Visible-Light-Absorbing Lindqvist-Type Polyoxometalates as Building Blocks for All-Inorganic Photosynthetic Assemblies

This study reports that polynuclear charge-transfer complexes consisting of Ce3+ and a Lindqvist-type polyoxometalate center, either W6O192− or Mo6O192−, function as an all-inorganic visible-light-absorbing chromophore. The polynuclear W6O19/Ce and Mo6O19/Ce complexes showed an intense absorption band from the UV region to 520 and 600 nm, respectively. The FTIR and Ce LIII-edge X-ray absorption measurements confirmed that the visible absorption is due to the oxo-bridged W6+/Ce3+ and Mo6+/Ce3+. As polyoxometalates have efficient redox and catalytic properties, their visible-light sensitization could provide a new building block for fabricating inorganic, molecular-based photosynthetic assemblies.