Synthesis and Electrocatalytic Activity of [FeFe]‐Hydrogenase Model Complexes with Non‐Innocent Chelating Nitrogen‐Donor Ligands

Biomimetics of [FeFe]-hydrogenases incorporating redox-active ligands: Synthesis, redox and spectroelectrochemistry of diiron-dithiolate complexes with ferrocenyl-diphosphines as Fe4S4 surrogates

[FeFe]-ase biomimics containing a redox-active ferrocenyl diphosphine have been prepared and their ability to reduce protons and oxidise H2 studied, including 1,1’-bis(diphenylphosphino)ferrocene (dppf) complexes Fe2(CO)4(-dppf)(-S(CH2)nS) (n = 2, edt; n...

Photocatalytic and electrocatalytic hydrogen production using nickel complexes supported by hemilabile and non-innocent ligands

Nickel complexes with non-innocent ligands generated by one-electron reduction of octahedral Schiff base nickel(ii) complexes with hemilabile ligands exhibited excellent catalytic activities of over 5000 TONs through a metal-ligand cooperation mechanism for hydrogen evolution from water under visible light irradiation.

The influence of phosphine ligand substituted [2Fe2S] model complexes as electro-catalyst on proton reduction

To probe the influence of phosphine ligand substitution on the well-known [2Fe2S] model, two new [FeFe]-hydrogenase model complexes with the phosphine ligands, PMe₃ or P(CH₃O)₃, were synthesized, such as μ-(SCH(CH₂CH₃)CH₂S)–Fe₂(CO)₅PMe₃1, and μ-(SCH(CH₂CH₃)CH₂S)–Fe₂(CO)₅P(CH₃O)₃2 Confirmation of structures was provided by FTIR, ¹H NMR, ¹³C NMR, ³¹P NMR, elemental analyses and single-crystal X-ray analysis. The crystal structure of complex 2 shows that the P(CH₃O)₃ ligand has less steric effect on the coordination geometry of the Fe atom than the PMe₃ ligand. In the presence of HOAc in CH₃CN solution, the hydrogen evolution overpotentials of complexes 1 and 2 were 0.91 V and 0.81 V, respectively. Comparatively, complex 2 produces hydrogen at an overpotential of 0.1 V, lower than that for complex 1. A further electrocatalytic study showed the maximum charges for 1 and 2 were 31.3 mC and 56.3 mC at −2.30 V for 10 min, respectively. These studies showed that the complexes 1 and 2 have the ability, as novel electrocatalysts, for catalysis of hydrogen production, and complex 2 has better electrocatalytic ability than complex 1.

To probe the influence of phosphine ligand substitution on the well-known [2Fe2S] model, two new [FeFe]-hydrogenase model complexes with the phosphine ligands, PMe₃ or P(CH₃O)₃, were synthesized.