Acta Chimica Sinica ›› 2012, Vol. 70 ›› Issue (23): 2451-2456.DOI: 10.6023/A12080571 Previous Articles    



童碧海a, 梅群波b, 李志文c, 董永平a, 张千峰a   

  1. a 安徽工业大学 冶金与资源学院 分子工程与应用化学研究所 马鞍山 243002;
    b 南京邮电大学信息材料与纳米技术研究院 江苏省有机电子与平板显示重点实验室 南京 210046;
    c 庆元中学 庆元 323800
  • 收稿日期:2012-08-23 出版日期:2012-12-14 发布日期:2012-11-14
  • 通讯作者: 梅群波
  • 基金资助:
    项目受国家自然科学基金(No. 50903001)资助.

Investigation on the Electrochemiluminescence Properties of a Series of Cyclometalated Iridium(III) Complexes Based on 2-Phenylquinoline Derivatives

Tong Bihaia, Mei Qunbob, Li Zhiwenc, Dong Yongpinga, Zhang Qianfenga   

  1. a College of Metallurgy and Resources, Institute of Molecular Engineering and Applied Chemistry, Anhui University of Technology, Maanshan 243002;
    b Jiangsu Key Lab of Organic Electronics & Information Displays and Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications (NUPT), Nanjing 210046;
    c Qingyuan Middle School, Qingyuan 323800
  • Received:2012-08-23 Online:2012-12-14 Published:2012-11-14
  • Supported by:
    Project supported by the National Natural Science Foundations of China (No. 50903001).

A series of cyclometalated iridium(III) complexes ([Ir(pqcm)2(bpy)][PF6] (1), [Ir(pqcm)2(dafo)[PF6] (2), [Ir(pqcm)2(phen)][PF6] (3), [Ir(pqcm)2(altpy)][PF6] (4), [Ir(pqcm)2(bbim)][PF6] (5), [Ir(pqcm)2(bvbbim)][PF6] (6), pqcm=2-phenyl-quinoline-4-carboxylic acid methyl ester, bpy=2,2'-bipyridine, dafo=4,5-diazafluoren-9-one, phen=1,10-phenanthroline, altpy=4'-allyloxy-2,2':6',2''-terpyridine, bbim=2,2'-bibenzimidazole, bvbbim=1,1'-diallyl-2,2'-bibenz- imidazole) were synthesized with cyclometalated ligand of pqcm and N^N typical assistant ligands. New iridium(III) complexes were characterized by the NMR and mass spectroscopies, and the single crystal structure of complex 1 was measured, the cationic distorted octahedrally coordinated iridium(III) center was ligated by two cyclometalated pqcm ligands and one chelating bpy ligand with a negative [PF6]- counter anion. In CH2Cl2 solution, the iridium(III) complexes 1, 2 and 3 displayed orange red emissions with wavelength about 610 nm, while the iridium(III) complexes 4, 5 and 6 displayed pure red emissions with wavelength about 620 nm, which was desirable for example in organic light-emitting devices applications. The iridium(III) complexes had lifetimes between 133 ns and 496 ns, quantum efficiencies between 0.7% and 16.6%. All these iridium(III) complexes had higher quantum efficiencies than Ru(bpy)32+. The electrochemiluminescence (ECL) of cationic cyclometalated iridium complexes, immobilized on the glassy carbon electrode was investigated in neutral phosphate buffer solution (PBS). The ECL peaks were obtained when oxalate was used as co-reactant and positive initial potential scan direction was adopted. The ECL of iridium(III) complexes were different from that of Ru(bpy)32+, Iridium(III) complexes had higher ECL potential and more than three times higher ECL intensity than Ru(bpy)32+, suggesting that these synthesized iridium complexes have great application potential in ECL detection. Unlike Ru(bpy)32+, most iridium(III) complexes could not only offer intensive anodic ECL peak but also provide a cathodic ECL peak. The ECL intensities of iridium(III) complexes had almost the same sequence with the quantum efficiencies of iridium(III) complexes.

Key words: cyclometalated iridium(III) complex, 2-phenylquinoline, electrochemiluminescence (ECL)