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

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