Aqueous isopolymolybdates(VI): an oxygen-17 and molybdenum-95 nuclear magnetic resonance study

Abstract

Aqueous molybdenum(VI) has been studied between pH 6 and 1.2 by ¹⁷O and ⁹⁵Mo n.m.r. spectroscopy. Heptamolybdate, [Mo₇O₂₄]^6–, its monoprotonated form, and β-octamolybdate, [Mo₈O₂₆]⁴, are clearly identified, and evidence has also been found for an intermediate species [H₃Mo₈O₂₈]^5–. The protonation site of heptamolybdate has been identified, and kinetic and structural data have been correlated to yield a scheme for the transformation of heptamolybdate to octamolybdate upon acidification.