Preparation of tetrabromotetrachloroperfluorododecanes

Abstract

A substantially pure mixture of tetrabromotetrachloroperfluorododecanes of the empirical formula C.sub.12 Br.sub.4 Cl.sub.4 F.sub.18, of which the isomer ##STR1## is a significant part, is prepared by oligomerizing bromotrifluoroethylene in the presence of chlorine and distilling, thereby obtaining a substantially pure mixture of trimers of the empirical formula C.sub.6 Br.sub.3 Cl.sub.2 F.sub.9, of which the isomer ##STR2## is a significant part and reacting the trimer mixture with zinc in the presence of acetic anhydride to form a perhalododecane. The product is especially useful as a gyroscopic flotation fluid because of its stability, homogeneity and density.

Dependencies are inferred from the claim text.