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化学学报
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化学学报 ›› 2003, Vol. 61 ›› Issue (10): 1608-1611. 上一篇    下一篇

研究论文

新型环形聚阴离子[{WO(H_2O)}_3(AsW_8O31)_3]~21-的结构及表征

刘斌;薛岗林;王继武;赵建设;何水样;史启祯   

  1. 西北大学化学系;延安大学化学化工学院
  • 发布日期:2003-10-15

A Novel Cyclic Heteropolyanion [{WO(H_2O)}_3(AsW_8O31)_3]~21-

Liu Bin;Xue Ganglin;Wang Jiwu;Zhao Jianshe;He Shuiyang;Shi Qizhen   

  1. Department of Chemistry, Northwest University;Department of Chemistry and Chemical Engineering, Yan'an University
  • Published:2003-10-15

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在pH=3.0的水溶液中，Na_2WO_4·2H_2O与NaAsO_2·6H_2O和NH_4Cl反应，得 到了新的杂多钨酸盐(MH_4)_19Na_2[{WO(H_2O)}_3(AsW_8O31)_3]·45H_2O单晶， 用X射线单晶衍射法及元素分析确定了其结构，晶体属单斜晶系，空间群C2/c，晶 胞参数为：a=3.1165(11)nm, b=1.7388(7)nm, c=2.2789(9)nm, β=97.342(6)°, V=12.248(8)nm~3, Z=4, R_1=0.0571,wR_2=0.0741[I＞2σ(I)]. 环型聚阴离子 [{WO(H_2O)}_3(AsW_8O31)_3]~21-是由三个{WO(H_2O)}桥连三个新发现的 {AsW_8O31}单元构成的，环聚离子[{WO(H_2O)}_3(AsW_8O31)_3]~21-具有近似D_ (3h)对称性。对该化合物还进行了~183W NMR, IR和TG表征。

关键词: 杂多酸, 钨酸盐, 钨, 砷, 晶体结构, X射线衍射分析, 核磁共振谱法, 红外分光光度法, 热重量分析

A novel heteropolyoxometalate (NH_4)_(19)Na_2 [ {WO (H_2O) }_3 (AsW_8O_(31) )_3 ]· 45H_2O was synthesized by the reaction of Na_2WO_4 · 2H_2O with NaAsO_2· 6H_2O and NH4CI in pH = 3.0 aqueous solution. The single crystal X-ray diffraction study shows that the crystal belongs to monoclinic system, space group C2/c, with a =3.1165(11) nm, 6 = 1.7388(7) nm, c = 2.2789(9) nm, β = 97.342(6)°, V= 12.248(8) nm3, Z = 4, R_1 = 0.0571, wR_2 = 0.0741 [I>2σ(I)]. The polyanion [ {WO (H_2O)}_3(AsW_8O_(31)]~(21-) consists of three new {AsW_8O_(31)} subunits related through a C3 axis and joined up by three extra { WO (H_2O)} group. Each {WO(H_2O) } joints two AsW_8O_(31) subunits by sharing two cis oxygen atoms with each other, the polyanion [ { WO (H_2O) }_3 (AsW_8O_(31) )_3]~(21-) has approximately D_(3h) symmetry. The compound was also characterized by ~(183)W NMR, IR and TG.

Key words: HETEROPOLYACID, TUNGSTATE, TUNGSTEN, ARSENIC, CRYSTAL STRUCTURE, XRD, NMR, IR, TG

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