Photosolvolysis of cis-[Ru(伪-diimine)2(4-aminopyridine)2]2+ Complexes: Photophysical, Spectroscopic, and Density Functional Theory Analysis

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• 作者：Mariana R. Camilo ; Carolina R. Cardoso ; Rose M. Carlos ; A. B. P. Lever
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：April 7, 2014
• 年：2014
• 卷：53
• 期：7
• 页码：3694-3708
• 全文大小：773K
• 年卷期：v.53,no.7(April 7, 2014)
• ISSN：1520-510X

文摘

The photochemical and photophysical properties of the cis-[Ru^II(伪-diimine)₂(4-APy)₂]²⁺ complexes, where 伪-diimine = 1,10-phenanthroline (phen) and 4-APy = 4-aminopyridine I, 4,7-diphenyl-1,10-phenanthroline (Ph₂phen) II, 2,2鈥?bipyridine (bpy) III, and 4,4鈥?dimethyl-2,2鈥?bipyridine (Me₂bpy) IV, are reported. The four complexes were characterized using high-performance liquid chromatography, ¹H NMR, UV鈥搗isible, emission, and transient absorption spectroscopy. Upon photolysis in acetonitrile solution these complexes undergo 4-APy dissociation to give the monoacetonitrile complex (for II, III, and IV) or the bis(acetonitrile) complex (for I). A fairly wide range of excitation wavelengths (from 420 to 580 nm) were employed to explore the photophysics of these systems. Quantum yields and transient spectra are provided. Density functional theory (DFT) and time-dependent DFT analysis of singlet and triplet excited states facilitated our understanding of the photochemical behavior. A detailed assessment of the geometric and electronic structures of the lowest energy spin triplet charge transfer state (³MLCT) and spin triplet metal centered state (³MC) (d蟺 鈫?蟽* transitions) for species I鈥揑V is presented. A second, previously unobserved, and nondissociative, ³MC state is identified and is likely involved in the primary step of photodissociation. This new ³MC state may indeed play a major role in many other photodissociation processes.