磷光型铱阳离子配合物的溶剂相关激发态动力学研究
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- 英文论文题名：Phosphorescent Cationic Iridium(Ⅲ) Complexes with 1,3,4-oxadiazole Cyclometalating Ligands:Solvent Dependent Excited State Dynamics
- 论文作者：匡卓然 ; 郭前进 ; 夏安东
- 英文论文作者：Zhuoran Kuang ; Qianjin Guo ; Andong Xia ; Institute of Chemistry ; Chinese Academy of Sciences
- 年：2016
- 作者机构：中国科学院化学研究所;
- 论文关键词：铱配合物 ; 激发态动力学 ; 溶剂化 ; 金属-配体电荷转移
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第四十四分会：化学动力学
- 语种：中文
- 分类号：O641.4
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第四十四分会 ; 化学动力学
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：179k
- 原文格式：D
- 会议级别：全国
摘要
本文利用飞秒及纳秒瞬态吸收光谱技术,研究了两种磷光型铱阳离子配合物[Ir(2,5-diphenyl-1,3,4-oxadi azole)_2(2,2’-bipyridine)]PF_6和[Ir(2,5-diphenyl-1,3,4-oxadiazole)2(2-(1H-pyrazol-1-yl)pyridine)]PF6的溶剂相关激发态动力学。~([1])依据稳态光谱和含时密度泛函计算结果可知,两种配合物的激发态均表现出显著的金属-配体电荷转移(MLCT)特性。在两种配合物的瞬态吸收光谱实验中,配合物被激发到~1MLCT态后,我们指征了一个受溶剂极性调控的快衰减过程(0.2–3 ps),对应于溶剂稳定的~3MLCT态的生成过程。随后通过振动冷却和结构稳定的慢过程(6–50 ps),到达辐射磷光的最低三重态。本工作针对铱配合物的溶剂调控的激发态弛豫动力学分析,旨在帮助深入理解过渡金属配合物的激发态动力学。
The solvent dependent excited-state dynamics of two phosphorescent cationic iridium(III) complexes, namely [Ir(2,5-diphenyl-1,3,4-oxadiazole)_2(2,2'-bipyridine)]PF6(1) and [Ir(2,5-diphenyl-1,3,4-oxadiazole)2(2-(1H-pyrazol-1-yl)pyridine)]PF_6(2), were investigated using femtosecond and nanosecond transient absorption spectroscopy. According to the results of steady-state spectra and TD-DFT calculations, the excited states of the both complexes show remarkable MLCT features. Performing the femtosecond transient absorption spectroscopy upon the photoexcitation to MLCT state for both 1 and 2, a rapid process(τ = 0.2–3 ps) suggesting the generation of solvent stabilized ~3MLCT, which is dependent on the solvent polarity, is observed. Besides, the relatively slow component(τ = 6–50 ps) is assigned to vibrational cooling and geometry relaxation in triplet manifold, leaving a long-lived(τ = ~1 μs) phosphorescent emission state. In light of the solvent-modified excited state relaxation dynamics,this work serves to further understand excited state solvation processes in transition metal complexes.
The solvent dependent excited-state dynamics of two phosphorescent cationic iridium(III) complexes, namely [Ir(2,5-diphenyl-1,3,4-oxadiazole)_2(2,2'-bipyridine)]PF6(1) and [Ir(2,5-diphenyl-1,3,4-oxadiazole)2(2-(1H-pyrazol-1-yl)pyridine)]PF_6(2), were investigated using femtosecond and nanosecond transient absorption spectroscopy. According to the results of steady-state spectra and TD-DFT calculations, the excited states of the both complexes show remarkable MLCT features. Performing the femtosecond transient absorption spectroscopy upon the photoexcitation to MLCT state for both 1 and 2, a rapid process(τ = 0.2–3 ps) suggesting the generation of solvent stabilized ~3MLCT, which is dependent on the solvent polarity, is observed. Besides, the relatively slow component(τ = 6–50 ps) is assigned to vibrational cooling and geometry relaxation in triplet manifold, leaving a long-lived(τ = ~1 μs) phosphorescent emission state. In light of the solvent-modified excited state relaxation dynamics,this work serves to further understand excited state solvation processes in transition metal complexes.
引文
[1]Wang,Z.;He,L.;Duan,L.;Yan,J.;Tang,R.;Pan,C.;Song,X.Dalton Trans.2015,44:15914.