Structural and functional synthetic model of mono-iron hydrogenase featuring an anthracene scaffold

Mono-iron hydrogenase was the third type of hydrogenase discovered. Its Lewis acidic iron( II ) centre promotes the heterolytic cleavage of the H–H bond and this non-redox H 2 activation distinguishes it from the well-studied dinuclear [FeFe] and [NiFe] hydrogenases. Cleavage of the H–H bond is followed by hydride transfer to the enzyme's organic substrate, H 4 MPT + , which serves as a CO 2 ‘carrier’ in methanogenic pathways. Here we report a scaffold-based synthetic approach by which to model mono-iron hydrogenase using an anthracene framework, which supports a biomimetic fac - C , N , S coordination motif to an iron( II ) centre. This arrangement includes the biomimetic and organometallic Fe–C σ bond, which enables bidirectional activity reminiscent of the native enzyme: the complex activates H 2 under mild conditions, and catalyses C–H hydride abstraction plus H 2 generation from a model substrate. Notably, neither H 2 activation nor C–H hydride abstraction was observed in the analogous complex with a pincer-type mer - C , N , S ligation, emphasizing the importance of the fac - C , N , S -iron( II ) motif in promoting enzyme-like reactivity. Mono-iron hydrogenase promotes the heterolytic cleavage of H 2 and subsequent hydride transfer to its organic substrate, H 4 MPT + , which serves as a CO 2 ‘carrier’ in methanogenic pathways. Now, using an anthracene-scaffold-based approach, a synthetic model featuring enzyme-like Fe- C,N,S facial coordination has been developed. The model complex enables the bidirectional activity of H 2 activation and evolution.