A Missing Member of the Anderson–Evans Family: Synthesis and Characterization of the Trimethylolmethane-Capped {MnMo 6 O 24 } Cluster

In this work, the synthesis and structural characterization of the smallest possible member of the family of bis -functionalized {MnMo 6 O 24 } Anderson–Evans polyoxometalates (POMs) is reported. The synthesis of the title compound TBA 3 {[HC(CH 2 O) 3 ] 2 MnMo 6 O 18 } ( 1 ) was accomplished by using trimethylolmethane as the capping unit (TBA: tetra( n -butyl)ammonium, n -B u 4N + ). The molecular structure of the organic–inorganic POM gave rise to yet undisclosed 1 H-NMR features, which are discussed thoroughly. Single-crystal X-ray diffraction (XRD) analysis revealed a highly regular 3D packing of the polyoxoanions within a matrix of TBA cations. The hybrid POM is of particular interest regarding potential applications in photocatalysis (i.e., hydrogen evolution) and energy storage. Thus, the electrochemical and thermal properties of 1 are also analyzed.