A tetranuclear sandwich-type polyoxometalate(coded as POM),Na3H13 [Cu4(H2O)2(P2W15O56)2]·72H2O(1),was synthesized viathe aqueous solution reaction of trivacant Dawson precursor Na12[α-P2W15O56]·24H2O plus CuCl2·6H2O and sodium phosphate as the starting materials.As-synthesized compound was characterized by X-ray single crystal diffraction,infrared spectrometry,ultraviolet spectrometry and X-ray powder diffraction,while its thermal stability was examined by varied temperature infrared spectrometry.Results in...