A polymeric chain formed by bicapped pseudo-Keggin polyoxometalate and [Ni(en)_2]~(2+) complexes: synthesis, structure and catalytic properties of {[H_3PMo_8V_6O_(46)][Ni(en)_2]} centre dot 2[Ni(en)_2] centre dot 5H_2O

摘要

A new compound {[H_3PMo_8V_6O_(46)][Ni(en)_2]} centre dot 2[Ni(en)_2] centre dot 5H_2O with a polymeric chain structure was hydrothermally synthesized and characterized by single crystal X-ray diffraction, IR and TG. The molybdovanadophosphate cluster anion is a bicapped 'pseudo-Keggin' structure, in which two vanadium atoms are located at two 'capping' metal atom positions, another four vanadium atoms and eight molybdenum atoms are arranged as phosphorus-centered alternate layers of molybdenum and vanadium oxides. The title compound exhibits high catalytic activity for selective oxidation of benzyl alcohol to benzaldehyde. The influence of catalyst amount, the ratio, H_2O_2/C_6H_5CH_2OH, reaction time and catalyst lifetime on the catalytic activity was studied.