新型2-取代苯基-1H-咪唑[4,5-f][1,10]邻菲啰啉基Ru(Ⅱ)配合物的光电性质

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

为获取具有活性官能团的接枝型、高性能荧光传感配合物,合成了2-(4-氨基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉(CImPB-NH2)、2-(4-羟基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉(CImPB-OH)、2-(4-羧基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉(CImPB-COOH)和2-(4-硝基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉(CImPB-NO2)四种配体,借助紫外-可见(UV-Vis)吸收光谱、荧光(PL)光谱、循环伏安法(CV)和含时密度泛函理论(TD-DFT)对上述四种配体与过渡金属元素钌(Ru)所形成的配合物的光电性能进行研究.结果表明:四种配合物均在可见光区域有较强吸收,发光范围覆盖绿色到红色光波段.在极性溶剂N,N-二甲基甲酰胺(DMF)中,以2-(4-氨基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉为配体所构建的钌配合物([Ru(CImPB-NH2)(bpy)2]2+的荧光量子产率(Φ)较不含咪唑环的5-氨基邻菲啰啉合钌([Ru(phen-NH2)(bpy)2]2+)的提高了67%,以2-(4-羧基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉所构建的钌配合物([Ru(CImPB-COOH)(bpy)2]2+)的Φ可达29.8%,是[Ru(phen-NH2)(bpy)2]2+的18倍.理论计算表明:配体中取代苯环、咪唑环和邻菲啰啉的稠环共平面,形成共价大π体系,其有效共轭长度较邻菲啰啉母体有显著增加,配合物是以Ru为中心的近似八面体构型,理论计算的电子吸收光谱和跃迁性质与实验结果相一致.上述研究有可能为接枝型、高性能荧光传感配合物的设计和筛选提供实验依据.

To obtain novel complexes with active grafting ability and high fluorescent sensing performance, four phenanthroline ligands 2-（4-aminophenyl）-lH-imidazole[4,5-f][1,10]phenanthrene （CImPB-NH2）, 2-（4- hydroxyphenyl）-1 H-imidazole[4,5-t＇J[1,10]phenanthrene （CImPB-OH）, 2-（4-carboxylphenyl）-I H-imidazole[4, 5-f] [1,10]phenanthrene （CImPB-COOH）, and 2-（4- nitrophenyl）- 1 H-imidazole[4,5-f] [1,10]phenanthrene （CImPB-NO2） and theirruthenium（ll） 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 E 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.