Synthesis and catalytic properties of an iron(III) complex supported by amine-bis(phenolate) ligand

Abstract

The reaction of FeCl3 with 2-tetrahydrofuranylamino-N,N-bis(2-methylene-4-ethyl-6-tert-butylphenol), H2[O3N]BuEtTHF (H2L) affords a new iron(III) complex, [LFeCl] 1, whose structure has been determined by X-ray crystallography. Electrochemical studies show that 1 can electrocatalyze hydrogen evolution both from acetic acid with a turnover frequency (TOF) of 39.98 mol of hydrogen per mole of catalyst per hour at an overpotential of 941.6 mV (in DMF) and water with a TOF of 284.29 mol of hydrogen per mole of catalyst per hour at an overpotential of 896.8 mV (in buffer, pH 7.0). Sustained water reduction catalysis occurs at glassy carbon to give H2 over a 2 h electrolysis period with 95.81% faradaic yield and no observable decomposition of the catalyst.