The preparation and some physical properties of osmium oxide pentafluoride, OsOF5

Abstract

The emerald green solid, OsOF₅, m. p. 59·2, b. p. 100·6°, is the major product of the fluorination of osmium dioxide. Vapour pressure–temperature relationships for the compound are: 32–59°(solid), log P_mm=–2266//_T+ 9·064; 59–105°(liquid), log P_mm=–1911//_T+ 7·994. The solid is dimorphic being orthorhombic below the transition point of 32·5° and body centred cubic, a= 6·14 Å, above it. It is paramagnetic and the susceptibility obeys the Curie-Weiss law approximately, with θ=+6°, the temperature independent magnetic moment being, µ= 1·47 B.M. The infrared spectrum of OsOF₅(gas) is similar to that of ReOF₅(gas) and is consistent with C_4v molecular symmetry.