Vanadyl compounds coordination complexes

A range of coordination complexes of has been prepared in which the vanadyl group is absent, a number of these compounds being synthesized as part of an effort to understand the nature of biological vanadium sites, such as amavadin," which contains an octadentate, hydroxyiminodipropionate ligand bound to vanadium A number of model complexes of this type have been prepared and discussion of this area can be found in the article Vanadium in Biology Further discussion in this section follows the main ligand donor atom to vanadium. 

This oxidation state is the most stable under ordinary conditions.353 Important compounds contain the V02+ unit (vanadyl(IV) ion or oxovanadium(IV) ion), which can persist through a variety of reactions and is considered the most stable oxycation of the first row transition ions.354 It forms stable anionic, cationic and neutral complexes with all types of ligands, and has one coordination position occupied by the vanadyl oxygen (Figure 15). 

---