u c t s and t r i m e t h y l t i n f l u o r i d e , t h e f o r m a t i o n o f w h i c h may be f a v o u r e d by i t s h i g h c r y s t a l s t a b i l i t y . Sec. V 134 ( C H 3 )3Sn-Mn(C0)5 r e a c t e d under t h e same c o n d i t i o n s w i t h t r i f l u o r o -e t h y l e n e t o g i v e o n l y d e c o m p o s i t i o n p r o d u c t s (CFH=CF)Mn(CO)5 and t r i m e t h y l t i n f l u o r i d e , i n d i c a t i n g t h a t t h e u n s t a b l e 1:1 a d d u c t , (CH 3) 3SnCFHCF 2Mn(CO)5 ,might be formed. The o r i e n t a t i o n o f CF 2=CFH i s b e l i e v e d t o be t h e CFH group r a t h e r t h a n t h e C F 2 group a t t a c h e d t o t h e t i n atom, w h i c h i s t h e o p p o s i t e d i r e c t i o n t o p o l a r i z a t i o n c o n s i d e r a t i o n s ( 2 5 ) . T h i s , t o g e t h e r w i t h t h e f a c t t h a t u l t r a v i o l e t l i g h t r e a d i l y a f f e c t s t h e r e a c t i o n y i e l d s , i n d i c a t e s a f r e e - r a d i c a l mechanism may b e . i n v o l v e d , b u t t h e r e i s no e v i d e n c e y e t t o e x c l u d e a f o u r - c e n t r e d t y p e o f mechanism. R e a c t i o n o f ( C H 3 )3Sn-Mn(C0)5 w i t h t r i f l u o r o c h l o r o e t h y l e n e p r o v i d e d no i n f o r m a t i o n r e g a r d i n g t h i s q u e s t i o n . W i t h e t h y l e n e t h e Sn-Mn bond was.not c l e a v e d , i n s t e a d one mole o f c a r b o n monoxide was r e p l a c e d by e t h y l e n e w h i c h i s bonded t o t h e manganese atom t h r o u g h i r - s y s t e m . . I n ( C H 3 )3Sn-Mn(C0) 5 , t h e c a r b o n - t i n , t i n - m a n g a n e s e , and manganese-c a r b o n y l bonds a r e t h e p o t e n t i a l p o i n t s o f a t t a c k . I t i s now c l e a r t h a t c l e a v a g e o f t h e s e bonds depends v e r y much on t h e n a t u r e o f t h e r e a g e n t s , e.g., H G 1 ' C 1 Z - c V s n C F 2 = C F 2 m S n _ C p 2 C p 2 _ M n ( i n s e r t i o n ) • 2 - j a d d u c t s ? ! — Sn-VMn. • C H 2 = C H 2 • MnVcO An immediate q u e s t i o n w h i c h a r i s e s i s what f a c t o r s d e t e r m i n e t h e v a r i o u s p o s s i b i l i t i e s o f r e a c t i o n s shown above. R e a c t i o n s o f ( C H 3 ) 3 S n - M n ( C 0 ) 5 w i t h t r i f l u o r o e t h y l e n e , and w i t h t r i f l u o r o c h l o r o e t h y l e n e gave t h e monomeric f l u o r o v i n y l i c d e r i v a t i v e s ( C 2 F 2 H ) M n ( C 0 ) 5 and ( C 2 F 2 C l ) M n ( C O ) 5 , r e s p e c t i v e l y . Why, t h e n , d i d n o t C-Sn-Mn-CO Sec. V 135 t h e r e a c t i o n w i t h t e t r a f l u o r o e t h y l e n e g i v e monomeric (CF 2-CF)Mn(C0) 5 r a t h e r t h a n a d i m e r i c [ ( C F 2 = C F ) M n ( C O ) 4 ] 2 o r (CF 2=CF)C0Mn(C0)5 ? I t i s i n t e r e s t i n g t o n o t e t h a t Stone e t a l . (78) p r e p a r e d , t h e t r i f l u o r o v i n y l t r a n s i t i o n - m e t a l d e r i v a t i v e s CF 2=CFRe(CO) 5 and CF 2=CFFe(CO) 2 ( T T - C 5 H 5 ) , by t r e a t i n g t h e c a r b o n y l a n i o n s i n t e t r a h y d r o f u r a n w i t h t r i f l u o r o c h l o r o -e t h y l e n e . They a l s o r e p o r t e d ( 7 8 ) , however, t h a t t h e same r e a c t i o n w i t h [Mn(CO). 5] a f f o r d e d a h y d r o g e n a b s t r a c t i o n compound HCFClCF 2Mn(C0) 5 r a t h e r t h a n CF 2=CFMn(CO)5 . The e x t e n s i o n o f t h i s s t u d y t o o t h e r m e t a l - m e t a l bonded compounds and t o a w i d e r v a r i e t y o f f l u o r o - o l e f i n s s h o u l d h e l p t o answer t h e above q u e s t i o n , and f u r t h e r , t o d e t e r m i n e t h e r o l e p l a y e d by t h e p o l a r i t y o f a mixed m e t a l - m e t a l bond. Sec. VI-A 136 V I . EXPERIMENTAL A. G e n e r a l T e c h n i q u e s . 1. Vacuum l i n e . R e a c t a n t s and r e s u l t i n g p r o d u c t s were m a n i p u l a t e d i n a s t a n d a r d vacuum sy s t e m ( 1 4 9 ) . P u r i f i c a t i o n o f v o l a t i l e r e a c t a n t s (b.p.< 0 ° ) , and rough s e p a r a t i o n o f r e a c t i o n m i x t u r e s were a c h i e v e d by p a s s i n g t h e s e v a p o u r m i x t u r e s t h r o u g h s e v e r a l c o l d t r a p s under 1-10 mm. Hg. p r e s s u r e . A l i s t o f s u i t a b l e c o l d b a t h s used t o c o o l t h e t r a p s i s g i v e n i n TABLE 28. 2. R e a c t i o n a p p a r a t u s . R e a c t i o n s were c a r r i e d out i n s e a l e d P y r e x C a r i u s t u b e s (about 100 m l . c a p a c i t y ) o r i n a s i l i c a C a r i u s t u b e s (about 70 m l . c a p a c i t y ) . A 200-watt u l t r a v i o l e t lamp ( w h i c h a l s o a c t e d as a h e a t s o u r c e ) was used f o r i r r a d i a t i o n . The u l t r a v i o l e t lamp, t o g e t h e r w i t h an a i r p i p e , were mounted i n a drum (25 cm. I.D., 30 cm. i n l e n g t h ) i n w h i c h t h e r e a c t i o n t u b e was a l s o p l a c e d . The t e m p e r a t u r e o f t h e r e a c t i o n tube c o u l d be c o n t r o l l e d by a d j u s t i n g t h e r a t e o f c o l d a i r f l o w o v e r t h e r e a c t i o n t u b e . 3. A n a l y s e s o f t h e p r o d u c t s . M i c r o a n a l y s e s were c a r r i e d out by t h e S c h w a r z k o p f M i c r o a n a l y t i c a l L a b o r a t o r y , Woodside 77, N.Y., U.S.A. ( f l u o r i n e a n a l y s i s f o r t i n compounds) TABLE 28 COLD BATHS. a B a t h Temperature (°C) I c e - w a t e r s l u s h 0 I c e - N a C l s o l u t i o n s l u s h 0 t o -20 Carbon t e t r a c h l o r i d e s l u s h -23 L i q u i d ammonia -33 t o -45 C h l o r o b e n z e n e s l u s h -45.2 C h l o r o f o r m s l u s h b -63.4 Dry i c e - a c e t o n e -78.5 E t h y l a c e t a t e s l u s h b -83.6 T o l u e n e s l u s h b -95 Carbon d i s u l f i d e s l u s h b -111.6 M e t h y l c y c l o h e x a n e s l u s h b -126.3 n-Pentane s l u s h b -130 i s o - P e n t a n e s l u s h b -160.5 L i q u i d n i t r o g e n -196 D a t a were t a k e n from r e f . (149) . These b a t h s a r e p r e p a r e d by s l o w l y a d d i n g l i q u i d n i t r o g e n t o t h e s t i r r e d l i q u i d . Sec. VI-A 1 3 8 and by A l f r e d B e r n h a r d t , M i k r o a n a l y t i s c h e s L a b o r a t o r i u m im Max-Planck-I n s t i t u t f u r K o h l e n f o r s c h u n g , M i i l h e i m ( R u h r ) , Germany ( f l u o r i n e a n a l y s i s f o r carbonylmanganese d e r i v a t i v e s ) . Carbon and hydrogen a n a l y s e s f o r a l l p r o d u c t s were p e r f o r m e d i n t h e M i c r o a n a l y t i c a l L a b o r a t o r y o f Department o f C h e m i s t r y , U n i v e r s i t y o f B r i t i s h C o l u m b i a . M o l e c u l a r w e i g h t s o f some i n v o l a t i l e compounds were measured i n benzene s o l u t i o n s on a Vapor P r e s s u r e Osmometer, Model 301A (Mechrolab I n c . , C a l i f o r n i a , U.S.A.). M o l e c u l a r w e i g h t s o f gases were measured by t h e R e g n a u l t method. Sec. VI~B~1 139 B. S p e c i a l T e c h n i q u e s , Three main t e c h n i q u e s were used i n t h e c o u r s e o f t h i s i n v e s t i g a t i o n f o r t h e p u r i f i c a t i o n o f t h e p r o d u c t s . 1. P r e p a r a t i v e chromatograph. A Beckman Gas Chromatograph, Model GC-2A (Beckman I n s t r u m e n t s I n e . , C a l i f o r n i a , U.S.A.) was used f o r t h e gas and v o l a t i l e l i q u i d a n a l y s e s and f o r p r e p a r a t i v e p u r p o s e s . Of t h e s t a n d a r d s i z e ( 1 / 4 - i n c h t u b i n g , 6 f e e t i n l e n g t h ) columns a v a i l a b l e , a d i n o n y l p h t h a l a t e column (packed w i t h 20% d i n o n y l p h t h a l a t e on chromosorb-w, a c i d - w a s h e d , 42/60 mesh) was found t o b e . t h e most e f f e c t i v e column f o r t h e s e p a r a t i o n o f m e t h y l t i n f l u o r o c a r b o n d e r i v a t i v e s . The p r e p a r a t i v e column ( 5 / 8 - i n c h t u b i n g , 10 f e e t i n l e n g t h ) was a l s o p a c k e d w i t h 30% d i n o n y l p h t h a l a t e on C-22 F i r e b r i c k , 42/60 mesh. D i f f i c u l t i e s were e n c o u n t e r e d w i t h t h e sample c e l l s s u p p l i e d by t h i s company ( C a t . No. 45407)'. These c e l l s can n e i t h e r be used f o r t h e c o l l e c t i o n o f a v e r y v o l a t i l e component be c a u s e t h e p r o d u c t e v a p o r a t e s a s - s o o n as t h e c o o l e d c e l l r e a c h e s room t e m p e r a t u r e , n o r can t h e y be u sed f o r a h i g h e r m e l t i n g p o i n t component (>-5°) s i n c e t h e i n l e t t u b i n g o f t h e c e l l i s b l o c k e d o u t v e r y e a s i l y . These d i f f i c u l t i e s were overcome by u s i n g t h e m o d i f i e d c o l l e c t i n g c e l l s shown i n F i g u r e 14. The c e l l shown i n 1 F i g u r e 14a was d e s i g n e d f o r a gaseous o r v e r y v o l a t i l e sample w h i c h i s condensed i n t h e c e l l w i t h a l i q u i d n i t r o g e n b a t h , and can be t r a n s f e r r e d i n t o t h e vacuum sy s t e m w i t h o u t c o n t a m i n a t i o n by m o i s t u r e o r a i r . A s m a l l e r c e l l shown i n F i g u r e 14b was used f o r a l e s s v o l a t i l e a i r - s t a b l e component. A f t e r c o l l e c t i o n , t h i s tube can be Sec. VI-B-2 140 c e n t r i f u g e d t o c o l l e c t t h e component i n t h e narrow t i p t h e n be p i p e t t e d out w i t h a h ypodermic n e e d l e . I _ r B-10 cone 4-mm s t o p c o r k The l i q u i d can 2-mm s t o p c o r k o i 1 1 u_ MS v < > — 12 mm B-10 cone B-5 cone 10 mm 15 mm F i g u r e 14. Sample c o l l e c t i o n c e l l s f o r t h e gas chromatograph. 2. Vacuum d i s t i l l a t i o n and s u b l i m a t i o n . The h i g h e r m o l e c u l a r w e i g h t p r o d u c t s from t h e r e a c t i o n s o f h e x a m e t h y l d i t i n and f l u o r o - o l e f i n s were u s u a l l y o b t a i n e d as v i s c o u s l i q u i d m i x t u r e s w h i c h c o u l d n o t be s e p a r a t e d w i t h c o n v e n t i o n a l d i s t i l l a -t i o n a p p a r a t u s . I n o r d e r t o s e p a r a t e t h e components o f t h e v i s c o u s l i q u i d p r o d u c t and c o l l e c t them e f f i c i e n t l y , a s p e c i a l h i g h vacuum d i s t i l l a t i o n u n i t , as shown i n F i g u r e 15, was u s e d . The m i x t u r e i s i n t r o d u c e d i n t o t h e c o n t a i n e r A w i t h a l o n g - c a p i l l a r y s y r i n g e , and t h e d i s t i l l a t i o n t e m p e r a t u r e i s c o n t r o l l e d by a nichrome h e a t i n g c o i l F i g u r e 15. H i g h vacuum d i s t i l l a t i o n a p p a r a t u s . F i g u r e 16. Vacuum s u b l i m a t i o n a p p a r a t u s f o r v i s c o u s l i q u i d s . Sec. V l - B - 3 142 a d j u s t e d t h r o u g h a p o w e r ^ s t a t . ' D u r i n g d i s t i l l a t i o n , a m a g n e t i c s t i r r e r o p e r a t e s b o t h t h e l a r g e and s m a l l m a g n e t i c b a r s i n t h e o i l b a t h and i n t h e c o n t a i n e r A. The component s e p a r a t e d t h r o u g h t h e f r a c t i o n a t i o n column condenses o n t o t h e c o o l e d f i n g e r and i s c o l l e c t e d i n c o n t a i n e r B, o r C. F o r t h e more v i s c o u s p r o d u c t s , a m o d i f i c a t i o n o f a vacuum s u b l i m a t i o n a p p a r a t u s was used ( F i g u r e 1 6 ) . The s h o r t range e v a p o r a t i o n p e r m i t s t h e h i g h l y v i s c o u s l i q u i d t o be s e p a r a t e d and condensed on t h e c o o l i n g f i n g e r t o w h i c h i s a t t a c h e d a c o n t a i n e r t o r e c e i v e t h e d r o p p i n g l i q u i d . 3. L i q u i d - p h a s e chromatograph. The p r o d u c t s from t h e r e a c t i o n between ( C H 3 ) 3 S n - M n ( C O ) 5 and f l u o r o -o l e f i n s a l ways c o n t a i n more t h a n two components. S i n c e t h e s e components a r e v e r y s i m i l a r i n v o l a t i l i t y , and because t h e y a r e s o l i d s i n t h e p u r e s t a t e , a s e p a r a t i o n u s i n g t h e a p p a r a t u s as d e s c r i b e d i n F i g u r e s 15 and 16 was g e n e r a l l y n o t s u c c e s s f u l , and l i q u i d - p h a s e chromatography was u s e d . The column (shown i n F i g u r e 17a) was p a c k e d by p o u r i n g i n a s l u r r y o f F l o r i s i l (100/2Q0 mesh) i n d i s t i l l e d n-pentane w i t h s low s t i r r i n g o f a s t a i n l e s s s t e e l r o d ( F i g u r e 17b). A f t e r t h e r o d was s l o w l y removed, t h e column was v i b r a t e d t o e n s u r e homogeneous p a c k i n g . The column was f i t t e d w i t h a w a t e r - j a c k e t , and k e p t a t room t e m p e r a t u r e o r l o w e r t o p r e v e n t b u b b l i n g . Columns o f 50 x 2 cm. were found s a t i s f a c t o r y . f o r t h e s e p a r a t i o n o f about 0.5 g. o f a m i x t u r e . The m i x t u r e was p i p e t t e d o n t o t h e t o p o f t h e column, and e l u t e d under a head o f n-pentane. The f i r s t t r a c e s o f t h e component were d e t e c t e d by a s c a n o f t h e c a r b o n y l r e g i o n o f t h e i n f r a r e d s p e c t r u m o f t h e e l u a t e , u s i n g an I n f r a c o r d s p e c t r o -p h o t o m e t e r . F r a c t i o n s , ( a b o u t 3 ml.) were t h e n c o l l e c t e d . The c a r b o n y l Sec. VI-B-3 143 o 9 P a c k i n g l e v e l O o L O 20 mm S t i r r i n g r o d Temperature c o n t r o l l e d w a t e r b a t h 16 mm c O e £ O if) c o o o 0 (b) F i g u r e 17. L i q u i d - p h a s e c h r o m a t o g r a p h i c c l o l u m n . r e g i o n o f t h e s p e c t r u m was o b t a i n e d f o r each f r a c t i o n , and t h e chromato-g r a p h i c bands c o u l d be t h e n i d e n t i f i e d by p l o t t i n g t h e c a r b o n y l band i n t e n s i t i e s a g a i n s t t h e e l u t i o n volumes. A t y p i c a l r u n i s i l l u s t r a t e d i n F i g u r e 18. F i g u r e 18. ZAX) band i n t e n s i t i e s v s . e l u t i o n volumes. Sec. VI-C-1 C. S p e c t r o s c o p i c T e c h n i q u e s 145 1. I n f r a r e d s p e c t r a . I n f r a r e d s p e c t r a were o b t a i n e d i n N u j o l m u l l s f o r t h e s o l i d compounds, as n e a t . f o r l i q u i d s , o r i n a 10-cm. gas c e l l ( p o t a s s i u m bromide windows) f o r g a s e s . The s p e c t r a o f r e a c t i o n p r o d u c t s , w h i c h were o b t a i n e d from h e x a m e t h y l d i t i n and f l u o r o - o l e f i n s , were r e c o r d e d on a P e r k i n - E l m e r Model 137 ( I n f r a c o r d ) s p e c t r o p h o t o m e t e r (sodium c h l o r i d e o p t i c s ) . The s p e c t r a o f carbonylmanganese d e r i v a t i v e s were r e c o r d e d on a P e r k i n - E l m e r Model 21 s p e c t r o p h o t o m e t e r (sodium c h l o r i d e o p t i c s ) . The s p e c t r a i n t h e f a r i n f r a r e d r e g i o n o f a l l compounds mentioned above were r e c o r d e d on a P e r k i n - E l m e r Model 137 P o t a s s i u m Bromide S p e c t r o p h o t o m e t e r . 2. ; N.M.R. s p e c t r a . The *H N.M.R. s p e c t r a were measured on a V a r i a n A s s o c i a t e s A-60 s p e c t r o m e t e r u s i n g c a r b o n t e t r a c h l o r i d e ( f o r t h e t r i m e t h y l t i n - f l u o r o -c a r b o n compounds) o r d e u t e r o c h l o r o f o r m ( f o r t h e carbonylmanganese d e r i v a t i v e s ) as s o l v e n t , and t e t r a m e t h y l s i l a n e as an i n t e r n a l r e f e r e n c e . The 1 9 F N.M.R. s p e c t r a were r e c o r d e d a t 56.4 Mc./sec. on a V a r i a n A s s o c i a t e s V-4300 s p e c t r o m e t e r . F l u o r i n e c h e m i c a l s h i f t s were o b t a i n e d w i t h r e s p e c t t o an e x t e r n a l t r i f l u o r o a c e t i c a c i d r e f e r e n c e i n a s e a l e d c a p i l l a r y t u b e . Sec. VI-D-1 1 4 6 D. R e a c t i o n s o f H e x a m e t h y l d i t i n w i t h F l u o r o - o l e f i n s . 1. P r e p a r a t i o n o f h e x a m e t h y l d i t i n . H e x a m e t h y l d i t i n was p r e p a r e d a c c o r d i n g t o t h e method d e s c r i b e d by. C l a r k and W i l l i s ( 2 3 ) . M e t h y l i o d i d e was s u p p l i e d by A l l i e d C h e m i c a l Co., N. J . , Code No. 1996, r e a g e n t grade;: :Anhydrous: s t a n n i c c h l o r i d e was s u p p l i e d by F i s h e r S c i e n t i f i c Co., N..J., C a t . No. T-140. Magnesium t u r n i n g s (260 g., 10.7 g. - atom) and 3.5 l i t e r s o f d r i e d and f r e s h l y d i s t i l l e d n - b u t y l e t h e r were p l a c e d i n t o a 5 - l i t e r , t h r e e -n e c k ed f l a s k e q u i p p e d w i t h a s t i r r e r and p r e v i o u s l y f l u s h e d w i t h n i t r o -gen gas. The c o n t e n t s were warmed up t o ca.. 50° w i t h a h e a t i n g m a n t l e , and t h e n 1160 g. (8.17 mole) o f f r e s h l y d i s t i l l e d m e t h y l i o d i d e were s l o w l y added t h r o u g h a d r o p p i n g f u n n e l . A f t e r f o u r h o u r s , when t h e r e a c t i o n m i x t u r e became deep b l a c k , 315 g. (1.21 mole) o f anhydrous s t a n n i c c h l o r i d e was added d r o p w i s e . D u r i n g t h e above r e a c t i o n s , v i g o r o u s s t i r r i n g and a c o o l i n g b a t h were r e q u i r e d . On t h e c o m p l e t i o n o f t h e r e a c t i o n , t h e s o l u t i o n was r e f l u x e d at.80° fo r . two h o u r s , t h e n a l l o w e d t o s t a n d o v e r n i g h t w i t h s t i r r i n g . T e t r a m e t h y l t i n was s e p a r a t e d by d i s t i l l a t i o n and p u r i f i e d by r e d i s t i l l a t i o n on an e f f i c i e n t column w h i c h gave a y i e l d o f 202 g. (95% on t h e b a s i s o f s t a n n i c c h l o r i d e t a k e n ) , b.p., 71-72°. A m i x t u r e o f t e t r a m e t h y l t i n (202 g., 1.13 mole) and d i m e t h y l t i n d i c h l o r i d e ( c a . 30g.) was i n t r o d u c e d i n t o a 500-ml., t h r e e - n e c k e d f l a s k f i t t e d w i t h a c o n d e n s e r , a thermometer., and a d r o p p i n g f u n n e l . 40 ml. (89.5 g., 0.344 mole) s t a n n i c c h l o r i d e , were s l o w l y added and t h e i n i t i a l h e a t o f t h e r e a c t i o n , caused t h e t e m p e r a t u r e o f t h e l i q u i d t o r i s e t o c a . 90°. A f t e r t h e a d d i t i o n was c o m p l e t e , t h e m i x t u r e was h e a t e d t o Sec. VI-D-2 147 160-170° f o r f o u r h o u r s , f o l l o w e d by d i s t i l l a t i o n on an e f f i c i e n t column t o a f f o r d 165 g. o f t r i m e t h y l t i n c h l o r i d e , (60.2% on t h e b a s i s o f s t a n n i c c h l o r i d e t a k e n ) , b.p., 138-142°. A s e c o n d c r o p o f t r i m e t h y l t i n c h l o r i d e was o b t a i n e d by t r e a t i n g the r e s i d u e w i t h a p r o p o r t i o n a l amount o f t e t r a -m e t h y l t i n , and f o l l o w i n g t h e above p r o c e d u r e . A l i q u i d ammonia s o l u t i o n o f sodium was p r e p a r e d by the a d d i t i o n o f 19 g. (0.826 g.-atoms) m e t a l l i c sodium weighed under p e t r o l e u m e t h e r , i n t o c a . one l i t e r o f l i q u i d ammonia i n a 2 - l i t e r , t h r e e - n e c k e d f l a s k u nder an atmosphere o f d r y n i t r o g e n . T r i m e t h y l t i n c h l o r i d e (150 g., 0.75 mole) was added as s o l i d , and t h e ammonia was t h e n a l l o w e d t o e v a p o r a t e . The r e s i d u e was e x t r a c t e d w i t h e t h e r , t h e e t h e r e x t r a c t washed w i t h w a t e r s e v e r a l t i m e s , d r i e d o v e r sodium s u l f a t e and d i s t i l l e d u nder r e d u c e d p r e s s u r e . The 78°/2.2 cm. Hg. f r a c t i o n was c o l l e c t e d and was shown by gas chromatography t o be p u r e h e x a m e t h y l d i t i n (81 g., 68%) w h i c h s o l i d i -f i e d on s t a n d i n g a t room t e m p e r a t u r e . 2. R e a c t i o n s w i t h t e t r a f l u o r o e t h y l e n e . Two t y p i c a l r e a c t i o n s were as f o l l o w s . (a) H e x a m e t h y l d i t i n (6.1 g., 18.3 mmole) was i n t r o d u c e d i n t o a P y r e x C a r i u s t u b e (70 m l . ) , w h i c h had p r e v i o u s l y been f i l l e d w i t h d r y n i t r o g e n , and a f t e r f r e e z i n g and e v a c u a t i n g t h e t u b e , t e t r a f l u o r o e t h y l e n e (1.85 g., 18.5 mmole), (which was p r e p a r e d by i g n i t i o n o f T e f l o n i n vacuo a t c a . 600°, and w a s - p u r i f i e d by vacuum f r a c t i o n a t i o n ) , condensed on. The s e a l e d t u b e was p l a c e d under u l t r a v i o l e t l i g h t at 25° f o r 17 h o u r s . Vacuum f r a c t i o n a t i o n gave t h r e e v o l a t i l e f r a c t i o n s , w h i c h condensed at 0°, -46°, and -196°, r e s p e c t i v e l y , and i n v o l a t i l e r e s i d u e (an orange mix-t u r e o f l i q u i d and s o l i d ) ( A ) . The -196° f r a c t i o n was t e t r a f l u o r o -Sec. VI-D-2 1 4 8 e t h y l e n e (7.95 mmole, 43% r e c o v e r y ) , i d e n t i f i e d by i t s i n f r a r e d s p e c t r u m and m o l e c u l a r w e i g h t measurement ( c a l c . 100; f o u n d : 1 0 0 ) . The -46° f r a c -t i o n was a c o l o u r l e s s l i q u i d (0.54 g.) w h i c h was s e p a r a t e d f u r t h e r by gas chromatography on a p r e p a r a t i v e d i n o n y l p h t h a l a t e column, a t 140° under 15 l b . / i n ? p r e s s u r e o f h e l i u m as c a r r i e r gas, t o g i v e two major components. The f i r s t component ( r e t e n t i o n t i m e 3.4 min.) was (1,1,2,2-t e t r a f l u o r o e t h y l ) t r i m e t h y l t i n , a ( C H 3 ) 3 S n C F 2 C F 2 H (0.19 g., 0.72 mmole), c h a r a c t e r i z e d by i t s i n f r a r e d and *H and 1 9 F N.M.R. s p e c t r a and a n a l y s e s [ c a l c . f o r C s H ^ F ^ S n : C, 22.6; H, 3.9; M.W., 265; f o u n d : C, 22.6; H, 4.1; M.W., 251 ] . The sec o n d component, 6.8 min. r e t e n t i o n t i m e , was shown by i t s i n f r a r e d and •'•H N.M.R. s p e c t r a t o be (1,1 , 2 , 2 , 3 , 3 , 4 , 4 - o c t a -f l u o r o b u t y l ) t r i m e t h y l t i n , ( C H 3 ) 3 S n C F 2 ( C F 2 ) 2 C F 2 H (0.31 g., 0.85 mmole). The 0° f r a c t i o n was u n r e a c t e d h e x a m e t h y l d i t i n (2.1 g., 6.4 mmole), i d e n -t i f i e d s p e c t r o s c o p i c a l l y . The l i q u i d - s o l i d m i x t u r e (A) was t r e a t e d w i t h 10 ml. e t h e r , and t h e w h i t e s o l i d ( B ) , w h i c h was s e p a r a t e d from t h e e t h e r s o l u t i o n by c e n t r i f u g i n g , was washed s e v e r a l t i m e s w i t h 2-ml. p o r t i o n s o f e t h e r . The combined e t h e r s o l u t i o n and t h e washings were t h e n t r a n s f e r r e d i n t o a d i s t i l l a t i o n - a p p a r a t u s , and t h e e t h e r was removed by d i s t i l l a t i o n (35°/76 cm. Hg). F u r t h e r d i s t i l l a t i o n u n d e r r e d u c e d p r e s s u r e (78°/2.2 cm. Hg) gave h e x a m e t h y l d i t i n (2.6 g., 7.95 mmole), l e a v i n g a t r a c e o f an orange o i l - l i k e r e s i d u e i n t h e a p p a r a t u s . The w h i t e s o l i d ( B ) , w h i c h was f r e e from h e x a m e t h y l d i t i n , was e x t r a c t e d w i t h h o t c a r b o n t e t r a c h l o -r i d e s e v e r a l t i m e s . The r e s i d u e was d e s i g n a t e d as ( C ) . The c a r b o n t e t r a c h l o r i d e e x t r a c t was e v a p o r a t e d w i t h a f l o w o f d r y n i t r o g e n gas (a) F o r b r e v i t y , compounds w i l l be named c o r r e c t l y a t t h e i r f i r s t i n t r o d u c t i o n i n t h i s s e c t i o n , and w i l l t h e r e a f t e r be r e p r e s e n t e d by t h e i r c h e m i c a l formulas. Sec. VI-D-2 149 u n t i l a w h i t e c l o u d i n e s s a ppeared, t h e n was c h i l l e d i n i c e t o a f f o r d 0.3 g. o f w h i t e s o l i d . The i n f r a r e d s p e c t r u m o f t h i s w h i t e s o l i d shows _1 s t r o n g and b r o a d C-F a b s o r p t i o n s a t .1211, 1150 cm. i n a d d i t i o n t o t h e bands a s s o c i a t e d w i t h ( C H 3 ) 3 S n group d i r e c t l y bonded t o a f l u o r o c a r b o n group (see Sec. I V - A - 1 ) . E l e m e n t a l a n a l y s e s a r e c o n s i s t e n t w i t h t h e f o r m u l a t i o n C 2 0 H 1 8 F 2 8 S n 2 , [ c a l c : C, 23.4; H, 1.7; F, 51.8; Sn, 23.1; found: C, 23.1; H, 1.6; F; 51.0; Sn, 2 3 . 9 ] . T h i s w h i t e s o l i d c o u l d t h u s be a m i x t u r e o f a d d u c t s e q u i v a l e n t t o t h e f o r m u l a (CH 3) 3 S n ( C 2 F i + ) ySn(CH 3) 3 . Treatment o f t h e r e s i d u e (C) w i t h h o t methanol l e f t a t r a c e o f a w h i t e s o l i d whose i n f r a r e d s p e c t r u m was i d e n t i c a l t o t h a t o f p o l y m e r i z e d t e t r a -f l u o r o e t h y l e n e (0.05 g . , ) . On e v a p o r a t i o n o f t h e methanol e x t r a c t , w h i t e c r y s t a l l i n e t r i m e t h y l t i n f l u o r i d e , ( C H 3 ) 3 S n F , (0.08 g., 0.44 mmole) [ c a l c . f o r C 3H. 9FSn : C, 19.8; H, 4.9; found: C, 19.7; H, 4.03), was o b t a i n e d . (b) H e x a m e t h y l d i t i n (7.0 g., 21.4 mmole) and t e t r a f l u o r o e t h y l e n e (2.2 g., 22 mmole) i n a s e a l e d s i l i c a t u b e (70 m l . ) , a f t e r f o u r h o u r s a t 75° under u l t r a v i o l e t i r r a d i a t i o n gave a ; r a t h e r complex m i x t u r e o f p r o -d u c t s . The -196° f r a c t i o n (0.10 mmole) c o n s i s t e d o f t e t r a f l u o r o e t h y l e n e and p e r f l u o r o p r o p a n e , a n a l y z e d by i t s i n f r a r e d s p e c t r a and gas chromato-graphy. The -126° f r a c t i o n was m a i n l y p e r f l u o r o - l , 3 - b u t a d i e n e , CF 2=CF-CF=CF 2,-(0.15 mmole) (M.W.) c a l c : 162; found: 1 5 9 ) , i d e n t i f i e d u n a m b i g u o u s l y by i t s i n f r a r e d s p e c t r u m (102) w h i c h c o n s i s t s o f t h e c h a r a c t e r i s t i c bands at. 1780 ( s ) , 1330 ( v s ) , 1190 ( s ) , 1140 (s) and 965, ' _1 (s) cm. The -76° f r a c t i o n was t e t r a m e t h y l t i n , (CH 3 )i+Sn (0.3 g., 1.7 mmole), i d e n t i f i e d by i t s i n f r a r e d s p e c t r u m (see Sec. I V - A - 1 ) . The i d e n t i f i c a t i o n o f t h e -76° f r a c t i o n i s f u r t h e r s u p p o r t e d by the gas c h r o m a t o g r a p h i c a n a l y s i s on t h e d i n o n y l p h t h a l a t e column (6 f t . ) a t 140° Sec. VI-D-2 1 5 0 under 15 l b . / i n ? p r e s s u r e o f h e l i u m gas. The r e t e n t i o n t i m e o f the -76° f r a c t i o n under such c o n d i t i o n s was.found t o be 2.2 min., i n a c c o r d w i t h t h a t shown by p u r e t e t r a m e t h y l t i n . Gas C h r o m a t o g r a p h i c s e p a r a t i o n o f t h e -46° f r a c t i o n gave ( C H 3 ) 3 S n C F 2 C F 2 H (0.12 g., 0.45 mmole) and ( C H 3 ) 3 S n C F 2 ( C F 2 ) 2 C F 2 H (0.08 g., 0.22 mmole). Because t h e i r s p e c t r a were i d e n t i c a l , t h e 0° f r a c t i o n and t h e i n v o l a t i l e l i q u i d , w h i c h was s e p a r a t e d from t h e s o l i d p r o d u c t s (A) by c e n t r i f u g i n g , were combined, and t h i s m i x t u r e was d i s t i l l e d u n d e r r e d u c e d p r e s s u r e (78°/2.2 cm. Hg) t o g i v e 2.6 g'. o f u n r e a c t e d h e x a m e t h y l d i t i n (37% r e c o v e r y ) and a brown o i l o f d i s t i l l a t i o n r e s i d u e ( B ) . E t h e r e x t r a c t i o n o f t h e s o l i d r e s i d u e (A) l e f t a w h i t e s o l i d w h i c h was t r e a t e d i n t u r n w i t h c a r b o n t e t r a c h l o r i d e , and t h e n w i t h h o t m e t h a n o l , as d e s c r i b e d i n e x p e r i m e n t (a).. There r e m a i n e d a w h i t e s o l i d (0.35 g.) whose i n f r a r e d s p e c t r u m was i d e n t i c a l t o t h a t o f p o l y m e r i z e d t e t r a f l u o r o -e t h y l e n e . E v a p o r a t i o n o f t h e methanol s o l u t i o n gave w h i t e c r y s t a l l i n e ( C H 3 ) 3 S n F (1.3 g., 7.1 mmole). E v a p o r a t i o n o f t h e c a r b o n t e t r a c h l o r i d e a f f o r d e d o n l y a t r a c e o f brown s o l i d . The e t h e r e x t r a c t was combined w i t h , t h e o i l r e s i d u e (B)< and oxygen was b u b b l e d t h r o u g h t h i s e t h e r s o l u t i o n , t o c o n v e r t t h e v l a s t t r a c e o f h e x a m e t h y l d i t i n t o t h e o x i d e , Which Was. the n removed by c e n t r i f u g i n g . E v a p o r a t i o n o f t h e e t h e r l e f t a v i s c o u s brown o i l w h i c h was t h e n t r a n s -f e r r e d i n t o a h i g h vacuum d i s t i l l a t i o n a p p a r a t u s ( F i g u r e 15 ) . When t h e a p p a r a t u s was c o m p l e t e l y e v a c u a t e d (10 cm. Hg), t h e t e m p e r a t u r e o f t h e c o n t e n t s was g r a d u a l l y i n c r e a s e d t o 40°. A l l v o l a t i l e p a r t s e v a p o r a t e d below 40° were t a k e n i n t o t h e vacuum system. The 40-60° f r a c t i o n (1.2 g.) was condensed o n t o t h e c o o l e d f i n g e r (0°) and was c o l l e c t e d i n t o one o f t h e s i d e arms. S i m i l a r l y , t h e 60-80° f r a c t i o n (0.5 g.) was c o l l e c t e d Sec. V I - D - 2 1 5 1 i n t o a n o t h e r s i d e arm, and a t 8 0 ° about 1 - 2 g. o f v i s c o u s r e s i d u e remained i n t h e a p p a r a t u s . A l l t h r e e f r a c t i o n s show complex i n f r a r e d s p e c t r a w h i c h c o n s i s t o f bands a t t r i b u t a b l e t o C - H s t r e t c h i n g , C - F s t r e t c h i n g , C H 3 - S n r o c k i n g , and Sn - C . s t r e t c h i n g v i b r a t i o n s . No f u r t h e r c h a r a c t e r i z a t i o n o f t h e 6 0 - 8 0 ° f r a c t i o n and t h e r e s i d u e was a c h i e v e d . The 4 0 - 6 0 ° f r a c t i o n , a c o l o u r l e s s l i q u i d ; , shows w i t h t h e b e s t r e s o l u t i o n , t h e bands i n t h e C - F a b s o r p t i o n r e g i o n a t 1 2 0 5 ( s , b ) , 1 1 5 0 ( s , b ) , 1 0 8 0 (s) , 1 0 4 0 ( s ) , and 1 0 2 0 (s) cm...\"1. I t s lH N.M.R. sp e c t r u m c o n s i s t s o f peaks a t - 0 . 3 4 , - 0 . 4 0 , and - 0 . 4 2 p.p.m,. (TMS), as w e l l as a t r i p l e t e d t r i p l e t a t - 6 . 0 8 p.p.m. ( J H F = 5 1 . . 8 c . p . s . , J 1 H F = 5 . 1 c . p . s . ) . The f i r s t t h r e e peaks a t h i g h e r f i e l d a r e c h a r a c t e r i s t i c o f t h e m e t h y l p r o t o n r e s o n a n c e s . The 1 9 F spectrum, shows seven peaks a t + 5 3 . 3 , + 4 5 . 8 , + 3 9 . 4 5 , + 3 7 . 8 , + 3 6 . 0 , + 3 4 . 6 , and + 2 5 . 8 p.p.m. (T F A ) , w i t h t h e peak a t + 5 3 . 3 p.p.m. b e i n g a d o u b l e t w i t h a J^p. v a l u e o f 5 2 c.p.s. T h i s con-f i r m s t h e p r e s e n c e o f a t e r m i n a l - C F 2 H group (see TABLES 12 and 1 3 J An attempted, gas ch r o m a t o g r a p h i c , s e p a r a t i o n ( d i n o n y l p h t h a l a t e column, 6 f t . , 1 4 0 ° , 1 5 . l b . / i n ? h e l i u m gas) suggested, t h e p r e s e n c e o f t h r e e components i n t h e a p p r o x i m a t e r a t i o o f 1 : 3 : 1 w i t h r e t e n t i o n t i m e s o f 1 2 , 2 1 . 5 , and 3 7 min., b u t the: v e r y low: v o l a t i l i t i e s p r e v e n t e d p r e p a r a -t i v e s e p a r a t i o n . The s e p a r a t i o n on a h i g h e r t e m p e r a t u r e column c o u l d not be a c h i e v e d because t h e r e was. an e v i d e n c e o f d e c o m p o s i t i o n on t h e column. The a n a l y t i c a l d a t a f o u n d f o r t h i s f r a c t i o n a r e : C , 2 2 . 0 ; H , 3 . 4 5 ; F, 3 0 . 0 ; M . W . , 4 4 1 . I t appears p r o b a b l e from t h e above e v i d e n c e t h a t t h e one component was p o l y f l u o r o h e x y l t r i m e t h y l t i n , [ ( C H 3 ) 3 S n C F 2 ( C F 2 ) i + C F 2 H , ( c a l c . f o r : C 9 H 1 0 F 1 2 S n : C , 2 3 . 2 ; H , 2 . 1 6 ; F, 4 9 . 2 ; M . W . , 4 6 5 ) ] , and t h e o t h e r two c o u l d be 1 , 2 - b i s ( t r i m e t h y l t i n ) -t e t r a f l u o r o e t h a n e , [ ( C H 3 ) 3 S n C F 2 C F 2 S n ( C H 3 ) 3 ( c a l c . f o r C ^ Q F h S n z : C,22.5; Sec. VM-D-3 152 H, 4.25; F, 17.8; M.W., 428)] and 1 , 4 - b i s ( t r i m e t h y l t i n ) o c t a f l u o r o b u t a n e [ ( C H 3 ) 3 S n C F 2 ( C F 2 ) 2 C F 2 S n ( C H 3 ) 3 ( c a l c . f o r C 1 0 H 1 8 F 8 S n 2 : C, 22.8; H, 3.42; F, 28.8; M.W., 5 2 7 ) ] . S p e c i e s c o n t a i n i n g , l o n g e r f l u o r o c a r b o n . c h a i n s would have a much h i g h e r f l u o r i n e , c o n t e n t and m o l e c u l a r w e i g h t , as w e l l as more peaks i n t h e 1 9 F N.M.R. sp e c t r u m t h a n were o b t a i n e d . The r e s u l t s o f t h e above two. e x p e r i m e n t s t o g e t h e r w i t h , t h o s e .of two o t h e r e x p e r i m e n t s under d i f f e r e n t c o n d i t i o n s a r e summarized i n TABLE 1 . 3. R e a c t i o n s w i t h h e x a f l u o r o p r o p e n e . A t y p i c a l r e a c t i o n was as f o l l o w s . The o l e f i n , s u p p l i e d by C o l u m b i a O r g a n i c C h e m i c a l Co., S. C., was u s u a l l y c o n t a m i n a t e d w i t h i m p u r i t i e s and was t h e r e f o r e f r a c t i o n a t e d i n t h e vacuum s y s t e m and t h e f r a c t i o n w h i c h condensed a t -126° was t a k e n f o r t h e r e a c t i o n s . H e x a m e t h y l d i t i n (7.2 g., 22 mmole) was a l l o w e d t o r e a c t w i t h hexa-f l u o r o p r o p e n e (3.84 g., 25.6 mmole). i n a s e a l e d s i l i c a C a r i u s t u b e a t 70° under u l t r a v i o l e t i r r a d i a t i o n . . A f t e r e i g h t , houus t h e tube was a t t a c h e d and opened i n t o t h e vacuum sy s t e m and vacuum f r a c t i o n a t i o n gave f o u r f r a c t i o n s w h i c h condensed a t -126°, -76°., -46°, and 0°, r e s p e c t i v e l y , l e a v i n g a b l a c k i s h brown r e s i d u e ( l i q u i d and. s o l i d ) i n t h e r e a c t i o n t u b e . The i n f r a r e d s p e c t r u m o f t h e -126° f r a c t i o n . (11.9 mmole, found M.W., 147) e x h i b i t e d bands, a t t r i b u t a b l e t o u n r e a c t e d h e x a f l u o r o p r o p e n e and s e v e r a l a d d i t i o n a l weak bands i n c l u d i n g , a C.=C. band a t 1751 cm. 1 w h i c h i s c h a r a -c t e r i s t i c o f a CF 2=C^ group (129) . T h i s f r a c t i o n was a l s o shown by gas chromatography t o be 95% p u r e h e x a f l u o r o p r o p e n e w i t h a s e c o n d component. A p p a r e n t l y a t r a c e o f a s e c o n d o l e f i n , was. p r o d u c e d . From t h e i n f r a r e d e v i d e n c e t o g e t h e r w i t h t h e M.W. measurement t h e second o l e f i n c o u l d be Sec. VI-D-3 153 1 , 1 , 3 , 3 , 3 - p e n t a f l u o r o p r o p - l - e n e , CF 2=CHCF 3 ( c a l c . f o r C 3HF 5: M.' W., 132). The -76° f r a c t i o n was i n j e c t e d i n t o a d i n o n y l p h t h a l a t e p r e p a r a t i v e column (80°). The f i r s t component was 1 , 1 , 1 , 2 , 3 , 3 , 3 - h e p t a f l u o r o p r o p a n e , C F 3 C F H C F 3 ( 0 . 1 m m o l e ) , c h a r a c t e r i z e d by i t s i n f r a r e d s p e c t r u m (102) and M.W. measurement ( c a l c . f o r C 3 F 7 H : 1,70; found: 1 76). The second and. l a s t component was, t e t r a m e t h y l t i n . (0.75 g., 4.21 mmole), i d e n t i f i e d by i t s i n f r a r e d s p e c t r u m . The -46° f r a c t i o n was a m i x t u r e o f two major components and i t s s e p a r a t i o n , . o n a. p r e p a r a t i v e d i n o n y l p h t h a l a t e column (80°) gave h e x a m e t h y l d i t i n a n d . ( 1 , 1 , 2 , 3 , 3 > 3 - h e x a f l u o r o p r o p y l ) t r i m e t h y l t i n , (CH 3) 3SnCF 2CF.(CF 3)H, (1.2 g., 3.8 mmole) ..[c a l c . f o r . C 6 H 1 0 F 6 S n : C, 22.9; H, 3.2; M.W., .315.; .found:.. C, .22.7; H, 3.0;M.Wr, 3 0 5 ] . The i n f r a r e d s p e c t r u m showed t h a t t h e 0° f r a c t i o n was. u n r e a c t e d h e x a m e t h y l d i t i n (0.7 g . ) . 10 m l . o f c a r b o n t e t r a c h l o r i d e , was.added t o t h e b l a c k i s h brown r e s i d u e , and oxygen gas was b u b b l e d through, t h e r e s u l t i n g , s o l u t i o n f o r 30 minutes when a m i l k y w h i t e s u s p e n s i o n formed. C e n t r i f u g a t i o n o f t h e m i x t u r e gave 3.4 g. o f w h i t e s o l i d , w h i c h was a m i x t u r e o f [ ( C H 3 ) 3 S n ] 2 0 and ( C H 3 ) 3 S n F . The s u p e r n a t a n t l i q u i d , e v a p o r a t e d u n d e r a f l o w o f d r y -3 a i r t o a minimum volume, was d i s t i l l e d , under 10 cm.Hg i n t h e h i g h vacuum d i s t i l l a t i o n apparatus.. The 40-80° f r a c t i o n w a s l , 2 - b i s ( t r i m e t h y -t i n ) h e x a f l u o r o p r o p a n e , ( C H 3 ) 3 S n C E 2 C F ( C F 3 ) S n ( C H 3 ) 3 > (1.2 g., 2.5 mmole) ( c a l c . f o r C 9 H 1 8 F 6 S h 2 : C, 22.6; H, 3.8; F, 23.85; M.W., 478; f o u n d C, 22.3; H, 3.5; F, 23.87; M. W., 48 6 ) . A l t h o u g h t h e 1H N.M.R. sp e c t r u m o f t h i s f r a c t i o n r e v e a l s t h e p r e s e n c e o f h i g h e r M.W. adducts and t r i -me.thyl.tin .chl.oride, w h i c h was p o s s i b l y formed d u r i n g t h e o x i d a t i o n o f h e x a m e t h y l d i t i n i n c a r b o n t e t r a c h l o r i d e s o l u t i o n (49,150), t h e y were t o o low i n q u a n t i t i e s to: a f f e c t t h e a n a l y t i c a l d a t a . A b l a c k gum (ca.. l g . ) w h i c h was p o s s i b l y a m i x t u r e o f h i g h e r M.W. add u c t s and p o l y m e r i z e d Sec. VI-D-4 154 d i m e t h y l t i n , r emained i n t h e d i s t i l l a t i o n a p p a r a t u s , and was n o t s t u d i e d f u r t h e r . The summary o f t h e above r e s u l t s t o g e t h e r w i t h t h o s e o f t h r e e o t h e r , e x p e r i m e n t s under d i f f e r e n t c o n d i t i o n s a r e p r e s e n t e d i n TABLE 2. 4. R e a c t i o n s w i t h t r i f l u o r o e t h y l e n e . A s t e e l c y l i n d e r c o n t a i n i n g t r i f l u o r o e t h y l e n e ( C o l u m b i a O r g a n i c C h e m i c a l Co., S. C.) was a t t a c h e d , t o : t h e vacuum sy s t e m and t h e o l e f i n was f r a c t i o n a t e d under vacuum, t h r o u g h t h e -126°, -150°, and -196° t r a p s . The -150° f r a c t i o n , shown by gas c h r o m a t o g r a p h i c a n a l y s i s t o be p u r e t r i f l u o r o e t h y l e n e , was used..for t h e r e a c t i o n s . . (a) H e x a m e t h y l d i t i n (.7.-85 g., 24.0 mmole) and t r i f l u o r o e t h y l e n e (1.96 g., 24.0 mmole) i n a s i l i c a t u b e were i r r a d i a t e d a t 85° f o r f o u r h o u r s . Vacuum, f r a c t i o n a t i o n . , f o l l o w e d by gas c h r o m a t o g r a p h i c and i n f r a r e d s p e c t r o s c o p i c e x a m i n a t i o n s showed, t h a t the. v o l a t i l e p a r t c o n t a i n e d t r i -f l u o r o e t h y l e n e (0.43 g«, 22% r e c o v e r y ) , a t r a c e o f f l u o r o c a r b o n gas, t e t r a m e t h y l t i n . (0.35. g., 1.95 mmole), h e x a m e t h y l d i t i n , and a f r a c t i o n (0.15 g.) w h i c h condensed a t - 4 6 T h e -46° f r a c t i o n c o u l d n o t be p u r i -f i e d gas c h r o m a t o g r a p h i c a l l y . because, of. d e c o m p o s i t i o n on t h e column, but i t may be i d e n t i f i e d on the. b a s i s , o f t h e f o l l o w i n g e v i d e n c e . I t s i n f r a r e d s p e c t r u m shows s t r o n g C-F a b s o r p t i o n s i n a d d i t i o n t o t h e e x p e c t e d bands f o r t h e ( Q ^ ^ S n group o f t r i m e t h y l t i n f l u o r o c a r b o n d e r i v a t i v e s , and f o r h e x a m e t h y l d i t i n (see S e c . I V - A - 1 , 3 ) . The. *H N.M.R. s p e c t r u m shows, i n a d d i t i o n t o t h r e e m e t h y l peaks a t -0.2 ( h e x a m e t h y l d i t i n ) , -0.25, and -0.30 p.p.m., a complex a b s o r p t i o n (34 l i n e s i n w h i c h seven l i n e s (a) T h i s f r a c t i o n , condensed i n t h e 0° t r a p , was o n l y a p a r t o f t h e t o t a l r e c o v e r y . Sec. VI-D-4 155 r e s u l t from o v e r l a p p i n g ) c e n t r e d a t -5.0 p.p.m. (TMS). T h i s s i g n a l appears e s s e n t i a l l y as a d o u b l e t ( J = 3.4 c . p . s . ) . Such a resonance, at. . low f i e l d , t a k e n i n t o a c c o u n t w i t h t h e v o l a t i l i t y , s u g g e s t e d t h a t t h i s f r a c t i o n may c o n t a i n s p e c i e s such, as, ( 1 , 2 . , 2 - t r i f l u o r o e t h y l ) t r i m e t h y l t i n , i . e . , ( C H 3 ) 3 S n C F H C F 2 H , and ( 1 , 2 , 2 , 3 , 4 , 4 - h e x a f l u o r o b u t y l ) t r i m e t h y l t i n , i . e . (CH 3) 3SnCFHCF 2CFHCF 2H, (and h e x a m e t h y l d i t i n . i n d i c a t e d by t h e -0.2 p.p.m. peak) and not. the. s p e c i e s , c o n t a i n i n g .a l o n g e r f l u o r o c a r b o n c h a i n . o r t h e b i s ( t r i m e t h y l t i n ) , adducts.. I t . s h o u l d be n o t e d t h a t t h e above two s t r u c t u r e s have t h e asymmetric, c a r b o n .atom. (or. a t o m s ) , r e s u l t i n g i n none-q u i v a l e n t environment of. .the: f l u o r i n e , atom(s) o f t h e -CF 2- g r o u p ( s ) . T h e r e f o r e t h e s e two s t r u c t u r e s , a r e e x p e c t e d .to show a d o u b l e t e d d o u b l e t due t o t h e v i c i n a l . H-F s p l i t t i n g s . The a l t e r n a t i v e s t r u c t u r e s o f t h e above two, such as. (CH 3) 3 S n C F 2 C F H 2 , (CH 3), 3SnCF 2CFHCF 2CFH 2, e t c . , s h o u l d show t h e ; v i c i n a l H-F s p l i t t i n g s as t r i p l e t s , w h i c h were c o m p l e t e l y absent from the. observed, s p e c t r u m . P a r t o f t h e u n r e a c t e d h e x a m e t h y l d i t i n was r e c o v e r e d from t h e i n v o l a -t i l e p a r t by d i s t i l l a t i o n a t 76°/2 cm. Hg. ( t o t a l r e c o v e r y , 2.7 g., 3 5 % ) , and t h e r e s i d u e was e x t r a c t e d w i t h c a r b o n t e t r a c h l o r i d e . .Oxygen was b u b b l e d t h r o u g h the. r e s u l t i n g s o l u t i o n t o remove the l a s t t r a c e o f h e x a m e t h y l d i t i n as t r i m e t h y l t i n oxide,, and a f t e r e v a p o r a t i o n o f t h e s o l -v e n t under a s t r e a m o f d r y a i r , , t h e r e m a i n i n g o i l was s e p a r a t e d by —3 vacuum d i s t i l l a t i o n (10. cm. Hg). i n t o , f r a c t i o n s w h i c h d i s t i l l e d i n t h e ranges 45-60°., and. 60-90°, r e s p e c t i v e l y . In. t h i s e x p e r i m e n t , b o t h f r a c t i o n s gave i d e n t i c a l i n f r a r e d , s p e c t r a , and hence were combined (1.1 g . ) . The 1H. >LM.R~ spectrum, shows two m e t h y l r e s o n a n c e s a t -0.30 and -0.33 p.p.m.. (TMS) (and a weak peak a t -0.2 p.p.m. due t o t h e me t h y l p r o t o n s o f h e x a m e t h y l d i t i n ) i n a d d i t i o n t o an u n r e s o l v e d band Sec. VI-D-4 156 c e n t r e d a t -5.0 p.p.m. T h i s , w i t h a n a l y t i c a l d a t a , s u g g e s t e d t h a t t he combined f r a c t i o n s c o n t a i n more t h a n 95% o f 1 , 4 - b i s ( t r i m e t h y l t i n ) - 1 , 1 , 2 , 1 2 3 4 3 , 3 , 4 - h e x a f l u o r o b u t a n e , (CH 3)3SnCF 2CFHCF 2CFHSn(CH3) 3 ( c a l c . f o r C 1 0 H 2 0 F 6 S n 2 : C, 24.4; H, 4.1; M.W., 490; fo u n d : C. 24.7; H, 3.5;M.W., 477). I t s h o u l d be n o t e d t h a t i n t h e above f o r m u l a t i o n t h e r e a r e two ty p e s o f m e t h y l g r o u p s , a c c o u n t i n g f o r the two m e t h y l p e a k s . The 1 9 F N.M.R. s p e c t r u m shows resonances, c e n t r e d a t +163, +138, +52, +46, +41, + 36, +31, and +25 p.p.m. ;(TFA).. S i n c e t h e u n s h i e l d i n g o f a f l u o r i n e atom i s a f f e c t e d by t h e amount o f charg e w h i c h f l u o r i n e atom i s a b l e t o draw from a c a r b o n atom (104)> t h e +163 and +138 p.p.m. peaks may be a s s i g n e d t o F ^ and F^). atoms r e s p e c t i v e l y . The peaks i n t h e +52 t o +25 p.p.m. r e g i o n p o s s i b l y r e s u l t from t h e o v e r l a p p i n g o f t h e two q u a r t e t s o f F 2 ^ and F 2 ^ a t o m s , w h i c h i n t u r n a r i s e from t h e asymmetry o f C^2-1 and atoms. (b) H e x a m e t h y l d i t i n (21.0 g., 64.2 mmole, 40% i n e x c e s s ) and t h e o l e f i n (3.8 g., 46 mmole) i n a s i l i c a t ube were i r r a d i a t e d a t 95° f o r e i g h t h o u r s . The d i s t r i b u t i o n and n a t u r e o f t h e p r o d u c t s o b t a i n e d were -3 much t h e same as i n . (a) e x c e p t t h a t vacuum d i s t i l l a t i o n (10 cm. Hg) o f the i n v o l a t i l e . o i l , f o l l o w e d by s p e c t r o s c o p i c , e x a m i n a t i o n , showed t h e p r e s e n c e o f s e v e r a l : components. The 45-60° and 60-90° f r a c t i o n s gave i d e n t i c a l i n f r a r e d and:N.;M.R... s p e c t r a : with.'thbse o f t h e c o r r e s p o n d i n g f r a c t i o n s i n . (a).. The. f r a c t i o n . w h i c h : d i s t i l l e d a t 35-45°, however, i n a d d i t i o n t o the. peaks e x p e c t e d from, e x p e r i m e n t (a) f o r t h e 1:2 a d d u c t , shows, i n t h e p r o t o n : s p e c t r u m two q u a r t e t s a t -6.5 p.p.m. [ JLJP(geminal) = 30 c . p . s . , J H F ( v i c i n a l . ) - 10 and 8 c . p . s . ] , w h i c h might be a s s i g n e d t o th e i n t e r n a l p r o t o n o f t h e 1:1: a d d u c t , ( C H 3 ) 3 S n C F H C F 2 S n ( C H 3 ) 3 . T h i s . i s . . . c o n s i s t e n t w i t h t h e appearance i n t h e 1 9 F s p e c t r u m o f t h r e e new peaks Sec. VI-D-5 157 a t +160, +'51, and +47 p.p.m., o f w h i c h t h e h i g h e r f i e l d peak might: be. a s s i g n e d t o t h e f l u o r i n e atom o f the -CFH- group and o t h e r two peaks might be components o f t h e q u a r t e t a r i s i n g from t h e f l u o r i n e atoms o f t h e -CF'F\"-group. (c) H e x a m e t h y l d i t i n (7.0 g., 21.4 mmole) and t h e o l e f i n (1.7 g., 21.1 mmole) i n a s e a l e d tube were a l l o w e d t o s t a n d i n t h e d a r k a t 100° o v e r n i g h t . The r e s u l t i n g l i q u i d was c o l o u r l e s s and c o n t a i n e d o n l y m e t a l l i c t i n (0.2 g . ) . Vacuum f r a c t i o n a t i o n gave t r i f l u o r o e t h y l e n e (1.6 g., 94% r e c o v e r y ) , t e t r a m e t h y l t i n (0.1 g., 0.55 mmoles), and h e x a m e t h y l d i t i n (6.4 g., 92% r e c o v e r y ) . The r e s u l t s , o f e x p e r i m e n t s (a) and ( b ) , t o g e t h e r w i t h o t h e r two e x p e r i m e n t s under d i f f e r e n t c o n d i t i o n s , a r e summarized i n TABLE 4. 5. R e a c t i o n s w i t h 1 , 1 - d i f l u o r o e t h y l e n e . The o l e f i n , was p u r i f i e d , i n t h e vacuum s y s t e m and t h e f r a c t i o n w h i c h condensed' at. -196° was employed f o r t h e r e a c t i o n s . Two e x p e r i m e n t s were p e r f o r m e d as f o l l o w s : (a) H e x a m e t h y l d i t i n . : (15.4 g.., 46.5-mmole) and 1 , 1 - d i f l u o r o e t h y l e n e (2.84 g. , 44.4 mmole.):: were - s e a l e d i n .a s i l i c a t u b e w h i c h was t h e n p l a c e d under u l t r a v i o l e t : i r r a d i a t i o n a t 75° .for: s i x ; hours.. A t r a c e o f m e t a l l i c t i n a ppeared d u r i n g t h e i r r a d i a t i o n . - ' Vacuum f r a c t i o n a t i o n gave 30% r e c o v e r y o f o r i g i n a l olefin,...(.13-5 mmole) , . . t e t r a m e t h y l t i n (0.6 g., 3.4 mmole), a f r a c t i o n (0.8 g.) w h i c h condensed a t -46°, and a brown r e s i d u e ( c a . 15 g . ) . The -46° f r a c t i o n . , , e x h i b i t i n g . i n f r a r e d bands due t o C-H, Sn-C, and C-F s t r e t c h i n g v i b r a t i o n s . , and..the. CH^-Sn r o c k i n g v i b r a t i o n , was i n j e c t e d i n t o t h e p r e p a r a t i v e , d i n o n y l . p h t h a l a t e column a t 150°. The. f i r s t component appeared a t 5.5 min., and e x h i b i t s a b s o r p t i o n bands a t Sec. VI-D-5 158 1670 ( s ) , 1650 ( s ) , 1171 ( v s ) , 1 1 5 5 ( s ) , 1146 ( v s ) , 1138 ( s ) , 9 3 5 ( s , b ) , _1 865 ( s ) , and 715 (m) cm. , a c h a r a c t e r i s t i c s p e c t r u m (151) o f mono-, f l u o r o e t h y l e n e , . CFH=CH 2 ( c a l c . , f o r , C 2 H 3 F : M.W., 46; fo u n d : 5 8 . 2 ) . The sec o n d component, a p p e a r i n g a t 11.0 min...,. shows i n f r a r e d bands a t 3030 (m) (C-H s t r . ) , 1690 (vs) (C=C str,.,) ,. 1405 (s) , 13.75 (s) , 1310 (s) , 1260 (m) 1210 ( v s ) , 1170 ( s ) , 1120 ( v s ) , 1085 ( v v s ) , 952 ( s , b ) , and 870 (vs,b) cm. * . A s u g g e s t e d f o r m u l a t i o n f o r t h i s component i s CF 2H-CH 2-CF=CH 2 ( c a l c . f o r C^HsF^: M.W., 110; found: ; 1 0 8 . 5 ) . I f t h i s i s t h e c a s e , i t appears t h a t t h e s e two. components.were d e r i v e d from . ( C H 3 ) 3 S n ( C H 2 C F 2 ) n H wh i c h decomposed on t h e column^ The. t h i r d and l a s t component was i d e n t i -f i e d by i t s r e t e n t i o n , t i m e as h e x a m e t h y l d i t i n , . C e n t r i f u g a t i o n o f the. i n v o l a t i l e p a r t gave 1.8 g. o f a w h i t e s o l i d whose i n f r a r e d spectrum, and. a n a l y t i c a l , d a t a were c o n s i s t e n t w i t h t h o s e o f ( C H 3 ) 3 S n F . The .s u p e r n a t a n t . l i q u i d was p u t i n t o a r e d u c e d p r e s s u r e d i s t i l l a t i o n a p p a r a t u s w h i c h was. a s s o c i a t e d .with a g l a s s - b e a d p a c k e d , h i g h e f f i c i e n c y f r a c t i o n a t i n g column.. H e x a m e t h y l d i t i n (8.2 g., 53% r e c o v e r y ) , l e a v i n g , a brown, o i l r e s i d u e (\"Dm\") . The r e s i d u e \"Dm\" was f u r t h e r s e p a r a t e d by vacuum d i s t i l l a t i o n . . . (10. cm. Hg) i n t o a f r a c t i o n (0.6 g.) which, d i s t i l l e d a t 30-60° and. a b l a c k i s h brown gum as r e s i d u e (2.5 g.: a n a l y s e s , f o u n d : C, 30.1; H, 4,4; M.W., 740). The 30-60° f r a c t i o n , a. p a l e : y e l l o w l i q u i d . , , shows i n the. i n f r a r e d s p e c t r u m s e v e r a l s t r o n g and v e r y broad, bands i n t h e C-F. a b s o r p t i o n r e g i o n i n a d d i t i o n t o the c h a r a c t e r i s t i c bands, o f t h e .(CH.^/jSn. group, o f , t r i m e t h y l t i n - f l u o r o -c a r b o n compounds:. I t s .^ H N.M.R.. spectrum: c o n s i s t s o f , i n a d d i t i o n t o t h e m u l t i p l e peaks, i n t h e m e t h y l r e s o n a n c e r e g i o n , , t h r e e , a b s o r p t i o n s c e n t r e d at -1.6,-. -2. .7:, and H6.3: p.p.m. (TMS), w i t h an i n t e n s i t y r a t i o o f 5:2:1, r e s p e c t i v e l y . The -1.6 p.p.m., r e s o n a n c e appears as a b r o a d t r i p l e t , Sec. VI-D-5 159 a p p a r e n t l y due t o s u p e r p o s i t i o n o f s e v e r a l n e a r l y e q u i v a l e n t t r i p l e t s . The -2.7 p.p.m. re s o n a n c e i s a m u l t i p l e t , w h i l e t h e -6.3 p.p.m. a b s o r p -t i o n i s a t r i p l e t e d t r i p l e t ( J = 55 c . p . s . , J ' = 4.8 c . p . s . ) , o b v i o u s l y a s s o c i a t e d w i t h t h e t e r m i n a l -CF 2H group.. Based on t h e assignment o f t h e s e t h r e e resonance, (see e x p e r i m e n t b ) , i n t e n s i t y r a t i o , and v o l a t i l i t y c o n s i d e r a t i o n , t h i s , f r a c t i o n may c o n t a i n : ( I ) ( 2 , 2 , 4 , 4 - t e t r a f l u o r o b u t y l ) t r i m e t h y l t i n , ( C H 3 ) 3 S n C H 2 C F 2 C H 2 C F 2 H ; ( I I ) 1 , 2 - b i s ( t r i m e t h y l t i n ) - 2 , 2 - d i f l u o r o e t h a n e , ( C H 3 ) 3 S n C H 2 C F 2 S n ( C H 3 ) 3 ; ( I I I ) 1 , 4 - b i s ( t r i m e t h y l t i n ) - 2 , 2 , 4 , 4 - t e t r a f l u o r o b u t a n e , (CH 3) 3SnCH 2CF 2CH 2CF 2Sn(CH 3.) 3. T h i s s u g g e s t i o n i s c o n s i s t e n t w i t h t h e M.W. measurement [ c a l c . f o r ( I ) , 293; f o r ( I I ) , 392; f o r ( I I I ) , . 4 5 8 ; f ound f o r t h e 30-60° f r a c t i o n : 4 1 8 ] . I t s h o u l d a l s o be n o t e d t h a t t h e h i g h e r i n t e n s i t y r a t i o o f t h e -1.6 p.p.m. a b s o r p t i o n i s . an i n d i c a t i o n , o f t h e p r e d o m i n a n t p r e s e n c e o f ( I I ) because i t s i n t e r n a l -CH 2-. group i s . r e s p o n s i b l e , f o r t h i s a b s o r p t i o n . (b) H e x a m e t h y l d i t i n (20.4 g:.., 62..2 mmole, 40% i n e x c e s s ) was added t o 1 , 1 - d i f l u o r o e t h y l e n e (2..84 g., 44.4 mmole) und e r u l t r a v i o l e t i r r a d i a -t i o n a t 92° f o r seven h o u r s . Vacuum f r a c t i o n a t i o n , f o l l o w e d by i n f r a r e d s p e c t r o s c o p i c s t u d y i n d i c a t e d t h e p r e s e n c e i n t h e v o l a t i l e p a r t o f o r i g i n a l o l e f i n (0.81 g.., 32% r e c o v e r y ) , CF. 2HCH 2CF=CH 2 (0.42 mmole), t e t r a m e t h y l t i n . (0.6 g.,.3.4 mmole), and the. components (-46° f r a c t i o n ) s i m i l a r t o t h o s e o f t h e -46° f r a c t i o n i n e x p e r i m e n t ( a ) . By t h e same manner as i n ( a ) , r e d u c e d p r e s s u r e d i s t i l l a t i o n (76°/2 cm. Hg) gave h e x a m e t h y l d i t i n (12.5 g., 47% r e c o v e r y ) , and t h e n h i g h . _3 vacuum d i s t i l l a t i o n (10 cm. Hg) a f f o r d e d a f r a c t i o n w h i c h d i s t i l l e d at Sec. VI-D-5 160 30-60° (1.66 g.) and l e f t \" a b l a c k i s h brown gum as r e s i d u e (3.7 g . ) . A w h i t e s o l i d (4.2 g . ) , w h i c h was s e p a r a t e d p r i o r to, the d i s t i l l a t i o n , was i n d i c a t e d s p e c t r o s c o p i c a l l y t o c o n t a i n c h i e f l y (CH3)3SnF as w e l l as f l u o r o c a r b o n p o l y m e r s . The 30-60° f r a c t i o n shows t h e i n f r a r e d , bands o b s e r v e d f o r t h e c o r r e s p o n d i n g f r a c t i o n i n (a) w i t h a b e t t e r r e s o l u t i o n i n t h e C-F a b s o r p t i o n r e g i o n , w h i c h a r e a t .1380 (m), 1188 ( v s , b ) , 1120 ( s ) , 1033 ( s ) , 996 ( s ) , .950 ( s , b ) , and 876 (m,b).cm. _ 1. The lH and 1 9 F N.M.R. s p e c t r a c o n s i s t o f t h e f o l l o w i n g r e s o n a n c e s : *H N.M.R. s p e c t r u m C H 3 r e s o n a n c e r e g i o n C h e m i c a l s h i f t (p.p.m., TMS) -0.3 -0.32 -0.34 I n t e n s i t y r a t i o (1.0) (1-5) (1-5) Lower f i e l d r e g i o n C h e m i c a l s h i f t -1.62 -1.65 -2.7 -6.3 (p.p.m.) C o u p l i n g c o n s t a n t t r i p l e t t r i p l e t m u l t i p l e t t r i p l e t e d ( c . p . s . ) 25.3 23.5 15.2 t r i p l e t ; 6.1 55.1 4.0 4.5 I n t e n s i t y r a t i o (1.5) (1.0) (1.0) (0.5) 1 9 F N.M.R. s p e c t r u m C h e m i c a l s h i f t +11.5 +16.2 +34.6 (p.p.m., TFA) C o u p l i n g c o n s t a n t m u l t i p l e t t r i p l e t t r i p l e t e d ( c . p . s . ) 25.0 d o u b l e t 54.5 12.0 I n t e n s i t y r a t i o (1.0) (1.5) (1.0) Sec. VI-D-6 161 I t i s e v i d e n t t h a t one o f t h e components must have a t e r m i n a l . T C F 2 H group w h i c h i s r e s p o n s i b l e f o r t h e -6.3 p.p.m. ( XH spectrum) and +34.6 p.p.m. ( 1 9 F spectrum) r e s o n a n c e s . T h i s , w i t h t he f a c t t h a t o n l y t h r e e r e s o n -ances w i t h u n e q u a l i n t e n s i t i e s were o b s e r v e d i n t h e 1 9 F s p e c t r u m , sug-g e s t e d t h e p r e s e n c e o f 1 2 3 4 . ( I . ) , ( C H 3 ) 3 S n C H 2 C F 2 C H 2 C F 2 H ; ( I I ) , ( C H 3 ) 3 S n C H 2 C F 2 S n ( C H 3 ) 3 . W i t h t h e s e f o r m u l a t i o n s t h e N.M.R s p e c t r a can be a s s i g n e d on t h e b a s i s o f t h e c o u p l i n g c o n s t a n t s and t h e i n t e n s i t y r a t i o s . The -1.62-p.p.m. ( XH) and +16.2 p.p.m. ( 1 9 F ) reso n a n c e s , w h i c h may a r i s e from t h e same s p e c i e s , were a s s i g n e d t o t h e i n t e r n a l p r o t o n s . a n d f l u o r i n e atoms o f ( I I ) , r e s p e c t i v e l y . The -1.65 p.p.m. (*H) might be a s s i g n e d t o t h e H 2 ^ atoms o f ( I ) because o f t h e s i m i l a r e n v i r o n m e n t t o t h a t o f i n t e r n a l T C H 2 -group o f ( I I ) . The -2.7 and -6.3 p.p.m. r e s o n a n c e s i n t h e XH s p e c t r u m were a s s i g n e d t o H 2 ^ and H ^ atoms, r e s p e c t i v e l y . W h i l e i n t h e 1 9 F f 4) s p e c t r u m t h e +36.6 p.p.m. r e s o n a n c e c o u l d w e l l be a s s i g n e d t o t h e F 2 (2) atoms; l e a v i n g t h e +11.5 p.p.m. m u l t i p l e t t o ac c o u n t f o r t h e F 2 ' atoms. 6. Re a c t i o n s w i t h t r i f l u o r o c h l o r o e t h y l e n e . : The o l e f i n / w a s i n t r o d u c e d i n t o t h e vacuum sy s t e m t h r o u g h -76°,, -126°., and -196° t r a p s . Pure. CF 2=CFC1 condensed a t t h e t h e se c o n d t r a p . (a) H e x a m e t h y l d i t i n (7.56 g., 22.9 mmole) and CF2=CFC1 (2.64. g. , 22.61 mmole), i n a s i l i c a t u b e , were s u b j e c t e d t o u l t r a v i o l e t i r r a d i a t i o n a t 90° f o r f o u r h o u r s . Vacuum f r a c t i o n a t i o n a f f o r d e d t h r e e f r a c t i o n s i n , t h e -126°, -76°, and 0° t r a p s . The -126° f r a c t i o n , as shown by t h e i n f r a -r e d s p e c t r a , was m a i n l y u n r e a c t e d . ^ o l e f i n (1.64 g., 63% r e c o v e r y ) as w e l l as a s m a l l amount of. s e c o n d o l e f i n w h i c h might be p r o d u c e d i n t h e r e a c t i o n . . The l a t t e r was i n d i c a t e d by t h e appearance o f new bands a t 3070 (C-H s t r . ) Sec. VI-D-6 ! ° 2 _ . l and 1710 cm. (C=C s t r , ) , i n t h e i n f r a r e d s p e c t r u m . The -76° f r a c t i o n , a c o l o u r l e s s l i q u i d , was i d e n t i f i e d s p e c t r o s c o p i c a l l y as t e t r a m e t h y l t i n (0.52 g., 2.8 mmole). • The 0° f r a c t i o n , a c o l o u r l e s s l i q u i d o r i g i n a l l y , became a y e l l o w , orange,, and f i n a l l y b r o w n . s o l i d .on s t a n d i n g under sun-l i g h t f o r .only 30 minutes... , The r e m a i n i n g c l e a r l i q u i d , w h i c h was s e p a r a -t e d f r o m the. brown s o l i d , b y c e n t r i f u g i n g , shows i n f r a r e d bands a t .14.70 (m), _ i 1220 (m), 1075 (vs.,b), and 1000 (m) cm* i n . a d d i t i o n t o t h o s e bands a s s o c i a t e d w i t h t e t r a m e t h y l t i n , h e x a m e t h y l d i t i n , and t h e ( C H 3 ) 3 S n groups o f t r i m e t h y l t i n - . f l u o r o c a r b o n d e r i v a t i v e s . The ltt N.M.R. sp e c t r u m c o n s i s t s o f f o u r peaks, i n t h e m e t h y l r e s o n a n c e r e g i o n at. -0.01, -0.2, -0.325, and -0.62 p.p.m.. The f i r s t , s e c o n d , and l a s t peak were a s s i g n e d t o t h e me t h y l p r o t o n r e s o n a n c e s o f t e t r a m e t h y l t i n ( 1 3 5 ) , h e x a m e t h y l d i t i n ( 1 3 4 ) , and t r i m e t h y l t i n c h l o r i d e ( 1 3 6 and t h i s work),. I n t h e lo w e r f i e l d t h e r e a r e e i g h t l i n e s o f e q u a l i n t e n s i t i e s c e n t r e d a t . - 6 . 3 p.p.m., whi c h c o u l d be d e f i n e d as a d o u b l e t - d o u b l e t - d o u b l e t , p a t t e r n (J.j = 48.5 c. p . s . , J 2 = 8.1 a 6 c . p . s . , and J 3 = 7.0 c . p . s . ) . T h i s s u g g e s t e d t h e p r e s e n c e o f -CF 2-CFC1H group, i n w h i c h the, s i g n a l o f Hg atom, i s e x p e c t e d t o be s p l i t i n t o a l a r g e d o u b l e t due t o c o u p l i n g w i t h Fe,. atom and each component* i s f u r t h e r s p l i t i n t o d o u b l e t e d d o u b l e t , due t o i n t e r a c t i o n w i t h t h e two h o n e q u i v a l e n t Fa atoms w h i c h i n t u r n a r i s e from t h e asymmetry o f 8-carbon atom.. S i n c e t h e r e l a t i v e i n t e n s i t y o f t h e H g r e s o n a n c e and t h e peak a t -0.325 p.p.m. i s about 1:10, and, t h e c h e m i c a l s h i f t , of. t h e l a t t e r i s c h a r a c t e r i s t i c f o r t h e (CH3) 3 S n group d i r e c t l y , bonded t o a. -CF2- group (135 , and TABLES 12,14 ),. t h e r e f o r e , , t h e re s o n a n c e s a t -0.32 and -6.2 p.p.m. were b e l i e v e d , t o a r i s e from t h e s a m e . s p e c i e s . w h i c h might be ( l , l , 2 - t r i f l u o r o r 2 - c h l o r o e t h y l ) t r i m e t h y l t i n , ( C H 3 ) 3 S n C F 2 G F H C l . From t h e i n v o l a t i l e r e s i d u e h e x a m e t h y l d i t i n (76°/2 cm. Hg) ( 5 g . , 66% Sec.VI-D-7 163 r e c o v e r y ) a n d . t r i m e t h y l t i n f l u o r i d e were i s o l a t e d . No e v i d e n c e o f t h e p r e s e n c e o f adducts was shown by a c a r e f u l s p e c t r o s c o p i c e x a m i n a t i o n among a l l the- f r a c t i o n s o f t h e r e a c t i o n m i x t u r e . B l a c k i s h gum was n o t formed i n t h i s r e a c t i o n . (b) An e q u i m o l a r m i x t u r e o f h e x a m e t h y l d i t i n and t h e o l e f i n was d i s s o l v e d i n 30 ml., o f pentane i n a s i l i c a t u b e . A f t e r e x p o s u r e t o u l t r a v i o l e t l i g h t a t 25° f o r 30 h o u r s , a q u a l i t a t i v e , i n v e s t i g a t i o n showed t h a t no adducts has been formed... The r e a c t a n t s , as w e l l as t h e s o l v e n t , were r e s e a l e d i n a s i l i c a tube, and t h e r e a c t i o n c o n t i n u e d under t h e same c o n d i t i o n s f o r a n o t h e r 40 h o u r s . E v a p o r a t i o n o f t h e s o l v e n t i n t o t h e vacuum s y s t e m , f o l l o w e d by vacuum f r a c t i o n a t i o n gave 0.8 g. o f ( C H 3 ) 3 S n C F 2 C F C l H , i d e n t i f i e d s p e c t r o s c o p i c a l l y . C e n t r i f u g a t i o n o f t h e i n v o l a t i l e . r e s i d u e gave a w h i t e s o l i d , i d e n t i f i e d by t h e i n f r a r e d , s p e c t -rum as t r i m e t h y l t i n f l u o r i d e , , and a c l e a r l i q u i d w h i c h was i n d i c a t e d by gas c h r o m a t o g r a p h i c . a n d i n f r a r e d s p e c t r o s c o p i c s t u d i e s t o be a m i x t u r e o f u n r e a c t e d h e x a m e t h y l d i t i n and t r i m e t h y l t i n c h l o r i d e . The complete . absence o f C-F a b s o r p t i o n i n t h e i n f r a r e d s p e c t r u m o f t h e c l e a r l i q u i d i n d i c a t e d t h e absence, o f a d d u c t s . 7. R e a c t i o n s w i t h t r i f l u o r o b r o m o e t h y l e n e . . S i n c e a s l i g h t amount o f C F 3 — C O F was f o u n d i n t h e s t e e l c y l i n d e r o f t r i f l u o r o b r o m o e t h y l e n e ( C o l u m b i a O r g a n i c C h e m i c a l Co., S. C ) , t h e o l e f i n , u s u a l l y condensed i n t h e -.126° t r a p , was p u r i f i e d by vacuum f r a c t i o n a t i o n s e v e r a l t i m e s t h r o u g h -76°, -126°, and -196° t r a p s . (a) H e x a m e t h y l d i t i n (7.15 g.., 2.1.8 mmole) and the o l e f i n (3.6 g., 2.2 mmole) i n a s i l i c a tube were i r r a d i a t e d a t 25° f o r 27 h o u r s . W i t h i n 10 h o u r s , on t h e t o p o f t h e i n s i d e w a l l o f t h e t u b e appeared an orange \\ Sec. VI-D-7 164 s o l i d w h i c h was n o t o b s e r v e d i n a l l r e a c t i o n s w i t h o t h e r o l e f i n s . The l i q u i d phase was c o l o u r l e s s a t t h e end o f i r r a d i a t i o n , and t u r n e d t o orange on s t a n d i n g o v e r n i g h t . Vacuum f r a c t i o n a t i o n gave u n r e a c t e d o l e f i n (2.7 g., 75% r e c o v e r y ) (-126° t r a p ) , t e t r a m e t h y l t i n (0.78 g., 4.4 mmole) as w e l l as a t r a c e o f f l u o r o c a r b o n gas (-76° t r a p ) , w h i c h were d e t e c t e d by gas c h r o m a t o g r a p h i c and t h e i n f r a r e d s p e c t r u m a n a l y s e s , a c l e a r l i q u i d (0.66 g.) (-46° t r a p ) , and a c o l o u r l e s s l i q u i d (0.9 g.) (0° t r a p ) . The -46° f r a c t i o n shows i n f r a r e d a b s o r p t i o n s ,at 1725 ( v s ) , 1280 ( s ) , _ l 1122 (s) , and 1010 (s), cm. i n a d d i t i o n t o t h e e x p e c t e d bands f o r t h e ( C H 3 ) 3 S n group l i n k e d t o a f l u o r o c a r b o n v i a Sn-C bond (see Sec. I V - A - 1 , 3 ) . S i n c e t h e bands i n t h e C-F a b s o r p t i o n r e g i o n a r e c h a r a c t e r i s t i c o f a -CF=CF2 group ( 9 2 ) , t h i s f r a c t i o n was s u g g e s t e d t o be ( p e r f l u o r o v i n y l ) -t r i m e t h y l t i n , ( C H 3 ) 3 S n C F = C F 2 . T h i s s u g g e s t i o n i s f u r t h e r s u p p o r t e d by gas c h r o m a t o g r a p h i c a n a l y s i s . The -46° f r a c t i o n showed i t s r e t e n t i o n t i m e on a 6 - f t . d i n o n y l p h t h a l a t e column a t 145° w i t h 15 l b . / i n 2 o f c a r r y i n g gas t o be 3.1 min.,. i n a c c o r d w i t h t h e v a l u e o b t a i n e d under t h e same c o n d i t i o n s f o r (CH 3) 3SnCF=CF2 w h i c h was p r e p a r e d from t h e r e -a c t i o n o f : C F 2 = C F B r , Mg, and ( C H 3 ) 3 S n B r (152) . The 0° f r a c t i o n , w h i c h became a y e l l o w , o r a n g e , and f i n a l l y brown s o l i d on s t a n d i n g i n t h e vacuum l i n e o n l y f o r 10 min., was e v a c u a t e d t o g i v e s m a l l p o r t i o n , o f c o l o u r l e s s l i q u i d w h i c h was shown by i t s i n f r a r e d s p e c t r u m t o be a m i x t u r e o f h e x a m e t h y l d i t i n and t e t r a m e t h y l t i n . The i n v o l a t i l e p a r t w a s . s e p a r a t e d i n t o a c o l o u r l e s s l i q u i d and a brown s o l i d by c e n t r i f u g i n g . The l i q u i d p o r t i o n was a m i x t u r e o f u n r e a c t e d h e x a m e t h y l d i t i n , t r i m e t h y l t i n b r o m i d e , ( C H 3 ) 3 S n B r , shown by gas c h r o m a t o g r a p h i c and s p e c t r o s c o p i c s t u d i e s . The s o l i d p o r t i o n was Sec. VI-D-8 165 t r e a t e d w i t h c a r b o n t e t r a c h l o r i d e t o remove s o l u b l e m a t e r i a l , and then, was e x t r a c t e d w i t h methanol s e v e r a l t i m e s . E v a p o r a t i o n o f t h e methanol e x t r a c t s l e f t ,a w h i t e s o l i d w h i c h was i d e n t i f i e d as , ( C H 3 ) 3 S n F (no .record f o r i t s y i e l d ) . . The e x t r a c t e d r e s i d u e shows a b r o a d band i n t h e C-F. a b s o r p t i o n r e g i o n , and t h u s p o s s i b l y c o n t a i n s f l u o r o c a r b o n p o l y m e r s . (b) H e x a m e t h y l d i t i n : (7.2 g. , 2 2 mmole) and t r i f l u o r o b r o m o e t h y l e n e (3.54 g., 22 mmole) were a l l o w e d t o r e a c t a t 20° under u l t r a v i o l e t i r r a d -i a t i o n . The u l t r a v i o l e t lamp was removed a f t e r 14 h o u r s when an orange s o l i d j u s t s t a r t e d t o form on t h e i n s i d e w a l l o f t h e t u b e . The d e v e l o p -ment o f an orange c o l o u r i n t h e o r i g i n a l l y c o l o u r l e s s l i q u i d phase was. o b s e r v e d a g a i n on s t a n d i n g o v e r n i g h t . On t r a n s f e r r i n g t h e tube c o n t e n t s , i n t o t h e vacuum s y s t e m , u n r e a c t e d o l e f i n . (2.86...,g.., 81% r e c o v e r y ) , t e t r a -m e t h y l t i n (0.16 g., 0.9 mmole), a t r a c e , o f f l u o r o c a r b o n gas, ( C H 3 ) 3SnCF=CF 2 (0.13 g., 0.53 mmole),, and .1.1 g. o f a c l e a r l i q u i d i n t h e 0° t r a p were o b t a i n e d . The . c l e a r l i q u i d was q u i c k l y removed f r o m the, t r a p b u t soon be-came an orange s o l i d . The i n v o l a t i l e p a r t c o n t a i n e d u n r e a c t e d h e x a -m e t h y l d i t i n as t h e c h i e f component, and ( C H 3 ) 3 S n B r , ( C H 3 ) 3 S n F , and f l u o r o c a r b o n p o l y m e r s . 8. R e a c t i o n w i t h e t h y l e n e . E t h y l e n e (99.91 mole p e r c e n t p u r i t y , P h i l l i p s P e t r o l e u m Co., O k l a . , L o t NO. 1100) was u s e d f o r . t h i s e x p e r i m e n t w i t h o u t f u r t h e r p u r i f i c a t i o n . H e x a m e t h y l d i t i n (.7.2 g.., 22 mmole) was a l l o w e d t o r e a c t w i t h e t h y l e n e (0.62 g., 22:.2 mmole), i n a s i l i c a t u b e u n d e r u l t r a v i o l e t l i g h t a t 25° . f o r one week. No change i n appearance was o b s e r v e d f o r b o t h gaseous, and l i q u i d p h a s e s . Vacuum f r a c t i o n a t i o n gave a n e g l i g i b l e amount o f Sec. VI-D-8 166 uncondens.able gas, u n r e a c t e d o l e f i n (0.56 g., 90% r e c o v e r y ) , a f r a c t i o n w h i c h condensed a t -76° (0.4 g . ) , and u n r e a c t e d h e x a m e t h y l d i t i n (6.8 g., 95% r e c o v e r y ) i n . t h e 0° t r a p and i n t h e i n v o l a t i l e p a r t . Gas c h r o m a t o g r a p h i c a n a l y s i s on d i n o n y l p h t h a l a t e column a t 150° w i t h He gas f l o w r a t e o f 15 l b . / i n ? showed t h e -76° f r a c t i o n t o be com-posed o f f i v e components w h i c h appeared a t 2.3, 3.1, 4.1, 5.7, 9.2 min. w i t h t h e r a t i o o f 90, 1, 1, 3, 5%, r e s p e c t i v e l y . The 2.3 and 9.2 min.. components were t e t r a m e t h y l t i n and h e x a m e t h y l d i t i n , r e s p e c t i v e l y , i d e n t i -f i e d by t h e i r r e t e n t i o n t i m e . The o t h e r t h r e e components were n o t s t u d i e d f u r t h e r b ecause o f t h e i r l i m i t e d q u a n t i t i e s . S i n c e : t h e a d d u c t , i f any, i s e x p e c t e d to. have a l o n g e r o r e q u i v a l e n t r e t e n t i o n t i m e as t h a t o f h e x a m e t h y l d i t i n , i . e , 9.2 min.» under above c o n d i t i o n s , and b e cause t h e s e t h r e e components have s h o r t e r r e t e n t i o n t i m e t h a n t h a t e x p e c t e d f o r t h e a d d u c t , i t t h u s appears t h a t adduct was n o t f ound i n t h i s r e a c t i o n . , The i n f r a r e d s p e c t r u m and gas c h r o m a t o g r a p h i c a n a l y s i s o f t h e i n v o l a t i l e p a r t show i t t o be a b s o l u t e l y p u r e h e x a m e t h y l d i t i n . Sec. VI-E-1 167 E. R e a c t i o n s o f T r i m e t h y l t i n - p e n t a c a r b o n y l m a n g a n e s e w i t h F l u o r o - o l e f i n s . 1. P r e p a r a t i o n o f t r i m e t h y l t i n - p e n t a c a r b o n y l m a n g a n e s e . T h i s compound was p r e p a r e d a c c o r d i n g t o a m o d i f i c a t i o n o f t h e method d e s c r i b e d by G o r s i c h ( 2 6 ) . D e c a c a r b o n y l d i m a n g a n e s e , t h e g i f t o f E t h y l Co., D e t r o i t , . U. S. A., was used w i t h o u t s u b l i m a t i o n . T r i m e t h y l t i n bromide was a p r o d u c t o f Orgmet, Hampstead, N. H. T e t r a h y d r o f u r a n (THF) was r e f l u x e d o v e r s u f f i c i e n t l i t h i u m . a l u m i n u m h y d r i d e f o r s e v e r a l h o u r s and d i s t i l l e d p r i o r t o use. To 500 g. o f mercury i n a 500-ml. f l a s k , 5 g. (217 mmole) o f s l i c e d m e t a l l i c sodium was s l o w l y added, f o l l o w e d by Mn2(CO)io (19.5 g., 50 mmole), i n 250 ml. o f THF. The r e a c t i o n m i x t u r e , w h i c h was m a i n t a i n e d under a n i t r o g e n atmosphere i n t h e d r y box, was s t i r r e d a t room tempera-t u r e f o r one h o u r . The r e s u l t i n g b r o w n i s h - g r e e n s o l u t i o n was s e p a r a t e d from mercury by d e c a n t a t i o n . S u b s e q u e n t l y , t r i m e t h y l t i n bromide (24.0 g., 100 mmole) was added. A f t e r s t i r r i n g a t room t e m p e r a t u r e f o r one h o u r , t h e r e a c t i o n m i x t u r e was a l l o w e d t o , s t a n d o v e r n i g h t , aoid t h e s u p e r n a t a n t s o l u t i o n was d e c a n t e d . The r e m a i n i n g s o l i d was washed w i t h 10-ml. p o r -t i o n s o f THF s e v e r a l t i m e s and s e p a r a t e d from t h e THF washings by c e n t r i -f u g i n g . The t o t a l volume o f combined s u p e r n a t a n t s o l u t i o n and t h e THF washings was r e d u c e d t o 50 ml. by. d i s t i l l a t i o n (64°/76 cm. Hg), and t h e r e s u l t i n g s o l u t i o n was r e d i s t i l l e d , on. an; e f f i c i e n t column under r e d u c e d p r e s s u r e . The l a s t t r a c e o f THF and u n r e a c t e d ( C H 3 )3SnBr were removed a t 25°/3 cm. Hg and a t 30°/l cm. Hg, r e s p e c t i v e l y . The f r a c t i o n w h i c h was c o l l e c t e d a t 47°/10 cm. Hg was a p a l e y e l l o w l i q u i d , w h i c h became Sec. VI-E-2 168 a w h i t e s o l i d on s t a n d i n g a t room t e m p e r a t u r e . T h i s was t r i m e t h y l t i n - . p e n t a c a r b o n y l m a n g a n e s e , ( C H 3 ) 3 S n - M n ( C O ) 5 , [26.0 g., 72.5 mmole, 72.5% y i e l d on.the b a s i s o f ( C H 3 ) 3 S n B r t a k e n ] , ( c a l c . f o r C 8H 9SnMn0 5: C, 26.8; H, 2.5; M.W., 358.8; found: C, 27.0; H, 3,3j M.W., 361.5); m.p., 29.5° ( u n c o r r e c t e d ) ; p 3 0', .1.62 g./ml. T h i s p r o d u c t . s h o w e d no change i n i t s i n f r a r e d s p e c t r u m a f t e r s t a n d -i n g i n a i r f o r s e v e r a l weeks. 2.. D e c o m p o s i t i o n o f t r i m e t h y l t i n - p e n t a c a r b o n y l m a n g a n e s e . a. P y r o l y s i s . The tin-manganese compound (0.83. g., 2.31 mmole) i n a s e a l e d t u b e was h e a t e d a t 130° i n t h e dark f o r . 4 8 h o u r s . No a p p r e c i a b l e change i n i t s appearance was o b s e r v e d t h r o u g h o u t t h e h e a t i n g . Vacuum f r a c t i o n a t i o n gave 0.01 mmole o f u n c o n d e n s a b l e gas, i d e n t i f i e d by i t s i n f r a r e d s p e c - . trum andM.W.. ( f o u n d , 27) as c a r b o n monoxide g a s , a t r a c e o f t e t r a -m e t h y l t i n condensed i n a -76° t r a p , and an i n v o l a t i l e r e s i d u e w h i c h was shown by i t s . i n f r a r e d s p e c t r u m , and by gas c h r o m a t o g r a p h i c a n a l y s i s t o be unchanged ( C H 3 ) 3 S n - M n ( C 0 ) 5 (0.81 g., 97% r e c o v e r y ) . b. P h o t o l y s i s . The tin-manganese compound (.1.. 12 g., 3.04 mmole) i n a s e a l e d s i l i c a tube was i r r a d i a t e d w i t h u l t r a v i o l e t l i g h t ( H a n o y i a 200 w a t t lamp) a t 50° f o r one h o u r . A p u r p l e c o l o u r formed i n s t a n t l y on e x p o s i n g t h e t u b e t o t h e u l t r a v i o l e t l i g h t , and t h e t u b e c o n t e n t was b l a c k i s h p u r p l e i n c o l o u r a t t h e end o f t h e i r r a d i a t i o n . Vacuum f r a c t i o n a t i o n gave c a r b o n monoxide (0.057 mmole) and (GH 3)i +Sn (0.02 g., 0.11 mmole) Sec. VI-E-3 169 as t h e v o l a t i l e p r o d u c t s . Unchanged ( C H 3 ) 3 S n - M n ( G 0 ) 5 (1.05 g., 94% r e c o v e r y ) was r e c o v e r e d from s u b l i m a t i o n o f t h e i n v o l a t i l e r e s i d u e , l e a v i n g 0.05 g. o f b l a c k gum. 3. R e a c t i o n s w i t h t e t r a f l u o r o e t h y l e n e . As p a r t o f t h i s s t u d y , t h e e f f e c t o f t h e r e a c t i o n c o n d i t i o n s , ( i . e . , t e m p e r a t u r e , u l t r a v i o l e t l i g h t , s o l v e n t , e t c . ) on t h e d i s t r i b u t i o n and y i e l d o f r e a c t i o n , p r o d u c t s was i n v e s t i g a t e d . A l l e x p e r i m e n t a l r e s u l t s a r e summarized i n TABLE 5 . The a n a l y t i c a l d a t a o f t h e p u r i f i e d new compounds a r e l i s t e d i n TABLE 29 ..A t y p i c a l r e a c t i o n i s d e s c r i b e d as f o l l o w s . (GH 3) 3SnMn(G0) 5 (3.3 g., 9.2 mmole) i n 6 ml... n-pentane was a l l o w e d t o r e a c t w i t h t e t r a f l u o r o e t h y l e n e (3.3 g., 33 mmole) i n a s e a l e d s i l i c a t u b e u n d e r . u l t r a v i o l e t i r r a d i a t i o n * No n o t i c e a b l e change i n the. r e a c t i o n m i x t u r e , was. .observed i n h a l f an h o u r . A f t e r f o u r h o u r s , when th e i r r a d i a t i o n was. s t o p p e d , a .pale, y e l l o w , l i q u i d , r e s u l t e d and a con-s i d e r a b l e amount o f w h i t e s o l i d had formed on t h e i n s i d e w a l l o f t h e , t u b e . The r e a c t i o n m i x t u r e was. c o o l e d t o -196° and, on o p e n i n g t h e t u b e t o t h e vacuum l i n e , 0.5.mmole o f u n c o n d e n s a b l e gas, w h i c h was i d e n t i f i e d by i t s i n f r a r e d , s p e c t r u m and M...W. measurement ( f o u n d * 29) as c a r b o n monoxide,, was. obtained... T r a n s f e r o f t h e v o l a t i l e -part at -10°/10 cm. Hg i n t o one of. vacuum l i n e t r a p s , f o l l o w e d by vacuum f r a c t i o n a t i o n , gave unchanged t e t r a f l u o r o e t h y l e n e (1.93 g., 19.3 mmole) i n t h e -196° t r a p , n-pentane i n b o t h -126° and -76° t r a p s , and 0.1 g. o f a c l e a r l i q u i d i n a -10° t r a p . The c l e a r l i q u i d showed i n f r a r e d bands a t 1789 ( s ) , 1712. ( s ) , 1685 (sh) ,, 1352 ( s ) , 1305 (s) , 1240 (m) , 1185 (s) , 1042 (sh) , 1039 ( v s ) , 1010 (m), 992 (m), and 960 ( s ) , i n a d d i t i o n t o t h e e x p e c t e d Sec. VI-E-3 170 a b s o r p t i o n s o f ( C H 3 ) 3 S n - M n ( C O ) 5 (TABLE. 16) and t h e M n ( C 0 ) 5 group o f RfMn(CO)5 (see Sec. IV-C-2b,d). By c o m p a r i s o n o f t h e above s p e c t r u m w i t h t h e i n f r a r e d f r e q u e n c i e s l i s t e d . i n ; TABLES 16 and 17, t h i s c l e a r l i q u i d was i d e n t i f i e d as. a m i x t u r e o f ( i ) ( C H 3 ) 3 S n - M n ( C O ) 5 , ( i i ) C 5 F 9 M n ( C O ) 5 , and ( i i i ) p e r f l u o r o a c r y l o y l p e n t a c a r b o n y l m a n g a n e s e [ i . e , CF2=CFC0Mn(C0)5 ] . I t s h o u l d be n o t e d t h a t t h e c h a r a c t e r i s t i c bands a s s o c i a t e d '.with t h e C=C s t r e t c h i n g , mode.s o f t h e l a s t two compounds a t .1789 and 1712 ( w i t h _1 a s h o u l d e r a t 1685) cm. , r e s p e c t i v e l y , a r e c l e a r l y o b s e r v e d i n t h i s , s p e c t r u m . F u r t h e r c h a r a c t e r i z a t i o n o f t h e s e two compounds w i l l be d e s c r i b e d l a t e r . . (TABLE 29 and Sec. V I - E - 5 , r e s e p c t i v e l y ) . I t was f o u n d by a c a r e f u l s p e c t r o s c o p i c e x a m i n a t i o n on each f r a c t i o n o f t h e v o l a t i l e p a r t t h a t t e t r a m e t h y l t i n was n o t formed i n t h i s r e a c t i o n . The C a r i u s . t u b e , c o n t a i n i n g t h e i n v o l a t i l e r e s i d u e , was r i n s e d w i t h 1-ml. p o r t i o n s o f n-pentane s e v e r a l . t i m e s , . The w h i t e s o l i d (1.6 g.,. d e s i g n a t e d as P) was s e p a r a t e d from t h e pentane s o l u t i o n ( d e s i g n a t e d as Q) by c e n t r i f u g i n g . . . E v a p o r a t i o n o f Q w i t h a s t r e a m o f d r y n i t r o g e n gas a f f o r d e d a brown o i l (3.15 g.) w h i c h was chromatographed on t h e F l o r i s i l column (2 x 50 cm.) i n f i v e p o r t i o n s , i . e , about 0.6 g. f o r each p o r t i o n . The chromatogram was d e v e l o p e d w i t h n-pentane and t h e c o l l e c t i o n o f 5-ml. - f r a c t i o n s s t a r t e d when t h e f i r s t t r a c e o f carbonylmanganese d e r i v a t i v e s a ppeared i n t h e e l u a t e as d e t e c t e d by an i n f r a r e d s p e c t r o s c o p i c examina-t i o n i n t h e c a r b o n y l s t r e t c h i n g region.. The same i n f r a r e d s p e c t r o s c o p i c e x a m i n a t i o n was r e p e a t e d i n d i v i d u a l l y on a l l 5 m l . - f r a c t i o n e l u a t e s . I t was shown, by p l o t t i n g t h e i n t e n s i t i e s o f t h e c a r b o n y l s t r e t c h i n g bands S e c i VI-E-3 171 a g a i n s t \"the e l u t e d volume, ,that: t h e brown, o i l was s e p a r a t e d i n t o , f o u r c h r o m a t o g r a p h i c : bands,. F o u r more runs o f t h e c h r o m a t o g r a p h i c s e p a r a t i o n , were made, u s i n g , t h e o t h e r p o r t i o n s o f ..the brown, oil.,.' and a l l f r a c t i o n s o f t h e , c o r r e s p o n d i n g , component were, combined, and n-pentane was e v a p o r a t e d (-10°/10 cm... Eg).. The, f i r s t e l u t e d band c o n t a i n e d m a i n l y t h e u n r e a c t e d ( C H 3 ) 3 S n - M n ( C O ) 5 1 g.) . A w h i t e s o l i d , r e c o v e r e d from, the s e c o n d band was r e c r y s t a l l i z e d i n . c y c l o h e x a n e t o a f f o r d t h e . 1 : 1 a d d u c t , 1 - t r i m e t h y l -t i n - 2 - p e n t a c a r b o n y l m a n g a n e s e - t e t r a f l u o r o e t h a n e , (CH 3) 3SnCF2CF2Mn(C0)5 (0.6 g., 1.3 mmole), m.p., 57.5°. The t h i r d e l u t e d component, a p a l e l i q u i d , was CsFgMnfCO^, which i s f o r m u l a t e d on the basis of elemental a n a l y t i -c a l d a t a and M.W. measurement (0.8 g., 1^8 mmole). The w h i t e , v e r y v o l a t i l e s o l i d o b t a i n e d as t h e l a s t e l u t e d component was s u b l i m e d — 3 (25°/10- cm.. Hg), t o g i v e : p e r f l u o r o a c r y l o y i p e n t a c a r b o n y l m a n g a n e s e , GF 2=GFC0Mn(C0) 5 .(0.4 :.g.,.1*7 mmole.)., nup.., ...41°... A brown r i n g r e m a i n i n g on t h e t o p o f t h e column Was f i n a l l y e l u t e d w i t h a 10% methanol-pentane m i x t u r e - E v a p o r a t i o n o f t h e s o l v e n t s under vacuum y i e l d e d about 0.1 g. o f a b l a c k i s h brown gum.. I t s i n f r a r e d _1 s p e c t r u m showed a b r o a d band of,medium i n t e n s i t y c e n t r e d a t 1700 cm ( a c y l , b r i d g e d c a r b o n y l , o r / a n d C=C s t r e t c h i n g , v i b r a t i o n s ) and two v e r y b r o a d and s t r o n g bands c e n t r e d a t 1150.and 1000 cm. (C-F s t r e t c h i n g modes) i n a d d i t i o n t o t h e a b s o r p t i o n s a s s o c i a t e d w i t h carbonylmanganese group. The w h i t e s o l i d r e s i d u e (P.) was e x t r a c t e d s e v e r a l t i m e s w i t h 1-ml.. p o r t i o n s o f acetone., l e a v i n g a w h i t e c r y s t a l l i n e r e s i d u e (R) which, was i d e n t i f i e d by i t s i n f r a r e d , s p e c t r u m as t r i m e t h y l t i n f l u o r i d e (0.9 g.., 4.95 mmole). No p o l y m e r i z e d t e t r a f l u o r o e t h y l e n e was d e t e c t e d i n ( R ) b y i n f r a r e d s p e c t r o s c o p i c e x a m i n a t i o n * The ace t o n e e x t r a c t s were combined Sec. VI-E-3 172 TABLE 29 ANALYTICAL DATA FOR THE REACTION PRODUCTS OF ( C H 3 ) 3 S n - M n ( C O ) 5 AND CF 2=CF 2. M.W. %C %H %F c a l c . f o u n d c a l c . f o u n d . c a l c . f ound c a l c f o u n d C 5 F 9 M n ( C O ) 5 426 435. 28.2 28.4 40.2 40.0, ( C H 3 ) 3 S n C F 2 C F 2 M n ( C O ) 5 458.2 482 26.2 26.5 26.3 1.96 1.89 ,. 1.65 16,7 16.6 [ C F 2 = C F M n ( C 0 ) 1 + ] 2 ( l ) 496 489 29.0 30.7 23.0 23.5 [ C F 2 = C F M n ( C 0 ) 4 ] 2 (2) 496 466 29.0 29.8 23.0 24.9 and a c e t o n e was removed c o m p l e t e l y w i t h a f l o w o f d r y n i t r o g e n gas. The r e s u l t i n g r e s i d u e was t h e e x t r a c t e d w i t h -four t o f i v e 2-ml. p o r t i o n s o f h o t carbon, t e t r a c h l o r i d e , and f i n a l l y washed t w i c e w i t h c h l o r o f o r m . The r e s i d u e , a. w h i t e s o l i d , , was f o u n d t o be one of, t h e i s o m e r s o f t h e d i m e r i c p e r f l u o r o v i n y l t e t r a c a r b o n y l m a n g a n e s e , [CF 2=CFMrt(C0) \\ ] 2 , d e s i g n a t e d as Dimer 2, (0.2 g., 0.42 mmole). The volume o f t h e combined c a r b o n t e t r a c h l o r i d e ; e x t r a c t s ; was r e d u c e d u n t i l a w h i t e c l o u d i n e s s formed..: A f t e r c h i l l i n g t h e s o l u t i o n i n i c e f o r about an h o u r , f i l t r a t i o n a f f o r d e d , t h e o t h e r i s o m e r o f [CF.2= CFMn(CO) 4] 2 , d e s i g n e d as Dimer 1, (0.4 g., 0.8 mmole). Both i s o m e r s have no d e f i n i t e m e l t i n g p o i n t . They decomposed a t 150° t o g i v e a brown s o l i d . They a l s o do n o t s u b l i m e 3 even a t 90°/10 cm. Hg. S e c VI-E-4 173 4. R e a c t i o n w i t h t r i f l u o r o e t h y l e n e . When ( C H 3 ) 3 S n - M n ( C O ) 5 (1.7 g., 4.7 mmole) i n 4 ml. o f n-pentane was a l l o w e d t o r e a c t w i t h t r i f l u o r o e t h y l e n e (1.9 g., 23.2 mmole) i n a s e a l e d s i l i c a tube under u l t r a v i o l e t i r r a d i a t i o n a t 63° f o r f o u r h o u r s , t h e f i n a l r e a c t i o n m i x t u r e was a brown l i q u i d c o n t a i n i n g w h i t e s o l i d . The r e a c t i o n t u b e was a t t a c h e d t o t h e vacuum l i n e and un c o n d e n s a b l e gas, CO gas, ( f o u n d : M.W., .25.5)(0.8 mmole) was removed. The v o l a t i l e p a r t of* t h e r e a c t i o n m i x t u r e was t r a n s f e r r e d i n t o a t r a p a t -10°/10 cm. Hg, and s e p a r a t e d by vacuum f r a c t i o n a t i o n t o g i v e u n r e a c t e d t r i f l u o r o -e t h y l e n e (1.7 g., 20.2 mmole) i n a -196° t r a p , t h e s o l v e n t i n b o t h -126° and -76° t r a p s , and 0.2 g. o f p a l e y e l l o w i i q u i d i n a -46° t r a p . The i n f r a r e d s p e c t r u m o f t h e -46° f r a c t i o n showed bands i n t h e C-F a b s o r p -t i o n r e g i o n : ,1720 (w), 1670 ( s ) , 1518 (w), 1275 ( s , b ) , 1232 (m),1144 ( s ) , _1 1120 ( s h ) , 1090 (s,b) 1015 (s,b) and 1010 (sh) cm. ; i n a d d i t i o n t o t h e e x p e c t e d a b s o r p t i o n s o f ( C H 3 ) 3 S n - M n ( C 0 ) 5 , ( C H 3 ) 3 S n X , and XMn(C0) 5 where X i s a f l u o r o c a r b o n group. S i n c e t h e (trans-CFH=CF)Mn(CO) 5 (see Sec. IV-C and below) g i v e s r i s e t o s t r o n g i n f r a r e d bands a t 1670, 1272, _1 . 1088, 1010 and 760 cm. i n a d d i t i o n t o t h e bands due t o t h e M n ( C 0 ) 5 group, and because ( C H 3 ) 3 S n C F = C F 2 (see Sec. VI-D-7) shows s t r o n g i n f r a r e d a b s o r p t i o n s a t 1725, 1280, 1122 and 1010 cm. 1 t o g e t h e r w i t h t h e a b s o r p t i o n s a s s o c i a t e d w i t h ( C H 3 ) 3 S n group, the p a l e y e l l o w l i q u i d was i d e n t i f i e d , on t h e b a s i s o f s p e c t r o s c o p i c e v i d e n c e , as a m i x t u r e o f trans-(CFH=CF)Mn(CO) 5, ( C H 3 ) 3 S n C F = C F 2 , and ( C H 3 ) 3 S n - M n ( C 0 ) 5 (see Sec. IV-C) i n t h e a p p r o x i m a t e l y r e l a t i v e r a t i o o f 4:1:4. The i n v o l a t i l e p a r t was t r e a t e d w i t h a c e t o n e (3 ml.) s e v e r a l t i m e s t o l e a v e a w h i t e s o l i d , w h i c h was shown by i t s i n f r a r e d s p e c t r u m (see Sec. VI-E-4 174 Sec. IV-A-1) to.be c h i e f l y ( C H 3 ) 3 S n F (0.55 g., 3 mmole) . The r e s u l t i n g . . acetone s o l u t i o n s were.combined, acetone was e v a p o r a t e d at -10°/4 cm. Hg., _ 3 and t h e r e s u l t i n g r e s i d u e was s u b l i m e d a t 25°/10 ' cm. Hg. A f r a c t i o n w h i c h went t h r o u g h t h e c o o l e d probe (10°) and condensed i n a -46° t r a p was chromatographed.on a F l o r i s i l column u s i n g n-pentane as the eluant,. The major component (0;„05 g,.., ,0.2. mmole) o f t h e e l u a t e was i n d e n t i f i e d as ( t r a n s - 1 , 2 - d i f l u o r o v i n y l ) - p e n t a c a r b o n y l m a n g a n e s e , (trans-CFH=CF.)Mn(CO) 5 , on t h e b a s i s o f i t s i n f r a r e d and lH N.M.R. sp e c t r a . . T h i s compound decomposed i n d e u t e r o c h l o r o f o r m on p r o l o n g e d s t a n d i n g , b e f o r e i t s . 1 9 F , N~M..R.. s p e c t r u m c o u l d be s t u d i e d . The sample was thu s n o t r e c o v e r e d from i t s s o l u t i o n f o r a n a l y s i s . . D e s p i t e t h e f a i l u r e , t o o b t a i n a n a l y t i c a l d a t a , t h e f o r m u l a t i o n o f t h i s compound was deduced from t h e f o l l o w i n g e v i d e n c e : ( i ) t h e v o l a t i l i t y i n d i c a t e s t h a t i t i s n o t a d i m e r , analogous t o [CF. 2=CFMn(C0) i^ ] 2 w h i c h does not s u b l i m e even at _3 90°/10 cm. Hg; ( i i ) i t s i n f r a r e d , s p e c t r u m i s very, s i m i l a r t o t h a t , o f i t s c i s - i s o m e r . (see See. IV-C and below.);. ( i i i ) i t s *H N.M.R. s p e c t r u m showed a q u a r t e t , o f i n t e n s i t y r a t i o 1:1:1:1 ( J i , 86.5 c.p.s.; J 2 10.2 c.p.s.) c e n t r e d at. -8.06 p.p.m. w i t h r e s p e c t t o TMS i n t e r n a l s t a n d a r d , i n a c c o r d w i t h the, s p e c t r u m of. a trans-.CFH=CF- group (see Sec. IV-D). The s u b l i m e d s o l i d on the. c o o l e d probe was washed w i t h t h r e e 0.5-ml. p o r t i o n s , of. c o l d n.-pentane,.and r e c r y s t a l l i z e d i n c y c l o h e x a n e t o y i e l d the. w h i t e , c r y s t a l l i n e . ( , c i s . - l . , 2 . - d i f l u o r o v i n y l ) . - p e n t a c a r b o n y l -manganese, (cis-CFH=CF)Mn(C0) 5 (0.35 g.., 1^4 mmole), ( c a l c . f o r C 7F 2HMn0 5: C, 32.55; H, 0.38; F, 14..74; M.W., 258; found: C, 32.64; H, 0.64, F, 14.85; M.W., 2 9 5 ) , m.p. 78° ( u n c o r r e c t e d ) . E v a p o r a t i o n (-10°/10 cm. Hg.) o f t h e pentane washings gave 0.4 g., (1.1 mmole) o f u n r e a c t e d ( C H 3 ) 3 S n - M n ( C 0 ) 5 . The s u b l i m a t i o n r e s i d u e (0.2 g . ) , a b l a c k i s h brown Sec. VI-E-5 _1 gum, showed two i n f r a r e d bands o f medium i n t e n s i t y a t 1700 and 1610 cm. _1 and a s t r o n g and b r o a d band c e n t r e d at 1100 cm. as w e l l as t h e e x p e c t e d a b s o r p t i o n s o f carbonylmanganese group. No f u r t h e r i n v e s t i g a t i o n was made o f t h i s f r a c t i o n . A complete e x a m i n a t i o n on t h e i n f r a r e d and *H N.M.R. s p e c t r a o f a l l f r a c t i o n s t h r o u g h o u t t h i s e x p e r i m e n t f a i l e d t o d e t e c t any t r a c e o f th e adduct analogous t o ( C H 3 ) 3 S n C F 2 C F 2 M n ( C O ) 5 . The a d d u c t , ( C H 3 ) 3 S n ( C F H C F 2 ) n M n ( C 0 ) 5 , s h o u l d show, i n i t s XH N.M.R. s p e c t r u m a t l e a s t one t r i p l e t e d d o u b l e t a s s o c i a t e d w i t h t h e p r o t o n o f th e p o l y f l u o r o -c a r b o n group, and a methyl r e s o n a n c e i n th e r e g i o n where t h e m e t h y l r e s o n a n c e o f ( C H 3 ) 3 S n group o-bonded t o a f l u o r o c a r b o n group, s h o u l d o c c u r . I n i t s i n f r a r e d s p e c t r u m , two a b s o r p t i o n s a r i s i n g from Sn-C s t r e t c h i n g modes o f t h e t y p e ( C H 3 ) 3 S n R f , a r e a l s o e x p e c t e d . S p e c t r a o b t a i n e d i n t h i s e x p e r i m e n t d i d n o t show t h i s c o m b i n a t i o n o f a b s o r p t i o n s . 5. R e a c t i o n w i t h t r i f l u o r o c h l o r o e t h y l e n e . The r e a c t i o n between (CH 3) 3Sn-Mn(CO) 5 (2.3 g., 6.3 mmole) I n 5 ml. o f n-pentane and t r i f l u o r o c h l o r o e t h y l e n e (4.7 g., 40.2 mmole) under u l t r a v i o l e t i r r a d i a t i o n a t 70° f o r t h r e e h o u r s gave 0.82 mmole o f carbo n monoxide, u r i r e a c t e d o l e f i n (which Was n o t measured because o f th e f a i l u r e t o i s o l a t e i t from t h e s o l v e n t ) , and an i n v o l a t i l e b l a c k i s h browrt o i l (about 2.8 g.) c o n t a i n i n g a s o l i d . T reatment o f th e s o l i d , w h i c h was s e p a r a t e d from t h e b l a c k i s h brown o i l by c e n t r i f u g i n g , w i t h t h r e e 2-ml. p o r t i o n s o f n-pentane, f o l l o w e d by f i v e 2-ml. p o r t i o n s o f a c e t o n e , y i e l d e d a w h i t e S o l i d w h i c h was shown by i t s i n f r a r e d s p e c t r u m t o c o n t a i n o n l y t r i m e t h y l t i n SEC. VI-E-5 f l u o r i d e (0.1 g., 0.55 mmole). E v a p o r a t i o n o f a c e t o n e from t h e e x t r a c t s w i t h a f l o w o f d r y n i t r o g e n gas gave 0.3 g. o f b l a c k gum. T h i s b l a c k gum c o r r e s p o n d s t o t h e f r a c t i o n i n t h e t e t r a f l u o r o e t h y l e n e r e a c t i o n from w h i c h t h e d i m e r s , [ C F 2 = C F M n ( C 0 ) J 2 , were i s o l a t e d . I n t h i s c a s e , however, t h i s gum does not show any a b s o r p t i o n e x p e c t e d f o r t h e d i m e r s . T h i s gum was n o t t r e a t e d f u r t h e r . n-Pentane was removed (-10°/10 cm. Hg) from t h e combined.washings and t h e r e s u l t i n g o i l was added t o t h e b l a c k i s h brown o i l . Chromato-g r a p h i c s e p a r a t i o n o f t h e o i l on F l o r i s i l column (n-pentane e l u a n t ) a f f o r d e d t h r e e f r a c t i o n s as f o l l o w s : ( i ) The f i r s t e l u t e d f r a c t i o n was unchanged ( C H 3 ) 3 S n - M n ( C 0 ) 5 (0.5 g., 1.4 mmole), i d e n t i f i e d s p e c t r o s c o p i c a l l y . ( i i ) The s e c o n d f r a c t i o n , a c l e a r l i q u i d (0.1 g . ) , was a m i x t u r e o f a t l e a s t t h r e e components i n d i c a t e d by i t s i n f r a r e d s p e c t r u m . The a b s o r p -t i o n s a r e a t 1790 (m), 1690 ( v s , b ) , 1640 (m), 1345 (m), 1300 (m), 1220 ( s , b ) ^ 1068 (m), 1050 (m), 1040 (m,b), 960 ( s , b ) , 825 ( s , b ) , 785 (m), 740 _1 (w), 550 (m,b), and 508 (w) cm. i n a d d i t i o n t o t h e a b s o r p t i o n s a s s o c i a t e d w i t h M n ( C 0 ) 5 group. The t h r e e bands a t 1790, 1690, and 1640 - _ l • ' cm. may a r i s e from C=C s t r e t c h i n g v i b r a t i o n , a l t h o u g h t h e p o s s i b i l i t y o f a c y l o r c a r b o n y l b r i d g e d d e r i v a t i v e s e x i s t i n g i n t h e m i x t u r e cannot be e l i m i n a t e d . T r a p - b y - t r a p f r a c t i o n a t i o n d i d n o t c l e a r l y s e p a r a t e d t h e components b u t t h e i n f r a r e d s p e c t r a o f t h e f r a c t i o n s i n each t r a p i n d i c a t e d , on t h e b a s i s o f t h e i r r e l a t i v e i n t e n s i t i e s , t h a t t h e t h r e e C=C a b s o r p t i o n s a r e due t o t h r e e d i f f e r e n t compounds r e s p e c t i v e l y . S i n c e t h e r e were no C-H s t r e t c h i n g and Q i 3 - S n r o c k i n g a b s o r p t i o n s , t h e _ ] bands a t 550 and 508 cm. c o u l d n o t be a t t r i b u t e d t o t h e Sn-C s t r e t c h i n g 177 Sec, VI-E-5 modes. The AH N.M.R. sp e c t r u m o f t h e c l e a r l i q u i d showed no p r o t o n r e s o n a n c e , s u p p o r t i n g t h e above o b s e r v a t i o n . I t s 1 9 F N.M.R., however, c o n s i s t e d o f t h r e e d i s t i n c t s e t s o f a b s o r p t i o n s a p p a r e n t l y a r i s i n g f rom t h r e e f l u o r o v i n y l g r oups. The t h r e e q u a r t e t s (each w i t h i n t e n s i t y r a t i o o f 1:1:1:1) c e n t r e d at +7.4, +51.0, and +64.9 p.p.m. (T F A ) , r e s -p e c t i v e l y , were u n d o u b t e d l y a s s o c i a t e d w i t h p e r f l u o r o a c r y l o y l p e n t a -carbonylmanganese, CF 2=CFCOMn(CO) 5, (see Sec. I V - D ) . The two d o u b l e t s c e n t r e d a t +23.6 and +43.6 p.p.m. (TFA) ( J p p , 126 c.p.s.) may be a s s i g n e d t o ( t r a n s - 1 , 2 - d i f l u o r o - 2 - c h l o r o v i n y l ) p e n t a c a r b o n y l m a n g a n e s e , ( t r a n s - C F C l = C F ) M n ( C O ) 5 , on t h e b a s i s o f t h e l a r g e magnitude o f t h e F-F c o u p l i n g c o n s t a n t (93,113). The two d o u b l e t s c e n t r e d a t -10.1 and +10.95 p.p.m. (Jp.p.» 58.5 c . p . s . ) , r e s p e c t i v e l y , may be a t t r i b u t e d t o e i t h e r t h e c i s - l , 2 - d i f l u o r o - 2 - c h l o r o v i n y l g roup, c i s - C F C l = C F - , o r t h e 2 , 2 - d i f l u o r o -1 - c h l o r o v i n y l group, C F 2=CC1-. However, i n v i e w o f the r e m a r k a b l e u n s h i e l d i n g o f one o f the f l u o r i n e atoms (-10.1 p.p.m.) w h i c h i s a c h a r a c t e r i s t i c c h e m i c a l s h i f t f o r a f l u o r i n e n u c l e u s o f th e C-F group d i r e c t l y l i n k e d t o a t r a n s i t i o n m e t a l t h r o u g h a c a r b o n - m e t a l bond ( 1 4 3 ) , t h e s e r e s o n a n c e s were t e n t a t i v e l y a s s i g n e d t o ( c i s - l , 2 - d i f l u o r o - 2 -c h l o r o v i n y l ) p e n t a c a r b o n y l m a n g a n e s e , (Cis-CFCl=CF)Mn(CO)5. J u d g i n g from t h e peak i n t e n s i t i e s i n , t h e • 1 9 F N.M.R. s p e c t r u m , t h e mass d i s t r i b u t i o n s ' i n t h i s m i x t u r e were 55% CF 2=CFC0Mn(C0)5 , 9% ( t r a n s - C F C l = C F ) M r i ( C O ) 5 , and 36% ( e i s - C F C l = C F ) M n ( C O ) 5 . _3 ( i i i ) The l a s t and t h e major f r a c t i o n was f u r t h e r s u b l i m e d (25°/10 cm. Hg) o n t o a c o o l e d probe a t -76° t o g i v e White c r y s t a l l i n e CF 2=*CFC0Mn(C0) 5 (1.1 g., 3.6 mmole) ( c a l c . f o r C 8F 3MnO e: . C, 31.6; F, 18.8; M.W., 3u4.0 found: C, 31.40; F, 18.85; M.W., 2 9 9 ) , m.p., 41° ( u n c o r r e c t e d ) . The column was f i n a l l y e l u t e d w i t h 10% methanol-pentane m i x t u r e Sec. VI-E-6 x ' ° _3 t o g i v e about 0.7 g. o f brown r e s i d u e . S u b l i m a t i o n (25°/10 cm. Hg), o f t h e r e s i d u e a f f o r d e d w h i t e c r y s t a l s on t h e -76° probe w h i c h were i d e n t i 1 -f i e d by t h e i n f r a r e d s p e c t r u m and *H N.M.R. s p e c t r a (,§CH3, -37 c.p.s., TMS) and m e l t i n g p o i n t (37°) t o be t r i m e t h y l t i n c h l o r i d e , ( C H 3 ) 3 S n C l (0.55 g., 2.8 mmole). S p e c t r o s c o p i c c omparisons between t h e o r i g i n a l b l a c k o i l and t h e i s o l a t e d p r o d u c t s , CF 2= CFC0Mn(C0) 5 and ( C H 3 ) 3 S n C l , i n d i c a t e d t h a t no d e c o m p o s i t i o n had t a k e n p l a c e d u r i n g t h e c o u r s e o f s e p a r a t i o n and p u r i -f i c a t i o n . P y r o l y s i s o f CF 2=C0Mn(C0) 5. When CF 2=CFC0Mn(C0) 5 (0.01 g., 0.032 mmole) was h e a t e d a t 100° i n the d a r k f o r t h r e e h o u r s , c a r b o n monoxide (0.025 mmole) was t h e o n l y v o l a t i l e p r o d u c t . S u b l i m a t i o n o f t h e i n v o l a t i l e r e s i d u e a f f o r d e d un-changed s t a r t i n g m a t e r i a l (0.003 g., 0.01 mmole) and 0.006 g. o f b l a c k o i l . The i n f r a r e d s p e c t r u m o f t h e l a t t e r showed a b s o r p t i o n s v e r y s i m i l a r t o t h o s e o f t h e b l a c k gum i s o l a t e d from t h e r e a c t i o n o f ( C H 3 ) 3 S n - M n ( C 0 ) 5 and t r i f l u o r o c h l o r o e t h y l e n e , b u t n e i t h e r Dimer 1 n o r Dimer 2 o f [ C F 2 = C F M n ( C 0 ) 4 ] 2 c o u l d be d e t e c t e d . I t s h o u l d be n o t e d t h a t t h e s e d i m e rs do n o t decompose below 150°. 6. R e a c t i o n w i t h e t h y l e n e , a. R e a c t i o n with- e t h y l e n e a t 10 atm. ( C H 3 ) 3 S n - M n ( C 0 ) 5 (1.4 g., 3.96 mmole) i n 3 ml. o f n-pentane was a l l o w e d t o r e a c t w i t h e t h y l e n e (0.6 g., 21.7 mmole) i n a s e a l e d s i l i c a t u b e under u l t r a v i o l e t i r r a d i a t i o n at 50° f o r f o u r h o u r s . On o p e n i n g the t u b e t o t h e vacuum l i n e , c a r b o n monoxide (0.8 mmole) and e t h y l e n e Sec. VI-E-6. 179 (21.0 mmole) were r e c o v e r e d . The s o l v e n t was e v a p o r a t e d , l e a v i n g a y e l l o w o i l w h i c h showed i t s i n f r a r e d a b s o r p t i o n s a t 1435 (w), 1230 - l • ! ( s , s h a r p ) , and 555 (m,b) cm. i n a d d i t i o n t o t h e a b s o r p t i o n s c o r r e s -p o n d i n g w i t h t h o s e o f ( C H 3 ) 3 S n - M n ( C 0 ) 5 . The y e l l o w o i l and e t h y l e n e , (21.0 mmole) t o g e t h e r w i t h 3 ml. o f pentane were r e s e a l e d i n a s i l i c a t u b e and exposed to, t h e u l t r a v i o l e t l i g h t a t 80° f o r 20 ho u r s when t h e r e a c t i o n m i x t u r e became b r o w n i s h orange. T r e a t i n g t h e r e a c t i o n t u b e i n t h e same manner as d e s c r i b e d above, gave c a r b o n monoxide (0.5 mmole) and e t h y l e n e (18.0 mmole), as w e l l as a brown o i l - s o l i d m i x t u r e (L.2 g . ) . The l a s t f r a c t i o n was e x t r a c t e d w i t h n-pentane (6 ml.), and a b l a c k s o l i d (0.1 g.) was removed by c e n t r i f u g i n g . E v a p o r a t i o n (-10°/10 cm. Hg) o f t h e combined pentane e x t r a c t s a f f o r d e d 1.1 g. o f brown o i l w h i c h was t h e n s u b l i m e d a t \\ \\ _3 25°/10 cm. Hg. The f i r s t s u b l i m a t e (0.5 g.) on t h e c o o l e d p r o b e . _3 (-76°) was removed, and c o n t i n u a t i o n o f t h e s u b l i m a t i o n (30°/10 cm. Hg) gave t h e y e l l o w o i l o f t r i m e t h y l t i n - t e t r a c a r b o n y l ( n - e t h y l e n e ) m a n g a n e s e , (CH 3) 3Sn-Mn(G0) i t ( 7 r - C 2 H l t ) (0.4 g., 1.1 mmole), ( c a l c . f o r C<3H1 sSnMnO^: C, 30.1; H, 3.6; M.W., 358.8 fo u n d : C, 30.0; H, 4.27; M.W., 3 4 9 ) . R e s u b l i m a t i o n o f t h e f i r s t s u b l i m a t e y i e l d e d a n o t h e r 0.2 g. (0.6 mmole) o f (CH 3) 3Sn-Mn(C0) i + ( T r - C 2 H i + ) [gave a t o t a l y i e l d o f 1.7 mmole, 43% on t h e b a s i s o f (CH 3) 3SniMn(CO) 5 taken] and 0.3 g. o f unchanged ( C H 3 ) 3 S n - M n ( C 0 ) 5 . The s u b l i m a t i o n r e s i d u e , b l a c k o i l (0.1 g . ) , and t h e e x t r a c t e d b l a c k s o l i d were n o t s t u d i e d . b. R e a c t i o n w i t h e t h y l e n e a t 1 atm. i n t h e p r e s e n c e o f hydro g e n gas. ( C H 3 ) 3 S n - M n ( C 0 ) 5 (1.5 g., 4.2 mmole) and e t h y l e n e (0.25 g. , Sec. VI-E-6 180 8.8 mmole) and 13 ml. o f n-pentane were condensed i n a 500-ml. s i l i c a t u b e , and 9 mmole o f hydrogen gas i n t r o d u c e d . The tube was s e a l e d by means o f a p a c k l e s s m e t a l b e l l o w s v a l v e w h i c h was u n i t e d t o t h e tu b e w i t h a m e t a l - g l a s s s e a l . A f t e r e x p o s i n g t h e tube t o u l t r a v i o l e t l i g h t a t 60° f o r f o u r h o u r s , u n c o n d e n s a b l e gases (7.3 mmole), a f r a c t i o n w h i c h condensed i n a -196° t r a p , and t h e s o l v e n t w h i c h condensed i n b o t h t h e -126° and -76° t r a p s , were o b t a i n e d . Gas c h r o m a t o g r a p h i c a n a l y s e s i n d i c a t e d t h a t t h e u n c o n d e n s a b l e gases c o n t a i n e d c a r b o n monoxide ( 1 5 % , 1.1 mmole) and h y d r o g e n gas ( 8 5 % , 6.2 mmole), and t h a t t h e -196° f r a c t i o n was a m i x t u r e o f e t h y l e n e ( 9 0 %, 7.0 mmole) and e t h a n e , C 2Hg, (1 0 % , 0.8 mmole), and b o t h were f u r t h e r i d e n t i f i e d by t h e i r i n f r a r e d s p e c t r a . S u b l i m a t i o n o f t h e i n v o l a t i l e r e s i d u e gave unchanged (CH 3) 3Sn-Mn(C0) 5 (0.8 g., 2.2 mmole) and (CH3) 3Sn-Mn(C0) i t ( T r - G 2 H i + ) (0.3 g., 0.85 mmole), i d e n t i f i e d s p e c t r o s c o p i c a l l y , l e a v i n g t h e s u b l i m a t i o n r e s i d u e (0.3 g.) a b l a c k o i l . 181 BIBLIOGRAPHY 1. A. Ladenburg, Ann. S u p p l . ( 1 8 6 9 ) , 8_, 69. 2. R . J . H a v i g h u r s t , J . Am. Chem. Soc. ( 1 9 2 6 ) , 48_, 2113. 3. F:A. C o t t o n and T.E. Haas, I n o r g . Chem. ( 1 9 6 4 ) , 3_> 1 0 -4. C.E. C o f f e y , J . Lewis and R.S. Nyholm, J . Chem. Soc. ( 1 9 6 4 ) , 1741; and t h e r e f e r e n c e s c i t e d t h e r e i n . 5. J . L e w i s , P u r e and A p p l . Chem. ( 1 9 6 5 ) , 10_, 11. 6. R.B. K i n g , Adv. i n Org a n o m e t a l . Chem., 2, e d i t e d by F.G.A. St o n e and R. West, Academic P r e s s , N.Y., 1964, p. 158-256; and t h e r e f e r e n c e s c i t e d t h e r e i n . 7. S.V. Dighe and M. , O r c h i n , J . Am. Chem. Soc. ( 1 9 6 4 ) , 86, 3895. 8. H.R.H. P a t i l and W.A.G. Graham, J . Am. Chem. Soc. ( 1 9 6 5 ) , 87_, 673. 9. S.V. Dighe and M. O r c h i n , J . Am. Chem. Soc. ( 1 9 6 5 ) , 87_, 1146. 10. R . J . C r o s s and F. G l o c k l i n g , J . Or g a n o m e t a l . Chem. ( 1 9 6 5 ) , 3_, 146. 11. R . J . C r o s s and F. G l o c k l i n g , J . Or g a n o m e t a l . Chem. ( 1 9 6 5 ) , 3_, 253. 12. H. G i l m a n and G.L. Schwebke, J . Or g a n o m e t a l . Chem. ( 1 9 6 5 ) , 3_, 382. 13. W.P. Neumann and K. K b n i g , Angew. Chem. (1965) , 76_, 892. 14. W.P. Neumann and K. K u h l e i n , T e t r a h e d r o n L e t t e r s ( 1 9 6 3 ) , Z3, 1541. 15. I.G.M. C a m p b e l l , G.W.A. Fowles a n d L . A . N i x o n , J . Chem. Soc; ( 1 9 6 4 ) , 1389. 16. I.G.M. C a m p b e l l , G.W.A. Fowles and L.A. Nixon,. J . Chem. Soc. ( 1 9 6 4 ) , 3026. 17. E.W. A b e l , Q u a r t . Rev. (1963),. 17_, 133; and t h e r e f e r e n c e s c i t e d t h e r e i n , 18. D. W i t t e n b e r g and H. G i l m a n , J . Am. Chem. Soc; ( 1 9 5 8 ) , 80_, 2677. 19. C A ; Kraus and W.K. N e l s o n , J . Am. Chem. Soc. ( 1 9 2 4 ) , 46_, 195. 20. C A . Kraus and W.V. S e s s i o n s , J . Am. Chem. Soc. ( 1 9 2 5 ) , 47, 2361. 21. H.D. Ka e s z , J.R. P h i l l i p s and F.G.A. S t o n e , Chem. I n d . (London) ( 1 9 5 9 ) , 1409. 22. H.D. K a e s z , J.R. P h i l l i p s and- F.G.A. S t o n e , J . Am. Chem. Soc. ( 1 9 6 0 ) , 82, 6228. 182 23. H.C. C l a r k and C.J. W i l l i s , J . Am. Chem. Soc- (1-960), 8_2, 1888. 24. R.D. Chambers, H.C. C l a r k and C.J . W i l l i s , Chem. I n d . (London) (1960) , 7 6 . , ' 25. R . J . C r o s s and F. G l o c k l i n g , P r o c . Chem. S o c ; ( 1 9 6 4 ) , 143. 26. R.D. G o r s i c h , J . Am. Chem. Soc. ( 1 9 6 2 ) , 84_, 2486. 27. F. H e i n and H. S c h e i t e r , Z. a n o r g . Chem. ( 1 9 4 9 ) , 259, 183. 28. W.R. C u l l e n , Can. J . Chem. ( 1 9 6 0 ) , 38_, 439. 29. M.A.A. Beg and H.C. C l a r k , Can. J . Chem. ( 1 9 6 2 ) , 40_, 283. 30. F. H e i n and E. Heu s e r , Z. an o r g . Chem. ( 1 9 4 2 ) , 249, 293. 31. R.B. K i n g , R.M. T r i e c h e l and F.G.A. S t o n e , Chem. I n d . (London) (1961) , 747. 32. M.A.A. Beg and H.C. C l a r k , Chem. I n d . (London) ( 1 9 6 2 ) , 140. 33. A.B. B u r g , J . Am. Chem. Soc. (1961) , 83_, 2226. 34. L.R. G r a n t , Ph.D. T h e s i s , U n i v e r s i t y o f S o u t h e r n C a l i f o r n i a , L.A., C a l i f . , 1961. 35. W.R. C u l l e n and N.K. H o t a , Can. J . Chem. ( 1 9 6 4 ) , 42, 1123. 36. W.R. C u l l e n , D.S. Dawson and G.E. S t y a n , J . Orga n o m e t a l . Chem. (1965) , 3^ 406. 37. (a) R.D. Cramer, E.L. J e n n e r , R.V. L i n d s e y , J r . , and U.G. S t o l b e r g , J . Am. Chem. Soc. ( 1 9 6 3 ) , 85_, 1691; 38. (b) R.V. L i n d s e y , J r . , G.W. P a r s h a l l and U.C. S t o l b e r g , J . Am. Chem. Soc. ( 1 9 6 5 ) , BI, 658; and t h e r e f e r e n c e s c i t e d t h e r e i n . 38. G.C. Bond and M. H e l l i e r , Chem. I n d . (London) ( 1 9 6 5 ) , 35. 39. H. A d k i n s and G. K r s e k , J . Am. Chem. Soc. ( 1 9 4 8 ) , 70, 383. 40. F. Calderazzo., I n o r g . Chem. ( 1 9 6 5 ) , 4_, 293. 41. P. Szabo and L. Mark6, J . Orga n o m e t a l . Chem. ( 1 9 6 5 ) , 3_> 364. 42. P.M. T r e i e h e l and F.G.A. S t o n e , Adv. i n Orga n o m e t a l . Chem., 1_, e d i t e d by F.G.A. Stone and R. West, Academic P r e s s , N.Y., 1964, p. 143-220. 43. H. M o r r i s and P.W. Selwood, J . Am. Chem. Soc. ( 1 9 4 1 ) , 63, 2509. 183 44. J.G.A. L u i j t e n and G.J.M. van d e r Ker k , \" I n v e s t i g a t i o n s i n t h e F i e l d o f O r g a n o t i n C h e m i s t r y \" , T i n R e s e a r c h I n s t i t u t e , M i d d l e s e x , E n g l a n d , 1955. 45.. H.D. K a e s z , S.L. S t a f f o r d and F.G.A. S t o n e , J . Am. Chem. Soc. (1959) , 81_, 6336. 46. R.D. Chambers, H.C. C l a r k and C . J . W i l l i s , J . Am. Chem. Soc. ( 1 9 6 0 ) , 82, 5298. 47. A.B. Burg and J.R. S p i e l m a n , J . Am. Chem. Soc. ( 1 9 6 1 ) , 83_, 2667. 48. G.A. Razuvaev, N.S. V y a z a n k i n , Yu. I . Dergunov and O.S. Dyachkovskaya, D o k l . Akd. Nauk, U.S.S.R. ( 1 9 6 0 ) , 152^ 364. 49. G.A. Razuvaev, N.S. V y a z a n k i n and O.A. S h c h e p e t k o v a , T e t r a h e d r o n ( 1 9 6 2 ) , 18, 667. 50. R.N. H a s z e l d i n e , M.J. Newland and J.B. Plumb, P r o c . Chem. Soc. (1960) , 147. 51. H.C. C l a r k , S.G. F u r n i v a l and J.T. Kwon, Can. J . Chem. ( 1 9 6 3 ) , 41, 2889. 52. W. D r e n t h , M.J. J a n s s e n and\"G.J.M. van d e r K e r k , J . Or g a n o m e t a l . Chem. (1964) , _2>_ 265 . 53. R.N. H a s z e l d i n e and R . J . Marklow, J . Chem. Soc. ( 1 9 5 6 ) , 962. 54. G.M. B u r c h , H. G o l d w h i t e and R.N. H a s z e l d i n e , J . Chem. Soc. ( 1 9 6 3 ) , 1083. 55. J . F . H a r r i s , J r . and F.W. S t a c e y , J . Am. Chem. Soc. ( 1 9 6 1 ) , 83_, 840. 56. J.R. Case, N.H. Ray and H.L. R o b e r t s , J . Chem. Soc. ( 1 9 6 1 ) , 2070. 57. R.N. H a s z e l d i n e and B.R. S t e e l e , J . Chem. Soc. ( 1 9 5 7 ) , 2800. 58. R.N. H a s z e l d i n e and J.C. Young, J . Chem. Soc. ( 1 9 6 0 ) , 4503. 59. R.N. H a s z e l d i n e and B.R. S t e e l e , J . Chem. Soc. ( 1 9 5 4 ) , 923. 60. R.N. H a s z e l d i n e and J .E. Osborne, J . Chem. Soc. ( 1 9 5 6 ) , 61. 61. R.N. H a s z e l d i n e , J , Chem. Soc. ( 1 9 5 3 ) , 3565. 62. J.R. L a c h e r , J . J . M c K i n l e y , C. Walden, K. Lea and J.D. Pa r k , J . Am. Chem. Soc. ( 1 9 4 9 ) , 71_, 1334; and t h e r e f e r e n c e s c i t e d t h e r e i n . 63. R.N. H a s z e l d i n e and B.R. S t e e l e , J . Chem. Soc. ( 1 9 5 3 ) , 1592. 64. R.N. H a s z e l d i n e and B.R. S t e e l e , J . Chem. Soc. ( 1 9 5 4 ) , 3747. 184 65. J.G. N o l t e s and G.J.M. van d e r . K e r k , \" F u n c t i o n a l l y S u b s t i t u t e d O r g a n o t i n Compounds\", T i n R e s e a r c h I n s t i t u t e , M i d d l e s e x , E n g l a n d , 1958. 66. F. H e i n , H. P o b l o t h a n d E . Heuser, Z. an o r g . Chem. (1 9 4 1 ) , 248, 84. 67. A.G. D a v i e s , G. W i l k i n s o n and J . F . Young, J . Am. Chem. Soc. ( 1 9 6 3 ) , 85, 1692. 68. L.E. O r g e l , I n o r g . Chem. ( 1 9 6 2 ) , 1_, 25. 69. F.A. C o t t o n and C.S. K r a i h a n z e l , J . Am. Chem. S o c . . ( 1 9 6 2 ) , 84_, 4432. 70.. N. F l i t c r o f t , D.K. Huggins'and H.D. Ka e s z , I n o r g . Chem. ( 1 9 6 4 ) , 3_, 1123; and t h e r e f e r e n c e s c i t e d t h e r e i n . 71. A.S. K a s e n a l l y , J . L e w i s , A.R. Manning, J.R. M i l l e r , R.S. Nyholm and M.H.B. S t i d d a r d , J . Chem. Soc. ( 1 9 6 5 ) , 3407. 72. T.L. Brown and G.L. Morgan, I n o r g : Chem. ( 1 9 6 3 ) , 2:, 736. 73. K.F. W a t t e r s o n and G. W i l k i n s o n , Chem. I n d . (London) ( 1 9 6 0 ) , 1358. 74. R.B. K i n g , J . Am, Chem. Soc. ( 1 9 6 3 ) , 85_, 1918. 75. J.B. W i l f o r d and F.G.A. S t o n e , I n o r g . Chem. ( 1 9 6 5 ) , A, 93. 76. R.F. Heck and D.S. B r e s l o w , J . Am. Chem. Soc. ( 1 9 6 1 ) , 83_, 1097. 77. H.C. C l a r k , J.H. T s a i and W.S. Ts a n g , Chem. Comm. ( 1 9 6 5 ) , 171. 78. P.W. J o l l y and F.G.A. S t o n e , Chem. Comm. ( 1 9 6 5 ) , 86. 79. R.N. H a s z e l d i n e and J.C. Young, P r o c . Chem. Soc. ( 1 9 5 9 ) , 394. 80. T.L. C o t t r e l l , \"The S t r e n g t h s o f C h e m i c a l Bonds\", B u t t e r w o r t h s S c i e n t i f i c P u b l i c a t i o n s , London, 1958. 81. T.H. C o f f i e l d , J . K o z i k o w s k i and R.D. C l o s s o n , Chem. Soc. (London) Spec. Pub l . . ( 1 9 5 9 ) , 13_, 126. 82. R.D. C l o s s o n , J . K o z i k o w s k i and T.H. C o f f i e l d , J . Org. Chem. ( 1 9 5 7 ) , 22_, 598. 83. (a) F. C a l d e r a r r o and F.A. C o t t o n , I n o r g . Chem. ( 1 9 6 2 ) , 1_, 30. (b) F. C a l d e r a z z o and F.A. C o t t o n , P r o c . 7 t h I n t e r n . Conf. C o o r d . Chem.,, S t o c k h o l m (1962) . 84. W. H i e b e r and G. Wagner, Ann. Chem. ( 1 9 5 8 ) , 618, 24. 85. W. H i e b e r , G. Braum and W. Beck, Chem. B e r . ( 1 9 6 0 ) , 91, 901. 86. H.P. K o g l e r and E.O. F i s c h e r , Z. N a t u r f o r s c h g . ( 1 9 6 0 ) , 15b, 676. 185 87. E.O. F i s c h e r and K. O f e l e , Angew. Chem. ( 1 9 6 1 ) , 73, 581. 88. R . J ; O ' B r i e n , Ph.D. T h e s i s , U .B .C., 1963; and t h e r e f e r e n c e s c i t e d t h e r e i n . 89. H.C. C l a r k , R . J . O ' B r i e n and J . T r o t t e r , J . Chem. Soc. ( 1 9 6 4 ) , 2332. 90. R. Okawara, D.E. Webster and E.G. Rochow, J . Am. Chem. Soc. ( 1 9 6 0 ) , 82, 3287. 91. W.F. E d g e l l a n d C . H . Ward, J . Am. Chem. Soc. ( 1 9 5 5 ) , 77_, 6486. 92. S.L. S t a f f o r d and F.G.A. S t o n e , S p e c t r o c h i m . A c t a (1961) , 17_, 412. 93. E; P i t c h e r and F.G.A. S t o n e , S p e c t r o c h i m . A c t a ( 1 9 6 1 ) , L7, 1244. 94. E. P i t c h e r and F.G.A. S t o n e , S p e c t r o c h i m . A c t a ( 1 9 6 2 ) , 18_, 585. 95. D.C. S m i t h , R.A. S a u n d e r s , J.R. N i e l s e n and E.E. F e r g u s o n , J . Chem. Phys. ( 1 9 5 2 ) , 20, 847. 96. J.R. N i e l s e n , C.Y. L i a n g , R.M. Sm i t h and D.C. S m i t h , J . Chem. Phys. (1953) , 21_, 383. 97. D.W. M c B r i d e , E. Dudek and F.G.A. S t o n e , J . Chem. Soc. ( 1 9 6 4 ) , 1752. 98. H.C. C l a r k and D. Whyman, P r o c . 2nd I n t e r n . M e e t i n g F l u o r i n e Chem. E s t e s P a r k , C o l o r a d o , 1962. 99. P.M. T r e i c h e l , E. P i t c h e r and F.G.A. S t o n e , I n o r g . Chem. ( 1 9 6 2 ) , 1,. 511: 100. P.M. T r e i c h e l , J.H. M o r r i s and F.G.A. S t o n e , J . Chem. Soc. ( 1 9 6 3 ) , 720. 101. J.B. W i l f o r d , P.M. T r e i c h e l and F.G.A. S t o n e , J . Org a n o m e t a l . Chem. ( 1 9 6 4 ) , 2, 119. 102. D.G. W e i b l e n , F l u o r i n e C h e m i s t r y , 2_, e d i t e d by J.H. Simons, Academic P r e s s , N.Y., ( 1 9 5 4 ) , p. 449-501. 103. W.F. E d g e l l and C.H. Ward, J . M o l . S p e c t r o s c o p y ( 1 9 6 2 ) , 8_, .343. 104. J.A. P o p l e , W.G. S c h n e i d e r and H.J. B e r n s t e i n , \" H i g h - r e s o l u t i o n N u c l e a r M a g n e t i c Resonance\", McG r a w - H i l l , : N.Y., '1959. 105. H.C. C l a r k , J.T. Kwon, L.W. Reeves•and E . J . W e l l s , Can. J . Chem. (1963) , 41_, 3005. 106. A.L. A l l r e d and E.G. Rochow, J . I n o r g . N u c l . Chem. ( 1 9 5 8 ) , 5_, 269. 107. M.P. Brown and D.E. Webster, J . Phys. Chem. ( 1 9 6 0 ) , 64_, 698. 108. R . J . Abraham and L. C a v a l l i , M o l . Phys. ( 1 9 6 5 ) , 9, 67. 186 109. D.D. E l l e m a n , L.C. Brown.and D. W i l l i a m s , J . M o l . . S p e c t r o s c o p y , (1961) , ]_, 307. 110. D.D. E l l e m a n , L.C. Brown and D. W i l l i a m s , J . M o l . S p e c t r o s c o p y ( 1 9 6 1 ) , ]_, 322. 111. J . J . D r y s d a l e and W.D. P h i l l i p s , J . Am. Chem. Soc. ( 1 9 5 7 ) , 79_, 319. 112. , J . Lee and L.H. S u t c h i f f e , Trans. F a r a d a y Soc. ( 1 9 5 8 ) , 54, 308. 113. D. S e y f e r t h , T. Wada and G.E. M a c i e l , I n o r g . Chem. ( 1 9 6 2 ) , 1_,-232. 114. A.H. L e w i n , J . Am. Chem. Soc. (1964),.86, 2303. 115. S. Ng and £.H; Sederholm, J . Chem. Phys. ( 1 9 6 4 ) , 4£, 2090; and t h e preferences c i t e d t h e r e i n . 116. W.D. P h i l l i p s , J . Chem. Phys . ( 1 9 5 6 ) , 25, 949. 117. G.V.D. T i e r s , J . Am. Chem. Soc. ( 1 9 5 6 ) , 78, 290. 118. D.M. Adams, J . Chem. Soc. ( 1 9 6 4 ) , 1771. 119. W.F. E d g e l l , I n t e r n a t i o n a l Symposium on F a r I n f r a r e d S p e c t r o s c o p y , C i n c i n n a t i , . O h i o , 1962. 120. J.B. W i l f o r d and F.G.A. S t o n e , I n o r g . Chem. ( 1 9 6 5 ) , 4_, 389. 121. F.A. C o t t o n , I n o r g . Chem. ( 1 9 6 4 ) , _3> 702. 122. R. Mason andD.R. R u s s e l l , Chem. Comm. ( 1 9 6 5 ) , 182. 123. J.B. W i l f o r d and F.G.A. S t o n e , J . Org a n o m e t a l . Chem. ( 1 9 6 4 ) , 2_, 371. 124. J . C h a t t and L.A. Duncanson, J . Chem. Soc. ( 1 9 5 3 ) , 2939. 125. C.C. B a r r a c l o u g h , J . Lewis and R.S. Nyholm, J . Chem. S o c ( 1 9 6 1 ) , 2582. 126. W.D. H o r r o c k s , J r . and R.H. Mann, S p e c t r o c h i m . A c t a ( 1 9 6 5 ) , 21_, 399. 127. D.E. Mann, N. A c q u i s t a and E.K. P l y l e r , J . Chem. Phys. ( 1 9 5 4 ) , 22_, 1199; and t h e r e f e r e n c e s c i t e d t h e r e i n . 128. D.E. Mann, N. A c q u i s t a and E.K. P l y l e r , J . Chem. Phys. ( 1 9 5 4 ) , 22_, 1586; 129. R.N. H a s z e l d i n e , J . Chem. Soc. ( 1 9 5 3 ) , 3559. 130. R.B. K i n g and M.B. B i s n e t t e , J . Organometal. Chem. ( 1 9 6 4 ) , 2_, 15. 131. W. B r u g e l , \"An I n t r o d u c t i o n t o I n f r a r e d S p e c t r o s c o p y \" , t r a n s l a t e d by A.R. K a t r i t z k y and A.J.D. K a t r i t z k y , J o h n W i l e y and Sons, I n c . , N.Y., 1962. 132. A.N. Nesmeyanov, A.E. B o r i s o v and A . I . B o r i s o v , I z v . Akad. Nauk, \" U.S.S.R., O t d . Khim, Nauk ( 1 9 6 2 ) , 1199. 187 133. W.R. C u l l e n , D.S. Dawson and G;E. S t y a n , Can. J . Chem. ( 1 9 6 5 ) , i n p r e s s . 134. H.C. C l a r k , J.T. Kwon, L.W. Reeves and E . J . W e l l s , C a n . J . Chem. ( 1 9 6 4 ) , 42, 941. 135. H.C. C l a r k , J.T. Kwon, L.W. Reeves and E . J . W e l l s , I n o r g . Chem. ( 1 9 6 4 ) , Z, 907. 136.. H. Schmidbaur and I . R u i d i s c h , I n o r g . . Chem. ( 1 9 6 4 ) , 3_, 599. 137. H. Schmidbaur, J . Am. Chem. Soc; ( 1 9 6 3 ) , 85_, 2336. 138. N.F. Ramsey, Phys. Rev. ( 1 9 5 3 ) , 91_, 303., 139. J.R. Holmes and H.D. K a e s z , J . Am. Chem. Soc. ( 1 9 6 1 ) , 83, 3903. 140. . L. P a u l i n g , \"The N a t u r e o f t h e C h e m i c a l Bonds and t h e S t r u c t u r e o f M o l e c u l e s and C r y s t a l s \" , C o r n e l l U n i v e r s i t y P r e s s , I t h a c a , N.Y., 1960. 141. B.T. K i l b o u r n and H.M. P o w e l l , Chem. I n d . (L o n d o n ) , ( 1 9 6 4 ) , 1578. 142. F.A. C o t t o n , I n o r g . Chem. ( 1 9 6 5 ) , 4_, 334. 143. E. P i t c h e r , A.D,. Buckingham and F.G.A. S t o n e , J . Chem. Phys. ( 1 9 6 2 ) , 36, 124. 144. H.M. M c C o n n e l l , C A . R e i l l y and A.D. McLean, J . Chem. Phys. ( 1 9 5 6 ) , 24_, 479. 145. T.D. Coyle, S.L.. S t a f f o r d and F.G.A. S t o n e , J . Chem. Soc. ( 1 9 6 1 ) , 743. 146. G.V.D. T i e r s , J . Chem. Phys. ( 1 9 6 2 ) , 36_, 1110. 147. J.D. Swalen and C A . R e i l l y , J . Chem. Phys. ( 1 9 6 1 ) , 34, 2122. 148. T.D. C o y l e , S.L. S t a f f o r d and F.G.A. S t o n e , S p e c t r o c h i m . A c t a ( 1 9 6 1 ) , 17, 968. 149. W.L. J o l l y , \" S y n t h e t i c I n o r g a n i c C h e m i s t r y \" , P r e n t i c e - H a l l , .Inc., ' N.J., 1960. 150. J.B. P e d l e y , H.A. S k i n n e r and C L . C h e r n i c k , T r a n s . F a r a d a y Soc. (1957) , 5J5, 1612. 151. B. Bak and D. C h r i s t e n s e n , S p e c t r o c h i m . A c t a ( 1 9 5 8 ) , 1_2, 355. 152'. A.D. B e v e r i d g e , H.C C l a r k and J.T. Kwon, Ca n . J . Chem. ( 1 9 6 5 ) , i n p r e s s . "@en ; edm:hasType "Thesis/Dissertation"@en ; edm:isShownAt "10.14288/1.0062217"@en ; dcterms:language "eng"@en ; ns0:degreeDiscipline "Chemistry"@en ; edm:provider "Vancouver : University of British Columbia Library"@en ; dcterms:publisher "University of British Columbia"@en ; dcterms:rights "For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use."@en ; ns0:scholarLevel "Graduate"@en ; dcterms:title "Some reactions of metal-metal bonds with fluoro-olefins"@en ; dcterms:type "Text"@en ; ns0:identifierURI "http://hdl.handle.net/2429/37632"@en .