Comparing the Structures of Two Allomorphic Polyoxotungstates and the Difference in Weak Interactions by Thermal-dependent 2D-COS IR to Identify

摘要

A three-dimensional(3D) Keggin-type heteropolytungstate{Zn(phen)3}3[ZnW12O40]· 9H2O 1(phen=1,10-phenanthroline) has been synthesized through a conventional hydrothermal synthesis and was characterized by X-ray single-crystal diffraction analysis,X-ray powder diffraction(XRD),IR,UV-DRS,thermogravimetric analysis(TGA),thermal-dependent 2D-IR correlation spectroscopy(2D-COS IR) and Raman spectrum.Crystal data for compound 1:trigonal system,space group R3 with a=b=25.268(4),c=17.462(5) ?,γ=120o,V=9655(4) ?3 and Z=3.Compound 1 is allomorphic to {Co(phen)3}3[CoW12O40]·9H2O 2,which has been reported by Feng Chai et al.In compound 2,its prominent feature is that the decisive role of water molecules(O–H···O) builds a 3D supramolecular structure.However,in the structure of compound 1,the interlayer space is filled by Zn(phen)3]2+ cations which linked the layers via C–H···O hydrogen bonding interactions to construct a three-dimensional framework.Two compounds are different in weak interactions,so we identify them by Thermal-dependent 2D-COS IR.Moreover,the fluorescence of compound 1 was also described.