Acta Chimica Sinica ›› 2013, Vol. 71 ›› Issue (01): 107-113.DOI: 10.6023/A12050254 Previous Articles     Next Articles

Article

具有优良传导性能杂多酸复合物{[Co(H2O)8][H(H2O)3](HINO)4(PW12O40)}n的合成, 结构和性质研究

段显英a,b, 郭利兵a, 王建莉a   

  1. a 河南省科学院化学研究所 郑州 450002;
    b 南京大学配位化学国家重点实验室 南京 210093
  • 收稿日期:2012-05-29 出版日期:2013-01-14 发布日期:2012-12-10
  • 通讯作者: 段显英 E-mail:dxynumber@163.com
  • 基金资助:
    项目受河南省基础与前沿技术研究计划(No. 122300410090)资助.

A Good Proton-conductive Polyoxometalate Complex {[Co(H2O)8][H(H2O)3](HINO)4(PW12O40)}n: Synthesis, Crystal Structure and Properties

Duan Xianyinga,b, Guo Libinga, Wang Jianlia   

  1. a Institute of Chemistry, Henan Academy of Sciences, Zhengzhou 450002, China;
    b State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, China
  • Received:2012-05-29 Online:2013-01-14 Published:2012-12-10
  • Supported by:
    Project supported by Henan Province (No. 122300410090).

One organic/inorganic hybrid complex {[Co(H2O)8][H(H2O)3](HINO)4(PW12O40)}n, was constructed by a self-assembly of H+(H2O)3 clusters, [Co(H2O)8]2+ clusters, [PW12O40]3- anions and isonicotinic acid N-oxide (HINO). It was characterized by X-ray diffraction analysis, elemental analysis, IR, TG, UV, XRD, proton conductivity analysis. In the synthetic procedure of title complex, a mixture of result heteropolyacid cobalt salts CoHPW12O40·nH2O (90 mg, 0.03 mmol) and HINO (17 mg, 0.12 mmol) was dissolved in enough acetonitrile/water (1∶1, V/V) to form a homogeneous solution. Finally, the solution was filtered and the solvent left to evaporate at room temperature. A week later, light red crystals appeared and were collected and dried in air after quickly being washed with water. Single-crystal X-ray diffraction analysis at 293 K showed that complex 1 crystallizes in orthorhombic crystal system, Pnnm, and there was exactly a three-dimensional (3D) hydrogen-bonded network with large one-dimensional (1D) channels, in which [PW12O40]3- anions just filled in the 1D channels and self-assembled into poly-Keggin-anion chains. The result of the UV spectra indicates that the saturated aqueous concentration of 1 is ca. 10-5 mol/L and it is insoluble in water. Thermogravimetric analysis shows no weight loss in the temperature range of 20~100 ℃, indicating that all water molecules in the structure are not easily lost below 100 ℃. The powder X-ray diffraction data exhibits that although crystallized water molecules are lost at 200 ℃, the evacuated complex has the same structure as the single-crystal of 1. Moreover, the powder sample after the proton-conductive measurement has the same supramolecular framework as that of complex 1. Interestingly, the title complex was characterized by a satisfactory ionic conductivity (1×10-3~2×10-3 S·cm-1) in the temperature range of 85 to 100 ℃ only. The mechanism of proton conduction of the title complex is, expected to be similar to that of the vehicle mechanism, that is, the direct diffusion of additional protons with water molecules (Grotthuss mechanism).

Key words: polyoxometalate, crystal structure, supramolecular complex, conducting materials, isonicotinic acid N-oxide