Halides and oxide halides of molybdenum and tungsten. II. Magnetic evidence for trinuclear clusters in tungsten(V) halides

Abstract

The magnetic properties of tungsten pentachloride, WCl₅, and tungsten pentabromide, WBr₅, have been re-examined as a function of temperature. The anomalous magnetic moment of each compound is rationalized on the basis of trinuclear clusters of tungsten atoms in the compounds. Evidence is presented for the presence of one ionic halide atom per molecular weight, the compounds thus being formulated as [W₃X₁₂]³⁺X₃^-.