Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (12): 2783-2789.doi: 10.3866/PKU.WHXB201210122

• THERMODYNAMICS, KINETICS, AND STRUCTURAL CHEMISTRY • Previous Articles     Next Articles

Structures, Thermodecomposition Kinetics and Luminescence Properties of Three Lanthanide-Based Supramolecular Compounds with 1H-Benzimidazole-2-carboxylic Acid

DUAN Lin-Qiang1, QIAO Cheng-Fang1,2, WEI Qing1, XIA Zheng-Qiang1, CHEN San-Ping1, ZHANG Guo-Chun2, ZHOU Chun-Sheng2, GAO Sheng-Li1,2   

  1. 1 Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, P. R. China;
    2 Department of Chemistry and Chemical Engineering, Shaanxi Key Laboratory of Comprehensive Utilization of Tailing Resources, Shangluo University, Shangluo 726000, Shaanxi Province, P. R. China
  • Received:2012-07-25 Revised:2012-10-11 Published:2012-11-14
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21173168, 21073142, 21127004) and Science Research Projects of Educational Department of Shaanxi Province, China (2010JK882, 2010JQ2007, 11JS110, 11JK0578).

Abstract:

Three lanthanide-based supramolecular compounds, [Ln(HBIC)3]n [Ln=Sm (1), Ho (2), Yb (3); H2BIC=1H-benzimidazole-2-carboxylic acid], were hydrothermally synthesized and structurally characterized by X-ray single crystal diffraction (compounds 1 and 2), powder X-ray diffraction (XRD) (compound3), elemental analysis, infrared (IR) spectroscopy, and thermal analysis. Structural analyses reveal that compounds 1-3 are isomorphous and display a two-dimensional (2D) plane, in which each lanthanide center is coordinated by three N and five O atoms from five flexible HBIC- ligands with two kinds of new coordination modes, giving rise to a slightly distorted two-capped triangle prism geometry. The 2D square networks are further assembled into a three-dimensional (3D) supramolecular framework through strong hydrogen-bonding interactions. Thermogravimetry analyses (TG) indicate that compounds 1-3 exhibit good thermostability and could be stable up to 360℃. By means of differential scanning calorimetry (DSC) techniques, the thermoanalysis kinetics parameters of the thermodecomposition of compound 1 were calculated by the Kissinger's and Ozawa-Doyle's methods; the pre-exponential factor AK was 1.286×108 s-1 and the apparent activation energy EK and EO were determined to be 199.3 and 205.2 kJ·mol-1, respectively. In addition, the luminescent properties of compounds 1 and 3 were also studied at room temperature in the solid state. The results reveal that compounds 1 and 3 exhibit characteristic emission bands of the corresponding lanthanide ions in the visible and near-infrared regions, respectively.

Key words: Lanthanide coordination compound, 1H-Benzimidazole-2-carboxylic acid, Structure analysis, Luminescence, Thermoanalysis kinetics

MSC2000: 

  • O641