INQUINOA-CONICET, Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 491, (T4000INI) San Miguel de Tucumán, Argentina.
Inorg Chem. 2010 May 3;49(9):4084-91. doi: 10.1021/ic901893q.
We report in this work the synthesis and characterization of new mono- and dinuclear complexes of formulas: Re(bpy)(CO)(3)(4,4'-azpy), 1 (bpy = 2,2'-bipyridine, 4,4'-azpy = 4,4'-azobis(pyridine)); (bpy)(CO)(3)Re(4,4'-azpy)Ru(NH(3))(5)(3).CH(3)CN.6H(2)O, 2 and the heterodinuclear species (bpy)(CO)(3)Re(4,4'-azpy)Ru(NH(3))(5), 3 (obtained in situ by electrochemical oxidation of 2). The molecular structure of 1 has been determined by X-ray diffraction. We also report the effect of controlled potential electrolysis, protonation, and light excitation on the absorption and emission properties of these complexes. In particular, complex 1, which is almost non-emissive at room temperature, recovers luminescence either by reduction of coordinated 4,4'-azpy or by trans- to cis-photoisomerization. The detected emission of 1 at 77 K is due to decay from a Re --> bpy metal-to-ligand charge transfer excited state. Time dependent density functional theory calculations support the interpretation of the photophysical changes induced by external stimuli.
我们在这项工作中报告了新的单核和双核配合物的合成和表征，化学式为：Re(bpy)(CO)(3)(4,4'-azpy)，1（bpy=2,2'-联吡啶，4,4'-azpy=4,4'-偶氮吡啶）；(bpy)(CO)(3)Re(4,4'-azpy)Ru(NH3)(5)3.CH3CN.6H2O，2 和异双核配合物(bpy)(CO)(3)Re(4,4'-azpy)Ru(NH3)(5)，3（通过 2 的电化学氧化原位获得）。1 的分子结构已通过 X 射线衍射确定。我们还报告了控制电位电解、质子化和光激发对这些配合物吸收和发射性质的影响。特别是，1 在室温下几乎不发光，但通过配位 4,4'-azpy 的还原或通过顺式-反式光异构化恢复发光。在 77 K 下检测到的 1 的发射归因于从 Re 到 bpy 的金属到配体电荷转移激发态的衰减。时变密度泛函理论计算支持对外部刺激引起的光物理变化的解释。
