1. Synthesis and electronic coupling studies of cyclometalated diruthenium complexes bridged by 3,3′,5,5′-tetrakis(benzimidazol-2-yl)-biphenyl.
- Author
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Wang, Hao, Shao, Jiang-Yang, Duan, Ran, Wang, Ke-Zhi, and Zhong, Yu-Wu
- Subjects
RUTHENIUM compounds ,DIPHENYL ,COUPLES ,LIGANDS (Chemistry) ,DENSITY - Abstract
Three cyclometalated diruthenium complexes bridged by 3,3′,5,5′-tetrakis(benzimidazol-2-yl)biphenyl (H-tbibp) and capped with different terminal ligands have been synthesized and examined. In addition, two monoruthenium complexes with H-tbibp have been prepared for the purpose of comparison studies. The degree of Ru–Ru electronic coupling of these diruthenium complexes has been investigated by electrochemical and intervalence charge-transfer (IVCT) analyses. These results suggest that when the same or similar terminal ligands are used, the strength of H-tbibp in mediating the Ru–Ru coupling is enhanced with respect to that of the previously reported bridging ligand 3,3′,5,5′-tetrakis(N-methylbenzimidazol-2-yl)biphenyl, but it is slightly inferior to that of the classical bridging ligand 3,3′,5,5′-tetrakis(pyrid-2-yl)biphenyl. This trend is also supported by CNS analyses based on the hole-superexchange mechanism. In addition, DFT calculations have been performed to probe the spin density distributions of the singly-oxidized diruthenium complexes with H-tbibp and TDDFT calculations are used to reproduce the IVCT transitions. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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