新型—维锯齿链状聚金属氧酸盐配位聚合物［｛La(DMSO)_6(H_2O)}·(PMo_(12)O_(40))·H_2O］_n的合成、结构及表征

以a-H_3PMo_(12)O_(40)·nH_2O, La_2O_3和二甲基亚砜（DMSO）为原料，在 乙腈和水的混合溶剂中制得了一维锯齿链状配位聚合物［｛La(DMSO)_6(H_2O)}· (PMo_(12)O_(40))·H_2O］_n,X射线单晶衍射结果表明，聚合物中金属配阳离子与 杂多阴离子骨架通过Mo-O_d-La-O_d-Mo相连并形成一维无限链，每一个不对称结构 单元中含一个结晶水，La~(3+)的配位数为九，三帽三棱柱构型，配位氧原子分别 来自6个DMSO分子，1个H_2O分子和2个相邻杂多阴离子的端氧，晶体氧于单斜晶系 ，P2_1/c空间群，a=1.3916(3)nm,b=1.7058(3)nm,c=2.4750(5)nm,β=99.16(3)~° ,Z=4,V=5.800(2)nm~3,D_c=2.825g/cm~3,R_1=0.0446,wR_2=0.0871,IR光谱和X射线 单晶衍射结果一致表明，在固态条件下配阳离子和杂多阴离子之间存在相互作用， UV光谱表明，在稀的水溶液中，由于溶剂化作用，杂多阴离子与配阳离子处于解离 状态，热性质研究表明，形成标题化合物后，杂多阴离子的热稳定性与磷钼酸相比 明显增强。

A Novel 1D Zigzag Chain Polyoxometallate-based Coordination Polymer[{La(DMSO)6(H2O)}(PMo12O40)@H2O]n: Synthesis,Crystal Structure and Characterization

The ID zigzag chain compound of {La(DMSO)_6(H2O)}(Pmo_(12)O_(40))· H2O]_n has been synthesized by reaction ofα-H3PMo12 O_(40)·Nh_2O, La2O_3 and DMSO in acetonitrile-water mixture and characterized by elemental analysis, IR and UV spectra, and X-ray single crystal structural analysis. The crystal structure indicates that the title compound forms an unprecedented one-dimensional zigzag chain built from the alternating polyanions and cationic units through Mo-O_d-La- O_d-Mo links. In the compound, there is a crystal water molecule in every unsymmetric structure unit and La~(3+) cations are nine- coordinated in a tricapped trigonal prism geometry environment with oxygen atoms from six DMSO molecules, one H2O molecule and two adjacent polyanions. It belongs to monoclinic space group P2_1/c, with unit cell dimensions a = 1.3916(3) nm, 6 = 1.7058(3) nm, c = 2.4750(5) nm, β= 99.16(3)°, V = 5.800(2) nm3, D_c = 2.825 g/cm3, Z = 4, R_1 = 0.0446, wR2 = 0.0871. The result of the single crystal X-ray diffraction analysis is in agreement with that of IR measurement, and both show that the metal cation units are coordinately bonded to the Keggin cluster. The UV spectrum of the title compound suggests that the compound is entirely disruptive in dilute solution. The result of TG-DTA shows that the title compound is thermally more table than that ofα-H_3Pmo_(12)O_(40) ·nH_2O.