SYNTHESIS, SPECTRAL PROPERTIES AND REDOX BEHAVIOR OF OXOVANADIUM(IV) COMPLEXES WITH TETRAAZA[14]ANNULENES

The preparation of a number of new oxovanadium(IV) complexes of gamma-substituted tetraaza[14]annulenes using a template synthesis is reported. The relative merits of this method compared to previously reported methods for related compounds are discussed. The oxovanadium(IV) complexes show FAB mass spectra with prominent parent peaks as the only ions and a V=O stretching band is observed around 950 cm-1 in the IR spectra. The electronic spectra show two peaks in the range 500-400 nm attributed to CT and pi-pi* transitions. Cyclic voltammetry studies, concentrating on the oxidative behaviour of the complexes, show at least one reversible oxidation for each of the derivatives.