51V FT-nmr investigations of metavanadate ions in aqueous solutions

Abstract

51V-nmr chemical shifts, line widths, and area ratios obtained for various vanadium(V) species in aqueous solutions as a function of counter ion, pH, and analytical vanadium concentration changes are reported. From these data the eight vanadium(V) species shown to be present in significant amounts are identified. In the pH range 8.5 to 7.0, 51V-nmr resonances were observed at 574 ppm and 582 ppm. The 574 ppm resonance is assigned to both V3O93− and V4O124− while the 582 ppm resonance has been assigned to the V6O174− species. The suggestion that tetra alkyl ammonium cations stabilize V4O124− species in solution is confirmed.