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设计并合成了四种联吡啶配体上共价修饰不同取代基的三羰基铼配合物fac-Re(L)(CO)_3Cl:即取代基分别为甲基(Re-Me)、羧基(Re-Ac)、季铵盐(Re-Qa)以及咪唑盐(Re-Im)的铼配合物,化合物的结构均经过核磁氢谱、质谱以及红外光谱的确认,测定了四种配合物第一和第二还原电位.分别以该系列铼配合物为催化剂和光敏剂、三乙醇胺为电子牺牲体构建了均相可见光催化还原CO_2体系,配体上取代基对催化剂的催化效果有显著的影响,催化活性Re-Qa>Re-Ac≈Re-Me>Re-Im.不同实验条件下四种催化剂的吸收光谱随时间变化研究表明,铼配合物的催化效果和其在催化过程中的失活速率密切相关,其变化趋势与催化剂失活速率一致,催化剂的失活发生在催化剂得到一个电子后的单电子还原态中间体(One-electron reduced species,OER).瞬态吸收光谱检测到了催化过程中的OER的生成,证实光催化还原CO_2过程通过生成OER中间体进行的.
This paper designed and synthesized fac-Re (L) (CO) _3Cl, which is covalently modified with different substituents on four bipyridyl ligands, that is, the substituents were methyl -Ac), quaternary ammonium salts (Re-Qa) and imidazole salts (Re-Im). The structures of the compounds were confirmed by 1H NMR, MS and FT-IR. The second reduction potential.The homogeneous catalytic reduction of CO_2 system was established by using the series of rhenium complexes as the catalyst and the photosensitizer, and the triethanolamine as the electron sacrificial body. The substituents on the ligand had a significant influence on the catalytic effect of the catalyst. The catalytic The results show that the catalytic effect of the rhenium complex and its deactivation rate during the catalysis process are close , The change tendency of which is consistent with the rate of catalyst deactivation, and the deactivation of the catalyst takes place after the catalyst has obtained one electron-electron one-electron reduced species (OER). The transient absorption spectroscopy OER generation, confirming the photocatalytic reduction of CO2 process By generating OER intermediates.