A New Type of Copolymer

Abstract

TRIFLUORONITROSOMETHANE, a deep blue monomeric gas^1,2, combines quantitatively with tetrafluoroethylene in the dark at − 45° to give perfluoro-2-methyl-1 : 2-oxazetidine, (30 per cent), and an involatile colourless viscous oil (65 per cent). The oil is insoluble in the common organic solvents, and is unaffected by hot concentrated sulphuric acid or hot concentrated aqueous potassium hydroxide; its infra-red spectrum fails to show the presence of groups such as N : O, NO₂, , ONO, ONO₂, C : C, N : N or C : N. The oil has the same empirical formula as perfluoro-2-methyl-1 : 2-oxazetidine, C₃NOF₇, showing a 1 : 1 ratio of trifluoronitrosomethane to tetrafluoroethylene. The oil is in fact a 1 : 1 copolymer of the reactants, formed by an ionic mechanism favoured by low temperatures: The formation of perfluoro-2-methyl-l : 2-oxazetidine from the intermediate is also readily visualized by this mechanism. Chain termination in the polymer might involve disproportionation to give NF(CF₃) and CF : CF₂ end-groups.