Delocalization and exchange effects in high-nuclearity vanadium clusters

A model is worked out for the interpretation of the magnetic properties of polyoxovanadium clusters, containing both localized and delocalized vanadium(IV). The role of exchange and delocalization is worked out parametrically for two model systems containing four localized and two and four delocalized vanadium(IV) over eight sites respectively. The effect of vibronic coupling is also taken into account.