Intramolecular hydrogen bonding interaction, a mechanism for the bridging linkages to exert electronic influence on diiron models of [FeFe]-hydrogenase

The bridging linkages affect significantly the electrochemical behaviours of the diiron carbonyl complexes via alternating both the compositions and energies of the frontier orbitals. DFT calculations reveal that the electronic effect exerted by bridging linkages is not only achieved through intramolecular hydrogen bonding interactions, but also the direct bonding between the iron core and the bridging linkages.