Li Ting-Ting, Li Fu-Min, Zhao Wei-Liang, Tian Yong-Hua, Chen Yong, Cai Rong, Fu Wen-Fu
Key Laboratory of Photochemical Conversion and Optoelectronic Materials and HKU-CAS Joint Laboratory on New Materials, Technical Institute of Physics and Chemistry and University of Chinese Academy of Sciences, CAS , Beijing 100190, People's Republic of China.
Inorg Chem. 2015 Jan 5;54(1):183-91. doi: 10.1021/ic5020972. Epub 2014 Dec 19.
Electronic coupling across a bridging ligand between a chromophore and a catalyst center has an important influence on biological and synthetic photocatalytic processes. Structural and associated electronic modifications of ligands may improve the efficiency of photocatalytic transformations of organic substrates. Two ruthenium-based supramolecular assemblies based on a chromophore-catalyst dyad containing a Ru-aqua complex and its chloro form as the catalytic components were synthesized and structurally characterized, and their spectroscopic and electrochemical properties were investigated. Under visible light irradiation and in the presence of [Co(NH3)5Cl]Cl2 as a sacrificial electron acceptor, both complexes exhibited good photocatalytic activity toward oxidation of sulfide into the corresponding sulfoxide with high efficiency and >99% product selectivity in neutral aqueous solution. The Ru-aqua complex assembly was more efficient than the chloro complex. Isotopic labeling experiments using (18)O-labeled water demonstrated the oxygen atom transfer from the water to the organic substrate, likely through the formation of an active intermediate, Ru(IV)═O.
发色团与催化剂中心之间通过桥连配体的电子耦合对生物和合成光催化过程具有重要影响。配体的结构及相关电子修饰可提高有机底物光催化转化的效率。合成了两种基于发色团 - 催化剂二元体系的钌基超分子组装体，其中含有钌 - 水配合物及其氯代形式作为催化组分，并对其进行了结构表征，同时研究了它们的光谱和电化学性质。在可见光照射下，以[Co(NH₃)₅Cl]Cl₂作为牺牲电子受体，两种配合物在中性水溶液中均对硫化物氧化为相应亚砜表现出良好的光催化活性，效率高且产物选择性大于99%。钌 - 水配合物组装体比氯代配合物更高效。使用(¹⁸)O标记水的同位素标记实验表明，氧原子可能通过形成活性中间体Ru(IV)═O从水转移至有机底物。
