Synthetic and Electrochemical Studies of [2Fe2S] Complexes Containing a 4‐Amino‐1,2‐dithiolane‐4‐carboxylic Acid Moiety

Apfel, Ulf‐Peter; Kowol, Christian R.; Morera, Enrico; Görls, Helmar; Lucente, Gino; Keppler, Bernhard K.; Weigand, Wolfgang

doi:10.1002/ejic.201000619

Cited by 9 publications

(8 citation statements)

References 44 publications

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“…Recently, there have been many attempts at finding complexes that are structurally related to the hydrogenases in the hopes that these models will have efficient molecular hydrogen producing capabilities similar to the natural [FeFe]-hydrogenase. − Many of the synthetic compounds contain the same butterfly structure as the hydrogenase, as well as similar ligands and bridge components, and their structures have been characterized using various methods. There has also been research directed toward investigating the catalytic activity of various models of [FeFe]-hydrogenase and how different structural characteristics affect the degree of catalytic activity. − …”

Section: Introductionmentioning

confidence: 99%

Time-Resolved Vibrational Spectroscopy of [FeFe]-Hydrogenase Model Compounds

et al. 2012

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Model compounds have been found to structurally mimic the catalytic hydrogen-producing active site of Fe-Fe hydrogenases and are being explored as functional models. The time-dependent behavior of Fe(2)(μ-S(2)C(3)H(6))(CO)(6) and Fe(2)(μ-S(2)C(2)H(4))(CO)(6) is reviewed and new ultrafast UV- and visible-excitation/IR-probe measurements of the carbonyl stretching region are presented. Ground-state and excited-state electronic and vibrational properties of Fe(2)(μ-S(2)C(3)H(6))(CO)(6) were studied with density functional theory (DFT) calculations. For Fe(2)(μ-S(2)C(3)H(6))(CO)(6) excited with 266 nm, long-lived signals (τ = 3.7 ± 0.26 μs) are assigned to loss of a CO ligand. For 355 and 532 nm excitation, short-lived (τ = 150 ± 17 ps) bands are observed in addition to CO-loss product. Short-lived transient absorption intensities are smaller for 355 nm and much larger for 532 nm excitation and are assigned to a short-lived photoproduct resulting from excited electronic state structural reorganization of the Fe-Fe bond. Because these molecules are tethered by bridging disulfur ligands, this extended di-iron bond relaxes during the excited state decay. Interestingly, and perhaps fortuitously, the time-dependent DFT-optimized exited-state geometry of Fe(2)(μ-S(2)C(3)H(6))(CO)(6) with a semibridging CO is reminiscent of the geometry of the Fe(2)S(2) subcluster of the active site observed in Fe-Fe hydrogenase X-ray crystal structures. We suggest these wavelength-dependent excitation dynamics could significantly alter potential mechanisms for light-driven catalysis.

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Section: Introductionmentioning

confidence: 99%

Time-Resolved Vibrational Spectroscopy of [FeFe]-Hydrogenase Model Compounds

et al. 2012

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“…However, this tripeptide provides little opportunity to tailor interactions with the metallocenter. To develop peptide models for [FeFe]-hydrogenases, methods have been developed to introduce [(μ-SRS)[Fe(CO) 3 ] 2 ] derivatives into peptides using both natural cysteine and an artificial dithiol modification − but, to date, peptide-based models of [NiFe]-hydrogenases are scarce. Jain and co-workers have constructed mononuclear [Ni(P Ph 2 N R 2 ) 2 ] 2+ complexes in which R is a mono or dipeptide, but their synthetic strategy necessarily imposes 4-fold symmetry on the peptide components and prevents direct modification of the metal first coordination sphere …”

Section: Introductionmentioning

confidence: 99%

Construction of Heterometallic Clusters in a Small Peptide Scaffold as [NiFe]-Hydrogenase Models: Development of a Synthetic Methodology

et al. 2012

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[NiFe]-hydrogenases are enzymes that catalyze the reversible interconversion of protons and hydrogen at a heterobimetallic site containing Ni and Fe. This organometallic site has served as an inspiration for the synthesis of a number of biomimetic complexes, but, unfortunately, most close structural mimics have shown little to no reactivity with either of the substrates for hydrogenases. This suggests that interactions between the metallo-active site and the protein scaffold are crucial in tuning reactivity. As a first step toward development of peptide-based models, in this paper we demonstrate a synthetic strategy for construction of peptide coordinated, cysteinyl thiolate bridged Ni-M complexes in which M is a hetero-organometallic fragment. We utilize the seven amino acid peptide ACDLPCG as a scaffold for construction of these peptide-coordinated metallocenters. This peptide binds Ni in an N(2)S(2) environment consisting of the amino terminus, an amide nitrogen, and the two cysteinyl thiolates. We show that these thiolates serve as reactive sites for formation of heterometallic complexes in which they serve as bridging ligands. The method is general, and a number of heterometallic fragments including Ru(η(6)-arene)(2+), M(CO)(4)(piperidine) for M = Mo and W, and Fe(2)(CO)(6) were successfully incorporated, and the resulting metallopeptides characterized via a range of spectroscopic techniques. This methodology serves as the first step to construction of hydrogenase peptidomimetics that incorporate defined outer coordination sphere interactions intended to tune reactivity.

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“…Well-known are those mimics bearing pyridine, bipyridine, or terpyridine moieties, − which are able to coordinate Ru complexes that can act as photosensitizers. Several Ru complexes are used as efficient photocatalysts to produce H 2 from diverse [FeFe]-hydrogenase mimics, although the process needs two equivalents of sacrificial oxidants (usually ascorbic acid or ascorbates) for each molecule of H 2 produced. , Additionally, ([(μ-SR) 2 Fe 2 (CO) 6 ]) fragments have been incorporated into peptide platforms, − CdSe quantum dots, polymer supports, , MOFs, , Si surfaces, − and others …”

Section: Introductionmentioning

confidence: 99%

Phosphite Bearing [(μ-ADT)^RFe₂(CO)₆] (ADT = Azadithiolate) Moieties: A Tool for the Building of Multimetallic [FeFe]-Hydrogenase Mimics

et al. 2023

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A new phosphite ligand having three [(μ-ADT) R Fe 2 (CO) 6 ] (R= p-HOC 6 H 4 ) moieties (2) has been prepared in good yield by the reaction of complex [(μ-ADT) R Fe 2 (CO) 6 ] (R= p-HOC 6 H 4 ) 1a with PCl 3 . Coordination of this phosphite to [PdCl 2 (MeCN) 2 ] or [PtCl 2 (DMSO) 2 ] forms heterometallic square planar complexes 5 (C 84 H 48 Cl 2 Fe 12 N 6 O 42 P 2 MS 12) (M = Pt, Pd) in e x c e l l e n t y i e l d s . T h r e e -l e g g e d p i a n o s t o o l c o m p l e x e s 6 (C 52 H 39 Cl 2 Fe 6 N 3 O 21 PMS 6 ) (M = Rh, Ir) were obtained by the reaction of phosphite 2 with [MCl 2 Cp*] 2 (M = Rh, Ir) in good yields. The formation of complexes 5 and 6 demonstrates the versatility of this new ligand for forming different heteropolymetallic complexes under mild reaction conditions.Moreover, the open-chain derivatives [(μ-ADT) R Fe 2 (CO) 6 ] (R= HOCH 2 CH 2 , o-HOC 6 H 4 ) (1b and 1c, respectively) form cyclic complexes 4 by spontaneous intramolecular CO substitution by the P atom in one of the three [FeFe] fragments. The electrocatalytic behavior of complexes 2 and 4 upon the addition of AcOH is similar to that of related [(μ-ADT)Fe 2 (CO) 6 ] derivatives. The successive additions of AcOH cause an increase in the current intensity in the wave at about −1.80 V for heteropolymetallic complexes 5 and 6. However, the appearance of a new wave around −1.40 V in complexes 5 points to an acid-promoted side reaction in the electrochemical process.

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Synthetic and Electrochemical Studies of [2Fe2S] Complexes Containing a 4‐Amino‐1,2‐dithiolane‐4‐carboxylic Acid Moiety

Cited by 9 publications

References 44 publications

Time-Resolved Vibrational Spectroscopy of [FeFe]-Hydrogenase Model Compounds

Time-Resolved Vibrational Spectroscopy of [FeFe]-Hydrogenase Model Compounds

Construction of Heterometallic Clusters in a Small Peptide Scaffold as [NiFe]-Hydrogenase Models: Development of a Synthetic Methodology

Phosphite Bearing [(μ-ADT)^RFe₂(CO)₆] (ADT = Azadithiolate) Moieties: A Tool for the Building of Multimetallic [FeFe]-Hydrogenase Mimics

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Synthetic and Electrochemical Studies of [2Fe2S] Complexes Containing a 4‐Amino‐1,2‐dithiolane‐4‐carboxylic Acid Moiety

Cited by 9 publications

References 44 publications

Time-Resolved Vibrational Spectroscopy of [FeFe]-Hydrogenase Model Compounds

Time-Resolved Vibrational Spectroscopy of [FeFe]-Hydrogenase Model Compounds

Construction of Heterometallic Clusters in a Small Peptide Scaffold as [NiFe]-Hydrogenase Models: Development of a Synthetic Methodology

Phosphite Bearing [(μ-ADT)RFe2(CO)6] (ADT = Azadithiolate) Moieties: A Tool for the Building of Multimetallic [FeFe]-Hydrogenase Mimics

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Phosphite Bearing [(μ-ADT)^RFe₂(CO)₆] (ADT = Azadithiolate) Moieties: A Tool for the Building of Multimetallic [FeFe]-Hydrogenase Mimics