SYNTHESIS AND CHARACTERISATION OF A NEW NIOBATE COMPLEX WITH CHROMIUM(III)

Abstract

A new hexaniobate complex with chromium(III) was prepared and characterised by analytical and spectroscopic techniques. The compound is a violet, non-crystalline solid, formulated as Cr₂(μ-OH)(H₃Nb₆O₁₉)(en)₃(H₂O)]. It was synthesised in aqueous solution by reaction of Cr(en)₃]³⁺, en = ethylenediammine, with the hexaniobate anion Nb₆O₁₉]^8-, at pH 8. Thermal decomposition yielded a mixture of CrNbO₄ and Nb₂O₅. The synthesis of this compound shows that the hexaniobate anion may form complexes at lower pH values than previously reported.