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 ν_CO bands upon reduction or oxidation is attributed to ligand-centered processes.