Synthesis and Characterization of a Reduced Molybdenum（V） Phosphate,（H3dien）2（H2dien）2[NaMo12O24（OH）6-（H2PO4）（HPO4）5（PO4）2]·nH2O （n = 10.92）

A new reduced molybdenum（V） phosphate （H3dien）2（H2dien）2NaMo12O24 （OH）6 （HEPO4）（HPO4）5（PO4）2]·nH2O （n= 10.92, dien = diethylenetriamine） has been synthesized under hydrothermal conditions and characterized by elemental analyses, IR and X-ray diffraction. C16H96.84MO12N12NaO72.92P8 （Mr = 3046.73） crystallizes in the monoclinic system, space group P21/c with a = 13.3575（18）, b = 21.907（3）, c = 15.654（2）A, β= 110.22（2）°, V= 4298.4（10） A^3 Dc = 2.354 g/cm^3, Z = 2,μ（MoKcr） = 1.966 mm^-1, F（000） = 2990.4, the final R = 0.0357 and wR = 0.1086 for 8739 observed reflections with I 〉 2σ（I）. It consists of sandwich-shaped cluster anions Na{Mo6P4}2]^10- held together into a three-dimensional supramolecular framework through intermolecular hydrogen-bonding contacts. A probe reaction of the oxidation of acetaldehyde with H2O2 showed that this compound has high catalytic activity in the reaction.