Photoreactivity of Fe 2S 2(CO) 6 originating from d σ* metal-to-ligand charge transfer excitation

Abstract

The longest-wavelength absorption of Fe 2S 2(CO) 6 near 460 nm is assigned to a metal-to-ligand charge transfer (MLCT) transition from the Fe–Fe bond to a S–S antibonding orbital. It is suggested that MLCT excitation leads to an oxidative addition. The primary photoproduct reacts with Fe 2S 2(CO) 6 to generate Fe 4S 4(CO) 12. This well known photodimerization proceeds with φ=0.045 at λ irr=436 nm.