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Metal Chelation-Assisted Amine-Amine Electronic Coupling through the 4,4'-Positions of 2,2'-Bipyridine.
- Source :
-
Inorganic Chemistry . 2/16/2015, Vol. 54 Issue 4, p1272-1282. 11p. - Publication Year :
- 2015
-
Abstract
- A redox-active diamine ligand, 4,4'-bis(di-p-anisylamino)-2,2'-bipyridine (NNbpy), has been prepared. Electrochemical and spectroscopic studies suggest that little electronic coupling is present between two amine groups in NNbpy. After chelation with Ru(bpy)2 (bpy is 2,2'-bipyridine), the resulting complex displays two N·+/0 processes at +1.02 and +1.16 V versus Ag/AgCl. In the mixed-valent state, rich near-infrared absorptions have been observed, which are believed to consist of multiple metal-to-ligand charge transfer and intervalence charge transfer transitions in the low-energy region. These results suggest that the amine-amine electronic coupling has been enhanced by chelation with Ru(bpy)2. In contrast, no efficient electronic coupling can be realized by chelation with Ir(ppy)2 (ppy is 2'-phenylpyridine) or Re(CO)3Cl. A ruthenium ion-mediated electron transfer mechanism, instead of through-space coupling, has been proposed to explain this phenomenon. For the purpose of comparison, a monoamine-substituted bpy ligand and corresponding Ru(bpy)2 complex have been synthesized and studied. In addition, EPR, DFT, and TDDFT studies have been performed to complement the experimental results [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00201669
- Volume :
- 54
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- Inorganic Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 101504554
- Full Text :
- https://doi.org/10.1021/ic5024967