Reactions of vanadium(V) oxide tribromide: preparation and properties of complex oxobromovanadates(IV)

Abstract

The reactions of VOBr₃ with various ionic bromides, acetonitrile, nitromethane, and ferrocene are reported. The following new complexes were prepared and their structure investigated: (Et₄N)₂[VOBr₄], (pyH)[VOBr₃], (pyH)[VOBr₃(CH₃CN)₂], (pyH)₂[VOBr₄], (quinH)₃[VOBr₅], [Fe(cp)₂][VOBr₃], and VOBr₂(CH₃CN)₃(py = pyridine, quin = quinoline, and cp =π-cyclopentadienyl). The first detailed study of the far-i.r. spectra of vanadium(IV) oxide dibromide complexes is reported, and evidence for a novel reversible transformation between C_2v and C_4v symmetry for the [VOBr₄]^2– anion is presented.