Modeling [FeFe] hydrogenase: Synthesis and protonation of a diiron dithiolate complex containing a phosphine-N-heterocyclic-carbene ligand

Morvan, Didier Le; Capon, Jean‐François; Gloaguen, Frédéric; Pétillon, François Y.; Schollhammer, Philippe; Talarmin, Jean; Yaouanc, Jean‐Jacques; Michaud, François; Kervarec, Nelly

doi:10.1016/j.jorganchem.2009.01.018

Cited by 47 publications

(21 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nonetheless, protonation of related complexes that lack the amine also can occur at a single Fe center. 13,15,16,19,40,41 We provide evidence that this regiochemistry results from initial protonation at sulfur followed by proton transfer to one Fe center.…”

Section: Discussionmentioning

confidence: 76%

Terminal vs Bridging Hydrides of Diiron Dithiolates: Protonation of Fe₂(dithiolate)(CO)₂(PMe₃)₄

et al. 2012

View full text Add to dashboard Cite

This investigation examines the protonation of diiron dithiolates, exploiting the new family of exceptionally electron-rich complexes Fe2(xdt)(CO)2(PMe3)4, where xdt is edt (ethanedithiolate, 1), pdt (propanedithiolate, 2), and adt (2)aza-1,3-propanedithiolate, 3), prepared by the photochemical substitution of the corresponding hexacarbonyls. Compounds 1-3 oxidize near −950 mV vs Fc+/0. Crystallographic analyses confirm that 1 and 2 adopt C2-symmetric structures (Fe-Fe = 2.616, 2.625 Å, respectively). Low temperature protonation of 1 afforded exclusively [μ-H1]+, establishing the nonintermediacy of the terminal hydride ([t-H1]+). At higher temperatures, protonation afforded mainly [t-H1]+. The temperature dependence of the ratio [t-H1]+/[μ-H1]+ indicates that the barriers for the two protonation pathways differ by ~4 kcal/mol. Low temperature 31P{1H} NMR measurements indicate that the protonation of 2 proceeds by an intermediate, proposed to be the S-protonated dithiolate [Fe2(Hpdt)(CO)2(PMe3)4]+ ([S-H2]+). This intermediate converts to [t)H2]+ and [μ)H2]+ by a first order process (t1/2 ~ 2.5 h, 20 °C). Protonation of the 3 affords exclusively terminal hydrides, regardless of the acid or conditions to give [t-H3]+, which isomerizes to [t-H3′]+ wherein all PMe3 ligands are basal. DFT calculations support transient protonation at sulfur and the proposal that the S-protonated species (e.g., [S-H2]+) rearranges to the terminal hydride intramolecularly via a low energy pathway.

show abstract

Section: Discussionmentioning

confidence: 76%

Terminal vs Bridging Hydrides of Diiron Dithiolates: Protonation of Fe₂(dithiolate)(CO)₂(PMe₃)₄

et al. 2012

View full text Add to dashboard Cite

show abstract

“…During the last few years, diiron complexes with bidentate ligands, such as diphosphine [16][17][18][19][20], phenanthroline [21,22] or carbene [23][24][25] were synthesized and their effect on the bimetallic site was appraised. Numerous functionalities with specific electronic and steric effects could be introduced in diiron systems through these chelating groups [26,27].…”

Section: Introductionmentioning

confidence: 99%

Non-innocent bma ligand in a dissymetrically disubstituted diiron dithiolate related to the active site of the [FeFe] hydrogenases

Charreteur

Capon

et al. 2010

Journal of Inorganic Biochemistry

Self Cite

View full text Add to dashboard Cite

“…Linear sweep voltammetry of 1 , while probing the IR spectrum, reveals bleaching of IR signals associated to the neutral complex, concomitant with the appearance of new red‐shifted bands assigned to the reduced species 1 – (Figure a). The absorption‐difference spectra show a small band growing in at 1730 cm –1 , which is characteristic for reduced diiron compounds with a bridging carbonyl ligand , . Complex 2 shows similar bands in its IR spectrum upon reduction (Figure b).…”

Section: Resultsmentioning

confidence: 92%

[FeFe]‐Hydrogenase Mimic Employing κ²‐C,N‐Pyridine Bridgehead Catalyzes Proton Reduction at Mild Overpotential

et al. 2019

View full text Add to dashboard Cite

Two novel κ2‐C,N‐pyridine bridged [FeFe]‐H2ase mimics (1 and 2) have been prepared and are shown to function as efficient molecular catalysts for electrocatalytic proton reduction. The elemental and structural composition of the complexes are confirmed by NMR and IR spectroscopy, high‐resolution mass spectrometry and single‐crystal X‐ray diffraction. Electrochemical investigations reveal that the complexes reduce protons at their first reduction potential, resulting in the lowest overpotential (120 mV) ever reported for [FeFe]‐H2ase mimics in proton reduction catalysis when mild acid (phenol) is used as proton source.

show abstract

Modeling [FeFe] hydrogenase: Synthesis and protonation of a diiron dithiolate complex containing a phosphine-N-heterocyclic-carbene ligand

Cited by 47 publications

References 69 publications

Terminal vs Bridging Hydrides of Diiron Dithiolates: Protonation of Fe₂(dithiolate)(CO)₂(PMe₃)₄

Terminal vs Bridging Hydrides of Diiron Dithiolates: Protonation of Fe₂(dithiolate)(CO)₂(PMe₃)₄

Non-innocent bma ligand in a dissymetrically disubstituted diiron dithiolate related to the active site of the [FeFe] hydrogenases

[FeFe]‐Hydrogenase Mimic Employing κ²‐C,N‐Pyridine Bridgehead Catalyzes Proton Reduction at Mild Overpotential

Contact Info

Product

Resources

About

Modeling [FeFe] hydrogenase: Synthesis and protonation of a diiron dithiolate complex containing a phosphine-N-heterocyclic-carbene ligand

Cited by 47 publications

References 69 publications

Terminal vs Bridging Hydrides of Diiron Dithiolates: Protonation of Fe2(dithiolate)(CO)2(PMe3)4

Terminal vs Bridging Hydrides of Diiron Dithiolates: Protonation of Fe2(dithiolate)(CO)2(PMe3)4

Non-innocent bma ligand in a dissymetrically disubstituted diiron dithiolate related to the active site of the [FeFe] hydrogenases

[FeFe]‐Hydrogenase Mimic Employing κ2‐C,N‐Pyridine Bridgehead Catalyzes Proton Reduction at Mild Overpotential

Contact Info

Product

Resources

About

Terminal vs Bridging Hydrides of Diiron Dithiolates: Protonation of Fe₂(dithiolate)(CO)₂(PMe₃)₄

Terminal vs Bridging Hydrides of Diiron Dithiolates: Protonation of Fe₂(dithiolate)(CO)₂(PMe₃)₄

[FeFe]‐Hydrogenase Mimic Employing κ²‐C,N‐Pyridine Bridgehead Catalyzes Proton Reduction at Mild Overpotential