Transient FTIR spectroelectrochemical and stopped-flow detection of a mixed valence {Fe(I)-Fe(II)} bridging carbonyl intermediate with structural elements and spectroscopic characteristics of the di-iron sub-site of all-iron hydrogenase

Iron( I) in biology?: one-electron oxidation of an {Fe(I)-Fe(I)} carbonyl cyanide precursor bearing a proximal thioether group leads to an {Fe(I)- Fe(II)} bridging carbonyl transient with spectral features similar to the di-iron sub-site of the CO inhibited paramagnetic centre of all-iron hydrogenase.