Chinese Journal of Applied Chemistry ›› 2017, Vol. 34 ›› Issue (9): 1017-1023.DOI: 10.11944/j.issn.1000-0518.2017.09.170144

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Assembly and Luminescence of Mononuclear Ln to Heteronuclear Ln-M Supramolecular Complexes

WANG Zheng,YIN Shaoyun,PAN Mei(),LIU Yu,SUN Sisi,WANG Haiping,FAN Ya'nan,SU Chengyong   

  1. Lehn Institute of Functional Materials,School of Chemistry,Sun Yat-Sen University,Guangzhou 510275,China
  • Received:2017-05-08 Accepted:2017-06-02 Published:2017-08-31 Online:2017-08-31
  • Contact: PAN Mei
  • Supported by:
    Supported by the National Natural Science Foundation of China(No.21373276), the Science and Technology Planning Project of Guangzhou (No.201510010246, No.201504010031)

Abstract:

Via stepwise assembly method, discrete mononuclear Ln(Ln=Tb/Sm/Yb) complexes were synthesized from 3- or 4-pyridyl modified tripodal ligands, which were then assembled into three dimensional Ln-M(M=Ag or Cd) metal-organic frameworks(MOFs) with different topologies through the linkage of pyridyl ends. The heteronuclear MOFs sustain a characteristic emission of Ln3+ coordination centers, but the energy levels of the ligands are lowered in the three-dimensional packing structures, which affects the energy transfer efficiency to lanthanide centers. As a result, a stronger near-infrared luminescence is obtained in 2-Yb-Ag compared with its mononuclear counterpart, and the decay lifetime increases from 4.3 μs to 6.7 μs. While 4-Tb-Cd simultaneously emits metal-centered and ligand-based emissions, in which the decay lifetime for Tb-centered emission shortens from 2.91 ms to 0.62 ms compared with the corresponding mononuclear complex.

Key words: lanthanide emission, metal-organic framework, heteronuclear complex