Ruthenium(II) Complexes Having a Pincer‐Type Ligand with Two N‐Heterocyclic Carbene Moieties
Abstract
Two novel RuII complexes, having 2,2′‐bipyridyl and a pincer‐type methylene‐bridged N‐heterocyclic carbene (NHC) ligand, were synthesized and characterized to evaluate the effects of structural features of the complexes on their redox and photochemical properties. The methylene‐bridged NHC ligand coordinated in a meridional manner and the isopropyl groups on the NHC rings exhibited intramolecular CH/π interaction with the 2,2′‐bipyridyl ligand, which played a role to strongly maintain the distorted ligand structure. In addition, the two Ru complexes exhibited reversible redox waves in the cyclic voltammograms and they were oxidized by an electron‐transfer oxidant to afford RuIII complexes, which were characterized by EPR spectroscopy and theoretical analyses.
