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Gravogl L, Keilwerth M, Körber E, Heinemann FW, Meyer K. From d 8 to d 1: Iron(0) and Iron(I) Complexes Complete the Series of Eight Fe Oxidation States within the TIMMN Mes Ligand Framework. Inorg Chem 2024; 63:15888-15905. [PMID: 39145894 DOI: 10.1021/acs.inorgchem.4c02129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2024]
Abstract
Reduction of the ferrous precursor [(TIMMNMes)Fe(Cl)]+ (1) (TIMMNMes = tris-[(3-mesitylimidazol-2-ylidene)methyl]amine) to the low-valent iron(0) complex [(TIMMNMes)Fe(CO)3] (2) is presented, where the tris(N-heterocyclic carbene) (NHC) ligand framework remains intact, yet the coordination mode changed from 3-fold to 2-fold coordination of the carbene arms. Further, the corresponding iron(I) complexes [(TIMMNMes)Fe(L)]+ (L = free site, η1-N2, CO, py) (3) are synthesized and fully characterized. Complexes 1-3 demonstrate the notable steric and electronic flexibility of the TIMMNMes ligand framework by variation of the Fe-N anchor and Fe-carbene distances and the variable size of the axial cavity occupation. This is further underpinned by the oxidation of 3-N2 in a reaction with benzophenone to yield the corresponding, charge-separated iron(II) radical complex [(TIMMNMes)Fe(OCPh2)]+ (4). We found rather surprising similarities in the reactivity behavior when going to low- or high-valent oxidation states of the central iron ion. This is demonstrated by the closely related reactivity of 3-N2, where H atom abstraction with TEMPO triggers the formation of the metallacycle [(TIMMNMes*)Fe(py)]+ (5), and the reactivity of the highly unstable Fe(VII) nitride complex [(TIMMNMes)Fe(N)(F)]3+ to give the metallacyclic Fe(V) imido complex [(TIMMNMesN)Fe(NMes)(MeCN)]3+ (6) upon warming. Thus, the employed tris(carbene) chelate is not only capable of stabilizing the superoxidized Fe(VI) and Fe(VII) nitrides but equally supports the iron center in its low oxidation states 0 and +1. Isolation and characterization of these zero- and monovalent iron complexes demonstrate the extraordinary capability of the tris(carbene) chelate TIMMN to support iron in eight different oxidation states within the very same ligand platform.
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Affiliation(s)
- Lisa Gravogl
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Martin Keilwerth
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Eva Körber
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Frank W Heinemann
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Karsten Meyer
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
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2
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Johansen C, Peters JC. Catalytic Reduction of Cyanide to Ammonia and Methane at a Mononuclear Fe Site. J Am Chem Soc 2024; 146:5343-5354. [PMID: 38361429 PMCID: PMC10910527 DOI: 10.1021/jacs.3c12395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 02/17/2024]
Abstract
Nitrogenase enzymes catalyze nitrogen reduction (N2R) to ammonia and also the reduction of non-native substrates, including the 7H+/6e- reduction of cyanide to CH4 and NH3. CN- and N2 are isoelectronic, and it is hence fascinating to compare the mechanisms of synthetic Fe catalysts capable of both CN- and N2 reduction. Here, we describe the catalytic reduction of CN- to NH3 and CH4 by a highly selective (P3Si)Fe(CN) catalyst (P3Si represents a tris(phosphine)silyl ligand). Catalysis is driven in the presence of excess acid ([Ph2NH2]OTf) and reductant ((C6H6)2Cr), with turnover as high as 73 demonstrated. This catalyst system is also modestly competent for N2R and structurally related to other tris(phosphine)Fe-based N2R catalysts. The choice of catalyst and reductant is important to observe high yields. Mechanistic studies elucidate several intermediates of CN- reduction, including iron isocyanides (P3SiFeCNH+/0) and terminal iron aminocarbynes (P3SiFeCNH2+/0). Aminocarbynes are isoelectronic to iron hydrazidos (Fe═N-NH2+/0), which have been invoked as selectivity-determining intermediates of N2R (NH3 versus N2H4 products). For the present CN- reduction catalysis, reduction of aminocarbyne P3SiFeCNH2+ is proposed to be rate but not selectivity contributing. Instead, by comparison with the reactivity of a methylated aminocarbyne analogue (P3SiFeCNMe2), and associated computational studies, formation of a Fischer carbene (P3SiFeC(H)(NH2)+) intermediate that is on path for either CH4 and NH3 (6 e-) or CH3NH2 (4 e-) products is proposed. From this carbene intermediate, pathways to the observed CH4 and NH3 products (distinct from CH3NH2 formation) are considered to compare and contrast the (likely) mechanism/s of CN- and N2 reduction.
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Affiliation(s)
- Christian
M. Johansen
- Division of Chemistry and
Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, United States
| | - Jonas C. Peters
- Division of Chemistry and
Chemical Engineering, California Institute
of Technology, Pasadena, California 91125, United States
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3
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Landaeta VR, Horsley Downie TM, Wolf R. Low-Valent Transition Metalate Anions in Synthesis, Small Molecule Activation, and Catalysis. Chem Rev 2024; 124:1323-1463. [PMID: 38354371 PMCID: PMC10906008 DOI: 10.1021/acs.chemrev.3c00121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 10/09/2023] [Accepted: 10/09/2023] [Indexed: 02/16/2024]
Abstract
This review surveys the synthesis and reactivity of low-oxidation state metalate anions of the d-block elements, with an emphasis on contributions reported between 2006 and 2022. Although the field has a long and rich history, the chemistry of transition metalate anions has been greatly enhanced in the last 15 years by the application of advanced concepts in complex synthesis and ligand design. In recent years, the potential of highly reactive metalate complexes in the fields of small molecule activation and homogeneous catalysis has become increasingly evident. Consequently, exciting applications in small molecule activation have been developed, including in catalytic transformations. This article intends to guide the reader through the fascinating world of low-valent transition metalates. The first part of the review describes the synthesis and reactivity of d-block metalates stabilized by an assortment of ligand frameworks, including carbonyls, isocyanides, alkenes and polyarenes, phosphines and phosphorus heterocycles, amides, and redox-active nitrogen-based ligands. Thereby, the reader will be familiarized with the impact of different ligand types on the physical and chemical properties of metalates. In addition, ion-pairing interactions and metal-metal bonding may have a dramatic influence on metalate structures and reactivities. The complex ramifications of these effects are examined in a separate section. The second part of the review is devoted to the reactivity of the metalates toward small inorganic molecules such as H2, N2, CO, CO2, P4 and related species. It is shown that the use of highly electron-rich and reactive metalates in small molecule activation translates into impressive catalytic properties in the hydrogenation of organic molecules and the reduction of N2, CO, and CO2. The results discussed in this review illustrate that the potential of transition metalate anions is increasingly being tapped for challenging catalytic processes with relevance to organic synthesis and energy conversion. Therefore, it is hoped that this review will serve as a useful resource to inspire further developments in this dynamic research field.
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Affiliation(s)
| | | | - Robert Wolf
- University of Regensburg, Institute
of Inorganic Chemistry, 93040 Regensburg, Germany
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4
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Garrido-Barros P, Chalkley MJ, Peters JC. Light Alters the NH 3 vs N 2 H 4 Product Profile in Iron-catalyzed Nitrogen Reduction via Dual Reactivity from an Iron Hydrazido (Fe=NNH 2 ) Intermediate. Angew Chem Int Ed Engl 2023; 62:e202216693. [PMID: 36592374 PMCID: PMC9998131 DOI: 10.1002/anie.202216693] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 01/01/2023] [Accepted: 01/02/2023] [Indexed: 01/03/2023]
Abstract
Whereas synthetically catalyzed nitrogen reduction (N2 R) to produce ammonia is widely studied, catalysis to instead produce hydrazine (N2 H4 ) has received less attention despite its considerable mechanistic interest. Herein, we disclose that irradiation of a tris(phosphine)borane (P3 B ) Fe catalyst, P3 B Fe+ , significantly alters its product profile to increase N2 H4 versus NH3 ; P3 B Fe+ is otherwise known to be highly selective for NH3 . We posit a key terminal hydrazido intermediate, P3 B Fe=NNH2 , as selectivity-determining. Whereas its singlet ground state undergoes protonation to liberate NH3 , a low-lying triplet excited state leads to reactivity at Nα and formation of N2 H4 . Associated electrochemical and spectroscopic studies establish that N2 H4 lies along a unique product pathway; NH3 is not produced from N2 H4 . Our findings are distinct from the canonical mechanism for hydrazine formation, which proceeds via a diazene (HN=NH) intermediate and showcase light as a tool to tailor selectivity.
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Affiliation(s)
- Pablo Garrido-Barros
- Division of Chemistry and Chemical Engineering, California Institute of Technology (Caltech), 1200 E California Blvd, Pasadena, CA-91125, USA
| | - Matthew J Chalkley
- Division of Chemistry and Chemical Engineering, California Institute of Technology (Caltech), 1200 E California Blvd, Pasadena, CA-91125, USA
| | - Jonas C Peters
- Division of Chemistry and Chemical Engineering, California Institute of Technology (Caltech), 1200 E California Blvd, Pasadena, CA-91125, USA
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5
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Kobayashi Y, Sunada Y. Germanium hydrides as an efficient hydrogen-storage material operated by an iron catalyst. Chem Sci 2023; 14:1065-1071. [PMID: 36756342 PMCID: PMC9891375 DOI: 10.1039/d2sc06011f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 12/29/2022] [Indexed: 01/22/2023] Open
Abstract
The use of metal hydrides such as NaBH4 as hydrogen-storage materials has recently received substantial research attention on account of the worldwide demand for the development of efficient hydrogen-production, -storage, and -transportation systems. Here, we report the quantitative production of H2 gas from a germanium hydride, Ph2GeH2, mediated by an iron catalyst at room temperature via dehydrogenative coupling, concomitant with the formation of (GePh2)5. Of particular importance is that Ph2GeH2 can be facilely recovered from (GePh2)5 by contact with 1 atm of H2 or PhICl2/LiAlH4 at 0 °C or 40 °C, respectively. A detailed reaction mechanism for the iron-catalyzed dehydrogenative coupling of Ph2GeH2 is proposed based on the isolation of four intermediate iron species.
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Affiliation(s)
- Yoshinao Kobayashi
- Department of Applied Chemistry, School of Engineering, The University of Tokyo4-6-1, Komaba, Meguro-kuTokyo 153-8505Japan
| | - Yusuke Sunada
- Department of Applied Chemistry, School of Engineering, The University of Tokyo 4-6-1, Komaba, Meguro-ku Tokyo 153-8505 Japan.,Institute of Industrial Science, The University of Tokyo 4-6-1, Komaba, Meguro-ku Tokyo 153-8505 Japan
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6
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McNeece AJ, Jaroš A, Batista ER, Yang P, Scott BL, Davis BL. Hydrazine Energy Storage: Displacing N 2 H 4 from the Metal Coordination Sphere. CHEMSUSCHEM 2022; 15:e202200840. [PMID: 35864078 PMCID: PMC9804637 DOI: 10.1002/cssc.202200840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 07/18/2022] [Indexed: 06/15/2023]
Abstract
Hydrogen carriers, such as hydrazine (N2 H4 ), may facilitate long duration energy storage, a vital component for resilient grids by enabling more renewable energy generation. Lanthanide coordination chemistry with N2 H4 as well as efforts to displace N2 H4 from the metal coordination sphere to develop an efficient catalytic production cycle were detailed. Modeling the equilibrium of different ligand coordination, it was predicted that strong sigma donor molecules would be required to displace N2 H4 . Monitoring competition experiments with nuclear magnetic resonance confirmed that trimethyl phosphine oxide, dimethylformamide, and dimethyl sulfoxide displaced N2 H4 in large or small lanthanide complexes.
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Affiliation(s)
- Andrew J. McNeece
- MS K763, MPA-11 Materials Synthesis and Integrated DevicesLos Alamos National LaboratoryLos AlamosNew Mexico87545USA
| | - Adam Jaroš
- MS B258, T-CNLS Center for Nonlinear StudiesLos Alamos National LaboratoryLos AlamosNew Mexico87545USA
| | - Enrique R. Batista
- MS B258, T-CNLS Center for Nonlinear StudiesLos Alamos National LaboratoryLos AlamosNew Mexico87545USA
| | - Ping Yang
- MS B221, T-1 Physics and Chemistry of MaterialsLos Alamos National LaboratoryLos AlamosNew Mexico87545USA
| | - Brian L. Scott
- MS K763, MPA-11 Materials Synthesis and Integrated DevicesLos Alamos National LaboratoryLos AlamosNew Mexico87545USA
| | - Benjamin L. Davis
- MS K763, MPA-11 Materials Synthesis and Integrated DevicesLos Alamos National LaboratoryLos AlamosNew Mexico87545USA
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7
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Najera DC, Peñas-Defrutos MN, García-Melchor M, Fout AR. γ-Agostic interactions in ( MesCCC)Fe-Mes(L) complexes. Chem Commun (Camb) 2022; 58:9626-9629. [PMID: 35959650 DOI: 10.1039/d2cc03260k] [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
Agostic interactions were observed in the bound mesityl group in a series of iron compounds bearing a bis(NHC) pincer CCC ligand. The L-type ligand on [(CCC)FeIIMes(L)] complexes influences the strength of the agostic interaction and is manifested in the upfield shift of the 1H NMR resonance for the mesityl methyl resonances. The nature of the interaction was further investigated by density functional theory calculations, allowing rationalization of some unexpected trends and proving to be a powerful predictive tool.
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Affiliation(s)
- Daniel C Najera
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801, USA.
| | - Marconi N Peñas-Defrutos
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin, College Green, Dublin 2, Ireland. .,Universidad de Valladolid, Valladolid, Spain
| | - Max García-Melchor
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin, College Green, Dublin 2, Ireland.
| | - Alison R Fout
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801, USA.
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8
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Fang H, Shimada S. Oxidative Addition of Water to Ir(I) Complexes Bearing a Pincer-Type Silyl Ligand. ACS OMEGA 2022; 7:20237-20240. [PMID: 35721963 PMCID: PMC9201899 DOI: 10.1021/acsomega.2c02168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
Reaction of water with in situ generated [(PSiP-R)IrI] (PSiP-R = [{2-(R2P)C6H4}2MeSi]-; R = cyclohexyl, tBu or iPr) from [(PSiP-R)Ir(H)4] and tert-butylethylene (tbe) showed high ligand dependency. Oxidative addition of water cleanly proceeded in the reaction of [(PSiP-tBu)IrI] in THF at room temperature to selectively afford a 16-electron hydrido-hydroxo complex [(PSiP- t Bu)Ir(H)(OH)] almost quantitatively. In contrast, the reaction of cyclohexyl and iPr derivatives was unselective and formed various products containing Ir-H bonds. In the case of iPr-derivative, a small amount of 18-electron hydrido-hydroxo aqua complex [(PSiP-iPr)Ir(H)(OH)(H2O)] was isolated and structurally characterized by X-ray crystallography.
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9
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Fantuzzi F, Moral R, Dewhurst RD, Braunschweig H, Phukan AK. Probing the Potential of Hitherto Unexplored Base‐Stabilized Borylenes in Dinitrogen Binding. Chemistry 2022; 28:e202104123. [DOI: 10.1002/chem.202104123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Indexed: 11/08/2022]
Affiliation(s)
- Felipe Fantuzzi
- School of Physical Sciences Ingram Building University of Kent Park Wood Rd Canterbury CT2 7NH UK
- Institute for Inorganic Chemistry Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Rubi Moral
- Department of Chemical Sciences Tezpur University Napaam 784028 Assam India
| | - Rian D. Dewhurst
- Institute for Inorganic Chemistry Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Ashwini K. Phukan
- Department of Chemical Sciences Tezpur University Napaam 784028 Assam India
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Michaliszyn K, Smirnova ES, Bucci A, Martin-Diaconescu V, Lloret-Fillol J. Well‐defined Nickel P3C Complexes as Hydrogenation Catalysts of N‐Heteroarenes Under Mild Conditions. ChemCatChem 2022. [DOI: 10.1002/cctc.202200039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | | | - Alberto Bucci
- ICIQ: Institut Catala d'Investigacio Quimica - SPAIN
| | | | - Julio Lloret-Fillol
- Institute of Chemical Research of Catalonia (ICIQ) - Ave. Paisos Catalans 16Spain 43005 Tarragona SPAIN
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11
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Devi K, Gorantla SMNVT, Mondal KC. EDA-NOCV analysis of carbene-borylene bonded dinitrogen complexes for deeper bonding insight: A fair comparison with a metal-dinitrogen system. J Comput Chem 2022; 43:757-777. [PMID: 35289411 DOI: 10.1002/jcc.26832] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 01/09/2023]
Abstract
Binding of dinitrogen (N2 ) to a transition metal center (M) and followed by its activation under milder conditions is no longer impossible; rather, it is routinely studied in laboratories by transition metal complexes. In contrast, binding of N2 by main group elements has been a challenge for decades, until very recently, an exotic cAAC-borylene (cAAC = cyclic alkyl(amino) carbene) species showed similar binding affinity to kinetically inert and non-polar dinitrogen (N2 ) gas under ambient conditions. Since then, N2 binding by short lived borylene species has made a captivating news in different journals for its unusual features and future prospects. Herein, we carried out different types of DFT calculations, including EDA-NOCV analysis of the relevant cAAC-boron-dinitrogen complexes and their precursors, to shed light on the deeper insight of the bonding secret (EDA-NOCV = energy decomposition analysis coupled with natural orbital for chemical valence). The hidden bonding aspects have been uncovered and are presented in details. Additionally, similar calculations have been carried out in comparison with a selected stable dinitrogen bridged-diiron(I) complex. Singlet cAAC ligand is known to be an exotic stable species which, combined with the BAr group, produces an intermediate singlet electron-deficient (cAAC)(BAr) species possessing a high lying HOMO suitable for overlapping with the high lying π*-orbital of N2 via effective π-backdonation. The BN2 interaction energy has been compared with that of the FeN2 bond. Our thorough bonding analysis might answer the unasked questions of experimental chemists about how boron compounds could mimic the transition metal of dinitrogen binding and activation, uncovering hidden bonding aspects. Importantly, Pauling repulsion energy also plays a crucial role and decides the binding efficiency in terms of intrinsic interaction energy between the boron-center and the N2 ligand.
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Affiliation(s)
- Kavita Devi
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, India
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12
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Karnamkkott HS, Gorantla SMNVT, Devi K, Tiwari G, Mondal KC. Bonding and stability of dinitrogen-bonded donor base-stabilized Si(0)/Ge(0) species [(cAAC Me-Si/Ge) 2(N 2)]: EDA-NOCV analysis. RSC Adv 2022; 12:4081-4093. [PMID: 35425464 PMCID: PMC8981037 DOI: 10.1039/d1ra07714g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 12/20/2021] [Indexed: 11/21/2022] Open
Abstract
Recently, dinitrogen (N2) binding and its activation have been achieved by non-metal compounds like intermediate cAAC-borylene as (cAAC)2(B-Dur)2(N2) [cAAC = cyclic alkyl(amino) carbene; Dur = aryl group, 2,3,5,6-tetramethylphenyl; B-Dur = borylene]. It has attracted a lot of scientific attention from different research areas because of its future prospects as a potent species towards the metal free reduction of N2 into ammonia (NH3) under mild conditions. Two (cAAC)(B-Dur) units, each of which possesses six valence electrons around the B-centre, are shown to accept σ-donations from the N2 ligand (B ← N2). Two B-Dur further provide π-backdonations (B → N2) to a central N2 ligand to strengthen the B–N2–B bond, providing maximum stability to the compound (cAAC)2(B-Dur)2(N2) since the summation of each pair wise interaction accounted for the total stabilization energy of the molecule. (cAAC)(B-Dur) unit is isolobal to cAAC–E (E = Si, Ge) fragment. Herein, we report on the stability and bonding of cAAC–E bonded N2-complex (cAAC–E)2(N2) (1–2; Si, Ge) by NBO, QTAIM and EDA-NOCV analyses (EDA-NOCV = energy decomposition analysis coupled with natural orbital for chemical valence; QTAIM = quantum theory of atoms in molecule). Our calculation suggested that syntheses of elusive (cAAC–E)2(N2) (1–2; Si, Ge) species may be possible with cAAC ligands having bulky substitutions adjacent to the CcAAC atom by preventing the homo-dimerization of two (cAAC)(E) units which can lead to the formation of (cAAC–E)2. The formation of E
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E bond is thermodynamically more favourable (E = Si, Ge) over binding energy of N2 inbetween two cAAC–E units. Dinitrogen (N2) binding and its activation have been achieved by non-metal compounds like intermediate cAACborylene with the general formula of (cAAC)2(B-Dur)2(N2) [cAAC = cyclic alkyl(amino)carbene; Dur = aryl group, 2,3,5,6-tetramethylphenyl; B-Dur = aryl-borylene].![]()
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Affiliation(s)
- Harsha S Karnamkkott
- Department of Chemistry, Indian Institute of Technology Madras Chennai 600036 India
| | | | - Kavita Devi
- Department of Chemistry, Indian Institute of Technology Madras Chennai 600036 India
| | - Geetika Tiwari
- Department of Chemistry, Indian Institute of Technology Madras Chennai 600036 India
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Dinitrogen Binding Relevant to FeMoco of Nitrogenase: Clear Visualization of σ‐Donation and π‐Backdonation from Deformation Electron Densities around Carbon/Silicon‐Iron Site. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202100931] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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Gorantla SMNVT, Chandra Mondal K. Estimations of Fe0/−1–N2 interaction energies of iron(0)-dicarbene and its reduced analogue by EDA-NOCV analyses: crucial steps in dinitrogen activation under mild conditions. RSC Adv 2022; 12:3465-3475. [PMID: 35425364 PMCID: PMC8979315 DOI: 10.1039/d1ra08348a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 12/14/2021] [Indexed: 11/22/2022] Open
Abstract
Metal complexes containing low valence iron atoms are often experimentally observed to bind with the dinitrogen (N2) molecule. This phenomenon has attracted the attention of industrialists, chemists and bio-chemists since these N2-bonded iron complexes can produce ammonia under suitable chemical or electrochemical conditions. The higher binding affinity of the Fe-atom towards N2 is a bit ‘mysterious’ compared to that of the other first row transition metal atoms. Fine powders of α-Fe0 are even part of industrial ammonia production (Haber–Bosch process) which operates at high temperature and high pressure. Herein, we report the EDA-NOCV analyses of the previously reported dinitrogen-bonded neutral molecular complex (cAACR)2Fe0–N2 (1) and mono-anionic complex (cAACR)2Fe−1–N2 (2) to give deeper insight of the Fe–N2 interacting orbitals and corresponding pairwise intrinsic interaction energies (cAACR = cyclic alkyl(amino) carbene; R = Dipp or Me). The Fe0 atom of 1 prefers to accept electron densities from N2via σ-donation while the comparatively electron rich Fe−1 centre of 2 donates electron densities to N2via π-backdonation. However, major stability due to the formation of an Fe–N2 bond arises due to Fe → N2 π-backdonation in both 1 and 2. The cAACR ligands act as a charge reservoir around the Fe centre. The electron densities drift away from cAAC ligands during the binding of N2 molecules mostly via π-backdonation. EDA-NOCV analysis suggests that N2 is a stronger π-acceptor rather than a σ-donor. The stable Fe–N2 bond of stable complex should have a sufficiently high interaction energy.![]()
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Affiliation(s)
| | - Kartik Chandra Mondal
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
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Gorantla SMVT, Mondal KC. EDA-NOCV Calculation for Efficient N 2 Binding to the Reduced Ni 3S 8 Complex: Estimation of Ni-N 2 Intrinsic Interaction Energies. ACS OMEGA 2021; 6:33389-33397. [PMID: 34926888 PMCID: PMC8674922 DOI: 10.1021/acsomega.1c03715] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 11/10/2021] [Indexed: 06/14/2023]
Abstract
The binding of the dinitrogen molecule to the metal center is the first and crucial step toward dinitrogen activation. Favorable interaction energies are desired by chemists and biochemists to study model complexes in the laboratory. An electrochemically reduced form of a previously isolated sulfur-bridged Ni3S8 complex is inferred to bind N2 at multiple Ni centers, and this bonded N2 undergoes reductive protonation to produce hydrazine (N2H4) as the product in the presence of a proton donor. Density functional theory (DFT) calculations and quantum theory of atoms in molecules (QTAIM) analysis have been carried out to shed light on the nature of N2 binding to an anionic trinuclear Ni3S8 complex. Additionally, energy decomposition analysis with the combination of natural orbital for chemical valence (EDA-NOCV) analysis has been performed to estimate the pairwise interaction energies between the Ni center and the N2 molecule under experimental conditions.
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16
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Gorantla SMVT, Mondal KC. Estimations of Fe-N 2 Intrinsic Interaction Energies of Iron-Sulfur/Nitrogen-Carbon Sites: A Deeper Bonding Insight by EDA-NOCV Analysis of a Model Complex of the Nitrogenase Cofactor. ACS OMEGA 2021; 6:33932-33942. [PMID: 34926940 PMCID: PMC8675039 DOI: 10.1021/acsomega.1c05238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/10/2021] [Indexed: 06/14/2023]
Abstract
The MoFe7S9C1- unit of the nitrogenase cofactor (FeMoco) attracts chemists and biochemists due to its unusual ability to bind aerial dinitrogen (N2) at ambient condition and catalytically convert it into ammonia (NH3). The mode of N2 binding and its reaction pathways are yet not clear. An important conclusion has been made based on the very recent synthesis and isolation of model Fe(I/0)-complexes with sulfur-donor ligands under the cleavage of one Fe-S bond followed by binding of N2 at the Fe(0) center. These complexes are structurally relevant to the nitrogenase cofactor (MoFe7S9C1-). Herein, we report the EDA-NOCV analyses and NICS calculations of the dinitrogen-bonded dianionic complex Fe0-N2 (1) (having a CAr ← Fe π-bond) and monoanionic complex FeI-N2 (2) (having a CAr-Fe σ-bond) to provide a deeper insight into the Fe-N2 interacting orbitals and corresponding pairwise interaction energies (EDA-NOCV = energy decomposition analysis coupled with natural orbital for chemical valence; NICS = nucleus-independent chemical shifts). The orbital interaction in the Fe-N2 bond is significantly larger than Coulombic interactions, with major pairwise contributions coming from d(Fe) orbitals to the empty π* orbitals of N2 (three Fe → N2). ΔE int values are in the range of -61 to -77 kcal mol-1. Very interestingly, NICS calculations have been carried out for the fragments before and after binding of the N2 molecule. The computed σ- and π-aromaticity values are attributed to the position of the Fe atoms, oxidation states of Fe centers, and Fe-C bond lengths of these two complexes.
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17
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Chang G, Zhang P, Yang W, Dong Y, Xie S, Sun H, Li X, Fuhr O, Fenske D. Synthesis of silyl iron dinitrogen complexes for activation of dihydrogen and catalytic silylation of dinitrogen. Dalton Trans 2021; 50:17594-17602. [PMID: 34792061 DOI: 10.1039/d1dt02832d] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three novel iron dinitrogen hydrides, [FeH(iPr-PSiMeP)(N2)(PMe3)] (1), [FeH(iPr-PSiPhP)(N2)(PMe3)] (2), and [FeH(iPr-PSiPh)(N2)(PMe3)] (3), supported by a silyl ligand are synthesized for the first time by changing the electronic effect and steric hindrance of the ligands through the reaction of ligands L1-L3 with Fe(PMe3)4 in a nitrogen atmosphere. The ligands containing an electron-donating group with large steric hindrance on the phosphorus atom are beneficial for the formation of dinitrogen complexes. A penta-coordinate iron hydride [FeH(iPr-PSiPh)(PMe3)2] (4) was formed through the reaction of ligand L3 with Fe(PMe3)4 in an argon atmosphere under the same conditions. The reactions between complexes 1-3 with an atmospheric pressure of dihydrogen gas resulted in Fe(II) dihydrides, [(iPr-PSiMe(μ-H)P)Fe(H)2(PMe3)] (5), [(iPr-PSiPh(μ-H)P)Fe(H)2(PMe3)] (6) and [(iPr-PSiPh(μ-H))Fe(H)2(PMe3)2] (7), with an η2-(Si-H) coordination. The isolation of dihydrides 5-7 demonstrates the ability of the dinitrogen complexes 1-3 to realize the activation of dihydrogen under ambient temperature and pressure. The molecular structures of complexes 1-7 were elucidated by single crystal X-ray diffraction analysis. The iron dinitrogen hydrides 1-3 are effective catalysts for the silylation of dinitrogen under ambient conditions and among them 3 is the best catalyst.
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Affiliation(s)
- Guoliang Chang
- School of Chemistry and Chemical Engineering, Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Shanda Nanlu 27, 250100 Jinan, People's Republic of China.
| | - Peng Zhang
- School of Chemistry and Chemical Engineering, Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Shanda Nanlu 27, 250100 Jinan, People's Republic of China.
| | - Wenjing Yang
- School of Chemistry and Chemical Engineering, Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Shanda Nanlu 27, 250100 Jinan, People's Republic of China.
| | - Yanhong Dong
- School of Chemistry and Chemical Engineering, Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Shanda Nanlu 27, 250100 Jinan, People's Republic of China.
| | - Shangqing Xie
- School of Chemistry and Chemical Engineering, Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Shanda Nanlu 27, 250100 Jinan, People's Republic of China.
| | - Hongjian Sun
- School of Chemistry and Chemical Engineering, Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Shanda Nanlu 27, 250100 Jinan, People's Republic of China.
| | - Xiaoyan Li
- School of Chemistry and Chemical Engineering, Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Shanda Nanlu 27, 250100 Jinan, People's Republic of China.
| | - Olaf Fuhr
- Institut für Nanotechnologie (INT) und Karlsruher Nano-Micro-Facility (KNMF), Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Dieter Fenske
- Institut für Nanotechnologie (INT) und Karlsruher Nano-Micro-Facility (KNMF), Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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18
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Gautam M, Tanaka S, Sekiguchi A, Nakajima Y. Long-Range Metal–Ligand Cooperation by Iron Hydride Complexes Bearing a Phenanthroline-Based Tetradentate PNNP Ligand. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00507] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Monika Gautam
- Interdisciplinary Research Center for Catalytic Chemistry (IRC3), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
- Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennoudai,Tsukuba, Ibaraki 305-8577, Japan
| | - Shinji Tanaka
- Interdisciplinary Research Center for Catalytic Chemistry (IRC3), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Akira Sekiguchi
- Interdisciplinary Research Center for Catalytic Chemistry (IRC3), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Yumiko Nakajima
- Interdisciplinary Research Center for Catalytic Chemistry (IRC3), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
- Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennoudai,Tsukuba, Ibaraki 305-8577, Japan
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19
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Rohde M, Laun K, Zebger I, Stripp ST, Einsle O. Two ligand-binding sites in CO-reducing V nitrogenase reveal a general mechanistic principle. SCIENCE ADVANCES 2021; 7:7/22/eabg4474. [PMID: 34049880 PMCID: PMC8163085 DOI: 10.1126/sciadv.abg4474] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/14/2021] [Indexed: 06/12/2023]
Abstract
Besides its role in biological nitrogen fixation, vanadium-containing nitrogenase also reduces carbon monoxide (CO) to hydrocarbons, in analogy to the industrial Fischer-Tropsch process. The protein yields 93% of ethylene (C2H4), implying a C-C coupling step that mandates the simultaneous binding of two CO at the active site FeV cofactor. Spectroscopic data indicated multiple CO binding events, but structural analyses of Mo and V nitrogenase only confirmed a single site. Here, we report the structure of a two CO-bound state of V nitrogenase at 1.05 Å resolution, with one μ-bridging and one terminal CO molecule. This additional, specific ligand binding site suggests a mechanistic route for CO reduction and hydrocarbon formation, as well as a second access pathway for protons required during the reaction. Moreover, carbonyls are strong-field ligands that are chemically similar to mechanistically relevant hydrides that may be formed and used in a fully analogous fashion.
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Affiliation(s)
- Michael Rohde
- Institute for Biochemistry, University of Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Konstantin Laun
- Institute of Chemistry, Technical University of Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Ingo Zebger
- Institute of Chemistry, Technical University of Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Sven T Stripp
- Institute of Experimental Physics, Department of Physics, Free University of Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Oliver Einsle
- Institute for Biochemistry, University of Freiburg, Albertstrasse 21, 79104 Freiburg, Germany.
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20
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Tanabe Y, Nishibayashi Y. Comprehensive insights into synthetic nitrogen fixation assisted by molecular catalysts under ambient or mild conditions. Chem Soc Rev 2021; 50:5201-5242. [PMID: 33651046 DOI: 10.1039/d0cs01341b] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
N2 is fixed as NH3 industrially by the Haber-Bosch process under harsh conditions, whereas biological nitrogen fixation is achieved under ambient conditions, which has prompted development of alternative methods to fix N2 catalyzed by transition metal molecular complexes. Since the early 21st century, catalytic conversion of N2 into NH3 under ambient conditions has been achieved by using molecular catalysts, and now H2O has been utilized as a proton source with turnover frequencies reaching the values found for biological nitrogen fixation. In this review, recent advances in the development of molecular catalysts for synthetic N2 fixation under ambient or mild conditions are summarized, and potential directions for future research are also discussed.
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Affiliation(s)
- Yoshiaki Tanabe
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
| | - Yoshiaki Nishibayashi
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
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21
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Winters KR, Montchamp JL. Evaluation and Development of Methodologies for the Synthesis of Thiophosphinic Acids. J Org Chem 2020; 85:14545-14558. [PMID: 32806089 DOI: 10.1021/acs.joc.0c01151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Thiophosphorus acids R1R2P(S)OH constitute an important class of organophosphorus compounds, in which the phosphorus atom is intrinsically chiral if R1 ≠ R2. In connection with a project aimed at the preparation of chiral thiophosphorus acids, various available literature methods were considered, but few fit the requirement of odorless reagents. Herein, the results of our studies on the synthesis of thiophosphinic acids are reported. Ultimately, two major approaches were selected: (1) the Stec reaction of phosphorus amides with carbon disulfide; and (2) the one-pot synthesis of thiophosphorus acids from H-phosphinates, an organometallic nucleophile, and quenching with elemental sulfur. An application to the preparation of a potential chiral phosphorus organocatalyst is also reported.
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Affiliation(s)
- Karen R Winters
- Department of Chemistry, Texas Christian University, PO Box 298860, Fort Worth, Texas 76129, United States
| | - Jean-Luc Montchamp
- Department of Chemistry, Texas Christian University, PO Box 298860, Fort Worth, Texas 76129, United States
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22
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Bruch QJ, Connor GP, McMillion ND, Goldman AS, Hasanayn F, Holland PL, Miller AJM. Considering Electrocatalytic Ammonia Synthesis via Bimetallic Dinitrogen Cleavage. ACS Catal 2020. [DOI: 10.1021/acscatal.0c02606] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Quinton J. Bruch
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Gannon P. Connor
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Noah D. McMillion
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Alan S. Goldman
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08903, United States
| | - Faraj Hasanayn
- Department of Chemistry, American University of Beirut, Beirut 1107 2020, Lebanon
| | - Patrick L. Holland
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Alexander J. M. Miller
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
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23
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Chalkley MJ, Drover MW, Peters JC. Catalytic N 2-to-NH 3 (or -N 2H 4) Conversion by Well-Defined Molecular Coordination Complexes. Chem Rev 2020; 120:5582-5636. [PMID: 32352271 DOI: 10.1021/acs.chemrev.9b00638] [Citation(s) in RCA: 187] [Impact Index Per Article: 46.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nitrogen fixation, the six-electron/six-proton reduction of N2, to give NH3, is one of the most challenging and important chemical transformations. Notwithstanding the barriers associated with this reaction, significant progress has been made in developing molecular complexes that reduce N2 into its bioavailable form, NH3. This progress is driven by the dual aims of better understanding biological nitrogenases and improving upon industrial nitrogen fixation. In this review, we highlight both mechanistic understanding of nitrogen fixation that has been developed, as well as advances in yields, efficiencies, and rates that make molecular alternatives to nitrogen fixation increasingly appealing. We begin with a historical discussion of N2 functionalization chemistry that traverses a timeline of events leading up to the discovery of the first bona fide molecular catalyst system and follow with a comprehensive overview of d-block compounds that have been targeted as catalysts up to and including 2019. We end with a summary of lessons learned from this significant research effort and last offer a discussion of key remaining challenges in the field.
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Affiliation(s)
- Matthew J Chalkley
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Marcus W Drover
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Jonas C Peters
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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24
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Vyas N, Kumar A, Ojha AK, Grover A. Electronic structure of iron dinitrogen complex [(TPB)FeN 2] 2−/1−/0: correlation to Mössbauer parameters. RSC Adv 2020; 10:7948-7955. [PMID: 35492201 PMCID: PMC9049905 DOI: 10.1039/c9ra10481j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 01/30/2020] [Indexed: 12/29/2022] Open
Abstract
Low-valent species of iron are key intermediates in many important biological processes such as the nitrogenase enzymatic catalytic reaction. These species play a major role in activating highly stable N2 molecules. Thus, there is a clear need to establish the factors which are responsible for the reactivity of the metal–dinitrogen moiety. In this regard, we have investigated the electronic structure of low-valent iron (2−/1−/0) in a [(TPB)FeN2]2−/1−/0 complex using density functional theory (DFT). The variation in the oxidation states of iron in the nitrogenase enzyme cycle is associated with the flexibility of Fe→B bonding. Therefore, the flexibility of Fe→B bonding acts as an electron source that sustains the formation of various oxidation states, which is necessary for the key species in dinitrogen activation. AIM calculations are also performed to understand the strength of Fe→B and Fe–N2 bonds. A detailed interpretation of the contributions to the isomer shift (IS) and quadrupole splitting (ΔEQ) are discussed. The major contribution to IS comes mainly from the 3s-contribution, which differs depending on the d orbital population due to different shielding. The valence shell contribution also comes from the 4s-orbital. The Fe–N2 bond distance has a great influence on the Mössbauer parameters, which are associated with the radial distribution, i.e. the shape of the 4s-orbital and the charge density at the nucleus. A linear relationship between IS with Fe–N2 and ΔEQ with Fe–N2 is observed. We use density functional theory studies to explore the electronic structure, bonding and spectroscopic analysis of a low-valent iron (2−/1−/0) complex [(TPB)FeN2]2−/1−/0 and reveled the factor which affects the reactivity of the metal–dinitrogen moiety.![]()
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Affiliation(s)
- Nidhi Vyas
- School of Biotechnology
- Jawaharlal Nehru University
- New Delhi-110067
- India
| | - Aditya Kumar
- Department of Physics
- Motilal Nehru National Institute of Technology
- Allahabad-211004
- India
| | - Animesh K. Ojha
- Department of Physics
- Motilal Nehru National Institute of Technology
- Allahabad-211004
- India
| | - Abhinav Grover
- School of Biotechnology
- Jawaharlal Nehru University
- New Delhi-110067
- India
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25
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Thompson CV, Arman HD, Tonzetich ZJ. Square-Planar Iron(II) Silyl Complexes: Synthesis, Characterization, and Insertion Reactivity. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00335] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- C. Vance Thompson
- Department of Chemistry, University of Texas at San Antonio (UTSA), San Antonio, Texas 78249, United States
| | - Hadi D. Arman
- Department of Chemistry, University of Texas at San Antonio (UTSA), San Antonio, Texas 78249, United States
| | - Zachary J. Tonzetich
- Department of Chemistry, University of Texas at San Antonio (UTSA), San Antonio, Texas 78249, United States
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26
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Nesbit MA, Oyala PH, Peters JC. Characterization of the Earliest Intermediate of Fe-N 2 Protonation: CW and Pulse EPR Detection of an Fe-NNH Species and Its Evolution to Fe-NNH 2.. J Am Chem Soc 2019; 141:8116-8127. [PMID: 31046258 DOI: 10.1021/jacs.8b12082] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Iron diazenido species (Fe(NNH)) have been proposed as the earliest intermediates of catalytic N2-to-NH3 conversion (N2RR) mediated by synthetic iron complexes and relatedly as intermediates of N2RR by nitrogenase enzymes. However, direct identification of such iron species, either during or independent of catalysis, has proven challenging owing to their high degree of instability. The isolation of more stable silylated diazenido analogues, Fe(NNSiR3), and also of further downstream intermediates (e.g., Fe(NNH2)), nonetheless points to Fe(NNH) as the key first intermediate of protonation in synthetic systems. Herein we show that low-temperature protonation of a terminally bound Fe-N2- species, supported by a bulky trisphosphinoborane ligand (ArP3B), generates an S = 1/2 terminal Fe(NNH) species that can be detected and characterized by continuous-wave (CW) and pulse EPR techniques. The 1H-hyperfine for ArP3BFe(NNH) derived from the presented ENDOR studies is diagnostic for the distally bound H atom ( aiso = 16.5 MHz). The Fe(NNH) species evolves further to cationic [Fe(NNH2)]+ in the presence of additional acid, the latter being related to a previously characterized [Fe(NNH2)]+ intermediate of N2RR mediated by a far less encumbered iron tris(phosphine)borane catalyst. While catalysis is suppressed in the present sterically very crowded system, N2-to-NH3 conversion can nevertheless be demonstrated. These observations in sum add support to the idea that Fe(NNH) plays a central role as the earliest intermediate of Fe-mediated N2RR in a synthetic system.
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Affiliation(s)
- Mark A Nesbit
- Division of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , California 91125 , United States
| | - Paul H Oyala
- Division of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , California 91125 , United States
| | - Jonas C Peters
- Division of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , California 91125 , United States
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27
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Schild DJ, Peters JC. Light Enhanced Fe-Mediated Nitrogen Fixation: Mechanistic Insights Regarding H 2 Elimination, HER, and NH 3 Generation. ACS Catal 2019; 9:4286-4295. [PMID: 31467770 DOI: 10.1021/acscatal.9b00523] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Despite their proposed accumulation at the Fe sites of the FeMo-cofactor of MoFe-nitrogenase, the presence of hydride ligands in molecular model systems capable of the nitrogen reduction reaction (N2RR) appears to diminish the catalytic N2-to-NH3 conversion. We find that for an iron-based system bearing the trisphosphine ligand P2PPh, a dramatic difference in yields is observed for N2RR catalyzed by precatalysts with zero, one, or two hydride ligands; however, irradiating the three different catalysts with a mercury lamp results in similar yields. Although the efficacy for N2RR versus the hydrogen evolution reaction (HER) is modest for this system by comparison to certain iron (and other metal) catalysts, the system provides an opportunity to study the role of hydrides in the selectivity for N2RR versus HER, which is a central issue in catalyst design. Stochiometric reactions with hydride containing precatalysts reveal a hydrogen evolution cycle in which no nitrogen fixation occurs. Irradiation of the dihydride precatalysts, observed during turnover, results in H2 elimination and formation of (P2PPh)Fe(N2)2, which itself is unreactive with acids at low temperature. N2 functionalization does occur with acids and silyl electrophiles for the reduced species [(P2PPh)Fe(N2)]- and [(P2PPh)Fe(N2)]2-, which have been characterized independently. The requirement of accessing such low formal oxidation states explains the need for strong reductants. The low selectivity of the system for functionalization at Nβ versus Fe creates off-path hydride species that participate in unproductive HER, helping to explain the low selectivity for N2RR over HER. The data presented here hence lends further insight into the growing understanding of the selectivity, activity, and required driving force relevant to iron (and other) N2RR catalysts.
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Affiliation(s)
- Dirk J. Schild
- Division of Chemistry and Chemical Engineering, California Institute of Technology (Caltech), Pasadena, California 91125, United States
| | - Jonas C. Peters
- Division of Chemistry and Chemical Engineering, California Institute of Technology (Caltech), Pasadena, California 91125, United States
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28
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Liu H, Wei L, Liu F, Pei Z, Shi J, Wang ZJ, He D, Chen Y. Homogeneous, Heterogeneous, and Biological Catalysts for Electrochemical N2 Reduction toward NH3 under Ambient Conditions. ACS Catal 2019. [DOI: 10.1021/acscatal.9b00994] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Huimin Liu
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
- TJU-NIMS
International
Collaboration Laboratory, School of Material Science and Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Li Wei
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Fei Liu
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
- State Key Laboratory
of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory
of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou, Guangdong 510070, People’s Republic of China
| | - Zengxia Pei
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Jeffrey Shi
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Zhou-jun Wang
- State Key Laboratory
of Chemical Resource Engineering, Beijing Key Laboratory of Energy
Environmental Catalysis, Beijing University of Chemical Technology, 15 Beisanhuan East Road, Beijing 100029, People’s Republic of China
| | - Dehua He
- Innovative Catalysis
Program, Key Laboratory of Organic Optoelectronics and Molecular Engineering
of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, People’s Republic of China
| | - Yuan Chen
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
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29
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Field LD, Li HL, Dalgarno SJ, McIntosh RD. Ammonia and Hydrazine from Coordinated Dinitrogen by Complexes of Iron(0). Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Leslie D. Field
- School of Chemistry University of New South Wales NSW 2052 Australia
| | - Hsiu L. Li
- School of Chemistry University of New South Wales NSW 2052 Australia
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30
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Gu NX, Ung G, Peters JC. Catalytic hydrazine disproportionation mediated by a thiolate-bridged VFe complex. Chem Commun (Camb) 2019; 55:5363-5366. [DOI: 10.1039/c9cc00345b] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A heterobimetallic VFe complex is demonstrated to catalyse hydrazine disproportionation with yields of up to 1073 equivalents of NH3 per catalyst, comparable to the highest turnover known for any molecular catalyst.
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Affiliation(s)
- Nina X. Gu
- Division of Chemistry and Chemical Engineering
- California Institute of Technology
- Pasadena
- USA
| | - Gaël Ung
- Department of Chemistry
- University of Connecticut
- Storrs
- USA
| | - Jonas C. Peters
- Division of Chemistry and Chemical Engineering
- California Institute of Technology
- Pasadena
- USA
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31
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Murphy LJ, Ferguson MJ, McDonald R, Lumsden MD, Turculet L. Synthesis of Bis(phosphino)silyl Pincer-Supported Iron Hydrides for the Catalytic Hydrogenation of Alkenes. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00807] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Luke J. Murphy
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, P.O. Box 15000, Halifax, Nova Scotia, Canada B3H 4R2
| | - Michael J. Ferguson
- X-Ray Crystallography Laboratory, Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Robert McDonald
- X-Ray Crystallography Laboratory, Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Michael D. Lumsden
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, P.O. Box 15000, Halifax, Nova Scotia, Canada B3H 4R2
| | - Laura Turculet
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, P.O. Box 15000, Halifax, Nova Scotia, Canada B3H 4R2
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32
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Bennett MA, Bhargava SK, Mirzadeh N, Privér SH. The use of [2-C 6 R 4 PPh 2 ] − (R = H, F) and related carbanions as building blocks in coordination chemistry. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2018.05.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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33
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Smirnova ES, Acuña‐Parés F, Escudero‐Adán EC, Jelsch C, Lloret‐Fillol J. Synthesis and Reactivity of Copper(I) Complexes Based on
C
3
‐Symmetric Tripodal HTIM(PR
2
)
3
Ligands. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800074] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ekaterina S. Smirnova
- Institute of Chemical Research of Catalonia (ICIQ) The Barcelona Institute of Science and Technology Avinguda Països Catalans 16 43007 Tarragona Spain
| | - Ferran Acuña‐Parés
- Institute of Chemical Research of Catalonia (ICIQ) The Barcelona Institute of Science and Technology Avinguda Països Catalans 16 43007 Tarragona Spain
| | - Eduardo C. Escudero‐Adán
- Institute of Chemical Research of Catalonia (ICIQ) The Barcelona Institute of Science and Technology Avinguda Països Catalans 16 43007 Tarragona Spain
| | - Christian Jelsch
- CRM2 UMR CNRS 7036 Université de Lorraine Vandoeuvre les Nancy CEDEX France
| | - Julio Lloret‐Fillol
- Institute of Chemical Research of Catalonia (ICIQ) The Barcelona Institute of Science and Technology Avinguda Països Catalans 16 43007 Tarragona Spain
- Catalan Institution for Research and Advanced Studies (ICREA) Passeig Lluïs Companys, 23 08010 Barcelona Spain
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34
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van de Watering FF, Stroek W, Ivar van der Vlugt J, de Bruin B, Dzik WI, Reek JNH. Coordination of 3-Methylindole-Based Tripodal Tetraphosphine Ligands to Iron(+II), Cobalt(+II), and Nickel(+II) and Investigations of their Subsequent Two-Electron Reduction. Eur J Inorg Chem 2018; 2018:1254-1265. [PMID: 29937690 PMCID: PMC5993305 DOI: 10.1002/ejic.201701209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Indexed: 11/13/2022]
Abstract
We report the coordination chemistry of indole based tripodal tetraphosphine ligands to iron(II), cobalt(II) and nickel(II). These complexes are formed by simple synthetic protocols and were characterized by a combination of spectroscopic techniques and single-crystal X-ray analysis. The molecular structures as determined by X-ray diffraction show that the geometry of the nickel and cobalt complexes are distorted trigonal bipyramidal. The monocationic iron(II) complexes also have distorted trigonal bipyramidal geometries, but the dicationic analogue has an octahedral geometry. Two-electron reduction of the cobalt(+II) and the nickel(+II) complexes in the presence of N2 did not lead to the coordination of N2. In contrast, two-electron reduction of the iron(+II) complexes did lead to coordination of dinitrogen to the iron center. The Fe0N2L1H complex has a trigonal bipyramidal geometry, and the N-N bond length of the coordinated dinitrogen ligand is longer than that of free dinitrogen, indicating that coordination to this iron(0) complex results in activation of the N≡N bond.
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Affiliation(s)
- Fenna F. van de Watering
- HomogeneousSupramolecular and Bio‐Inspired CatalysisVan ‘t Hoff Institute for Molecular SciencesUniversity of AmsterdamScience Park 9041098 XHAmsterdamThe Netherlands
| | - Wowa Stroek
- HomogeneousSupramolecular and Bio‐Inspired CatalysisVan ‘t Hoff Institute for Molecular SciencesUniversity of AmsterdamScience Park 9041098 XHAmsterdamThe Netherlands
| | - Jarl Ivar van der Vlugt
- HomogeneousSupramolecular and Bio‐Inspired CatalysisVan ‘t Hoff Institute for Molecular SciencesUniversity of AmsterdamScience Park 9041098 XHAmsterdamThe Netherlands
| | - Bas de Bruin
- HomogeneousSupramolecular and Bio‐Inspired CatalysisVan ‘t Hoff Institute for Molecular SciencesUniversity of AmsterdamScience Park 9041098 XHAmsterdamThe Netherlands
| | - Wojciech I. Dzik
- HomogeneousSupramolecular and Bio‐Inspired CatalysisVan ‘t Hoff Institute for Molecular SciencesUniversity of AmsterdamScience Park 9041098 XHAmsterdamThe Netherlands
| | - Joost N. H. Reek
- HomogeneousSupramolecular and Bio‐Inspired CatalysisVan ‘t Hoff Institute for Molecular SciencesUniversity of AmsterdamScience Park 9041098 XHAmsterdamThe Netherlands
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35
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Stucke N, Flöser BM, Weyrich T, Tuczek F. Nitrogen Fixation Catalyzed by Transition Metal Complexes: Recent Developments. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201701326] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Nadja Stucke
- Institute of Inorganic Chemistry; Christian Albrechts University Kiel; Max-Eyth-Str. 2 24098 Kiel Germany
| | - Benedikt M. Flöser
- Institute of Inorganic Chemistry; Christian Albrechts University Kiel; Max-Eyth-Str. 2 24098 Kiel Germany
| | - Thomas Weyrich
- Institute of Inorganic Chemistry; Christian Albrechts University Kiel; Max-Eyth-Str. 2 24098 Kiel Germany
| | - Felix Tuczek
- Institute of Inorganic Chemistry; Christian Albrechts University Kiel; Max-Eyth-Str. 2 24098 Kiel Germany
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36
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Ren S, Xie S, Zheng T, Wang Y, Xu S, Xue B, Li X, Sun H, Fuhr O, Fenske D. Synthesis of silyl iron hydride via Si–H activation and its dual catalytic application in the hydrosilylation of carbonyl compounds and dehydration of benzamides. Dalton Trans 2018; 47:4352-4359. [DOI: 10.1039/c8dt00289d] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A silyl iron hydride as a dual catalyst was synthesized for the reduction of carbonyl compounds and the dehydration of amides.
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37
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3-Methylindole-Based Tripodal Tetraphosphine Ruthenium Complexes in N2 Coordination and Reduction and Formic Acid Dehydrogenation. INORGANICS 2017. [DOI: 10.3390/inorganics5040073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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38
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Thalangamaarachchige VD, Li H, Cordes DB, Unruh DK, Krempner C. Zwitterionic Alkali-Metal Silanides of Tripodal Ligand Geometry: Synthesis, Structure, and Lewis Acid–Base Chemistry. Inorg Chem 2017; 56:9869-9879. [DOI: 10.1021/acs.inorgchem.7b01227] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Hui Li
- Department of Chemistry & Biochemistry, Texas Tech University, Box 1061, Lubbock, Texas 79409-1061, United States
| | - David B. Cordes
- Department of Chemistry & Biochemistry, Texas Tech University, Box 1061, Lubbock, Texas 79409-1061, United States
| | - Daniel K. Unruh
- Department of Chemistry & Biochemistry, Texas Tech University, Box 1061, Lubbock, Texas 79409-1061, United States
| | - Clemens Krempner
- Department of Chemistry & Biochemistry, Texas Tech University, Box 1061, Lubbock, Texas 79409-1061, United States
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39
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Petuker A, Reback ML, Apfel U. Carbon/Silicon Exchange at the Apex of Diphos‐ and Triphos‐Derived Ligands – More Than Just a Substitute? Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201700388] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Anette Petuker
- Ruhr University Bochum Inorganic Chemistry I ‐ Bioinorganic Chemistry Universitätsstraße 150 44801 Bochum Germany
| | - Matthew L. Reback
- Ruhr University Bochum Inorganic Chemistry I ‐ Bioinorganic Chemistry Universitätsstraße 150 44801 Bochum Germany
| | - Ulf‐Peter Apfel
- Ruhr University Bochum Inorganic Chemistry I ‐ Bioinorganic Chemistry Universitätsstraße 150 44801 Bochum Germany
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40
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Coste SC, Vlaisavljevich B, Freedman DE. Magnetic Anisotropy from Main-Group Elements: Halides versus Group 14 Elements. Inorg Chem 2017; 56:8195-8202. [DOI: 10.1021/acs.inorgchem.7b00923] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Scott C. Coste
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Bess Vlaisavljevich
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Danna E. Freedman
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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41
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Proppe J, Reiher M. Reliable Estimation of Prediction Uncertainty for Physicochemical Property Models. J Chem Theory Comput 2017; 13:3297-3317. [PMID: 28581746 DOI: 10.1021/acs.jctc.7b00235] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
One of the major challenges in computational science is to determine the uncertainty of a virtual measurement, that is the prediction of an observable based on calculations. As highly accurate first-principles calculations are in general unfeasible for most physical systems, one usually resorts to parameteric property models of observables, which require calibration by incorporating reference data. The resulting predictions and their uncertainties are sensitive to systematic errors such as inconsistent reference data, parametric model assumptions, or inadequate computational methods. Here, we discuss the calibration of property models in the light of bootstrapping, a sampling method that can be employed for identifying systematic errors and for reliable estimation of the prediction uncertainty. We apply bootstrapping to assess a linear property model linking the 57Fe Mössbauer isomer shift to the contact electron density at the iron nucleus for a diverse set of 44 molecular iron compounds. The contact electron density is calculated with 12 density functionals across Jacob's ladder (PWLDA, BP86, BLYP, PW91, PBE, M06-L, TPSS, B3LYP, B3PW91, PBE0, M06, TPSSh). We provide systematic-error diagnostics and reliable, locally resolved uncertainties for isomer-shift predictions. Pure and hybrid density functionals yield average prediction uncertainties of 0.06-0.08 mm s-1 and 0.04-0.05 mm s-1, respectively, the latter being close to the average experimental uncertainty of 0.02 mm s-1. Furthermore, we show that both model parameters and prediction uncertainty depend significantly on the composition and number of reference data points. Accordingly, we suggest that rankings of density functionals based on performance measures (e.g., the squared coefficient of correlation, r2, or the root-mean-square error, RMSE) should not be inferred from a single data set. This study presents the first statistically rigorous calibration analysis for theoretical Mössbauer spectroscopy, which is of general applicability for physicochemical property models and not restricted to isomer-shift predictions. We provide the statistically meaningful reference data set MIS39 and a new calibration of the isomer shift based on the PBE0 functional.
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Affiliation(s)
- Jonny Proppe
- Laboratorium für Physikalische Chemie, ETH Zürich , Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Markus Reiher
- Laboratorium für Physikalische Chemie, ETH Zürich , Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
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42
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43
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Creutz SE, Peters JC. Exploring secondary-sphere interactions in Fe-N x H y complexes relevant to N 2 fixation. Chem Sci 2017; 8:2321-2328. [PMID: 28451336 PMCID: PMC5363375 DOI: 10.1039/c6sc04805f] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 12/07/2016] [Indexed: 12/11/2022] Open
Abstract
Hydrogen bonding and other types of secondary-sphere interactions are ubiquitous in metalloenzyme active sites and are critical to the transformations they mediate. Exploiting secondary sphere interactions in synthetic catalysts to study the role(s) they might play in biological systems, and to develop increasingly efficient catalysts, is an important challenge. Whereas model studies in this broad context are increasingly abundant, as yet there has been relatively little progress in the area of synthetic catalysts for nitrogen fixation that incorporate secondary sphere design elements. Herein we present our first study of Fe-N x H y complexes supported by new tris(phosphine)silyl ligands, abbreviated as [SiPNMe3] and [SiPiPr2PNMe], that incorporate remote tertiary amine hydrogen-bond acceptors within a tertiary phosphine/amine 6-membered ring. These remote amine sites facilitate hydrogen-bonding interactions via a boat conformation of the 6-membered ring when certain nitrogenous substrates (e.g., NH3 and N2H4) are coordinated to the apical site of a trigonal bipyramidal iron complex, and adopt a chair conformation when no H-bonding is possible (e.g., N2). Countercation binding at the cyclic amine is also observed for anionic {Fe-N2}- complexes. Reactivity studies in the presence of proton/electron sources show that the incorporated amine functionality leads to rapid generation of catalytically inactive Fe-H species, thereby substantiating a hydride termination pathway that we have previously proposed deactivates catalysts of the type [EPR3]FeN2 (E = Si, C).
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Affiliation(s)
- Sidney E Creutz
- California Institute of Technology , Division , of Chemistry and Chemical Engineering , Pasadena , California 91125 , USA .
| | - Jonas C Peters
- California Institute of Technology , Division , of Chemistry and Chemical Engineering , Pasadena , California 91125 , USA .
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44
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Li H, Aquino AJA, Cordes DB, Hase WL, Krempner C. Electronic nature of zwitterionic alkali metal methanides, silanides and germanides - a combined experimental and computational approach. Chem Sci 2017; 8:1316-1328. [PMID: 28451273 PMCID: PMC5360169 DOI: 10.1039/c6sc02390h] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 10/06/2016] [Indexed: 11/24/2022] Open
Abstract
Zwitterionic group 14 complexes of the alkali metals of formula [C(SiMe2OCH2CH2OMe)3M], (M-1), [Si(SiMe2OCH2CH2OMe)3M], (M-2), [Ge(SiMe2OCH2CH2OMe)3M], (M-3), where M = Li, Na or K, have been prepared, structurally characterized and their electronic nature was investigated by computational methods. Zwitterions M-2 and M-3 were synthesized via reactions of [Si(SiMe2OCH2CH2OMe)4] (2) and [Ge(SiMe2OCH2CH2OMe)4] (3) with MOBu t (M = Li, Na or K), resp., in almost quantitative yields, while M-1 were prepared from deprotonation of [HC(SiMe2OCH2CH2OMe)3] (1) with LiBu t , NaCH2Ph and KCH2Ph, resp. X-ray crystallographic studies and DFT calculations in the gas-phase, including calculations of the NPA charges confirm the zwitterionic nature of these compounds, with the alkali metal cations being rigidly locked and charge separated from the anion by the internal OCH2CH2OMe donor groups. Natural bond orbital (NBO) analysis and the second order perturbation theory analysis of the NBOs reveal significant hyperconjugative interactions in M-1-M-3, primarily between the lone pair and the antibonding Si-O orbitals, the extent of which decreases in the order M-1 > M-2 > M-3. The experimental basicities and the calculated gas-phase basicities of M-1-M-3 reveal the zwitterionic alkali metal methanides M-1 to be significantly stronger bases than the analogous silanides M-2 and germanium M-3.
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Affiliation(s)
- H Li
- Texas Tech University , Department of Chemistry and Biochemistry , Box 41061 , Lubbock , Texas 79409-1061 , USA .
| | - A J A Aquino
- Texas Tech University , Department of Chemistry and Biochemistry , Box 41061 , Lubbock , Texas 79409-1061 , USA .
| | - D B Cordes
- Texas Tech University , Department of Chemistry and Biochemistry , Box 41061 , Lubbock , Texas 79409-1061 , USA .
| | - W L Hase
- Texas Tech University , Department of Chemistry and Biochemistry , Box 41061 , Lubbock , Texas 79409-1061 , USA .
| | - C Krempner
- Texas Tech University , Department of Chemistry and Biochemistry , Box 41061 , Lubbock , Texas 79409-1061 , USA .
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45
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Herrmann R, Wittwer P, Braun T. Platinum Complexes Bearing a Tripodal Germyl Ligand. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201600652] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Roy Herrmann
- Department of Chemistry; Humboldt-Universität zu Berlin; Brook-Taylor-Straße 2 12489 Berlin Germany
| | - Philipp Wittwer
- Department of Chemistry; Humboldt-Universität zu Berlin; Brook-Taylor-Straße 2 12489 Berlin Germany
| | - Thomas Braun
- Department of Chemistry; Humboldt-Universität zu Berlin; Brook-Taylor-Straße 2 12489 Berlin Germany
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46
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Chen S, Li Y, Yang D, Luo L, Qu J, Luo Y. Studies on the electronic structure of thiolate-bridged diiron complexes and their single-electron reduction reactions. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.08.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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47
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Ouyang Z, Cheng J, Li L, Bao X, Deng L. High-Spin Iron(I) and Iron(0) Dinitrogen Complexes Supported by N-Heterocyclic Carbene Ligands. Chemistry 2016; 22:14162-5. [DOI: 10.1002/chem.201603390] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Zhenwu Ouyang
- State Key Laboratory of Organometallic Chemistry; Shanghai Institute of Organic Chemistry; Chinese Academy of Sciences; 345 Lingling Road Shanghai 200032 P. R. China
| | - Jun Cheng
- State Key Laboratory of Organometallic Chemistry; Shanghai Institute of Organic Chemistry; Chinese Academy of Sciences; 345 Lingling Road Shanghai 200032 P. R. China
| | - Lingling Li
- Instrumental Analysis Center; Shanghai Jiao Tong University; 800 Dongchuan Road Shanghai 200240 P. R. China
| | - Xiaoli Bao
- Instrumental Analysis Center; Shanghai Jiao Tong University; 800 Dongchuan Road Shanghai 200240 P. R. China
| | - Liang Deng
- State Key Laboratory of Organometallic Chemistry; Shanghai Institute of Organic Chemistry; Chinese Academy of Sciences; 345 Lingling Road Shanghai 200032 P. R. China
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48
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Miura-Akagi PM, Nakashige ML, Maile CK, Oshiro SM, Gurr JR, Yoshida WY, Royappa AT, Krause CE, Rheingold AL, Hughes RP, Cain MF. Synthesis of a Tris(phosphaalkene)phosphine Ligand and Fundamental Organometallic Reactions on Its Sterically Shielded Metal Complexes. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00250] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Preston M. Miura-Akagi
- Department
of Chemistry, University of Hawai‘i at Ma̅noa, 2545
McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Mika L. Nakashige
- Department
of Chemistry, University of Hawai‘i at Ma̅noa, 2545
McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Caitlin K. Maile
- Department
of Chemistry, University of Hawai‘i at Ma̅noa, 2545
McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Shelly M. Oshiro
- Department
of Chemistry, University of Hawai‘i at Ma̅noa, 2545
McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Joshua R. Gurr
- Department
of Chemistry, University of Hawai‘i at Ma̅noa, 2545
McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Wesley Y. Yoshida
- Department
of Chemistry, University of Hawai‘i at Ma̅noa, 2545
McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - A. Timothy Royappa
- Department
of Chemistry, University of California, San Diego, 9500 Gilman
Drive, La Jolla, California 92093, United States
| | - Colleen E. Krause
- Department
of Chemistry, University of Hartford, 200 Bloomfield Avenue, West Hartford, Connecticut 06117, United States
| | - Arnold L. Rheingold
- Department
of Chemistry, University of California, San Diego, 9500 Gilman
Drive, La Jolla, California 92093, United States
| | - Russell P. Hughes
- 6128
Burke Laboratory, Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Matthew F. Cain
- Department
of Chemistry, University of Hawai‘i at Ma̅noa, 2545
McCarthy Mall, Honolulu, Hawaii 96822, United States
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49
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Del Castillo TJ, Thompson NB, Peters JC. A Synthetic Single-Site Fe Nitrogenase: High Turnover, Freeze-Quench (57)Fe Mössbauer Data, and a Hydride Resting State. J Am Chem Soc 2016; 138:5341-50. [PMID: 27026402 PMCID: PMC5079282 DOI: 10.1021/jacs.6b01706] [Citation(s) in RCA: 192] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The mechanisms of the few known molecular nitrogen-fixing systems, including nitrogenase enzymes, are of much interest but are not fully understood. We recently reported that Fe-N2 complexes of tetradentate P3(E) ligands (E = B, C) generate catalytic yields of NH3 under an atmosphere of N2 with acid and reductant at low temperatures. Here we show that these Fe catalysts are unexpectedly robust and retain activity after multiple reloadings. Nearly an order of magnitude improvement in yield of NH3 for each Fe catalyst has been realized (up to 64 equiv of NH3 produced per Fe for P3(B) and up to 47 equiv for P3(C)) by increasing acid/reductant loading with highly purified acid. Cyclic voltammetry shows the apparent onset of catalysis at the P3(B)Fe-N2/P3(B)Fe-N2(-) couple and controlled-potential electrolysis of P3(B)Fe(+) at -45 °C demonstrates that electrolytic N2 reduction to NH3 is feasible. Kinetic studies reveal first-order rate dependence on Fe catalyst concentration (P3(B)), consistent with a single-site catalyst model. An isostructural system (P3(Si)) is shown to be appreciably more selective for hydrogen evolution. In situ freeze-quench Mössbauer spectroscopy during turnover reveals an iron-borohydrido-hydride complex as a likely resting state of the P3(B)Fe catalyst system. We postulate that hydrogen-evolving reaction activity may prevent iron hydride formation from poisoning the P3(B)Fe system. This idea may be important to consider in the design of synthetic nitrogenases and may also have broader significance given that intermediate metal hydrides and hydrogen evolution may play a key role in biological nitrogen fixation.
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Affiliation(s)
| | | | - Jonas C. Peters
- Division of Chemistry and Chemical Engineering, California Institute of Technology (Caltech), Pasadena, California 91125, United States
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50
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Travieso-Puente R, Broekman JOP, Chang MC, Demeshko S, Meyer F, Otten E. Spin-Crossover in a Pseudo-tetrahedral Bis(formazanate) Iron Complex. J Am Chem Soc 2016; 138:5503-6. [DOI: 10.1021/jacs.6b01552] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Raquel Travieso-Puente
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - J. O. P. Broekman
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Mu-Chieh Chang
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Serhiy Demeshko
- Institut
für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraße
4, 37077 Göttingen, Germany
| | - Franc Meyer
- Institut
für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraße
4, 37077 Göttingen, Germany
| | - Edwin Otten
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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