Peroxo-complexes: triperoxovanadates(V) complexes

Triperoxovanadates of the type MI[V(O–O)3(AA)],nH2O and MI3[V(O–O)3(AA)′],H2O [M1= NH4, K or Na;(AA)= phen or bipy; (AA)′= C2O4(phen = 1,10-phenanthroline, bipy = 2,2′-bipyridyl)] have been prepared by reaction of the ligands with solutions of metavanadates in hydrogen peroxide. The molar conductivities of these salts in aqueous solution show the presence of 1 : 1 and 3 : 1 electrolytes. The existence, splitting, and shift of some i.r. bands including, in the 550–650 cm–1 region, bands assigned to the [graphic omitted] group show that the peroxophen, bipy and oxalato-groups are co-ordinated as bidentate ligands. U.v. spectra, magnetic susceptibilities, and an X-ray analysis are also reported. These complexes, in which the vanadium is probably eight-co-ordinate, are compared with the corresponding niobium and tantalum derivatives.