ChemInform Abstract: Synthesis and Characterization by Raman Spectroscopy of AsBr4AsF6; Its Thermodynamic and Kinetic Stability and that of Related Salts.

Abstract

Synthesis and Characterization by Raman Spectroscopy of AsBr4AsF6; Its Thermodynamic and Kinetic Stability and that of Related Salts.-The title compound is prepared by oxidation of AsBr3 and Br2 by AsF5, as outlined in the scheme. Characterization of the thermodynamically and kinetically unstable salt by using Raman spectroscopy at -196 . degree.C shows that its decomposition to AsF3 and Br2 follows a course via AsBr3. Attempts to prepare the more stable AsBr4AlBr4 by reaction of stoichiometric amounts of AsBr3, Br2 and AlBr3 fail. The viscous liquid obtained is shown to be an equilibrium mixture of AsBr4AlBr4 with AsBr3, Br2, and AsBr4Al2Br7. The low stability of AsBr4AsF6, contrasting with that of AsCl4AsF6, is discussed in terms of a simple energetics model. -(KLAPOETKE, T.; PASSMORE, J.; J. Chem. Soc., Dalton Trans. (1990) 12, 3815-3822; Dep. Chem., Univ. New Brunswick, Fredericton, New Brunswick, Can. E3B 6E2; EN)