Formation of 2,3-epoxyperfluoropropionylfluoride from the mercury photosensitized oxidation of 1,3-perfluorobutadiene

Abstract

The mercury photosensitized oxidation of 1,3-C,F, gives nearly equal amounts of C F 2 0 and a new compound 2,3-epoxyperfluoropropionylfiuoride and smaller amounts of c-C3F4. The infrared (i.r.) and mass spectra of 2,3-epoxyperfiuoropropionylfluoride are presented.Canadian Journal of Chemistry, 47, 2329 (1969) We wish to report the synthesis and identifica-under all operating conditions, though their tion of 2,3-epoxyperfluoropropionylfluoride (I) absolute quantum yields varied markedly. Perfluorocyclopropene, which has been described /O\ ,Yo previously (2), is produced in smaller quantities.

Relative Rate and Product Studies of the Reactions of Atomic Chlorine with Tetrafluoroethylene, 1,2-Dichloro-1,2-difluoroethylene, 1,1-Dichloro-2,2-difluoroethylene, and Hexafluoro-1,3-butadiene in the Presence of Oxygen

“…One is CF 2 O, and the other is the epoxy compound OCF 2 CFC­(F)O where the first O atom is bonded to both of the first two C atoms. This 2,3-epoxyperfluoro­propionyl­fluoride species has been noted before in the mercury-sensitized photolysis of O 2 /CF 2 CF–CFCF 2 mixtures . The published IR spectrum is of low resolution.…”

“…We can speculate about the mechanism leading to the epoxy product. Stuckey et al 35 suggested that in their mercurysensitized O 2 /C 4 F 6 system energy was transferred first to O 2 and then to C 4 F 6 , which then reacted with O 2 to yield triplet Here we note that Cl-catalyzed chemistry of the kind proposed above could accomplish the same transformation, which we illustrate in Figure 8. We can imagine two pathways from a possible ketone intermediate to the final epoxy product.…”

“…This 2,3-epoxyperfluoropropionylfluoride species has been noted before in the mercury-sensitized photolysis of O 2 /CF 2 CF−CFCF 2 mixtures. 35 The pub-lished IR spectrum is of low resolution. Accordingly, we prepared a sample photochemically via UV photolysis for 1.5 h of a mixture of 0.7 mbar of CF 2 CF−CFCF 2 , 4 mbar of O 2 , and 1.6 mbar of Cl 2 , which was then put through freeze− pump−thaw cycles at 77 and 195 K. The spectrum is shown in Figure 7.…”

“…We can speculate about the mechanism leading to the epoxy product. Stuckey et al suggested that in their mercury-sensitized O 2 /C 4 F 6 system energy was transferred first to O 2 and then to C 4 F 6 , which then reacted with O 2 to yield triplet CF 2 and the diradical CF 2 CFCF­(F)­OO, which might rearrange by either of two pathways to the final product. Here we note that Cl-catalyzed chemistry of the kind proposed above could accomplish the same transformation, which we illustrate in Figure .…”