通过水热方法合成了2个由多铌酸盐和过渡金属配合物形成的有机-无机杂化配合物[Cu(TETA)]4[VNb12(VO)4040][OHj.10H20(1)和[Cu(TETA)]4[VNbl2(VO)6040][OH]5·5H20(2)(TETA=三亚乙基四胺).化合物1和2的多阴离子分别是由4个{VO,}帽和6个{VO,}帽加盖在Keggin型多铌酸盐的方形缺口上形成的,它们通过多酸阴离子中Nb-o1(O1=端氧)与[Cu(TETA)]^2+配合物的金属中心配位构筑形成三维结构.价键计算结果表明,Keggin中心的钒为+5价,帽位的钒为+4价,X射线光电子能谱分析(XPS)结果也证实了这一结论.通过单晶X射线衍射分析、红外光谱(IR)、粉末x射线衍射(PXRD)、热重(TG)分析和元素分析对这2个化合物的结构和性质进行了表征.
Two organic-inorganic hybrid compounds constructed from polyoxoniobates and transition metal coordination complexes, [ Cu (TETA) 74 I WNbl2 ( WO )4040 I I OH 3 * 10H20 ( 1 ) and [ Cu (TETA) ]4 . [ VNb12 (VO) 6 040 ] I OH ] 5 . 5 n2O ( 2 ) ( TETA = triethylenetetramine), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analyses, IR spectra, X-ray photoelectron spectrum ( XPS), powder X-ray diffraction( PXRD), thermogravimetric analysis(TGA) and elemental analyses. Com- pound 1 is a 3D tetra-capped vanadoniobates and compound 2 is a 3D hexa-capped vanadoniobates which are constructed from heteropolyoxometalates and [ C culations indicates that the vanadium centers of u(TETA) ]2+ fragments. The result of bond valence sum cal- VO4 tetrahedral in { VNb12 / Keggin unit in compounds 1 and 2 are in oxidation state + V whereas the remaining vanadium centers are in oxidation state +IV . This is in line with the analysis of X-ray photoelectron spectrum.