Ruthenium(II) Complexes Containing 8-(Dimethylphosphino)quinoline (Me2Pqn): Preparation, Crystal Structures, and Electrochemical and Spectroscopic Properties of [Ru(bpy or phen)3
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- 作者：Takayoshi Suzuki ; Takashi Kuchiyama ; Shinobu Kishi ; Sumio Kaizaki ; Hideo D. Takagi ; and Masako Kato
- 刊名：Inorganic Chemistry
- 出版年：2003
- 出版时间：February 10, 2003
- 年：2003
- 卷：42
- 期：3
- 页码：785 - 795
- 全文大小：242K
- 年卷期：v.42,no.3(February 10, 2003)
- ISSN：1520-510X
文摘
Several new ruthenium(II) complexes containing 8-(dimethylphosphino)quinoline (Me2Pqn) were synthesized, andtheir structures and electrochemical/spectroscopic properties have been investigated. In addition to the mono(Me2Pqn) complex [Ru(bpy or phen)2(Me2Pqn)](PF6)2 (1 or 1'; bpy = 2,2'-bipyridine; phen = 1,10-phenanthroline),the geometrical isomers trans(P)- and C1-[Ru(bpy)(Me2Pqn)2](PF6)2 (tP-2 and C1-2) and mer- andfac-[Ru(Me2Pqn)3](PF6)2 (m-3 and f-3) were also selectively synthesized and isolated. It was found that complexestP-2 and m-3 were converted quantitatively to the corresponding C1-2 and f-3 isomers, respectively, by irradiationof light corresponding to the MLCT transition energy. The strong trans influence of the Me2P- donor group ofMe2Pqn was confirmed by the X-ray structural analyses for 1, tP-2, m-3, and f-3. Cyclic voltammetry of a seriesof complexes, [Ru(bpy)3](PF6)2, 1, C1-2, and f-3, exhibited a reversible one-electron oxidation wave and two orthree one-electron reduction waves. The oxidation potentials of the complexes gave a large positive shift withincreasing number of coordinated Me2Pqn molecules, indicating a larger 
-acceptability of the Me2P- group comparedwith bpy or qn. Complex f-3 in EtOH/MeOH (4:1) glass at 77 K exhibited an intense long-lived (
= 920 
s)emission arising from the quinoline-based 3(-*) excited state. In contrast, the mixed-ligand complexes 1, 1',and C1-2 showed a characteristic dual emission, giving a double-exponential emission decay, and the dual emissionoriginates from both the bpy-based 3MLCT and the quinoline-based 3(-*) emitting states.
-acceptability of the Me2P- group comparedwith bpy or qn. Complex f-3 in EtOH/MeOH (4:1) glass at 77 K exhibited an intense long-lived ( = 920 s)emission arising from the quinoline-based 3(-*) excited state. In contrast, the mixed-ligand complexes 1, 1',and C1-2 showed a characteristic dual emission, giving a double-exponential emission decay, and the dual emissionoriginates from both the bpy-based 3MLCT and the quinoline-based 3(-*) emitting states.