Electrocatalytic proton reduction by [Fe(CO)2(κ2-dppv)(κ1-SAr)2] (dppv = cis-1,2-bis(diphenylphosphino)ethylene; Ar = C6F5, C6H5, C6H4CH3-p)

DOI: 10.1016/j.poly.2017.08.008

Authors: Shishir Ghosh (University College London; Jahangirnagar University) , Nathan Hollingsworth (University College London) , Mark Warren (Diamond Light Source) , Katherine B. Holt (University College London) , Graeme Hogarth (King’s College London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Polyhedron

State: Published (Approved)
Published: August 2017

Abstract: Electrocatalytic reduction of protons to hydrogen by mononuclear iron complexes which are developed as models of the distal iron center of [FeFe]-hydrogenase active site are described. A series of iron(II) bis(thiolate) complexes [Fe(CO)2(κ2-dppv)(κ1-SAr)2] (1, Ar = C6F5; 2, Ar = C6H4; 3, Ar = C6H4CH3-p; dppv = cis-1,2-bis(diphenylphosphino)ethylene) have been prepared from direct reactions between the corresponding hexacarbonyl [Fe2(CO)6(μ-SAr)2] and dppv at elevated temperatures. Structurally they are similar being coordinated by a chelating dppv, two carbonyls and two thiolato ligands bonded in an all cis-arrangement. Solution spectroscopic data indicate that they exist in two isomeric forms in solution. All reversibly protonate at sulphur atom(s) upon addition of HBF4·Et2O and lose a thiolate ligand as thiol. They show a common quasi-reversible reductive feature (attributed to the FeII/FeI couple) in their CVs in addition to other redox responses and are able to catalyze reduction of protons to hydrogen at their Fe(I) oxidation state in presence of HBF4·Et2O. Complex 1 is the most efficient catalyst and catalyzes proton reduction at ca. –1.5 V showing icat/ip ≥ 46 in the presence of ten equivalents of HBF4·Et2O.

Journal Keywords: Iron(II) complexes; Thiolate; Diphosphine; Hydrogenase biomimics; Electrocatalysis

Subject Areas: Chemistry


Instruments: I19-Small Molecule Single Crystal Diffraction

Added On: 23/08/2017 10:19

Discipline Tags:

Molecular Complexes Physical Chemistry Catalysis Chemistry

Technical Tags:

Diffraction Single Crystal X-ray Diffraction (SXRD)