Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (07): 1408-1414.doi: 10.3866/PKU.WHXB201305081


Heterobinuclear Zn-Eu or Zn-Tb Complexes Formed from Benzimidazole Derivatives and Metal Salts: Synthesis, Structures and Photophysical Properties

ZHAO Shun-Sheng1, ZHANG Zhao2, SHI Guo-Xiang2, FENG Wei-Xu2, LÜ Xing-Qiang2, LIU Xiang-Rong1   

  1. 1 College of Chemistry and Chemical Engineering, Xi’an University of Science & Technology, Xi’an 710054, P. R. China;
    2 Shaanxi Key Laboratory of Physico-inorganic Chemistry, Northwest University, Xi’an 710069, Shaanxi, P. R. China
  • Received:2013-02-04 Revised:2013-05-08 Published:2013-06-14
  • Contact: ZHAO Shun-Sheng, Lü Xing-Qiang;
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21103135, 21173165, 21073139), Natural Science Basic Research Plan in Shaanxi Province of China (2011JQ2011), Scientific Research Program Funded by Shaanxi Provincial Education Commission, China (12JK0622), and Foundation of Xi'an University of Science and Technology, China (2010QDJ030)


Four isostructural heterobinuclear Zn-Ln (Ln=Eu or Tb) complexes are prepared through the self-assembly of benzimidazole derivatives 2-(2-hydroxy-3-methoxyphenyl)benzimidazole (HL1) or 2-(5-bromo-2-hydroxy-3-methoxyphenyl)benzimidazole (HL2) with Zn(CH3COO)2·2H2O and Eu(NO3)3·6H2O or Tb(NO3)3·6H2O). The complexes are characterized by single-crystal X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, elementary analysis, and electrospray ionization mass spectrometry (ESIMS). Three of the complexes form single crystals, while the fourth is polycrystalline. UV-Vis absorption, excitation and emission spectra of the Tb3+-based complexes reveal strong, characteristic luminescence from Tb3+ with emissive lifetimes in the microsecond range. Therefore, Tb3+ has been sensitized from the excited state of the ligands because of effective intramolecular energy transfer. The Eu3+ complexes do not show characteristic emission because of deactivation by a different pathway.

Key words: Benzimidazole derivative, Sensitization, Energy transfer, Antennae effect, Characteristic emission