Mutual effects on the spectroscopic and electrochemical properties of μ3-oxo-trinuclear ruthenium complexes modified with a bridged [Ru(2,2′-bipy)2(CN)] moiety
摘要:
基于光谱和电化学技术对不对称二聚体 [Ru3O(CH3COO)6(py)2(B)Ru(2,2â²-联吡)2(L)](PF6)2(其中 B = 4,4â²-联吡或 bpa(1,2-双(4-吡啶基)乙烷)和 L = Clâ 或 CNâ 进行了表征,并研究了 CNâ 配位和桥接配体的影响。在桥接配体为Ï-共轭 4,4â²-联吡的二聚体中,氰配体与[Ru(2,2â²-联吡)2]分子的配位会使与[Ru3O]核心相关的所有 E1/2 变为更正值。我们通过光物理分析探究了[Ru3O(CH3COO)6(py)2]片段对[Ru(2,2â²-联吡)2]光谱特性的影响;在室温下,B = 4,4â²-联吡的二聚体检测不到发光,而 B = bpa 的复合物则显示出发光,与前体[Ru(2,2â²-联吡)2(B)(CN)]PF6 相比,Ï 值较低。在 77 K 时,两种二聚体都显示出微弱的发光。根据δGâ 值推测,主要的淬灭途径是通过电子转移机制进行的。
Ligand selective monosubstitution with complete enantiomeric retention in Delta and Lambda -cis-[Ru(bpy)(2)(DMSO)(Cl)]PF6 has been achieved photochemically. Irradiation in the presence of various ligands, including 4,4'-bipyridine, results in the replacement of the DMSO by the new ligand with complete enantioretention. This is revealed by the retention of the sign of the LC region CD Cotton effects, with the corresponding thermal reaction resulting in the racemic product. Importantly, 4,4'-bipyridine only coordinates through one pyridyl group, leaving the other for for subsequent reactions.[GRAPHICS]