Synthetic Designs and Structural Investigations of Biomimetic Ni–Fe Thiolates

Abstract

Described are the syntheses of several Ni(μ-SR) 2 Fe complexes, including hydride derivatives, in a search for improved models for the active site of [NiFe]-hydrogenases. The nickel(II) precursors include (i) nickel with tripodal ligands: Ni(PS 3 ) − and Ni(NS 3 ) − (PS 3 3-= tris(phenyl-2thiolato)phosphine, NS 3 3-= tris(benzyl-2-thiolato)amine) (ii) traditional diphosphine-dithiolates, including chiral diphosphine R,R-DIPAMP, (iii) cationic Ni(phosphine-imine/amine) complexes,

Computational and Experimental Studies on Dual Bridged Bimetallic Catalyst Enabled by the Synergistic Effect of Lewis Acid and eg Orbital Interaction

“…(3) The mono-SPO mechanistic model proposed by previous studies could be suspicious due to lack of evidence. We suggested a new dual-phosphinito bridged Ni-Al complex (dual-SPO) to be an active catalyst shown in scheme 1c, which is quite similar to the structure of double thio-bridged nickel-iron hydrogenase in biological chemistry 41,42 . Further NMR study and computational study provided more evidences and applications for this novel model in this work.…”

Heteroleptic nickel complexes bearing O‐methyldithiophosphate and aminodiphosphine monosulfide ligands as robust molecular electrocatalysts for hydrogen evolution

“…Biocatalysts, such as [FeFe]-and [NiFe]-hydrogenases that efficiently and reversibly catalyze hydrogen evolution and oxidation in biological systems, encourage sciences to mimic their active sites. [5][6][7][8][9][10] Alternatively, noble metals such as platinum and palladium are always known as excellent catalysts for production and oxidation of hydrogen. However, bio-enzymes are difficult to adapt for the commercial applications, and the stability is often limited outside of the native environment, [11] as well as the scarcity and high cost of platinum and palladium limit the widespread application for hydrogen production.…”

“…[18] Because of the P S fragment in the thiophosphorylated calix [4]resorcinol ligand, the nickel atom is in a S 4 coordination sphere, leading to the nickel complexes can mimic the active sites of [NiFe]-hydrogenases, in which the nickel atom is also coordinated to four sulfur atoms. [7] The aminodiphosphine monosulfide as a hemilabile ligand continues to attract much attentions owing to the diversity in the coordination modes (mainly incorporate the P-monodentate and the hybrid P,S-chelate ligands). Furthermore, particularly, both the five-membered chelate ring and/or the P,P S donor set and the nature of the N-substituent influence the catalytic performances of the metal complexes.…”

High Turnover Frequency H2 Evolution Electrocatalysis at Low Acid Concentration Promoted by Bioinspired (NCS2)Ni(II) Complexes

“…[17][18][19] Further 1H + /1ereduction of the Ni-C state leads to the Ni-R state that releases H2 and regenerates the Ni-SIa state to complete the catalytic cycle. These Ni-L and Ni-C states of [NiFe] hydrogenases have been the inspiration for designing biomimetic catalysts for HER or HOR, 16,[20][21][22][23][24][25] however research efforts to utilize those catalysts in practical devices have had limited success. Furthermore, there are very few reports on the synthesis of complexes proposed to contain a Ni III -H species, 16,[26][27][28] Although recently molecular electrocatalysts bearing first-row transition metals such as nickel, [29][30][31][32] cobalt, [33][34][35] or iron [36][37][38] have gained significant recognition in the library of different catalysts for HER, the formation of H2 from 2H + and 2ewith high turnover under mild conditions is still challenging despite its thermodynamic simplicity.…”