新型酰胺功能化铱[III]配合物的光电性能

设计并制备三种具不同官能团的铱III]邻菲啰啉配合物: Ir(ppy)₂phen-Br]Cl, Ir(ppy)₂phen-COOH]Cl, Ir(ppy)₂phen-Si]Cl,以及对比参照物Ir(ppy)₂phen-NH₂]Cl.其中, ppy为2-苯基吡啶, phen-Br为2-溴-2甲基-N-(1, 10-菲啰啉-5-基)丙酰胺, phen-COOH为4-(1, 10-菲啰啉-5-基)氨基]-4-酰基丁烯酸, phen-Si为5-N, N-二-3-(三乙氧硅)基]酰亚胺-1, 10-菲啰啉, phen-NH₂为5-氨基-邻菲啰啉,并采用核磁共振(NMR)、质谱(MS)、紫外-可见(UV-Vis)吸收光谱、荧光(PL)光谱法和循环伏安法(CV)等对上述配合物进行了分析和表征.光物理性能研究结果表明:这些配合物在蓝-紫色可见光区域有较强吸收,可发射出明亮的黄色到橙红色荧光,量子效率达到12%以上.相比较于参照物Ir(ppy)₂phen-NH₂]Cl (5.78 μs),三种新型配合物在量子效率未明显降低甚至提高的前提下,荧光寿命有了显著的提高(9.18-12.00 μs).其中, Ir(ppy)₂phen-Br]Cl (1)不但有最高的荧光量子产率(32%)和最长的荧光寿命(12.00 μs),而且也具有最好的氧传感性能, I₀/I (无氧与纯氧条件下的荧光强度比值)可达到10.91.这使得Ir(ppy)₂phen-Br]Cl有望成为接枝型,较高性能的光学氧传感器的候选氧敏指示剂.除此之外,还通过含时密度泛函理论(TD-DFT)计算对配合物光电性能进行补充说明,理论计算表明:这些配合物是以铱为中心的近似八面体结构,理论计算结果与实际实验数据相一致.

Photoelectric Properties of Novel Amide-Functionalized Ir(III) Complexes

A series of luminescent cyclometalated Ir(III) complexes functionalized with amide derivatives were prepared and compared with Ir(ppy)₂phen-NH₂]Cl. The complexes were Ir(ppy)₂phen-Br]Cl, Ir(ppy)₂phen-COOH]Cl, and Ir(ppy)₂phen-Si]Cl, where ppy is 2-phenylpyridine, phen-NH₂ is 5-amino-^{1, 10]}-phenanthroline, phen-Br is 2-bromo-2-methyl-N-(1, 10-phenanthrolin-5-yl)propanamide, phen-COOH is 4-(1, 10-phenanthrolin-5-yl)amino]-4-oxobut-2-enoic acid, and phen-Si is 5-N, N-bis-3-(triethoxysilyl) propyl]ureyl-1, 10-phenanthroline. They were characterized using nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), ultraviolet-visible (UV-Vis) absorption spectroscopy, photoluminescence (PL) spectroscopy, and cyclic voltammetry (CV). The three novel complexes have intense absorptions in the blue-purple region. The complexes show bright yellow to orange PL emissions under UV irradiation, and the quantum yields (Φ) of these complexes are higher than 12%. The excited-state lifetimes of the novel complexes are 9.18-12.00 μs, much longer than that of Ir(ppy)₂phen-NH₂]Cl (5.78 μs). With both the highest quantum yield (32%) and longest lifetime (12.00 μs), Ir(ppy)₂phen-Br]Cl also shows the best oxygen-sensing properties and the largest I₀/I factor, 10.91 (I₀: the PL intensity of the complex in the absence of O₂, I: the PL intensity of the complex under pure oxygen). These results suggest that Ir(ppy)₂phen-Br]Cl may be a promising candidate for use in oxygen sensors based on covalent grafting. Time-dependent density functional theory (TD-DFT) calculations were used to supplement the photoelectric property studies. Theoretical calculations indicate that all the mononuclear complexes have approximately octahedral structures with Ir(III) as the coordination center. The computational results agree well with the experimental data.