Abstract
The advantages of the use of synchrotron radiation for single crystal X-ray diffraction experiments were exploited to obtain a deeper understanding of the chemistry of polyoxometalates through structural investigations. The pH dependence of the structures of {Mo154-x} mixed-valence oxomolybdate clusters were investigated by analyzing the structures of systematically prepared compounds containing wheel-shaped mixed-valence polyoxometalates with 138, 142, 148, 150, or 152 molybdenum atoms. Direct correlation was observed between the nuclearity of the clusters with the pH of the mother liquor. On the other hand, the geometries of extended structures do not show apparent correlation with the pH. They turned out to be determined by the structures of the constituent polyoxometalate. The pH of the mother liquor exerts influence on the extended structure through the structures of the constituent clusters. Such systematic preparation—structure determination study was enabled by the use of synchrotron radiation.
