Synthesis, characterization and electrocatalysis of diiron propanediselenolate derivatives as the active site models of [FeFe]-hydrogenases

Di-, tri- and tetraphosphine-substituted Fe/Se carbonyls: Synthesis, Characterization and electrochemical properties

The active sites of [FeFe]-hydrogenase promoted by Fe/E (E=S, Se) clusters have attracted considerable interest due to their significance for understanding the interconversion of hydrogen with protons and electrons. As...

Mechanism of Diiron Hydrogenase Complexes Controlled by Nature of Bridging Dithiolate Ligand

Bio-inorganic complexes inspired by hydrogenase enzymes are designed to catalyze the hydrogen evolution reaction (HER). A series of new diiron hydrogenase mimic complexes with one or two terminal tris(4-methoxyphenyl)phosphine and different μ-bridging dithiolate ligands and show catalytic activity towards electrochemical proton reduction in the presence of weak and strong acids. A series of propane- and benzene-dithiolato-bridged complexes was synthesized, crystallized, and characterized by various spectroscopic techniques and quantum chemical calculations. Their electrochemical properties as well as the detailed reaction mechanisms of the HER are elucidated by density functional theory (DFT) methods. The nature of the μ-bridging dithiolate is critically controlling the reaction and performance of the HER of the complexes. In contrast, terminal phosphine ligands have no significant effects on redox activities and mechanism. Mono- or di-substituted propane-dithiolate complexes afford a sequential reduction (electrochemical; E) and protonation (chemical; C) mechanism (ECEC), while the μ-benzene dithiolate complexes follow a different reaction mechanism and are more efficient HER catalysts.

[FeFe]-Hydrogenases: maturation and reactivity of enzymatic systems and overview of biomimetic models

[FeFe]-hydrogenases recieved increasing interest in the last decades. This review summarises important findings regarding their enzymatic reactivity as well as inorganic models applied as electro- and photochemical catalysts.

Phosphine-substituted Fe–Te clusters related to the active site of [FeFe]-H2ases

Mono-, di-, and tetranuclear phosphine-substituted Fe/Te clusters 1–6 were described.

Electrocatalytic hydrogen production using [FeFe]-hydrogenase mimics based on tetracene derivatives

The synthesis, structure, physical properties, and electrocatalytic hydrogen production of tetrathiatetracene ligand based [FeFe]-hydrogenase mimic molecules were investigated.

Sulphur–sulphur, sulphur–selenium, selenium–selenium and selenium–carbon bond activation using Fe3(CO)12: an unexpected formation of an Fe2(CO)6 complex containing a μ2,κ3-C,O,Se-ligand

Four diiron hexacarbonyl-complexes containing dithiolato (5), diselenolato (6), selenolato-thiolato (7) and μ²,κ³-C,O,Se-ligands (8), respectively have been prepared as [FeFe]-hydrogenase mimics.

Selenium makes the difference: protonation of [FeFe]-hydrogenase mimics with diselenolato ligands

The synthetic models of the active site of an [FeFe]-hydrogenase containing a Sn atom in the bridgehead of the diselenato ligand, namely [Fe₂(CO)₆{μ-(SeCH₂Se)SnMe₂}],3and [Fe₂(CO)₆{μ-(SeCH₂)₂SnMe₂}],4have been synthesized and characterized by spectroscopic methods.

[FeFe]-Hydrogenase H-cluster mimics mediated by naphthalene monoimide derivatives of peri-substituted dichalcogenides

Synthetic models of the active site of [FeFe]-hydrogenase containing naphthalene monoimide as bridging linker.

Synthesis, characterization, and H/D exchange of μ-hydride-containing [FeFe]-hydrogenase subsite models formed by protonation reactions of (μ-TDT)Fe2(CO)4(PMe3)2 (TDT = SCH2SCH2S) with protic acids

The first TDT ligand-containing μ-hydride models of [FeFe]-hydrogenases (2–7) have been prepared and the H/D exchange reactions of 7 with deuterium reagents such as D₂, D₂O, and DCl are studied.

Steric effect of the dithiolato linker on the reduction mechanism of [Fe2(CO)6{μ-(XCH2)2CRR′}] hydrogenase models (X = S, Se)

Investigations of the electrochemical properties of [Fe₂(CO)₆{μ-(XCH₂)₂CRR′}] (X = S, Se; R or R′ = H or Me) showed that the complex with the bulkiest CMe₂moiety undergoes reduction with potential inversion.

[N,N′-Bis(2,6-diisopropylphenyl)acenaphthene-1,2-diimine-1κ2N,N′]heptacarbonyl-1κC,2κ3C,3κ3C-di-μ3-tellurido-triiiron(II)(2Fe—Fe)

The sterically hindered title complex, [Fe3Te2(C36H40N2)(CO)7], was obtained by substitution of two carbonyl groups in the [Fe3(μ3-Te)2(CO)9] cluster by the bulky redox-activeN,N′-bis(2,6-diisopropylphenyl)acenaphthene-1,2-diimine (dpp-BIAN) ligand. The asymmetric unit contains two molecules of the same geometry. The C=N bond lengths in dpp-BIAN indicate a rather low level of electron transfer from the cluster core to the dpp-BIAN ligand.