Non-innocent ligand reservoirs for reducing or oxidizing equivalents in carbonylrhenium(I) complexes: 1,1′-Bis(diphenylphosphino)ferrocene (dppf) and bis-triazinyl-pyridine (BTP)

Organometallic complexes of Re(I) with ligands having opposite redox properties have been synthesized and structurally characterized. X-ray crystal structures of the complexes show typical fac-Re-I(CO)(3) coordination to the redox active ligands. Complete electrochemical and spectroelectrochemical studies on the ligands and the metal complexes were performed. The IR-spectroelectrochemical responses were monitored using the fac-Re(CO)(3) unit as a probe. The 15-20 cm(-1) hypsochromic or bathochromic shift of the nu(CO) bands upon reduction or oxidation is attributed to ligand-centered processes. (C) 2011 Elsevier B.V. All rights reserved.