An Iron(III) Dithiolene Complex as a Functional Model of Iron Hydrogenase

An Iron(III) Dithiolene Complex as a Functional Model of Iron Hydrogenase:

The iron(III) dithiolene complex [PPh₄]₂[Fe(mnt)₂(SPh)] (1, mnt = maleonitrile dithiolate) has a highly distorted square-pyramidal geometry and an intermediate spin ferric ion (S_Fe = 3/2), and catalyzes electrochemical H₂ evolution at the lowest achievable reduction potential known for iron-containing electrocatalytic systems to date: E_p = –0.309 V in CH₃CN and E_p = –0.53 V in water vs. Ag/AgCl using a modified glassy carbon working electrode. Control experiments suggest that the electrochemical H₂ evolution at low potential is promoted by metal-assisted protonation at the S donors of the thiophenolato and mnt ligands, which liberate H₂ gas upon electrochemical reduction.

The iron(III) dithiolene complex [PPh₄]₂[Fe(mnt)₂(SPh)] (1) has a highly distorted square-pyramidal geometry and an intermediate spin ferric ion, which catalyzes electrochemical H₂ evolution at the lowest achievable reduction potential known to date: E_p = –0.309 V in CH₃CN and E_p = –0.53 V in H₂O.

Sarkar, EJIC. Maria to check overpotential and rate please