Electronic Structure, Spectra, and Magnetic Properties of Oxycations. V. The Electronic Spectra of Some Vanadyl Complexes

Abstract

The observation of four low‐intensity absorption bands below 20 000 cm—1 for the C 2v molecule vanadyl bisacetylacetonate is verified and four such bands are reported for C 4v vanadyl species. The likelihood of these four bands representing the whole of the d—d series and the plausibility of understanding the splitting of the crystal field levels in the C 4v molecules in terms of a spin—orbit coupling mechanism is discussed. The time course of the oxidation V(iv) to V(v) has been followed spectrally; the results identify the d—d series of transitions and suggest that the ∼25 000 cm—1 transition is charge transfer in nature. The paper should be regarded as a critique of two alternative energy‐level schemes of the vanadyl ion, that scheme which is proposed herein being heavily favored by the arguments presented.