Distorted Square Planar Ni(II)−Chalcogenolate Carbonyl Complexes [Ni(CO)(SPh)n(SePh)3-n]-(n= 0, 1, 2):  Relevance to the Nickel Site in CO Dehydrogenases and [NiFeSe] Hydrogenase

Liaw, Wen‐Feng; Horng, Yih-Chern; Ou, Der-Shiaw; Ching, Chao-Yi; Lee, Gene‐Hsiang; Peng, Shie‐Ming

doi:10.1021/ja971705c

Cited by 49 publications

(21 citation statements)

References 31 publications

(28 reference statements)

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“…All structures starting with either carefully chosen trigonal bipyramidal, or square pyramidal geometries, converge to four‐coordinate structures with the additional ligand (either CO or H 2 O) detached from the Ni center, with or without Grimme's D3 dispersion correction . Additionally, there have been several reports since the original work investigating this catalyst that have found crystal structures of square planar Ni(II), often serving as structural models of the same CODH enzyme, albeit often distorted . These observations support the suggestion that the iminothiolate ligand is indeed unique in making the Ni center softer than the usual Ni(II), thus, facilitating π‐backbonding to CO, yielding an interesting target for spectroscopic characterization.…”

Section: Resultssupporting

confidence: 62%

Mechanistic study of CO/CO₂ conversion catalyzed by a biomimetic Ni(II)‐iminothiolate complex

Rudshteyn

Warnke

et al. 2017

Int J of Quantum Chemistry

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We investigate the CO oxidation into CO 2 catalyzed by a biomimetic Ni(II)-iminothiolate complex in the presence of the sacrificial oxidizing agent methylviologen. We propose a catalytic mechanism supported by the density functional theory analysis of reaction intermediates that agrees with available experimental observations and kinetic data. We rule out a fivecoordinate Ni(II) species as well as a Ni(III) intermediate which was previously proposed and instead identify a key four-coordinate Ni(II) carbonyl species. We find that the turnoverlimiting step is likely the formation of the Ni(II) carboxylic acid species, although if a worse oxidant were used or if the concentration was less, then the oxidation of the Ni(I) species would be the turnover-limiting step. The reported findings should enable the design of better catalysts to favor one of the two competing pathways for CO to CO 2 conversion as catalyzed by this particular complex.catalytic mechanism, CO oxidation, CO 2 conversion, DFT, nickel catalyst 1 | I N TR ODU C TI ON CO/CO 2 conversion is central to a wide range of reaction mechanisms from carbon metabolism in biology to H 2 production in industrial applications based on the water-gas shift reaction. [1] The conversion mechanism could also provide meaningful insights into the reverse reaction that converts the greenhouse gas CO 2 into CO, a key intermediate on the path to liquid fuels. [2][3][4] In Nature, reversible CO/CO 2 conversion is catalyzed by the natural enzyme carbon monoxide dehydrogenase (CODH) which has a catalytically active Ni(II) center, [5][6][7][8] We focus on a Ni(II)-iminothiolate catalyst, proposed and synthesized by Crabtree and coworkers as a functional biomimetic CODH model system (Scheme 1). The Ni(II)-iminothiolate complex converts CO to CO 2 at room temperature in the water/methanol mixed solvent (Scheme 2) in the presence of the oxidizing agent methylviologen (mv 21 ) and acetate (AcO -) as a weak base. [9,10] A five-step catalytic cycle has been suggested for the mechanism of CO to CO 2 conversion, [9,10] in which the decarboxylation of LNi I -CO 2 is the turnover limiting step, as supported by the overall reaction rate dependence on P CO , [mv 21 ], [H 2 O], [Ni], and solution pH. However, the proposed intermediates have yet to be supported (or, otherwise ruled out) by spectroscopic and theoretical studies.Herein, we carry out a theoretical analysis of the catalytic mechanism at the density functional theory (DFT) level. The reported findings provide valuable insights into the reaction intermediates as well as guidelines for computational design of molecular catalysts for CO 2 /CO conversion in this class of compounds, using inverse design methodologies demonstrated for other systems. [11] Yueshen Wu and Benjamin Rudshteyn contributed equally to this study.Int J Quantum Chem. 2018;118:e25555.We have analyzed for the first time the catalytic mechanism of CO/CO 2 conversion by the Ni(II)-iminothiolate catalyst at the DFT level. Our results and direct comparisons to experime...

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Section: Resultssupporting

confidence: 62%

Mechanistic study of CO/CO₂ conversion catalyzed by a biomimetic Ni(II)‐iminothiolate complex

Rudshteyn

Warnke

et al. 2017

Int J of Quantum Chemistry

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“…The best fit of the Se EXAFS data for both HDR samples is a model that contains one Se–C bond (at 1.98 Å) and one Se–Fe interaction at ∼2.4 Å (Table 1, fits 10, 13). The Cambridge Structural Database (Wavefunction, Inc.) was searched for Fe–Se–C fragments, from which a chemically reasonable average Se–Fe bond distance of 2.42 ± 0.02 Å was found [10–16], consistent with our determination of 2.41 Å for HDR + CoM–SeH.…”

Section: Discussionsupporting

confidence: 66%

“…d Values in square brackets were fixed during optimization. 11,14). Apparently, Se-Se and Se-Fe scattering have sufficiently similar phase that they are difficult to distinguish a priori.…”

Section: Discussionmentioning

confidence: 99%

Direct interaction of coenzyme M with the active‐site Fe–S cluster of heterodisulfide reductase

et al. 2005

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Heterodisulfide reductase (HDR) catalyzes the formation of coenzyme M (CoM-SH) and coenzyme B (CoB-SH) by the reversible reduction of the heterodisulfide, CoM-S-S-CoB. This reaction recycles the two thiol coenzymes involved in the final step of microbial methanogenesis. Electron paramagnetic resonance (EPR) and variable-temperature magnetic circular dichroism spectroscopic experiments on oxidized HDR incubated with CoM-SH revealed a S = 1/2 [4Fe-4S] 3+ cluster, the EPR spectrum of which is broadened in the presence of CoM-33 SH [Duin, E.C., Madadi-Kahkesh, S., Hedderich, R., Clay, M.D. . These results provide indirect evidence that the disulfide binds to the iron-sulfur cluster during reduction. We report here direct structural evidence for this interaction from Se X-ray absorption spectroscopic investigation of HDR treated with the selenium analog of coenzyme M (CoM-SeH). Se K edge extended X-ray absorption fine structure confirms a direct interaction of the Se in CoM-SeH-treated HDR with an Fe atom of the Fe-S cluster at an Fe-Se distance of 2.4 Å .

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“…The Fe(1)-C(3) bond [1.96(4) and 1.92(5) Å ] is elongated with respect to a pure terminal Fe II -alkylidene, revealing a vinyl character [52][53][54][55]. The Fe(1)-Se(1) distance [2.391(8) and 2.357(9) Å ] is in keeping with previously reported iron(II)-selenide bonds [56][57][58][59][60]. The perfectly planar five-membered ring [mean deviation from the Fe(1)-Se(1)-C(1)-C(2)-C(3) least-squares plane 0.0094 and 0.0409 Å ] can be described as a zwitterionic ferra-selenophene-iminium, and to the best of our knowledge is unprecedented in organometallic chemistry.…”

Section: Synthesis and Characterization Of Compoundssupporting

confidence: 86%

Mono-, Di- and Tetra-iron Complexes with Selenium or Sulphur Functionalized Vinyliminium Ligands: Synthesis, Structural Characterization and Antiproliferative Activity

Agonigi

Batchelor

Ferretti³

et al. 2020

Molecules

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A series of diiron/tetrairon compounds containing a S- or a Se-function (2a–d, 4a–d, 5a–b, 6), and the monoiron [FeCp(CO){SeC1(NMe2)C2HC3(Me)}] (3) were prepared from the diiron μ-vinyliminium precursors [Fe2Cp2(CO)( μ-CO){μ-η1: η3-C3(R’)C2HC1N(Me)(R)}]CF3SO3 (R = R’ = Me, 1a; R = 2,6-C6H3Me2 = Xyl, R’ = Ph, 1b; R = Xyl, R’ = CH2OH, 1c), via treatment with S8 or gray selenium. The new compounds were characterized by elemental analysis, IR and multinuclear NMR spectroscopy, and structural aspects were further elucidated by DFT calculations. The unprecedented metallacyclic structure of 3 was ascertained by single crystal X-ray diffraction. The air-stable compounds (3, 4a–d, 5a–b, 6) display fair to good stability in aqueous media, and thus were assessed for their cytotoxic activity towards A2780, A2780cisR, and HEK-293 cell lines. Cyclic voltammetry, ROS production and NADH oxidation studies were carried out on selected compounds to give insights into their mode of action.

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Distorted Square Planar Ni(II)−Chalcogenolate Carbonyl Complexes [Ni(CO)(SPh)_n(SePh)_3-n]^-(n= 0, 1, 2): Relevance to the Nickel Site in CO Dehydrogenases and [NiFeSe] Hydrogenase

Cited by 49 publications

References 31 publications

Mechanistic study of CO/CO₂ conversion catalyzed by a biomimetic Ni(II)‐iminothiolate complex

Mechanistic study of CO/CO₂ conversion catalyzed by a biomimetic Ni(II)‐iminothiolate complex

Direct interaction of coenzyme M with the active‐site Fe–S cluster of heterodisulfide reductase

Mono-, Di- and Tetra-iron Complexes with Selenium or Sulphur Functionalized Vinyliminium Ligands: Synthesis, Structural Characterization and Antiproliferative Activity

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Distorted Square Planar Ni(II)−Chalcogenolate Carbonyl Complexes [Ni(CO)(SPh)n(SePh)3-n]-(n= 0, 1, 2): Relevance to the Nickel Site in CO Dehydrogenases and [NiFeSe] Hydrogenase

Cited by 49 publications

References 31 publications

Mechanistic study of CO/CO2 conversion catalyzed by a biomimetic Ni(II)‐iminothiolate complex

Mechanistic study of CO/CO2 conversion catalyzed by a biomimetic Ni(II)‐iminothiolate complex

Direct interaction of coenzyme M with the active‐site Fe–S cluster of heterodisulfide reductase

Mono-, Di- and Tetra-iron Complexes with Selenium or Sulphur Functionalized Vinyliminium Ligands: Synthesis, Structural Characterization and Antiproliferative Activity

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Distorted Square Planar Ni(II)−Chalcogenolate Carbonyl Complexes [Ni(CO)(SPh)_n(SePh)_3-n]^-(n= 0, 1, 2): Relevance to the Nickel Site in CO Dehydrogenases and [NiFeSe] Hydrogenase

Mechanistic study of CO/CO₂ conversion catalyzed by a biomimetic Ni(II)‐iminothiolate complex

Mechanistic study of CO/CO₂ conversion catalyzed by a biomimetic Ni(II)‐iminothiolate complex