Revisiting the synthesis of [Mo6(η5-C5Me5)O18]–. X-Ray structural analysis, UV-visible, electrochemical and multinuclear NMR characterization

Abstract

In methanol, [n-Bu₄N][MoCp*O₃] reacted with [n-Bu₄N]₂[Mo₄O₁₀(OMe)₄Cl₂] to yield [n-Bu₄N][Mo₆Cp*O₁₈] in reasonable yield, thus opening a new route in the synthesis of organometallic derivatives of polyoxometalates. The crystal and molecular structure of [n-Bu₄N][Mo₆Cp*O₁₈]·Me₂CO has been determined by single-crystal X-ray diffraction. The ion [Mo₆Cp*O₁₈]^– has been thoroughly characterized by multinuclear NMR in solution. The ⁹⁵Mo and ¹⁷O NMR data support the conclusion that the Cp* ligand is a better σ + π donor than the oxo ligand. The complex is electrochemically active and displays three successive one-electron reduction processes.