Synthesis and physico-chemical studies of newer mono and diperoxo heteroligand complexes of vanadium

Abstract

The synthesis of monoperoxo-vanadium(V) complexes, [VO(O₂)QL] (Q = 8-quinolinolate and L = EtOH, DMF, DMSO, or THF), and diperoxovanadates(V), A₃[VO(O₂)₂(HPO₄)].2H₂O (A = K or NH₄) are described. While the [VO(O₂)QL] complexes have been synthesized from the reaction of V₂O₅ with H₂O₂ and a solution of 8-quinolinol in different donor solvents (L) at pH ca. 2, the oxodiperoxo(hydrophosphato) vanadate(V) dihydrates, A₃,[VO(O₂)₂(HPO₄)].2H₂O, have been prepared from the reaction of V₂O₅ with H₂O₂ and phosphoric acid at pH 6 of the reaction medium. The compounds have been characterized by chemical analyses, magnetic susceptibility, and molar conductance measurements, and by IR, laser Raman, ¹H NMR, and electronic spectroscopic studies. Evidence has been provided for triangularly bonded peroxide (O₂^2-) and coordinated heteroligands. The existence and stability of the complex [VO(O₂)₂(HPO₄]^3- in solution have been ascertained from solution Raman spectroscopy and conductance measurements.