Hydrothermal synthesis and crystal structure of novel alkali trimolybdates

Novel alkali trimolybdates of the triclinic (M, M')(2)Mo3O10 (M = Rb; M' = K, Cs) type were obtained through a systematic hydrothermal approach based on the reaction Of MoO3 with alkali halide solutions at 180 degrees C. The crystal structures were determined from X-ray single crystal data. The alkali trimolybdates extend the family of known alkali trimolybdates in an unexpected fashion, because they contain a distorted variation Of [Mo3O10](2-) chains as a key structural motif that has only been found in a single compound before, namely ethylenedi ammonium trimolybdate, (C2H10N2)[Mo3O10]. The applied hydrothermal strategy is discussed in the general context of systematic pathways to polyoxomolybdates. Furthermore, the templating role of the alkali cations and their interaction with the polyoxomolybdate surroundings is compared to (C2H10N2)[Mo3O10] in terms of electrostatic calculations.