Formation and characterization of uranium(VI) chloride fluorides,UFnCl6–n(n= 1–5)

Abstract

Fluorine-19 n.m.r. measurements show that UF₆ undergoes facile halide exchange with either SiMe₃Cl or UCl₆ in CFCl₃ or CF₂Cl₂ solution at temperatures below –60 °C. Hence all the uranium (VI) chloride fluorides in the series UF_nCl_6-n(n= 1–5) have been characterized virtually definitively. The visible and mass spectra of the mixed halides have been investigated also. Unlike UF₆ and UCl₆, the mixed halides decompose at temperatures above –60 °C liberating chlorine gas and giving halides of uranium(IV) or uranium(V).