3866
i0ns,3~a result which contrasts with observations in the present study. Another question which remains unsettled is the following. Do the pathways for solvolysis of trans2+ with transition states of net (H20)4Cr(OS(CH3)2)I charge 2+ and 1+ yield intermediates which are in rapid equibrium with one another? Regrettably the form of the equation giving the hydrogen ion dependence of the ratio of the isomeric (H20)4Cr(OS(CH3)2)23+ products is the same whether independent intermediates are produced or a rapidly established proton dissociation-association equilibrium of the intermediates exists, giving a common pool of intermediates which go on to yield bis(dimethy1 sulfoxide)chromium(III) products regardless of the pathway by which the intermediates are formed. The equation relating [cis-Cr(OS(CH3)2)2 "+I/[tran~-Cr(OS(CH3)~)2 3+] to [H+] has the form [ci~-Cr(0S(CH3)&~+]- A[H+] [trans-Cr(OS(CH3)~)~~+] - C[H+]
+B +1
The uncorrected data presented in Table I1 are correlated with this equation with the parameters A = 10.1 1. mol-1, B = 2.0, and C = 48 1. mol-'. The (33) D. W. Hoppenjans, G. Gordon, and J. R. Hunt, Inorg. Chem., 10,754 (1971).
parameter B (2.0) can be compared with A/C (0.21). Each of these is the ratio of rate constants for formation of the cis isomer compared to the trans isomer; B is the ratio for the case where the precursor contains hydroxide ion, and A / C is the ratio for the case where the precursor does not contain hydroxide ion. The cis product is formed more readily from the precursor containing hydroxide. (This qualitative conclusion would not be altered by use of corrected values of the product ratio.) The limited data (Table 11) showing an appreciable dependence of the relative yields of the isomeric bis(dimethyl sulfoxide)chromium(III) products upon the ionic strength reveal additional complexity in this system. Perchlorate ion appears to play a role in the reaction. Presumably this is due to an intermediate containing perchlorate ion, either iodoperchloratochromium(II1) or perchlorato(dimethy1su1foxide)chromium(111) ion, 34 which produces relatively more trans bis product . Acknowledgment. The authors acknowledge preliminary experiments on some aspects of this study by Dr. S. P. Ferraris in 1969-1970. (34) D. M. Jones and J. Bjerrum, Acto Chem. Scond., 19,974 (1965), have shown the existence of an inner-sphere perchloratochromium(I1) in concentrated perchloric acid.
Reactions of Bis( trifluoromethyl) Trioxide' Frederick A. Hohorst, Darryl D. DesMarteau,* L. R. Anderson, D. E. Gould, and W. B. Fox Contributionfrom the Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, and The Industrial Chemical Laboratory, Allied Chemical Corporation, Morristown, New Jersey 07960. Received October 2,1972 Reactions of bis(trifluoromethy1) trioxide, CFaOOOCFs,with a variety of inorganic compounds are described. The trioxide is shown to be a convenient source of compounds containing CFaO- and CFaOO- groups. Improved syntheses of the previously reported CF30NF2,CF300S02F,and (CFa0)SF4are described, and the new compounds CF,00S020CF3,cis-CF300SFdOCF3,and CF300C(0)OCF,are reported. Abstract:
P
erfluoroalkyl trioxides are the only catenated oxygen compounds of the type sufficiently stable for isolation and study in the pure state under ambient conditions. The four known examples are CF3000CF3,2.3CF3OOOC2F5, C2F5000C2F5,and CF3000CF200CF3. Based on the chemistry of peroxides, trioxides are expected to behave similarly with facile cleavage of the 0-0 bonds forming RtO. and RfOO. radicals. Because of its symmetry, availability, and the decreasing stability of higher perfluoroalkoxy radicals, CF30 0 0 C F 3 is the most suitable trioxide for study in order to provide information on the chemistry of these novel calSociety, New York, N. Y., Aug 27-Sept 1, i972. (2) L. R. Anderson and W. B. Fox, J . Amer. Chem. Soc., 89, 4313 (1967) ~.~ -.
(3)'P. G. Thompson, J . Amer. Chem. Soc., 89,4316 (1967). (4) I. J. Solomon, Li. S . COG.Res. Deoelop. Rep., 70, 71 (1970). ( 5 ) D. D. DesMarteau, Inorg. Chem., 9,2179 (1970).
Journal of the American Chemical Society 1 95:12
materials. In this paper reactions of C F 3 0 0 0 C F 3 with a variety of inorganic substrates are reported. Convenient syntheses of the previously known CF3ONF2,BS7CF300SOzF,8 and (CF30)SF49~10 are given and the new compounds CF300S020CF3,CFaOOSF4OCF,, and CF300C(0)OCFBare reported.
Results and Discussion Bis(trifluoromethy1) trioxide is a convenient chemical source of both CF,O- and CF300- moieties; its reactions with S206F2,NzF4, and SO3 yield CFaOderivatives exclusively, while reactions with SF4, SOZ, 1516(1965). (7) W. H. Hale and S. M. Williamson, Inorg. Chem., 4,1342 (1965). (8) W. P. Van Meter and G. H. Cady, J . Amer. Chem. SOC.,82,6005 (1960).
June 13, 1973
(9) C. I. Merrill and G. H. Cady, J. Amer. Chem. SOC.,85,909 (1963). (10) L. C. Duncan and G. H. Cady, Inorg. Chem., 3,850 (1964).
3867
0 0 N 0 2 , 1 2CF300POF2,and CF30POF213and may be common for other CF30- and CF300- derivatives. In nearly all cases C F 3 0 0 X Fis formed in greater amounts than CF30XF, which is consistent with the fact that CF30NO2 is unknown and that CF3OOPOFz has greater thermal stability than CF3OPOFz. However, CFaOOOCFs +CFaOO. + CFaO. C F 3 0 0 X . and CF30X. may also react with F. donors CFaOO. + CFaOO. +CFaOOCFa + 01 present among the intermediates of these reactions and CFaO. + CFaO. +CFaOOCFa thus could be formed directly. The identities of the new compounds CF300S02and the reaction chemistry of C F 3 0 0 0 C F 3is that of OCF3, CF300SF40CF3,and CF300C(0)OCF3 are C F 3 0 . and C F 3 0 0 . radicals. The relatively inert convincingly established by the data given in the peroxide, CFaOOCF3, formed in decomposition has Experimental Section. Their ir spectra, though unique, little importance in the chemistry of the trioxide as it has are in all cases sufficiently similar to those of the previously been shown not to react with most of the corresponding (CF30)2X compounds so that assignsubstrates under these conditions. The high yield of the known compounds CF3ONFZ6Jand CF300S02F8 ments for the majority of the bands may be made by simple comparisons. The nmr spectra of these new derived from reactions of the trioxide with N2F4 and peroxy compounds are particularly revealing in that all SzOeFz probably involve C F 3 0 radicals combining show two distinct CF3 peaks of equal area which can with the NFz. and F S 0 3 . radicals known to arise from be assigned unambiguously to OCF3 ($* = 5 8 ) and the symmetrical homolytic scission of these reactants. OOCF3 ($* 68).3,5,14 No evidence could be found for the compounds The nmr spectrum of cis-CF300SF40CF3 is of CFaOONFzand C F 3 0 0 0 S O z Fthat would result from special interest because there appear to be three types simple combination of C F 3 0 0 . with NF2. and FSOa.. of fluorines attached to sulfur. We therefore postulate This implies that either C F 3 0 0 . has a short lifetime the structure CF3EOOSFZB(F)A(F)COCF3D where fluounder the conditions of the experiments or that the rines E and D are cis to each other and trans to A and C, peroxy products are unstable. With SF4, both (CF30)2SF46p10 and CF300SF40CF3 respectively. The fluorines within each CFa group are equivalent and do not couple with that sulfur fluorine are formed, but no (CF300)2SF4is observed. Simwhich is trans to the group or with the other CF3 group. ilarly, (CF30)2C0 and CF300C(0)OCF3 are formed Coupling to the remaining three fluorines on sulfur is with CO as are (CF30),SOz and C F 3 0 0 S 0 2 0 C F 3with identical and results in splitting of each CF3 peak into SOz. The following reaction scheme is proposed to 1 :3 :3 :1 quartets. Limitations on storage prevented explain the products (X = SOz, SF4, or CO). complete computer analysis of the system; however, A CFaOOOCFa +CFaO. + CFaOO. the calculated splitting for the SF4 group, as plotted by (1) the computer, is shown in Figure 1C. Each peak CFaOO. + M +CFaO. + '/zOz + M* (2) shown there is subsequently split by one or both CFa CFaOO. + X +CFaOOX. (3) groups to give the experimental spectrum shown in CFaO. + X +CFaOX. (4) Figure 1B. The similarity of the nmr spectrum of this compound to that of cis-CF30SF4NFz is readily CFsOOX. + CFaOOOCFa +CFaOOXOCFa + CFsOO. ( 5 ) apparent, even though the latter could not be analyzed CFaOX. + CFaOO0CFa +CFaOXOCFa + CFaOO. (6) completely because the chemical shift of FC and FB's CFaOOX. + CFsO. +CFiOOXOCFa (7) were nearly identical. l5 CFaOX. + CFsO* +CFaOXOCF3 (8) In conclusion, C F 3 0 0 0 C F 3is perhaps the best single source of compounds containing CF30- and CF300CFaO. + CFaO. +CFaOOCFa (9) groups. When reaction does occur, products conWe visualize [CF3OO.] < [CF30.]
