A rhodium(I) dicarbonyl complex with a redox-active ferrocenyl phosphine-NHC ligand: Enhanced reactivity of the metal centre through ferrocene oxidation

A rhodium(l) dicarbonyl complex bearing a bidentate ferrocenyl phosphine-NHC ligand has been synthesized and characterized by NMR, IR spectroscopy, mass spectrometry and X-ray diffraction methods. Its behaviour towards oxidation was investigated and revealed that changing the oxidation state of ferrocene can significantly modify the electron density at rhodium. Oxidation of the rhodium(I) dicarbonyl complex in acetonitrile furnished an air-stable rhodium(III) complex, stabilized by acetonitrile molecules and with an interesting C-H bond activation at ferrocene. This new rhodium(III) complex is active for the hydrosilylation of acetophenone and its derivatives. (C) 2014 Elsevier Ltd. All rights reserved.