Aqueous vanadosilicates

Abstract

Silicate anions were shown by ⁵¹V and ¹⁷O NMR spectroscopy to combine with aqueous [HVO₄]^2– in aqueous alkaline solution, forming the anions [H₂VSiO₇]^3–, [H₃VSiO₇]^2– and various related monovanadooligosilicate species. Approximate equilibrium constants have been derived, and shown to depend only weakly upon ionic strength. The ion [H₂VSiO₇]^3– at higher concentrations also dimerises to give an anion with a SiOVOVOSi linkage, as shown by selective inversion-transfer subtraction spectra.