化学学报 ›› 2003, Vol. 61 ›› Issue (11): 1839-1843. 上一篇    下一篇

研究论文

咪唑配位的夹心型杂多化合物Na_9[{Na(H_2O)}_3{Co(C_3H_4N_2)}_3(BiW_9O_(33))_2]·33H_2O的合成,结构和磁性质研究

王虎林;薛岗林;王继武;王大奇;李君;史启桢   

  1. 西北大学化学系;延安大学化学化工学院;聊城大学化学系
  • 发布日期:2003-11-15

Synthesis, Structure and Magnetic Properties of Imidazole Coordinated Sandwich-type Bismuth Tungstate Na_9[{Na(H_2O)}_3{Co (C_3H_4N_2)}_3(BiW_9O_(33))_2]·33H_2O

Wang Hulin;Xue Ganglin;Wang Jiwu;Wang Daqi;Li Jan;Shi Qizhen   

  1. Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry, Northwest University;Department of Chemistry and Chemical Engineering, Yan'an University;Department of Chemistry, Liaocheng Unive
  • Published:2003-11-15

在pH=7.5的水溶液中,咪唑与Na_2WO_4,Bi(NO_3)_3及Co(NO_3)_2反应,得到 了咪唑配位的新型杂多钨酸盐Na_9[{Na(H_2O)}_3{Co(C_3H_4N_2)}_3(BiW_9O_(33) )_2]·33H_2O,用X射线单晶衍射法及元素分析确定了其结构,晶胞参数为:空间 群P3,a=1.3904(4)nm, b=1.3904(4)nm, c=3.3169(13)nm, γ=120 °,V=5.553(3) nm~3, Z=2, R_1=0.0361,wR_2=0.0507(I>2σ)。杂多阴离子[{Na(H_2O)_3}{Co (C_3H_4N_2)}_3(BiW_9O_(33))_2]~(9-)为夹心式结构,两个三空缺Keggin离子α- B-BiW_9O_(33)~(9-)夹层中的中心离子为交替排列的三个Na(H_2O)~+和三个Co (C_3H_4N_2)~(2+),中心离子钴的配位数为5,该杂多阴离子具有C_(3v)对称性。 对标题化合物进行了磁性质表征,拟合结果为J=6.90cm~(-1),g=2.10,θ=0.25K, 表明该化合物中的Co(II)三核簇存在着铁磁偶合。

关键词: 杂多酸, 钨酸盐, 晶体结构, 磁性, 夹心化合物, 咪唑, 钠络合物, 钴络合物, 铋络合物, 耦合

The imidazole coordinated novel heteropolyoxometalate Na_9[{Na (H_2O}_3{Co(C_3H_4N_2)}_3(BiW_9O_(33)_2]·33H_2O was synthesized by the reaction of Na_2WO_4·2H_2O with Bi(NO_3)_3 and Co(NO_3)_2 in pH = 7.5 aqueous solution. The single crystal X-ray diffraction study shows that the ciystal belongs to trigonal system, space group P3 , with a = 1.3904(4) nm, b = 1.3904(4) nm, c = 3.3169(13) nm, γ = 120°, V = 5. 553(3) nm~3, Z = 2, R_1 = 0.0361, wR_2 = 0.0507 (I>2σ). The structure of anion [{Na(H_2O)}_3{Co(C_3H_4N_2)}_3(BiW_9O_(33))_2]~(9-) reveals a sandwich-like arrangement of two {α-B-AsW_9} moieties enclosing three Co(C_3H_4N_2)~(2+) and three Na(H_2O)~+ . The coordination number of Co~(2+) and Na~+ in the sandwich anion are all five, and the polyanion has C_(3v) symmetry. Magnetic data have been fitted assuming that the only exchange-coupled centers are the cobalts, the compound exhibits ferromagnetic coupling with J = 6.90 cm~(-1), g = 2.10, and θ = 0.25 K.

Key words: HETEROPOLYACID, TUNGSTATE, CRYSTAL STRUCTURE, MAGNETISM, SANDWICH COMPOUNDS, GLYOXALINE P, SODIUM COMPOUNDS, COBALT COMPLEX, BISMUTH COMPLEX, COUPLING

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