Molecular Scylla and Charybdis: Maneuvering between pH Sensitivity and Excited-State Localization in Ruthenium Bi(benz)imidazole Complexes
作者:Alexander K. Mengele、Carolin Müller、Djawed Nauroozi、Stephan Kupfer、Benjamin Dietzek、Sven Rau
DOI:10.1021/acs.inorgchem.0c01022
日期:2020.9.8
hence, introduce highly pH-dependent properties into the complexes. Previous results for ruthenium complexes containing R2bbim ligands with alkylic or arylic N,N′-substitution indicated that, although pH insensitivity was accomplished, unexpected losses of spectator ligand features incurred simultaneously. Here, we report the synthesis and photophysical characterization of a series of differently N,N′-alkylated
在钌配合物中充当N,N-螯合物的Bi(benz)咪唑(b(b)im)代表一类独特的配体。如果在N原子上没有引入取代基,则它们在可见光激发下不会在钌多吡啶基络合物中包含金属-配体电荷转移(MLCT)激发态。因此,它们可用于将光驱动电子传输路径转向所需方向。但是,游离的N原子易于质子化,因此将高度依赖pH的特性引入复合物中。含R 2 bbim配体与烷基或芳基N,N'的钌配合物的先前结果-取代表明,尽管实现了pH不敏感性,但同时引起了观众配体特征的意外损失。在这里,我们报告了一系列不同的N,N'-烷基化的b(b)im配体及其相应的[(tbbpy)2 Ru(R 2 b(b)im)](PF 6)的合成和光物理特性2个复合物(tbbpy = 4,4'- tert-丁基-2,2'-联吡啶)。数据表明,仅一个亚甲基的刚性乙烯桥基的延伸就大大提高了所得配合物的发射量子产率,发射寿命和光稳定性。量子化学计算支