A rare bond between a soft metal (FeI) and a relatively hard base (RO−, R = phenolic moiety)

Reacting a bidentate ligand H2L, 2-(2-methoxybenzyl)-2-methylpropane-1,3-dithiol, with Fe3(CO)12 formed a diiron hexacarbonyl complex (1Me) from which a diiron hexacarbonyl complex (1H) pendant with a phenolic group was derived via in-situ demethylation. Further deprotonation of complex 1H gave a diiron pentacarbonyl species (1) in which a rare bond between the soft metal FeI and the relatively hard base phenolate formed, FeI-OR (R = phenolic moiety). This bonding may be a suitable mimic of the bonding feature, {FeIFeI}R-OH/OH2 found in the [FeFe]-hydrogenase.

Graphical abstractDeprotonation of complex 1H led to the formation of a diiron pentacarbonyl species 1, possibly via an anionic intermediate, which possesses a rare bond between a soft metal FeI and relatively hard base phenolate and ought to have some relevance to the structural feature, {FeIIFeI}–OH2/OH−, found in the diiron sub-unit of [FeFe]-hydrogenase.Figure optionsDownload full-size imageDownload as PowerPoint slide