Synthesis and Crystal Structure of Polyoxometalate [(C_4H_9)_4N]_6[PMo_(12)O_(40)]_2·0.5H_2O

The single crystal of a polyoxometalate,[(C_4H_9)_4N]_6[PMo_(12)O_(40)]_2·0.5H_2O,was prepared in CH3CN-H2O solution,and characterized by single crystal X-ray diffraction.The compound belongs to monoclinic system,with space group C2/c,unit cell: a=4.996(10) nm,b=1.411(3) nm,c=2.633(5) nm,β=114.804(4),V=16.844 nm3,Z=1,R1=0.0843,wR2 =0.2546.The molecule of the compound consists of six tetrabutylammonium cations,two heteropolyanions of [PMo12O40]3-and a half water molecule.