Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (11): 2465-2474.doi: 10.3866/PKU.WHXB201310085

• PHOTOCHEMISTRY AND RADIATION CHEMISTRY • Previous Articles     Next Articles

Photoelectric Properties of Novel Substituted 2-Phenyl-1H-imidazole[4,5-f][1,10]phenanthrene Ruthenium(II) Complexes

LING Huan-Huan, LI Nan, YANG Fan, JI Xin, XIA Yong, CAO Du, QI Zheng-Jian   

  1. College of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, P. R. China
  • Received:2013-07-29 Revised:2013-10-07 Published:2013-10-30
  • Contact: QI Zheng-Jian E-mail:qizhengjian@seu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21075015) and Technology Support Project of Jiangsu Province, China (BE2012810).

Abstract:

To obtain novel complexes with active grafting ability and high fluorescent sensing performance, four phenanthroline ligands 2-(4-aminophenyl)-1H-imidazole[4,5-f][1,10]phenanthrene (CImPB-NH2), 2-(4-hydroxyphenyl)-1H-imidazole[4,5-f][1,10]phenanthrene (CImPB-OH), 2-(4-carboxylphenyl)-1H-imidazole[4, 5-f][1,10]phenanthrene (CImPB-COOH), and 2-(4-nitrophenyl)-1H-imidazole[4,5-f][1,10]phenanthrene (CImPB-NO2) and theirruthenium(II) complexes were synthesized. The photoelectric properties of the four complexes were evaluated with UV-Vis absorption measurements, fluorescence spectrometry, cyclic voltammetry, and time-dependent density functional theory (TD-DFT) calculations. UV-Vis and photoluminescence (PL) spectroscopy results show that the four complexes have broad, strong absorption in the visible light region, and display bright luminescence, exhibiting colors from green to red. In N,N-dimethylformamide (DMF) solution, compared with that of [Ru(phen-NH2)(bpy)2]2+ which has no phenylimidazole group, the fluorescence quantum yield of the [Ru(CImPB-NH2) (bpy)2]2+ is increased by about 67% and that of [Ru(CImPB-COOH)(bpy)2]2+ is enhanced 18 times to 29.8%, emitting bright red light from 600 to 620 nm. Calculation results indicate that an extending conjugated π system is formed along the whole ligand molecular skeleton among the aromaticities of benzene, imidazole and phenanthrene, the effective conjugation length of which is increased significantly compared with the single phenanthrene ligand, and a approximate octahedral configuration is built between Ru and the functional phenanthrene ligand. All the data indicate that the results of the theoretical calculations are in good agreement with the experimental results. These investigations might provide valuable data for designing grafting and fluorescent sensors with high performance.

Key words: Fluorescent sensor, Ruthenium(II) complex, 2-Phenyl-1H-imidazole[4,5-f]-[1,10]phenanthrene, Photoelectric property, Time-dependent density functional theory

MSC2000: 

  • O644