Geometrical influence on the non-biomimetic heterolytic splitting of H by bio-inspired [FeFe]-hydrogenase complexes: a rare example of frustrated Lewis pair based reactivity.

Despite the high levels of interest in the synthesis of bio-inspired [FeFe]-hydrogenase complexes, H oxidation, which is one specific aspect of hydrogenase enzymatic activity, is not observed for most reported complexes. To attempt H-H bond cleavage, two disubstituted diiron dithiolate complexes in the form of [Fe(μ-pdt)L(CO)] (L: PMe, dmpe) have been used to play the non-biomimetic role of a Lewis base, with frustrated Lewis pairs (FLPs) formed in the presence of B(CF) Lewis acid. These unprecedented FLPs, based on the bimetallic Lewis base partner, allow the heterolytic splitting of the H molecule, forming a protonated diiron cation and hydrido-borate anion.