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He J, Wei J, Xu G, Chen XD. Stepwise Construction of Mo-Fe-S Clusters Using a LEGO Strategy. Inorg Chem 2022; 61:4150-4158. [PMID: 35200007 DOI: 10.1021/acs.inorgchem.1c03998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The rational synthesis of iron-sulfur clusters with excellent control of the core ligands has been a significant challenge in biomimetic chemistry. In this work, the rational construction of versatile Mo-Fe-S cubane clusters was realized using a LEGO strategy. (LEGO is a line of plastic construction toys consisting of various interlocking plastic bricks which can be assembled and connected in different ways to construct versatile objects. Herein we use "LEGO strategy" as an analogy for the stepwise synthetic methodology, and we use "brick" to represent a corner atom of the cubane structure.) Through careful synthetic control, the ⟨Fe⟩, ⟨S⟩, and ⟨Cl⟩ bricks were mounted piece-by-piece onto the basic ⟨MoS3⟩ frame to stepwise construct the incomplete cubane core ⟨MoFe2S3Cl⟩ and the complete cubane core ⟨MoFe3S3Cl⟩. The significantly elongated Fe-Cl bonds for the bridging chlorides in the ⟨MoFe2S3Cl⟩ and ⟨MoFe3S3Cl⟩ cores permit ligand metatheses to introduce 2p donors at the bridging sites, which used to be a challenge in traditional iron-sulfur chemistry. Therefore, in subsequent controlled reactions, the bridging ⟨Cl⟩ bricks of the ⟨MoFe2S3Cl⟩ and ⟨MoFe3S3Cl⟩ frames could be easily replaced by ⟨N⟩ , ⟨O⟩, or ⟨S⟩ bricks to generate the ⟨MoFe2S3N⟩, ⟨MoFe2S3O⟩, ⟨MoFe3S3N⟩, and ⟨MoFe3S4⟩ cluster cores, demonstrating more choices for the LEGO synthetic strategy. The series of Mo-Fe-S clusters and their derivatives, together with related synthetic strategies, offers a good platform and methodology for biomimetic chemistry in relation to nitrogenase, especially the FeMo cofactor.
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Affiliation(s)
- Juan He
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, Jiangsu, China
| | - Jia Wei
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, Jiangsu, China
| | - Gan Xu
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, Jiangsu, China
| | - Xu-Dong Chen
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, Jiangsu, China.,State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, Jiangsu, China
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2
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Xue L, Xu G, Wang Z, Chen XD. Nitride-incorporated W-Fe-S double cubane clusters: terminal ligand substitutions and redox behaviors. Dalton Trans 2021; 50:6840-6847. [PMID: 33912872 DOI: 10.1039/d1dt00414j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Structural mimicking of the nitrogenase FeMo cofactor has long been a challenge in synthetic inorganic chemistry and bioinorganic chemistry. This already very tough task had become even harder after the discovery of an interstitial light atom, which was later evidenced to be carbide. From a synthetic point of view, to introduce such a 2p atom into the core of a Fe-S cluster would have to overcome the coordination competition from overwhelming sulfide ligands. Recently, we have reported a controlled synthetic strategy named redox metathesis based on template-assisted structure design, and have successfully synthesized a couple of nitride-incorporated edge-bridged double cubane (N-EBDC) W-Fe-S clusters. In this work, we have systematically studied the terminal ligand substitutions of heteroleptic N-EBDC clusters, utilizing ethanethiolate, thiophenolate, p-thiocresolate, azide, and methoxide to replace the terminally bound chloride ligands. Structural analysis of this family of N-EBDC clusters reveals that different terminal ligands affect the fine structures of the cluster cores at different levels. Further studies by cyclic voltammetry indicate that these N-EBDC clusters with distinct terminal ligands exhibit different redox behaviors, furnishing in-depth information on the electronic structure of these clusters potentially related to their reactivity. This study provided useful information for the investigation of nitrogenase related Fe-S clusters toward structural and functional mimicking of the nitrogenase FeMo cofactor.
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Affiliation(s)
- Lian Xue
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, Jiangsu, China.
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3
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Engel A, Dehnen S. Amino Acid Functionalized Organotin Trichlorides and Their Tin Sulfide Clusters. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900528] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Annikka Engel
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW) Philipps‐Universität Marburg Hans‐Meerwein‐Straße 4 35043 Marburg Germany
| | - Stefanie Dehnen
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW) Philipps‐Universität Marburg Hans‐Meerwein‐Straße 4 35043 Marburg Germany
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4
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Xu G, Zhou J, Wang Z, Holm RH, Chen XD. Controlled Incorporation of Nitrides into W-Fe-S Clusters. Angew Chem Int Ed Engl 2019; 58:16469-16473. [PMID: 31489739 DOI: 10.1002/anie.201908968] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Indexed: 11/08/2022]
Abstract
Incorporation of monatomic 2p ligands into the core of iron-sulfur clusters has been researched since the discovery of interstitial carbide in the FeMo cofactor of Mo-dependent nitrogenase, but has proven to be a synthetic challenge. Herein, two distinct synthetic pathways are rationalized to install nitride ligands into targeted positions of W-Fe-S clusters, generating unprecedented nitride-ligated iron-sulfur clusters, namely [(Tp*)2 W2 Fe6 (μ4 -N)2 S6 L4 ]2- (Tp*=tris(3,5-dimethyl-1-pyrazolyl)hydroborate(1-), L=Cl- or Br- ). 57 Fe Mössbauer study discloses metal oxidation states of WIV 2 FeII 4 FeIII 2 with localized electron distribution, which is analogous to the mid-valent iron centres of FeMo cofactor at resting state. Good agreement of Mössbauer data with the empirical linear relationship for Fe-S clusters indicates similar ligand behaviour of nitride and sulfide in such clusters, providing useful reference for reduced nitrogen in a nitrogenase-like environment.
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Affiliation(s)
- Gan Xu
- Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, Jiangsu, 210023, China
| | - Jie Zhou
- Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, Jiangsu, 210023, China
| | - Zheng Wang
- Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, Jiangsu, 210023, China
| | - Richard H Holm
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Xu-Dong Chen
- Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, Jiangsu, 210023, China
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5
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Xu G, Zhou J, Wang Z, Holm RH, Chen X. Controlled Incorporation of Nitrides into W‐Fe‐S Clusters. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201908968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Gan Xu
- Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power BatteriesSchool of Chemistry and Materials ScienceNanjing Normal University Nanjing Jiangsu 210023 China
| | - Jie Zhou
- Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power BatteriesSchool of Chemistry and Materials ScienceNanjing Normal University Nanjing Jiangsu 210023 China
| | - Zheng Wang
- Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power BatteriesSchool of Chemistry and Materials ScienceNanjing Normal University Nanjing Jiangsu 210023 China
| | - Richard H. Holm
- Department of Chemistry and Chemical BiologyHarvard University Cambridge MA 02138 USA
| | - Xu‐Dong Chen
- Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power BatteriesSchool of Chemistry and Materials ScienceNanjing Normal University Nanjing Jiangsu 210023 China
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6
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Drover MW, Nagata K, Peters JC. Fusing triphenylphosphine with tetraphenylborate: introducing the 9-phosphatriptycene-10-phenylborate (PTB) anion. Chem Commun (Camb) 2018; 54:7916-7919. [PMID: 29951661 PMCID: PMC6095131 DOI: 10.1039/c8cc04321c] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In a fusion of two ubiquitous organometallic reagents, triphenylphosphine (PPh3) and tetraphenylborate (BPh4-), the 9-phosphatriptycene-10-phenylborate (PTB) anion has been prepared for the first time. This borato species has been fully characterized by a suite of spectroscopic methods, and initial reactivity studies introduce it as a competent ligand for transition metals, including Co(ii) and Fe(ii).
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Affiliation(s)
- Marcus W Drover
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, 91125, USA.
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7
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Lee Y, Jeon IR, Abboud KA, García-Serres R, Shearer J, Murray LJ. A [3Fe–3S]3+ cluster with exclusively μ-sulfide donors. Chem Commun (Camb) 2016; 52:1174-7. [DOI: 10.1039/c5cc07813j] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
A [3Fe–3(μ-S)]3+ cluster is reported in which each ferric center has a distorted trigonal pyramidal geometry, with an S = 1/2 ground state for the cluster and unusually anisotropic hyperfine coupling constants as determined by variable temperature magnetometry and Mössbauer spectroscopy.
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Affiliation(s)
- Yousoon Lee
- Department of Chemistry
- Center for Catalysis
- University of Florida
- Gainesville
- USA
| | - Ie-Rang Jeon
- Department of Chemistry
- Northwestern University
- Evanston
- USA
| | - Khalil A. Abboud
- Department of Chemistry
- Center for Catalysis
- University of Florida
- Gainesville
- USA
| | | | - Jason Shearer
- Department of Chemistry
- University of Nevada
- Reno
- Reno
- USA
| | - Leslie J. Murray
- Department of Chemistry
- Center for Catalysis
- University of Florida
- Gainesville
- USA
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8
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Bjornsson R, Delgado-Jaime MU, Lima FA, Sippel D, Schlesier J, Weyhermüller T, Einsle O, Neese F, DeBeer S. Molybdenum L-Edge XAS Spectra of MoFe Nitrogenase. Z Anorg Allg Chem 2014. [PMID: 26213424 PMCID: PMC4510703 DOI: 10.1002/zaac.201400446] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A molybdenum L-edge X-ray absorption spectroscopy (XAS) study is presented for native and oxidized MoFe protein of nitrogenase as well as Mo-Fe model compounds. Recently collected data on MoFe protein (in oxidized and reduced forms) is compared to previously published Mo XAS data on the isolated FeMo cofactor in NMF solution and put in context of the recent Mo K-edge XAS study, which showed a MoIII assignment for the molybdenum atom in FeMoco. The L3-edge data are interpreted within a simple ligand-field model, from which a time-dependent density functional theory (TDDFT) approach is proposed as a way to provide further insights into the analysis of the molybdenum L3-edges. The calculated results reproduce well the relative spectral trends that are observed experimentally. Ultimately, these results give further support for the MoIII assignment in protein-bound FeMoco, as well as isolated FeMoco.
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Affiliation(s)
- Ragnar Bjornsson
- Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany ; Present address: Science Institute University of Iceland, Dunhaga 3, 107 Reykjavik, Iceland
| | - Mario U Delgado-Jaime
- Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Frederico A Lima
- Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany ; Present address: Centro Nacional de Pesquisa,em Energia e Materiais, Brazilian Synchrotron Light Laboratory - LNLS, CP 6192 13084-971 Campinas, SP, Brazil
| | - Daniel Sippel
- Institute for Biochemistry Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Julia Schlesier
- Institute for Biochemistry Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Thomas Weyhermüller
- Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Oliver Einsle
- Institute for Biochemistry Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Frank Neese
- Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer
- Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany
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9
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Lee SC, Lo W, Holm RH. Developments in the biomimetic chemistry of cubane-type and higher nuclearity iron-sulfur clusters. Chem Rev 2014; 114:3579-600. [PMID: 24410527 PMCID: PMC3982595 DOI: 10.1021/cr4004067] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
| | - Wayne Lo
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1 Canada and the Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138
| | - R. H. Holm
- Corresponding Authors: S. C. Lee: . R. H. Holm:
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10
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Bjornsson R, Lima FA, Spatzal T, Weyhermüller T, Glatzel P, Bill E, Einsle O, Neese F, DeBeer S. Identification of a spin-coupled Mo(iii) in the nitrogenase iron–molybdenum cofactor. Chem Sci 2014. [DOI: 10.1039/c4sc00337c] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The molybdenum atom in FeMoco is imperative to the high activity of the enzyme and has been proposed to be Mo(iv). We demonstrate that only Mo(iii) fits Mo HERFD XAS data, the first example of Mo(iii) in biology. Theoretical calculations further reveal an unusual spin-coupled Mo(iii).
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Affiliation(s)
- Ragnar Bjornsson
- Max-Planck-Institut für Chemische Energiekonversion
- 45470 Mülheim an der Ruhr, Germany
| | - Frederico A. Lima
- Max-Planck-Institut für Chemische Energiekonversion
- 45470 Mülheim an der Ruhr, Germany
| | - Thomas Spatzal
- Institute for Biochemistry
- Albert-Ludwigs-Universität Freiburg
- 79104 Freiburg, Germany
| | - Thomas Weyhermüller
- Max-Planck-Institut für Chemische Energiekonversion
- 45470 Mülheim an der Ruhr, Germany
| | - Pieter Glatzel
- European Synchrotron Radiation Facility
- 38043 Grenoble Cedex, France
| | - Eckhard Bill
- Max-Planck-Institut für Chemische Energiekonversion
- 45470 Mülheim an der Ruhr, Germany
| | - Oliver Einsle
- Institute for Biochemistry
- Albert-Ludwigs-Universität Freiburg
- 79104 Freiburg, Germany
| | - Frank Neese
- Max-Planck-Institut für Chemische Energiekonversion
- 45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer
- Max-Planck-Institut für Chemische Energiekonversion
- 45470 Mülheim an der Ruhr, Germany
- Department of Chemistry and Chemical Biology
- Cornell University
- Ithaca, USA
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11
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Bose M, Moula G, Sarkar S. Electronic Structure of Monodithiolated IronOxotungsten Heterometallic Complexes: Integer-Spin FeW Assembly. Chem Asian J 2013; 8:1128-38. [DOI: 10.1002/asia.201300245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Indexed: 11/07/2022]
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12
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Kamiguchi S, Takeda K, Kajio R, Okumura K, Nagashima S, Chihara T. Application of Solid-State Molybdenum Sulfide Clusters with an Octahedral Metal Framework to Catalysis: Ring-Opening of Tetrahydrofuran to Butyraldehyde. J CLUST SCI 2012. [DOI: 10.1007/s10876-012-0534-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Chen XD, Zhang W, Duncan JS, Lee SC. Iron–Amide–Sulfide and Iron–Imide–Sulfide Clusters: Heteroligated Core Environments Relevant to the Nitrogenase FeMo Cofactor. Inorg Chem 2012; 51:12891-904. [DOI: 10.1021/ic301868m] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Xu-Dong Chen
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L
3G1
| | - Wei Zhang
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L
3G1
| | - Jeremiah S. Duncan
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L
3G1
| | - Sonny C. Lee
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L
3G1
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14
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Ohta S, Ohki Y, Hashimoto T, Cramer RE, Tatsumi K. A Nitrogenase Cluster Model [Fe8S6O] with an Oxygen Unsymmetrically Bridging Two Proto-Fe4S3 Cubes: Relevancy to the Substrate Binding Mode of the FeMo Cofactor. Inorg Chem 2012; 51:11217-9. [DOI: 10.1021/ic301348f] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shun Ohta
- Department of Chemistry, Graduate School of Science, and Research Center for Meterials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602,
Japan
| | - Yasuhiro Ohki
- Department of Chemistry, Graduate School of Science, and Research Center for Meterials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602,
Japan
| | - Takayoshi Hashimoto
- Department of Chemistry, Graduate School of Science, and Research Center for Meterials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602,
Japan
| | - Roger E. Cramer
- Department
of Chemistry, University of Hawaii, Honolulu, Hawaii
96822, United States
| | - Kazuyuki Tatsumi
- Department of Chemistry, Graduate School of Science, and Research Center for Meterials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602,
Japan
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15
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Moula G, Bose M, Maiti BK, Sarkar S. Oxomolybdenum monodithiolene complexes linked with sulfur bridged iron: antiferromagnetically coupled Fe(iii)Mo(v) systems. Dalton Trans 2012; 41:12926-35. [DOI: 10.1039/c2dt31743e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Zhao Q, Harris TD, Betley TA. [(HL)2Fe6(NCMe)m]n+ (m = 0, 2, 4, 6; n = −1, 0, 1, 2, 3, 4, 6): An Electron-Transfer Series Featuring Octahedral Fe6 Clusters Supported by a Hexaamide Ligand Platform. J Am Chem Soc 2011; 133:8293-306. [DOI: 10.1021/ja2015845] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Qinliang Zhao
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge Massachusetts 02138, United States
| | - T. David Harris
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge Massachusetts 02138, United States
| | - Theodore A. Betley
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge Massachusetts 02138, United States
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17
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Chen XD, Duncan JS, Verma AK, Lee SC. Selective Syntheses of Iron−Imide−Sulfide Cubanes, Including a Partial Representation of the Fe−S−X Environment in the FeMo Cofactor. J Am Chem Soc 2010; 132:15884-6. [DOI: 10.1021/ja106478k] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Xu-Dong Chen
- Department of Chemistry, Princeton University, Princeton, New Jersey 08540, United States, and Department of Chemistry, University of Waterloo, Waterloo, ON, Canada N2L 3G1
| | - Jeremiah S. Duncan
- Department of Chemistry, Princeton University, Princeton, New Jersey 08540, United States, and Department of Chemistry, University of Waterloo, Waterloo, ON, Canada N2L 3G1
| | - Atul K. Verma
- Department of Chemistry, Princeton University, Princeton, New Jersey 08540, United States, and Department of Chemistry, University of Waterloo, Waterloo, ON, Canada N2L 3G1
| | - Sonny C. Lee
- Department of Chemistry, Princeton University, Princeton, New Jersey 08540, United States, and Department of Chemistry, University of Waterloo, Waterloo, ON, Canada N2L 3G1
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19
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Koutmos M, Georgakaki IP, Tsiolis P, Coucouvanis D. Synthesis and Characterization of MoFe3S4 and Mo2Fe2S4 Single Cubanes. Z Anorg Allg Chem 2008. [DOI: 10.1002/zaac.200700419] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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20
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X-ray crystallographic structure and physical properties of the pentacoordinated [TPAFeCl]+ complex. Polyhedron 2007. [DOI: 10.1016/j.poly.2007.04.041] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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21
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Synthesis, structure and physical properties of trinuclear M3tdt3(PEt3)3 (M=FeII, CoII) clusters containing metal–metal bonds. Polyhedron 2007. [DOI: 10.1016/j.poly.2007.01.052] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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22
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Pesavento RP, Berlinguette CP, Holm RH. Stabilization of reduced molybdenum-iron-sulfur single- and double-cubane clusters by cyanide ligation. Inorg Chem 2007; 46:510-6. [PMID: 17279830 PMCID: PMC2546524 DOI: 10.1021/ic061704y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recent work has shown that cyanide ligation increases the redox potentials of Fe(4)S(4) clusters, enabling the isolation of [Fe(4)S(4)(CN)4]4-, the first synthetic Fe(4)S(4) cluster obtained in the all-ferrous oxidation state (Scott, T. A.; Berlinguette, C. P.; Holm, R. H.; Zhou, H.-C. Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 9741). The generality of reduced cluster stabilization has been examined with MoFe(3)S(4) clusters. Reaction of single-cubane [(Tp)MoFe(3)S(4)(PEt(3))3]1+ and edge-bridged double-cubane [(Tp)2Mo(2)Fe(6)S(8)(PEt(3))4] with cyanide in acetonitrile affords [(Tp)MoFe(3)S(4)(CN)3]2- (2) and [(Tp)2Mo(2)Fe(6)S(8)(CN)4]4- (5), respectively. Reduction of 2 with KC(14)H(10) yields [(Tp)MoFe(3)S(4)(CN)3]3- (3). Clusters were isolated in approximately 70-90% yields as Et(4)N+ or Bu(4)N+ salts; clusters 3 and 5 contain all-ferrous cores, and 3 is the first [MoFe(3)S(4)]1+ cluster isolated in substance. The structures of 2 and 3 are very similar; the volume of the reduced cluster core is slightly larger (2.5%), a usual effect upon reduction of cubane-type Fe(4)S(4) and MFe(3)S(4) clusters. Redox potentials and 57Fe isomer shifts of [(Tp)MoFe(3)S(4)L3]2-,3- and [(Tp)2Mo(2)Fe(6)S(8)L(4)]4-,3- clusters with L = CN-, PhS-, halide, and PEt3 are compared. Clusters with pi-donor ligands (L = halide, PhS) exhibit larger isomer shifts and lower (more negative) redox potentials, while pi-acceptor ligands (L = CN, PEt3) induce smaller isomer shifts and higher (less-negative) redox potentials. When the potentials of 3/2 and [(Tp)MoFe(3)S(4)(SPh)3]3-/2- are compared, cyanide stabilizes 3 by 270 mV versus the reduced thiolate cluster, commensurate with the 310 mV stabilization of [Fe(4)S(4)(CN)4]4- versus [Fe(4)S(4)(SPh)4]4- where four ligands differ. These results demonstrate the efficacy of cyanide stabilization of lower cluster oxidation states. (Tp = hydrotris(pyrazolyl)borate(1-)).
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Affiliation(s)
- Russell P Pesavento
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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Koutmos M, Georgakaki IP, Coucouvanis D. Borohydride, azide, and chloride anions as terminal ligands on Fe/Mo/S clusters. Synthesis, structure and characterization of [(Cl4-cat)(PPr3) MoFe3S4(X)2]2(Bu4N)4 and [(Cl4-cat)(PPr3)MoFe3S4 (PPr3)(X)]2(Bu4N)2 (X = N3-, BH4-, Cl-) double-fused cubanes. NMR reactivity studies of [(Cl4-cat)(PPr3) MoFe3S4(BH4)2]2(Bu4N)4. Inorg Chem 2006; 45:3648-56. [PMID: 16634597 DOI: 10.1021/ic052156b] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Our explorations of the reactivity of Fe/Mo/S clusters of some relevance to the FeMoco nitrogenase have led to new double-fused cubane clusters with the Mo2Fe6S8 core as derivatives of the known (Cl4-cat)2Mo2Fe6S8(PPr3)6 (I) fused double cubane. The new clusters have been obtained by substitution reactions of the PPr3 ligands with Cl-, BH4-, and N3-. By careful control of the conditions of these reactions, the clusters [(Cl4-cat)(PPr3)MoFe3S4(BH4)2]2(Bu4N)4 (II), [(Cl4-cat)(PPr3)MoFe3S4(PPr3)(BH4)]2(Bu4N)2 (III), [(Cl4-cat)(PPr3)MoFe3S4(N3)2]2(Bu4N)4 (IV), [(Cl4-cat)(PPr3)MoFe3S4(PPr3)(N3)]2(Bu4N)2 (V), and [(Cl4-cat)(PPr3)MoFe3S4Cl2]2(Et4N)4 (VI) have been obtained and structurally characterized. A study of their electrochemistry shows that the reduction potentials for the derivatives of I are shifted to more positive values than those of I, suggesting a stabilization of the reduced clusters by the anionic ligands BH4- and N3-. Using 1H NMR spectroscopy, we have explored the lability of the BH4- ligand in II in coordinating solvents and its hydridic character, which is apparent in its reactivity toward proton sources such as MeOH or PhOH.
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Affiliation(s)
- Markos Koutmos
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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Rearrangement of the Mo/Fe/S Cluster under the Reducing Conditions; Alternative Synthesis of MoFe4S6(PEt3)4Cl Cluster from [(Cl4-cat)Mo(MeCN)Fe3S4Cl3](Et4N). B KOREAN CHEM SOC 2006. [DOI: 10.5012/bkcs.2006.27.1.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Koutmos M, Coucouvanis D. Metal Clusters as Ligands. Substitution of Fe Ions in Fe/Mo/S Clusters by Thiophilic CuI Ions. Inorg Chem 2006; 45:1421-3. [PMID: 16471948 DOI: 10.1021/ic051860p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The reactivity of Fe/S and Fe/Mo/S clusters, similar or analogous to those occurring in biological systems, with thiophilic metal ions has not been explored. In this Communication, we demonstrate that synthesis of heteropolynuclear clusters with different coordination geometries for different metals at different sites is possible by metal substitution or by metal addition reactions. The two clusters we report herein ([(Cl4-cat)2Mo2Cu5Fe4S9(PnPr3)7(SPnPr3)2]PF6 and [(Cl4-cat)2Mo2Cu6Fe4S10(PnPr3)8]) contain Fe, Mo, and Cu, which display pseudotetrahedral, pseudooctahedral, and pseudotrigonal geometries, respectively. The synthesis of these clusters is achieved by the addition of appropriate amounts of [Cu(CH3CN)4]+ to [(Cl4-cat)2Mo2Fe8(PnPr3)6]. The formation of the different products is temperature- and solvent-dependent. The Cu(I) units incorporated into the metal cluster framework, either bind to available lone pairs of the already bridging S ligands or displace the less thiophilic Fe atoms. Among the essential features of these new molecules are recognizable Fe/S fragments including an Fe6S9 core in the first cluster and the pentlandite Fe4Cu4S6 core in the second cluster.
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Affiliation(s)
- Markos Koutmos
- Department of Chemistry, The University of Michigan, Ann Arbor, 48109, USA
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Takuma M, Ohki Y, Tatsumi K. Sulfido-Bridged Dinuclear Molybdenum−Copper Complexes Related to the Active Site of CO Dehydrogenase: [(dithiolate)Mo(O)S2Cu(SAr)]2- (dithiolate = 1,2-S2C6H4, 1,2-S2C6H2-3,6-Cl2, 1,2-S2C2H4). Inorg Chem 2005; 44:6034-43. [PMID: 16097823 DOI: 10.1021/ic050294v] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The [MoCu] carbon monoxide dehydrogenase (CODH) is a Cu-containing molybdo-flavoprotein, the active site of which contains a pterin-dithiolene cofactor bound to a sulfido-bridged dinuclear Mo-Cu complex. In this paper, the synthesis and characterization of dinuclear Mo-Cu complexes relevant to the active site of [MoCu]-CODH are described. Reaction of [MoO2S2]2- with CuCN affords the dinuclear complex [O2MoS2Cu(CN)]2- (1), in which the CN- ligand can be replaced with various aryl thiolates to give rise to a series of dinuclear complexes [O2MoS2Cu(SAr)]2- (Ar = Ph (2), o-Tol (3), and p-Tol (4)). An alternative synthesis of complex 2 is the reaction of [MoO2S2]2- with [Cu(SPh)3]2-. Similarly, [O2MoS2Cu(PPh3)]- (5), [O2MoS2Cu(dppe)]- (dppe = 1,2-bis(diphenylphosphino)ethane) (6), and [O2MoS2Cu(triphos)]- (triphos = 1,1,1-tris[(diphenylphosphino)methyl]ethane) (7) were prepared from the reactions of [MoO2S2]2- with the Cu(I) phosphine complexes. Treatment of 1, 2, 4, or 5 with dithiols (1,2-(SH)2C6H4, 1,2-(SH)2C6H2-3,6-Cl2, and 1,2-(SH)2C2H4), in acetonitrile, leads to the replacement of a molybdenum-bound oxo ligand to yield [(dithiolate)Mo(O)S2CuL]2- (L = CN, SAr; dithiolate = 1,2-S2C6H4, 1,2-S2C6H2-3,6-Cl2, or 1,2-S2C2H4) (8-13) or [(1,2-S2C6H4)Mo(O)S2Cu(PPh3)]- (14) complexes.
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Affiliation(s)
- Motoki Takuma
- Department of Chemistry, Graduate School of Science and Research Center for Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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Heterometal cubane-type WFe3S4 and related clusters trigonally symmetrized with hydrotris(3,5-dimethylpyrazolyl)borate. Inorganica Chim Acta 2005. [DOI: 10.1016/j.ica.2004.11.051] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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28
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Koutmos M, Coucouvanis D. Metal Clusters as Ligands: Substitution of Fe ions in Fe/Mo/S Clusters by Thiophilic CuI Ions To Give Clusters with [Cu4Mo2Fe2S8]4+ and [Cu5Mo3Fe4S11]6+ Cores. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200462596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Koutmos M, Coucouvanis D. Metal Clusters as Ligands: Substitution of Fe ions in Fe/Mo/S Clusters by Thiophilic CuI Ions To Give Clusters with [Cu4Mo2Fe2S8]4+ and [Cu5Mo3Fe4S11]6+ Cores. Angew Chem Int Ed Engl 2005; 44:1971-4. [PMID: 15724256 DOI: 10.1002/anie.200462596] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Markos Koutmos
- Department Of Chemistry, The University Of Michigan, Ann Arbor, MI 48109-1055, USA
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Han J, Coucouvanis D. Synthesis and structure of the organometallic MFe2(µ3-S)2clusters (M = Mo or Fe). Dalton Trans 2005:1234-40. [PMID: 15782259 DOI: 10.1039/b419051c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New organometallic clusters with the MFe2(mu3-S)2 core (M = Mo or Fe) have been synthesized from inorganic [MoFe3S4] or [Fe4S4] clusters under high pressure CO. The reaction of (Cl4-cat)2Mo2Fe6S8(PR3)6[R = Et, (n)Pr] with high pressure CO produced the crystalline [MoFe2S2]4+ clusters, (Cl4-cat)Mo(O)Fe2S2(CO)(n)(PR3)6-n[n= 4, Et =I, (n)Pr =II; n = 5, Et =III] after flash column chromatography. The similar [MoFe2S2]4+ cluster, (Cl4-cat)2MoFe2S2(CO)2(depe)(2)(IV), also has been achieved by the reactions of (Cl4-cat)MoFe3S3(CO)6(PEt3)2 with depe by reductive decoupling of the cluster. For the [Fe3(mu3-S)2]4+ cluster, [Fe4S4(PcHex3)4](BPh4) was reacted with high pressure CO to produce a new Fe3S2(CO)7(PcHex)(2)(V) compound. These reactions generalized the preparation of organometallic compounds from inorganic clusters. All the compounds have been characterized by single crystal X-ray crystallography. A possible reaction pathway for the synthesis of the MFe2(mu3-S) clusters (M = Mo or Fe) has also been suggested.
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Affiliation(s)
- Jaehong Han
- Metalloenzyme Research Group, BET Research Institute and Department of Biotechnology, Chung-Ang University, Anseong, Korea.
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Koutmos M, Coucouvanis D. Borohydride Anions as Terminal Ligands on a Fe/Mo/S Cluster. Synthesis, Structure, and Characterization of the [(Cl4-cat)(PPr3)MoFe3S4(BH4)2]2(Bu4N)4 Double-Fused Cubane. Inorg Chem 2004; 43:6508-10. [PMID: 15476337 DOI: 10.1021/ic049275w] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis and structure of the first Mo/Fe/S/BH(4) cluster is reported. Reaction of (Cl(4)-cat)(2)Mo(2)Fe(6)S(8)(PPr(3))(6) with 4 equiv of Bu(4)NBH(4) results in the formation of [(Cl(4)-cat)(PPr(3))MoFe(3)S(4)(BH(4))(2)](2)(Bu(4)N)(4) (Cl(4)-cat = tetrachloro-catecholate) which has been fully characterized. X-ray structural determination of this double-fused cubane reveals four BH(4)(-) ligands bound to four Fe atoms in a bidentate fashion. A synopsis of the solution characterization as well as the reactivity of this cluster is also presented.
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Affiliation(s)
- Markos Koutmos
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan 48109, USA
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Lee SC, Holm RH. The clusters of nitrogenase: synthetic methodology in the construction of weak-field clusters. Chem Rev 2004; 104:1135-58. [PMID: 14871151 DOI: 10.1021/cr0206216] [Citation(s) in RCA: 273] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sonny C Lee
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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QUANTUM CHEMICAL INVESTIGATIONS INTO THE PROBLEM OF BIOLOGICAL NITROGEN FIXATION: SELLMANN-TYPE METAL–SULFUR MODEL COMPLEXES. ADVANCES IN INORGANIC CHEMISTRY 2004. [DOI: 10.1016/s0898-8838(04)56003-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Seino H, Masumori T, Hidai M, Mizobe Y. Synthesis of Bimetallic Cubane-Type Mo2M2S4 Clusters (M = Ir, Rh, Ru) and Reductive Cleavage of the N−N Bond of 1,1-Methylphenylhydrazine Affording N-Methylaniline Using Mo2Ir2S4 and Mo2Rh2S4 Clusters as Catalyst Precursors. Organometallics 2003. [DOI: 10.1021/om030231p] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hidetake Seino
- Institute of Industrial Science, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8505, Japan, and Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Noda, Chiba 278-8510, Japan
| | - Tadao Masumori
- Institute of Industrial Science, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8505, Japan, and Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Noda, Chiba 278-8510, Japan
| | - Masanobu Hidai
- Institute of Industrial Science, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8505, Japan, and Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Noda, Chiba 278-8510, Japan
| | - Yasushi Mizobe
- Institute of Industrial Science, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8505, Japan, and Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Noda, Chiba 278-8510, Japan
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New heteronuclear Mo/Fe/S clusters. The syntheses and structures of (Cl4-cat)Mo(PEt3)Fe3S4(SPEt3)2Cl and (Cl4-cat)2MoFe2S2(PEt3)2(CO)4 clusters. Polyhedron 2002. [DOI: 10.1016/s0277-5387(02)01208-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Coucouvanis D, Han J, Moon N. Synthesis and characterization of sulfur-voided cubanes. Structural analogues for the MoFe(3)S(3) subunit in the nitrogenase cofactor. J Am Chem Soc 2002; 124:216-24. [PMID: 11782173 DOI: 10.1021/ja0110832] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new class of Mo/Fe/S clusters with the MoFe(3)S(3) core has been synthesized in attempts to model the FeMo-cofactor in nitrogenase. These clusters are obtained in reactions of the (Cl(4)-cat)(2)Mo(2)Fe(6)S(8)(PR(3))(6) [R = Et (I), (n)Pr (II)] clusters with CO. The new clusters include those preliminarily reported: (Cl(4)-cat)MoFe(3)S(3)(PEt(3))(2)(CO)(6) (III), (Cl(4)-cat)(O)MoFe(3)S(3)(PEt(3))(3)(CO)(5) (IV), (Cl(4)-cat)(Pyr)MoFe(3)S(3)(PEt(3))(2)(CO)(6) (VI), and (Cl(4)-cat)(Pyr)MoFe(3)S(3)(P(n)Pr(3))(3)(CO)(4) (VIII). In addition the new (Cl(4)-cat)(O)MoFe(3)S(3)(P(n)Pr(3))(3)(CO)(5) cluster (IVa), the (Cl(4)-cat)(O)MoFe(3)S(3)(PEt(3))(2)(CO)(6)cluster (V), the (Cl(4)-cat)(O)MoFe(3)S(3)(P(n)Pr(3))(2)(CO)(6) cluster (Va), the (Cl(4)-cat)(Pyr)MoFe(3)S(3)(P(n)Pr(3))(2)(CO)(6) cluster (VIa), and the (Cl(4)-cat)(P(n)Pr(3))MoFe(3)S(3)(P(n)Pr(3))(2)(CO)(6) cluster (VII) also are reported. Clusters III-VIII have been structurally and spectroscopically characterized. EPR, zero-field (57)Fe-Mössbauer spectroscopic characterizations, and magnetic susceptibility measurements have been used for a tentative assignment of the electronic and oxidation states of the MoFe(3)S(3) sulfur-voided cuboidal clusters. A structural comparison of the clusters with the MoFe(3)S(3) subunit of the FeMo-cofactor has led to the suggestion that the storage of reducing equivalents into M-M bonds, and their use in the reduction of substrates, may occur with the FeMo-cofactor, which also appears to have M-M bonding. On the basis of this argument, a possible N(2)-binding and reduction mechanism on the FeMoco-cofactor is proposed.
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Affiliation(s)
- Dimitri Coucouvanis
- Department of Chemistry and the Biophysics Research Division, The University of Michigan, Ann Arbor, Michigan 48109-1055, USA
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