磷钼杂多化合物[H_3PMo_(12)O_(40)]·2(4,4'-bipy)·1.75H_2O的合成、结构及电化学性能研究

Synthesis,Crystal Structure and Electrochemical Property of a Hybrid Polyoxometalate:[H_3PMo_(12)O_(40)]·2( 4,4'-bipy) ·1. 75H_2O

采用水热法合成了一个有机-无机杂化的Keggin型磷钼杂多化合物[H3PMo12O40]·2(4,4'-bipy)·1.75H2O(简称化合物1 bipy=联吡啶);通过元素分析、单晶X-射线衍射对其结构进行表征.结果表明,该化合物属于单斜晶系,P2(1)/c空间群,晶胞参数a=1.146 6(3)nm,b=2.122 7(6)nm,c=2.146 1(7)nm,β=98.082(12)°,V=5.171 0(3)nm3,C20H19Mo12N4O41.75P,Mr=2 165.64,Z=4,Dc=2.782 Mg·m-3,μ(MoKα)=2.946 mm-1,F(000)=4 080,R=0.062 2和wR=0.182 2.该化合物由一个Keggin型结构的多阴离子[PMo12O40]3-、两个2,2'-联吡啶和1.75个晶格水分子组成.杂多阴离子中的端氧原子、联吡啶分子中的氮原子以及水分子中的氧原子之间通过氢键作用形成超分子结构而使晶体稳定存在.通过循环伏安法详细研究了该化合物的微粒修饰电极的电化学行为和电催化性能.

A Keggin POM of formula [H3PMo12O40]·2（4,4＇-bipy）·1.75H2O （1）（ bipy = bipyridine） has been synthesized by hydrothermal method and structurally characterized by element analysis and single crystal X-ray diffraction. The data show that the crystal of 1 belongs to monoci- line,space groupP2（1）/c,a=1.1466（3）nm,b=2.1227（6）nm,c=2.1461（7）nm,β=98.082（12）°,V=5.1710（3）nm^3,C20H19Mo12N4O41.75P,Mr=2165.64,Z=4,Dc=2.782Mg·m^-3,μ（MoKα）=2.946mm^-1,F（000）=4080,R=0.0622 and wR=0.1822. X-ray diffraction analysis revealed that the molecular structure of 1 consists of a Keggin [ PMo12 040 ] 3- polyoxoanion, two discreted 4,4＇-bipy molecule and lattice water molecules. Heteropolyoxoanions[PMo12O40]^3- in 1 with alternating alignment, combined with the discrete organic substrates 4,4＇-bi- pyridines, and water molecules by hydrogen bond interactions afford a supramolecular network structure. Furthermore, the electrochemical behaviors and electrocatalytic activities of 1 has also been studied in detail by cyclic vohammograms.