†Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Quillota 980, Viña del Mar, Valparaíso, Chile.
‡Institut Quimic de Sarrià, Universitat Ramon Llull, Via Augusta, 390, 08017 Barcelona, Spain.
J Phys Chem A. 2015 Apr 30;119(17):3929-35. doi: 10.1021/jp512614w. Epub 2015 Apr 15.
The spectroscopic, electrochemical, and photophysical properties of the new complex [P,N-{(C6H5)2(C5H4N)P}Re(CO)3Br] are reported. The UV-vis spectrum in dichloromethane shows an absorption maximum centered at 315 nm and a shoulder at 350 nm. These absorption bands have been characterized to have MLCT character. Excitation at both wavelengths (maximum and shoulder) leads to an emission band centered at 550 nm. Cyclic voltammetry experiments show two ill-defined irreversible oxidation waves around +1.50 and 1.80 V that are assigned to Re(I)/Re(II) and Re(II)/Re(III) couples whereas an irreversible reduction signal centered at -1.80 V is likewise assigned to a ligand reduction process. These results support the proposal of the MLCT nature of the states implied by the emission of the complex. The luminescent decay fits to a biexponential function, where the lifetimes and emission quantum yields are dependent on the solvent polarity. DFT calculations suggest that dπ → πpyridine and dπ → πphenyl excited states may account for the existence of two decay lifetimes.
报道了新配合物[P,N-{(C6H5)2(C5H4N)P}Re(CO)3Br]的光谱、电化学和光物理性质。二氯甲烷中的紫外-可见光谱显示出一个吸收最大值位于 315nm 处，一个肩峰位于 350nm 处。这些吸收带被特征化为具有 MLCT 特性。在两个波长（最大值和肩峰）激发下，会导致一个发射带位于 550nm 处。循环伏安实验显示，在 +1.50 和 1.80 V 左右有两个定义不明确的不可逆氧化波，它们被分配给 Re(I)/Re(II)和 Re(II)/Re(III) 对，而位于 -1.80 V 处的不可逆还原信号也被分配给配体还原过程。这些结果支持了配合物发射所暗示的 MLCT 性质的状态的提议。荧光衰减拟合为双指数函数，其中寿命和发射量子产率取决于溶剂极性。DFT 计算表明，dπ → π吡啶和 dπ → π苯基激发态可能解释了两个衰减寿命的存在。
