Monitoring ECE transformations of metal carbonyls by in situ spectroelectrochemistry; SNIFTIRS of [Co3(CO)9C]2

An in situ subtractively normalised interfacial FTIR spectroscopy (SNIFTIRS) investigation of [Co 3 (CO) 9 C] 2 in dichloromethane is used to illustrate the application of these techniques to follow ECE transformations of metal carbonyls in a thin layer cell. SNIFTIRS data obtained at a platinum electrode show that the major species at ambient temperature is not the radical anion [Co 3 (CO) 9 C] 2 − . Within the timescale of the measurement [Co 3 (CO) 9 C] 2 − transforms to a new species with a bridged carbonyl configuration; this species forms a chemically reversible redox couple in the thin layer. The consequences for the redox chemistry of [Co 3 (CO) 9 C] 2 are discussed.