The BIAN ligand 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene: An electron sponge or a “normal” α-diimine ligand?

Despite a capacity for multistep reduction there is no evidence for special multielectron transfer behavior of the BIAN ligand system in carbonylmetal complexes beyond the established two-electron process for CO2/CO conversion.