Hydrothermal synthesis of [Cr-2(III)(OH)(4)Nb10O30](8-) in gram-scale quantities leads to a new polyoxometalate ion composed of two CrNb6O19 Lindqvist-type units that are fused via shared faces. The two Cr-III atoms are located in the centre of the molecule and are bridged by two mu(4)-O atoms. Electronic transitions are calculated using density functional theory and compare well with the measured UV-Vis spectra.
Son, J-H., Ohlin, C. A., & Casey, W. H. (2012). A new class of soluble and stable transition-metal-substituted polyoxoniobate: [Cr-2(OH)(4)Nb10O30](8-). Dalton Transactions, 41(41), 12674 - 12677. https://doi.org/10.1039/C2DT31760E