Electron spin resonance spectra of trigonal-prismatic bis[pentane-2,4-dione benzoylhydrazonato(2—)]vanadium(IV) and bis[4-phenylbutane-2,4-dione benzoylhydrazonato(2—)]vanadium(IV)

Abstract

The e.s.r. spectra of the trigonal-prismatic title complexes have been recorded. The spectra show axial symmetry and are characterised by g_∥= 2.00 and g_⊥= 1.956 and g_∥= 2.00 and g_⊥= 1.971 respectively. Analysis of the values of the hyperfine coupling to vanadium, namely A_∥= 22 G and A_⊥= 138 G, indicates that the unpaired electron is mainly (92 and 95%) in a metal d_z² orbital. On addition of acids the complexes decompose to [VO]²⁺ions.