Synthesis, Characterization, and Photophysics of Oxadiazole- and Diphenylaniline-Substituted Re(I) and Cu(I) Complexes

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• 作者：Raphael Horvath ; Michael G. Fraser ; Scott A. Cameron ; Allan G. Blackman ; Pawel Wagner ; David L. Officer ; Keith C. Gordon
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：February 4, 2013
• 年：2013
• 卷：52
• 期：3
• 页码：1304-1317
• 全文大小：812K
• 年卷期：v.52,no.3(February 4, 2013)
• ISSN：1520-510X

文摘

Transition-metal complexes of the types [Re(CO)₃Cl(NN)], [Re(CO)₃py(NN)]⁺, and [Cu(PPh₃)₂(NN)]⁺, where NN = 4,4鈥?bis(5-phenyl-1,3,4-oxadiazol-2-yl)-2,2鈥?bipyridine (OX) and 4,4鈥?bis(N,N-diphenyl-4-[ethen-1-yl]-aniline)-2,2鈥?bipyridine (DPA), have been synthesized and characterized. Crystal structures for [Re(CO)₃Cl(DPA)] and [Cu(PPh₃)₂(OX)]BF₄ are presented. The crystal structure of the rhenium complex shows a trans arrangement of the ethylene groups, in agreement with density functional theory calculations. The structure of the copper complex displays the planar aromatic nature of the bpy鈥搊xadiazole ligand. Density functional theory modeling of the complexes was supported by comparison of calculated and experimental normalized Raman spectra; the mean absolute deviations of the complexes were <10 cm^鈥?. The Franck鈥揅ondon state was investigated using UV鈥搗is and resonance Raman spectroscopic as well as density functional theory computational techniques. It was shown that the lowest energy absorption peaks are metal to ligand charge transfer and ligand-centered charge transfer for the oxadiazole- and diphenylaniline-substituted bipyridine ligands, respectively. The lowest energy excited states were characterized using transient emission and absorption spectroscopic techniques in conjunction with density functional theory calculations. These showed that the DPA complexes had ligand-centered nonemissive 鈥渄ark鈥?states with lifetimes ranging from 300 to 2000 ns.