1
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Kfoury J, Oláh J. Role of Lewis acid/base anchor atoms in catalyst regeneration: a comprehensive study on biomimetic EP 3Fe nitrogenases. Phys Chem Chem Phys 2024; 26:12520-12529. [PMID: 38605679 DOI: 10.1039/d4cp00483c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
In the quest for sustainable ammonia synthesis routes, biomimetic complexes have been intensively studied. Here we focus on the Peter's group Fe-nitrogenase catalyst with EPPP scorpionate ligands, and explore the effect of anchor atom selection (B, Al, Ga, N and P) and the impact of chloro substitution on the phenyl rings on nitrogen fixation. The reaction profiles of complexes with Lewis basic anchor atoms exhibited energy-demanding reduction steps, with more exergonic protonation steps compared to the smoother reaction profiles observed for catalysts with Lewis acid anchor atoms, also implying that catalyst regeneration is especially challenging for catalysts with Lewis basic anchor atoms. The binding affinities of N2 and H2 to the complexes suggest that the autocatalytic hydrogen evolution reaction (HER), which ultimately leads to consumption of reactants and catalyst deactivation, is likely to become more prevalent for heavier anchor atoms and be more significant for Lewis basic anchor atom complexes. Out of the studied complexes, boron showed the smoothest reaction profile and the smallest affinity for H2, which supports its superiour role as an anchor atom in accordance with experimental data.
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Affiliation(s)
- Joseph Kfoury
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Műegyetem rkp. 3, H-1111 Budapest, Hungary.
| | - Julianna Oláh
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Műegyetem rkp. 3, H-1111 Budapest, Hungary.
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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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Zapata-Rivera J, Calzado CJ. Dinitrogen Activation Mediated by the (P 2P Ph)Fe Complex: Electronic Structure, Dimerization Mechanism, and Magnetic Coupling. Inorg Chem 2024; 63:1633-1641. [PMID: 38194669 PMCID: PMC10954229 DOI: 10.1021/acs.inorgchem.3c03813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/18/2023] [Accepted: 12/22/2023] [Indexed: 01/11/2024]
Abstract
Herein, we report the estimation of the extent of dinitrogen activation by different charged and structural forms of (P2PPh)Fe biomimetic catalysts, which, in the presence of light, exhibit significant yield in the N2-to-NH3 conversion. Complete active space self-consistent field (CASSCF) calculations have been used to determine the electronic structure of different reduced forms of the mononuclear complexes: the neutral (P2PPh)Fe(N2)2 adduct and the anionic [(P2PPh)Fe(N2)]- and [(P2PPh)Fe(N2)]2- complexes. These calculations also revealed that the extent of reduction of a dinitrogen molecule reaches up to one electron (N21-) due to the back-bonding from the Fe center, in agreement with the changes observed in the vibration frequency of the N-N bond in these complexes. In addition, the energy profile of the dimerization of the mononuclear (P2PPh)Fe(N2)2 complex to the dinuclear mono-N2-bridged [(P2PPh)Fe]2(μ-N2) complex has been determined by means of density functional theory (DFT) calculations. A three-step mechanism has been proposed for the dimerization, favored by both kinetics and thermodynamics criteria. Finally, the magnetic coupling constant in the diiron (μ-N2) complex is estimated from CASSCF/NEVPT2 calculations. Such a dinuclear complex presents a strong antiferromagnetic coupling resulting from the interaction between two S = 1 d6 Fe2+ ions, bridged by a highly activated dinitrogen molecule (N22-) with two electrons on the π* orbitals.
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Affiliation(s)
- Jhon Zapata-Rivera
- Facultad
de Ciencias Naturales y Exactas, Departamento de Química, Universidad del Valle, Calle 13 N° 100–00, 25360 Cali, Colombia
| | - Carmen J. Calzado
- Departamento
de Química Física, Universidad
de Sevilla, c/Profesor
García González, s/n, 41012 Sevilla, Spain
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4
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Bhardwaj A, Mondal B. μ 2 -η 1 :η 1 -N 2 Bridged Bimetallic Dinitrogen Complexes: Geometry of the First Excited State in Connection to N 2 π-Photoactivation. Chemistry 2023; 29:e202301984. [PMID: 37578813 DOI: 10.1002/chem.202301984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/08/2023] [Accepted: 08/14/2023] [Indexed: 08/15/2023]
Abstract
Bimetallic end-on μ2 -η1 :η1 -N2 bridging dinitrogen complexes have served as the platform for photochemical N2 activation, mainly for the N-N cleavage. However, the alternate N-N π-photoactivation route has remained largely unexplored. This study strengthens the notion of weakening the N-N bond through the population of π* orbital upon electronic excitation from the ground to the first excited state using four prototypical complexes based on Fe (1), Mo (2), and Ru (3,4). The complexes 1-4 possess characteristic N-N π* based LUMO (π*-π*-π*) centered on their M-N-N-M core, which was earlier postulated to play a central role in the N2 photoactivation. Vertical electronic excitation of the highest oscillator strength involves transitions to the N-N π*-based acceptor orbital (π*-π*-π*) in complexes 1-4. This induces geometry relaxation of the first excited metal-to-nitrogen (π*) charge transfer (1 MNCT) state leading to a "zigzag" M-N-N-M core in the equilibrium structure. Obtaining the equilibrium geometry in the first excited state with the full-sized complexes widens the scope of N-N π-photoactivation with μ2 -η1 :η1 -N2 bridging dinitrogen complexes. Promisingly, the elongated N-N bond and bent ∠MNN angle in the photoexcited S1 state of 1-4 resemble their radical- and di-anion forms, which lead toward thermodynamically feasible N-N protonation in the S1 excited state.
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Affiliation(s)
- Akhil Bhardwaj
- School of Chemical Sciences, Indian Institute of Technology Mandi, Himachal, Pradesh, 175075, India
| | - Bhaskar Mondal
- School of Chemical Sciences, Indian Institute of Technology Mandi, Himachal, Pradesh, 175075, India
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5
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Barchenko M, O’Malley PJ, de Visser SP. Mechanism of Nitrogen Reduction to Ammonia in a Diiron Model of Nitrogenase. Inorg Chem 2023; 62:14715-14726. [PMID: 37650683 PMCID: PMC10498488 DOI: 10.1021/acs.inorgchem.3c02089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Indexed: 09/01/2023]
Abstract
Nitrogenase is a fascinating enzyme in biology that reduces dinitrogen from air to ammonia through stepwise reduction and protonation. Despite it being studied in detail by experimental and computational groups, there are still many unknown factors in the catalytic cycle of nitrogenase, especially related to the addition of protons and electrons and their order. A recent biomimetic study characterized a potential dinitrogen-bridged diiron cluster as a synthetic model of nitrogenase. Using strong acid and reductants, the dinitrogen was converted into ammonia molecules, but details of the mechanism remains unknown. In particular, it was unclear from the experimental studies whether the proton and electron transfer steps are sequential or alternating. Moreover, the work failed to establish what the function of the diiron core is and whether it split into mononuclear iron fragments during the reaction. To understand the structure and reactivity of the biomimetic dinitrogen-bridged diiron complex [(P2P'PhFeH)2(μ-N2)] with triphenylphosphine ligands, we performed a density functional theory study. Our computational methods were validated against experimental crystal structure coordinates, Mössbauer parameters, and vibrational frequencies and show excellent agreement. Subsequently, we investigated the alternating and consecutive addition of electrons and protons to the system. The calculations identify a number of possible reaction channels, namely, same-site protonation, alternating protonation, and complex dissociation into mononuclear iron centers. The calculations show that the overall mechanism is not a pure sequential set of electron and proton transfers but a mixture of alternating and consecutive steps. In particular, the first reaction steps will start with double proton transfer followed by an electron transfer, while thereafter, there is another proton transfer and a second electron transfer to give a complex whereby ammonia can split off with a low energetic barrier. The second channel starts with alternating protonation of the two nitrogen atoms, whereafter the initial double proton transfer, electrons and protons are added sequentially to form a hydrazine-bound complex. The latter split off ammonia spontaneously after further protonation. The various reaction channels are analyzed with valence bond and orbital diagrams. We anticipate the nitrogenase enzyme to operate with mixed alternating and consecutive protonation and electron transfer steps.
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Affiliation(s)
- Maxim Barchenko
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess Street, Manchester M1 7DN, U.K.
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Patrick J. O’Malley
- Department
of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Sam P. de Visser
- Manchester
Institute of Biotechnology, The University
of Manchester, 131 Princess Street, Manchester M1 7DN, U.K.
- Department
of Chemical Engineering, The University
of Manchester, Oxford
Road, Manchester M13 9PL, U.K.
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6
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Boyd EA, Peters JC. Highly Selective Fe-Catalyzed Nitrogen Fixation to Hydrazine Enabled by Sm(II) Reagents with Tailored Redox Potential and p Ka. J Am Chem Soc 2023. [PMID: 37376713 DOI: 10.1021/jacs.3c03352] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Controlling product selectivity in multiproton, multielectron reductions of unsaturated small molecules is of fundamental interest in catalysis. For the N2 reduction reaction (N2RR) in particular, parameters that dictate selectivity for either the 6H+/6e- product ammonia (NH3) or the 4H+/4e- product hydrazine (N2H4) are poorly understood. To probe this issue, we have developed conditions to invert the selectivity of a tris(phosphino)borane iron catalyst (Fe), with which NH3 is typically the major product of N2R, to instead favor N2H4 as the sole observed fixed-N product (>99:1). This dramatic shift is achieved by replacing moderate reductants and strong acids with a very strongly reducing but weakly acidic SmII-(2-pyrrolidone) core supported by a hexadentate dianionic macrocyclic ligand (SmII-PH) as the net hydrogen-atom donor. The activity and efficiency of the catalyst with this reagent remain high (up to 69 equiv of N2H4 per Fe and 67% fixed-N yield per H+). However, by generating N2H4 as the kinetic product, the overpotential of this Sm-driven reaction is 700 mV lower than that of the mildest reported set of NH3-selective conditions with Fe. Mechanistic data support assignment of iron hydrazido(2-) species FeNNH2 as selectivity-determining: we infer that protonation of FeNNH2 at Nβ, favored by strong acids, releases NH3, whereas one-electron reduction to FeNNH2-, favored by strong reductants such as SmII-PH, produces N2H4 via reactivity initiated at Nα. Spectroscopic data also implicate a role for SmIII-binding to anionic FeN2- (via an Fe-N2- -SmIII species) with respect to catalytic efficacy.
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Affiliation(s)
- Emily A Boyd
- 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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7
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VanderWeide A, Prokopchuk DE. Cyclopentadienyl ring activation in organometallic chemistry and catalysis. Nat Rev Chem 2023:10.1038/s41570-023-00501-1. [PMID: 37258685 DOI: 10.1038/s41570-023-00501-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2023] [Indexed: 06/02/2023]
Abstract
The cyclopentadienyl (Cp) ligand is a cornerstone of modern organometallic chemistry. Since the discovery of ferrocene, the Cp ligand and its various derivatives have become foundational motifs in catalysis, medicine and materials science. Although largely considered an ancillary ligand for altering the stereoelectronic properties of transition metal centres, there is mounting evidence that the core Cp ring structure also serves as a reservoir for reactive protons (H+), hydrides (H-) or radical hydrogen (H•) atoms. This Review chronicles the field of Cp ring activation, highlighting the pivotal role that Cp ligands can have in electrocatalytic H2 production, N2 reduction, hydride transfer reactions and proton-coupled electron transfer.
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8
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Mebs S. In Silico Partial N 2 to NH 3 Conversion with a Light Atom Molecule. Chemphyschem 2023; 24:e202200621. [PMID: 36416275 DOI: 10.1002/cphc.202200621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 11/20/2022] [Accepted: 11/22/2022] [Indexed: 11/24/2022]
Abstract
N2 can be stepwise converted in silico into one molecule NH3 and a secondary amide with a bond activator molecule consisting only of light main group elements. The proposed N2 -activating pincer-related compound carries a silyl ion (Si(+) ) center as well as three Lewis acidic (-BF2 ) and three Lewis basic (-PMe2 ) sites, providing an efficient binding pocket for gaseous N2 within the framework of intramolecular frustrated Lewis pairs (FLP). In addition, it exhibits supportive secondary P-B and F⋅⋅⋅B contacts, which stabilize the structure. In the PSi(+) -N-N-BP environment the N≡N triple bond is extended from 1.09 Å to remarkable 1.43 Å, resembling a N-N single bond. The strongly activated N-N-fragment is prone to subsequent hydride addition and protonation steps, resulting in the energy efficient transfer of two hydrogen equivalents. The next hydride added causes the release of one molecule NH3 , but leaves the ligand system as poisoned R3 Si(+) -NH2 -PMe2 or R3 Si(+) -NH3 dead-end states behind. The study indicates that approximately tetrahedral constrained SiBP2 -pockets are capable to activate N2 , whereas the acid-rich SiB3 - and SiB2 P-pocktes, as well as the base-rich SiP3 -pockets fail, hinting towards the high relevance of the acid-base proportion and relative orientation. The electronic structure of the N2 -activated state is compared to the corresponding state of a recently published peri-substituted bond activator molecule featuring a PSi(+) -N-N-Si(+) P site (S. Mebs, J. Beckmann, Physical Chemistry Chemical Physics 2022, 24, 20953-20967).
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Affiliation(s)
- Stefan Mebs
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
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9
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Junge J, Engesser TA, Tuczek F. N 2 Reduction versus H 2 Evolution in a Molybdenum- or Tungsten-Based Small-Molecule Model System of Nitrogenase. Chemistry 2023; 29:e202202629. [PMID: 36458957 DOI: 10.1002/chem.202202629] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 11/24/2022] [Accepted: 12/02/2022] [Indexed: 12/04/2022]
Abstract
Molybdenum dinitrogen complexes have played a major role as catalytic model systems of nitrogenase. In comparison, analogous tungsten complexes have in most cases found to be catalytically inactive. Herein, a tungsten complex was shown to be supported by a pentadentate tetrapodal (pentaPod) phosphine ligand, under conditions of N2 fixation, primarily catalyzes the hydrogen evolution reaction (HER), in contrast to its Mo analogue, which catalytically mediates the nitrogen-reduction reaction (N2 RR). DFT calculations were employed to evaluate possible mechanisms and identify the most likely pathways of N2 RR and HER activities exhibited by Mo- and W-pentaPod complexes. Two mechanisms for N2 RR by PCET are considered, starting from neutral (M(0) cycle) and cationic (M(I) cycle) dinitrogen complexes (M=Mo, W). The latter was found to be energetically more favorable. For HER three scenarios are treated; that is, through bimolecular reactions of early M-Nx Hy intermediates, pure hydride intermediates or mixed M(H)(Nx Hy ) species.
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Affiliation(s)
- Jannik Junge
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Strasse 2, 24118, Kiel, Germany
| | - Tobias A Engesser
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Strasse 2, 24118, Kiel, Germany
| | - Felix Tuczek
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Strasse 2, 24118, Kiel, Germany
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10
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García-de-Jesus OJ, Mondragón-Díaz A, Donnadieu B, Muñoz-Hernández MÁ. Tuning of Cu-Al Interactions in Complexes Derived from Tris(pyridonyl-6-methyl)aluminum Metalloligands. Inorg Chem 2023; 62:2518-2529. [PMID: 36706381 DOI: 10.1021/acs.inorgchem.2c02273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A series of bioinspired polar atrane Cu-Al complexes were studied with a combined experimental and computational approach to assess the range and nature of Cu-Al interactions in these novel species. The aluminum metalloligand [Na{Me2Al(OPy-6-Me)2}] (2) was furnished in excellent yield (92%) from the nucleophilic attack of Na(OPy-6-Me) to AlMe3 and the subsequent alkane elimination reaction with 6-methyl-2-hydroxypyridine. At the same time, the metalloligand [Al(OPy-6-Me)3] (3) was isolated in an also excellent yield (95%) via alkane elimination of AlMe3 with 6-methyl-2-hydroxypyridine. The zwitterionic Cu-Al atranes [Cu{MeAl(OPy-6-Me)3}] (5Me) and [Cu{MesAl(OPy-6-Me)3}] (5Mes) were isolated (73 and 97% yields) from metalloligands 2 and 3, respectively. [(Cu{Al(OPy-6-Me)4})2(μ-Cu)]+ ([6+][B(ArCF3)4]) was isolated via a reaction that involves alkane elimination and redistribution reacting from 5Me with [H(OEt2)2][B(ArCF3)4] in benzene solution. Alkane elimination in benzene of either 5Me or 5Mes with [HNEt3][B(ArCF3)4] renders [Cu{(Et3N)Al(OPy-6-Me)3}]+ (Et3N-5+). The Lewis base-free cationic complex [Cu{Al(OPy-6-Me)3}]+ (5+) was isolated in 68% yield upon reacting 3 with [Cu(COD)2][B(ArCF3)4] in benzene. Metalloligands and complexes were fully characterized with an array of spectroscopic and analytical techniques that include multinuclear NMR, ATR-IR, ESI-spectrometry, combustion microanalysis, cyclic voltammetry (CV), and, whenever feasible, SCXRD. X-ray and DFT parameters indicate that the strength of the Cu→Al transannular interaction follows the trend 5+ > Et3N-5+ > [6+][B(ArCF3)4], 5Me, and 5Mes in a smooth transition from zwitterionic species where the Cu-Al interaction is nonexistent to moderate Cu-Al Z-type interactions. CV, in conjunction with DFT calculations of Et3N-5+ and 5+, hint at the generation in the electrochemical cell of the radical species 5rad at -1.82 V and the anionic complex 5- at -2.32 V vs Fc/Fc+, respectively. The proposed species 5rad exhibits 2-center/1-electron (2c/1e) σ bonding whereas 5- a 2-center/2-electron (2c/2e) bond.
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Affiliation(s)
- Omar J García-de-Jesus
- Department of Chemistry, Mississippi State University, P.O. Box 9573, Mississippi State, Mississippi 39762, United States
| | - Alexander Mondragón-Díaz
- Department of Chemistry, Mississippi State University, P.O. Box 9573, Mississippi State, Mississippi 39762, United States
| | - Bruno Donnadieu
- Department of Chemistry, Mississippi State University, P.O. Box 9573, Mississippi State, Mississippi 39762, United States
| | - Miguel-Ángel Muñoz-Hernández
- Department of Chemistry, Mississippi State University, P.O. Box 9573, Mississippi State, Mississippi 39762, United States
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11
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Abstract
Homogeneous electrocatalysis has been well studied over the past several decades for the conversion of small molecules to useful products for green energy applications or as chemical feedstocks. However, in order for these catalyst systems to be used in industrial applications, their activity and stability must be improved. In naturally occurring enzymes, redox equivalents (electrons, often in a concerted manner with protons) are delivered to enzyme active sites by small molecules known as redox mediators (RMs). Inspired by this, co-electrocatalytic systems with homogeneous catalysts and RMs have been developed for the conversion of alcohols, nitrogen, unsaturated organic substrates, oxygen, and carbon dioxide. In these systems, the RMs have been shown to both increase the activity of the catalyst and shift selectivity to more desired products by altering catalytic cycles and/or avoiding high-energy intermediates. However, the area is currently underdeveloped and requires additional fundamental advancements in order to become a more general strategy. Here, we summarize the recent examples of homogeneous co-electrocatalysis and discuss possible future directions for the field.
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Affiliation(s)
- Amelia G Reid
- Department of Chemistry, University of Virginia, P.O. Box 400319, Charlottesville, Virginia 22904-4319, United States
| | - Charles W Machan
- Department of Chemistry, University of Virginia, P.O. Box 400319, Charlottesville, Virginia 22904-4319, United States
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12
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Huang W, Peng LY, Zhang J, Liu C, Song G, Su JH, Fang WH, Cui G, Hu S. Vanadium-Catalyzed Dinitrogen Reduction to Ammonia via a [V]═NNH 2 Intermediate. J Am Chem Soc 2023; 145:811-821. [PMID: 36596224 DOI: 10.1021/jacs.2c08000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The catalytic transformation of N2 to NH3 by transition metal complexes is of great interest and importance but has remained a challenge to date. Despite the essential role of vanadium in biological N2 fixation, well-defined vanadium complexes that can catalyze the conversion of N2 to NH3 are scarce. In particular, a V(NxHy) intermediate derived from proton/electron transfer reactions of coordinated N2 remains unknown. Here, we report a dinitrogen-bridged divanadium complex bearing POCOP (2,6-(tBu2PO)2-C6H3) pincer and aryloxy ligands, which can serve as a catalyst for the reduction of N2 to NH3 and N2H4. Low-temperature protonation and reduction of the dinitrogen complex afforded the first structurally characterized neutral metal hydrazido(2-) species ([V]═NNH2), which mediated 15N2 conversion to 15NH3, indicating that it is a plausible intermediate of the catalysis. DFT calculations showed that the vanadium hydrazido complex [V]═NNH2 possessed a N-H bond dissociation free energy (BDFEN-H) of as high as 59.1 kcal/mol. The protonation of a vanadium amide complex ([V]-NH2) with [Ph2NH2][OTf] resulted in the release of NH3 and the formation of a vanadium triflate complex, which upon reduction under N2 afforded the vanadium dinitrogen complex. These transformations model the final steps of a vanadium-catalyzed N2 reduction cycle. Both experimental and theoretical studies suggest that the catalytic reaction may proceed via a distal pathway to liberate NH3. These findings provide unprecedented insights into the mechanism of N2 reduction related to FeV nitrogenase.
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Affiliation(s)
- Wenshuang Huang
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Ling-Ya Peng
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Jiayu Zhang
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, P. R. China
| | - Chenrui Liu
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Guoyong Song
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, P. R. China
| | - Ji-Hu Su
- CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Shaowei Hu
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
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13
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Gorantla SMNVT, Karnamkkott HS, Arumugam S, Mondal S, Mondal KC. Stability and bonding of carbon(0)-iron-N 2 complexes relevant to nitrogenase co-factor: EDA-NOCV analyses. J Comput Chem 2022; 44:43-60. [PMID: 36169176 DOI: 10.1002/jcc.27012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 08/26/2022] [Accepted: 09/06/2022] [Indexed: 11/05/2022]
Abstract
The factors/structural features which are responsible for the binding, activation and reduction of N2 to NH3 by FeMoco of nitrogenase have not been completely understood well. Several relevant model complexes by Holland et al. and Peters et al. have been synthesized, characterized and studied by theoretical calculations. For a matter of fact, those complexes are much different than real active N2 -binding Fe-sites of FeMoco, which possesses a central C(4-) ion having an eight valence electrons as an μ6 -bridge. Here, a series of [(S3 C(0))Fe(II/I/0)-N2 ]n- complexes in different charged/spin states containing a coordinated σ- and π-donor C(0)-atom which possesses eight outer shell electrons [carbone, (Ph3 P)2 C(0); Ph3 P→C(0)←PPh3 ] and three S-donor sites (i.e. - S-Ar), have been studied by DFT, QTAIM, and EDA-NOCV calculations. The effect of the weak field ligand on Fe-centres and the subsequent N2 -binding has been studied by EDA-NOCV analysis. The role of the oxidation state of Fe and N2 -binding in different charged and spin states of the complex have been investigated by EDA-NOCV analyses. The intrinsic interaction energies of the Fe-N2 bond are in the range from -42/-35 to -67 kcal/mol in their corresponding ground states. The S3 C(0) donor set is argued here to be closer to the actual coordination environment of one of the six Fe-centres of nitrogenase. In comparison, the captivating model complexes reported by Holland et al. and Peter et al. possess a stronger π-acceptor C-ring (S2 Cring donor, π-C donor) and stronger donor set like CP3 (σ-C donor) ligands, respectively.
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Affiliation(s)
| | | | - Selvakumar Arumugam
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, India
| | - Sangita Mondal
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, India
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14
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Chauhan A, Karnamkkott HS, Gorantla SMNV, Mondal KC. Dinitrogen Binding and Activation: Bonding Analyses of Stable V(III/I)-N 2-V(III/I) Complexes by the EDA-NOCV Method from the Perspective of Vanadium Nitrogenase. ACS OMEGA 2022; 7:31577-31590. [PMID: 36092593 PMCID: PMC9453968 DOI: 10.1021/acsomega.2c04472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
The FeVco cofactor of nitrogenase (VFe7S8(CO3)C) is an alternative in the molybdenum (Mo)-deficient free soil living azotobacter vinelandii. The rate of N2 reduction to NH3 by FeVco is a few times higher than that by FeMoco (MoFe7S9C) at low temperature. It provides a N source in the form of ammonium ions to the soil. This biochemical NH3 synthesis is an alternative to the industrial energy-demanding production of NH3 by the Haber-Bosch process. The role of vanadium has not been clearly understood yet, which has led chemists to come up with several stable V-N2 complexes which have been isolated and characterized in the laboratory over the past three decades. Herein, we report the EDA-NOCV analyses of dinitrogen-bonded stable complexes V(III/I)-N2 (1-4) to provide deeper insights into the fundamental bonding aspects of V-N2 bond, showing the interacting orbitals and corresponding pairwise orbital interaction energies (ΔE orb(n)). The computed intrinsic interaction energy (ΔE int) of V-N2-V bonds is significantly higher than those of the previously reported Fe-N2-Fe bonds. Covalent interaction energy (ΔE orb) is more than double the electrostatic interaction energy (ΔE elstat) of V-N2-V bonds. ΔE int values of V-N2-V bonds are in the range of -172 to -204 kcal/mol. The V → N2 ← V π-backdonation is four times stronger than V ← N2 → V σ-donation. V-N2 bonds are much more covalent in nature than Fe-N2 bonds.
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15
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Fritz M, Rupp S, Kiene CI, Kisan S, Telser J, Würtele C, Krewald V, Schneider S. Photoelectrochemical Conversion of Dinitrogen to Benzonitrile: Selectivity Control by Electrophile‐ versus Proton‐Coupled Electron Transfer. Angew Chem Int Ed Engl 2022; 61:e202205922. [PMID: 35714100 PMCID: PMC9542086 DOI: 10.1002/anie.202205922] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Indexed: 11/10/2022]
Abstract
Nitride complexes are key species in homogeneous nitrogen fixation to NH3 via stepwise proton‐coupled electron transfer (PCET). In contrast, direct generation of nitrogenous organic products from N2‐derived nitrides requires new strategies to enable efficient reductive nitride transfer in the presence of organic electrophiles. We here present a 2‐step protocol for the conversion of dinitrogen to benzonitrile. Photoelectrochemical, reductive N2 splitting produces a rhenium(V) nitride with unfavorable PCET thermochemistry towards ammonia generation. However, N‐benzoylation stabilizes subsequent reduction as a basis for selective nitrogen transfer in the presence of the organic electrophile and Brønsted acid at mild reduction potentials. This work offers a new strategy for photoelectrosynthetic nitrogen fixation beyond ammonia—to yield nitrogenous organic products.
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Affiliation(s)
- Maximilian Fritz
- Institut für Anorganische Chemie Georg August Universität Göttingen Tammannstraße 4 37077 Göttingen Germany
| | - Severine Rupp
- Theoretische Chemie Technische Universität Darmstadt Alarich-Weiss-Straße 4 64287 Darmstadt Germany
| | - Ciara I. Kiene
- Institut für Anorganische Chemie Georg August Universität Göttingen Tammannstraße 4 37077 Göttingen Germany
| | - Sesha Kisan
- Institut für Anorganische Chemie Georg August Universität Göttingen Tammannstraße 4 37077 Göttingen Germany
| | - Joshua Telser
- Department of Biological Physical and Health Sciences Roosevelt University 430 S. Michigan Avenue Chicago IL 60605 USA
| | - Christian Würtele
- Institut für Anorganische Chemie Georg August Universität Göttingen Tammannstraße 4 37077 Göttingen Germany
| | - Vera Krewald
- Theoretische Chemie Technische Universität Darmstadt Alarich-Weiss-Straße 4 64287 Darmstadt Germany
| | - Sven Schneider
- Institut für Anorganische Chemie Georg August Universität Göttingen Tammannstraße 4 37077 Göttingen Germany
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16
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Mebs S, Beckmann J. In silico activation of dinitrogen with a light atom molecule. Phys Chem Chem Phys 2022; 24:20953-20967. [PMID: 35993454 DOI: 10.1039/d2cp02516g] [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
The NN triple bond can be cleaved in silico with a light atom molecule containing only the earth abundant elements C, H, Si, and P. Extensive density functional theory (DFT) computations on various classes of peri-substituted scaffolds containing Lewis acidic and basic sites in the framework of frustrated Lewis pairs (FLP) indicate that the presence of two silyl cations and two P atoms in a flexible but not too flexible arrangement is essential for energy efficient N2-activation. The non-bonding lone-pair electrons of the P atoms thereby serve as donors towards N2, whereas the lone-pairs of N2 donate into the silyl cations. Newly formed lone-pair basins in the N2-adducts balance surplus charge. Thereby, the N-N bond distance is increased by astonishing 0.3 Å, from 1.1 Å in N2 gas to 1.4 Å in the adduct, which makes this bond prone to subsequent addition of hydride ions and protonation, forming two secondary amine sites in the process and eventually breaking the NN triple bond. Potential formation of dead-end states, in which the dications ("active states") aversively form a Lewis acid (LA)-Lewis base (LB) bond, or in which the LA and LB sites are too far away from each other to be able to capture N2, are problematic but might be circumvented by proper choice of spacer molecules, such as acenaphthalene or biphenylene, and the ligands attached to the LA and LB atoms, such as phenyl or mesityl, and by purging the reaction solutions with gaseous N2 in the initial reaction steps. Charge redistributions via N2-activation and splitting were monitored by a variety of real-space bonding indicators (RSBIs) derived from the calculated electron and electron pair densities, which provided valuable insight into the bonding situation within the different reaction steps.
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Affiliation(s)
- Stefan Mebs
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
| | - Jens Beckmann
- Institut für Anorganische Chemie und Kristallographie, Universität Bremen, Leobener Straße 7, 28359 Bremen, Germany
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17
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Fritz M, Rupp S, Kiene CI, Kisan S, Telser J, Würtele C, Krewald V, Schneider S. Photoelectrochemical Conversion of Dinitrogen to Benzonitrile: Selectivity Control by Electrophile‐ versus Proton‐Coupled Electron Transfer. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202205922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Maximilian Fritz
- University of Göttingen: Georg-August-Universitat Gottingen Institut für Anorganische Chemie GERMANY
| | - Severine Rupp
- TU Darmstadt: Technische Universitat Darmstadt Theoretische Chemie GERMANY
| | - Ciara Isabel Kiene
- University of Göttingen: Georg-August-Universitat Gottingen Institut für Anorganische Chemie GERMANY
| | - Sesha Kisan
- University of Göttingen: Georg-August-Universitat Gottingen Institut für Anorganische Chemie GERMANY
| | - Joshua Telser
- Roosevelt University Department of Biological, Physical and Health Sciences UNITED STATES
| | - Christian Würtele
- University of Göttingen: Georg-August-Universitat Gottingen Institut für Anorganische Chemie GERMANY
| | - Vera Krewald
- Darmstadt University of Technology: Technische Universitat Darmstadt Theoretische Chemie GERMANY
| | - Sven Schneider
- University of Goettingen Institute for inorganic Chemistry Tammannstr. 4 37077 Göttingen GERMANY
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18
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Kfoury J, Benedek Z, Szilvási T, Oláh J. H 2 and N 2 Binding Affinities Are Coupled in Synthetic Fe Nitrogenases Limiting N 2 Fixation. Organometallics 2022. [DOI: 10.1021/acs.organomet.1c00681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Joseph Kfoury
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Műegyetem rakpart 3, 1111 Budapest, Hungary
| | - Zsolt Benedek
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Műegyetem rakpart 3, 1111 Budapest, Hungary
- Wigner Research Centre for Physics, H-1525 Budapest, Hungary
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Tibor Szilvási
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Julianna Oláh
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Műegyetem rakpart 3, 1111 Budapest, Hungary
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Connor GP, Delony D, Weber JE, Mercado BQ, Curley JB, Schneider S, Mayer JM, Holland PL. Facile conversion of ammonia to a nitride in a rhenium system that cleaves dinitrogen. Chem Sci 2022; 13:4010-4018. [PMID: 35440977 PMCID: PMC8985503 DOI: 10.1039/d1sc04503b] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 02/22/2022] [Indexed: 11/21/2022] Open
Abstract
Rhenium complexes with aliphatic PNP pincer ligands have been shown to be capable of reductive N2 splitting to nitride complexes. However, the conversion of the resulting nitride to ammonia has not been observed. Here, the thermodynamics and mechanism of the hypothetical N–H bond forming steps are evaluated through the reverse reaction, conversion of ammonia to the nitride complex. Depending on the conditions, treatment of a rhenium(iii) precursor with ammonia gives either a bis(amine) complex [(PNP)Re(NH2)2Cl]+, or results in dehydrohalogenation to the rhenium(iii) amido complex, (PNP)Re(NH2)Cl. The N–H hydrogen atoms in this amido complex can be abstracted by PCET reagents which implies that they are quite weak. Calorimetric measurements show that the average bond dissociation enthalpy of the two amido N–H bonds is 57 kcal mol−1, while DFT computations indicate a substantially weaker N–H bond of the putative rhenium(iv)-imide intermediate (BDE = 38 kcal mol−1). Our analysis demonstrates that addition of the first H atom to the nitride complex is a thermochemical bottleneck for NH3 generation. Rhenium–PNP complexes split N2 to nitrides, but the nitrides do not give ammonia. Here, the thermodynamics of the hypothetical N–H bond forming steps are evaluated through the reverse reaction, showing that the first H addition is the bottleneck.![]()
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Affiliation(s)
- Gannon P Connor
- Department of Chemistry, Yale University New Haven Connecticut USA
| | - Daniel Delony
- Institute of Inorganic Chemistry, Georg-August-Universität Göttingen Göttingen Germany
| | - Jeremy E Weber
- Department of Chemistry, Yale University New Haven Connecticut USA
| | | | - Julia B Curley
- Department of Chemistry, Yale University New Haven Connecticut USA
| | - Sven Schneider
- Institute of Inorganic Chemistry, Georg-August-Universität Göttingen Göttingen Germany
| | - James M Mayer
- Department of Chemistry, Yale University New Haven Connecticut USA
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20
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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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21
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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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22
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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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23
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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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Li HJ, Feng R, Wang GX, Wei J, Xi Z. Dinitrogen activation by a phosphido-bridged binuclear cobalt complex. Dalton Trans 2022; 51:16811-16815. [DOI: 10.1039/d2dt03320h] [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
The reduction of PNPCoBr under a N2 atmosphere yielded a binuclear cobalt dinitrogen anion complex via the C–P bond cleavage of the PNP ligand.
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Affiliation(s)
- Hai-Jun Li
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Rui Feng
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Gao-Xiang Wang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Junnian Wei
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Zhenfeng Xi
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
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25
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Kong Y, Li Y, Sang X, Yang B, Li Z, Zheng S, Zhang Q, Yao S, Yang X, Lei L, Zhou S, Wu G, Hou Y. Atomically Dispersed Zinc(I) Active Sites to Accelerate Nitrogen Reduction Kinetics for Ammonia Electrosynthesis. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2103548. [PMID: 34725867 DOI: 10.1002/adma.202103548] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 10/28/2021] [Indexed: 06/13/2023]
Abstract
Developing highly active and stable nitrogen reduction reaction (NRR) catalysts for NH3 electrosynthesis remains challenging. Herein, an unusual NRR electrocatalyst is reported with a single Zn(I) site supported on hollow porous N-doped carbon nanofibers (Zn1 N-C). The Zn1 N-C nanofibers exhibit an outstanding NRR activity with a high NH3 yield rate of ≈16.1 µg NH3 h-1 mgcat -1 at -0.3 V and Faradaic efficiency (FE) of 11.8% in alkaline media, surpassing other previously reported carbon-based NRR electrocatalysts with transition metals atomically dispersed and nitrogen coordinated (TM-Nx ) sites. 15 N2 isotope labeling experiments confirm that the feeding nitrogen gas is the only nitrogen source in the production of NH3 . Structural characterization reveals that atomically dispersed Zn(I) sites with Zn-N4 moieties are likely the active sites, and the nearby graphitic N site synergistically facilitates the NRR process. In situ attenuated total reflectance-Fourier transform infrared measurement and theoretical calculation elucidate that the formation of initial *NNH intermediate is the rate-limiting step during the NH3 production. The graphitic N atoms adjacent to the tetracoordinate Zn-N4 moieties could significantly lower the energy barrier for this step to accelerate hydrogenation kinetics duing the NRR.
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Affiliation(s)
- Yan Kong
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Yan Li
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xiahan Sang
- Research and Testing Centre of Material School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, China
| | - Bin Yang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Zhongjian Li
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Sixing Zheng
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Qinghua Zhang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Siyu Yao
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xiaoxuan Yang
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, NY, 14260, USA
| | - Lecheng Lei
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
- Institute of Zhejiang University - Quzhou, Quzhou, 324000, China
| | - Shaodong Zhou
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
- Institute of Zhejiang University - Quzhou, Quzhou, 324000, China
| | - Gang Wu
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, NY, 14260, USA
| | - Yang Hou
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
- Institute of Zhejiang University - Quzhou, Quzhou, 324000, China
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26
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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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27
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Agarwal RG, Coste SC, Groff BD, Heuer AM, Noh H, Parada GA, Wise CF, Nichols EM, Warren JJ, Mayer JM. Free Energies of Proton-Coupled Electron Transfer Reagents and Their Applications. Chem Rev 2021; 122:1-49. [PMID: 34928136 DOI: 10.1021/acs.chemrev.1c00521] [Citation(s) in RCA: 140] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We present an update and revision to our 2010 review on the topic of proton-coupled electron transfer (PCET) reagent thermochemistry. Over the past decade, the data and thermochemical formalisms presented in that review have been of value to multiple fields. Concurrently, there have been advances in the thermochemical cycles and experimental methods used to measure these values. This Review (i) summarizes those advancements, (ii) corrects systematic errors in our prior review that shifted many of the absolute values in the tabulated data, (iii) provides updated tables of thermochemical values, and (iv) discusses new conclusions and opportunities from the assembled data and associated techniques. We advocate for updated thermochemical cycles that provide greater clarity and reduce experimental barriers to the calculation and measurement of Gibbs free energies for the conversion of X to XHn in PCET reactions. In particular, we demonstrate the utility and generality of reporting potentials of hydrogenation, E°(V vs H2), in almost any solvent and how these values are connected to more widely reported bond dissociation free energies (BDFEs). The tabulated data demonstrate that E°(V vs H2) and BDFEs are generally insensitive to the nature of the solvent and, in some cases, even to the phase (gas versus solution). This Review also presents introductions to several emerging fields in PCET thermochemistry to give readers windows into the diversity of research being performed. Some of the next frontiers in this rapidly growing field are coordination-induced bond weakening, PCET in novel solvent environments, and reactions at material interfaces.
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Affiliation(s)
- Rishi G Agarwal
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Scott C Coste
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Benjamin D Groff
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Abigail M Heuer
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Hyunho Noh
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Giovanny A Parada
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States.,Department of Chemistry, The College of New Jersey, Ewing, New Jersey 08628, United States
| | - Catherine F Wise
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Eva M Nichols
- Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Jeffrey J Warren
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - James M Mayer
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
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28
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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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29
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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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30
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Furan S, Molkenthin M, Winkels K, Lork E, Mebs S, Hupf E, Beckmann J. Tris(6-diphenylphosphinoacenaphth-5-yl)gallium: Z-Type Ligand and Transmetalation Reagent. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sinas Furan
- Institut für Anorganische Chemie, Universität Bremen, Leobener Straße 7, 28359 Bremen, Germany
| | - Martin Molkenthin
- Institut für Anorganische Chemie, Universität Bremen, Leobener Straße 7, 28359 Bremen, Germany
| | - Konrad Winkels
- Institut für Anorganische Chemie, Universität Bremen, Leobener Straße 7, 28359 Bremen, Germany
| | - Enno Lork
- Institut für Anorganische Chemie, Universität Bremen, Leobener Straße 7, 28359 Bremen, Germany
| | - Stefan Mebs
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Emanuel Hupf
- Institut für Anorganische Chemie, Universität Bremen, Leobener Straße 7, 28359 Bremen, Germany
| | - Jens Beckmann
- Institut für Anorganische Chemie, Universität Bremen, Leobener Straße 7, 28359 Bremen, Germany
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31
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García-Romero Á, Martín-Álvarez JM, Colebatch AL, Plajer AJ, Miguel D, Álvarez CM, García-Rodríguez R. Synthesis of tris(3-pyridyl)aluminate ligand and its unexpected stability against hydrolysis: revealing cooperativity effects in heterobimetallic pyridyl aluminates. Dalton Trans 2021; 50:13059-13065. [PMID: 34581366 DOI: 10.1039/d1dt02351a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We report the elusive metallic anion [EtAl(3-py)3]- (3-py = 3-pyridyl) (1), the first member of the anionic tris(3-pyridyl) family. Unexpectedly, the lithium complex 1Li shows substantial protic stability against water and alcohols, unlike related tris(2-pyridyl)aluminate analogues. This stability appears to be related to the inability of the [EtAl(3-py)3]- anion to chelate Li+, which precludes a decomposition pathway involving Li/Al cooperativity.
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Affiliation(s)
- Álvaro García-Romero
- GIR MIOMeT-IU Cinquima-Química Inorgánica Facultad de Ciencias, Universidad de Valladolid; Campus Miguel Delibes, 47011 Valladolid, Spain.
| | - Jose M Martín-Álvarez
- GIR MIOMeT-IU Cinquima-Química Inorgánica Facultad de Ciencias, Universidad de Valladolid; Campus Miguel Delibes, 47011 Valladolid, Spain.
| | - Annie L Colebatch
- Chemistry Department. Cambridge University, Lensfield Road, Cambridge CB2 1EW, UK.,Research School of Chemistry. Australian National University, Canberra, ACT, 2601, Australia
| | - Alex J Plajer
- Chemical Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK
| | - Daniel Miguel
- GIR MIOMeT-IU Cinquima-Química Inorgánica Facultad de Ciencias, Universidad de Valladolid; Campus Miguel Delibes, 47011 Valladolid, Spain.
| | - Celedonio M Álvarez
- GIR MIOMeT-IU Cinquima-Química Inorgánica Facultad de Ciencias, Universidad de Valladolid; Campus Miguel Delibes, 47011 Valladolid, Spain.
| | - Raúl García-Rodríguez
- GIR MIOMeT-IU Cinquima-Química Inorgánica Facultad de Ciencias, Universidad de Valladolid; Campus Miguel Delibes, 47011 Valladolid, Spain.
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32
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Choi C, Gu GH, Noh J, Park HS, Jung Y. Understanding potential-dependent competition between electrocatalytic dinitrogen and proton reduction reactions. Nat Commun 2021; 12:4353. [PMID: 34272379 PMCID: PMC8285508 DOI: 10.1038/s41467-021-24539-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 06/18/2021] [Indexed: 02/06/2023] Open
Abstract
A key challenge to realizing practical electrochemical N2 reduction reaction (NRR) is the decrease in the NRR activity before reaching the mass-transfer limit as overpotential increases. While the hydrogen evolution reaction (HER) has been suggested to be responsible for this phenomenon, the mechanistic origin has not been clearly explained. Herein, we investigate the potential-dependent competition between NRR and HER using the constant electrode potential model and microkinetic modeling. We find that the H coverage and N2 coverage crossover leads to the premature decrease of NRR activity. The coverage crossover originates from the larger charge transfer in H+ adsorption than N2 adsorption. The larger charge transfer in H+ adsorption, which potentially leads to the coverage crossover, is a general phenomenon seen in various heterogeneous catalysts, posing a fundamental challenge to realize practical electrochemical NRR. We suggest several strategies to overcome the challenge based on the present understandings.
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Affiliation(s)
- Changhyeok Choi
- Department of Chemical and Biomolecular Engineering (BK21 four), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Geun Ho Gu
- Department of Chemical and Biomolecular Engineering (BK21 four), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Juhwan Noh
- Department of Chemical and Biomolecular Engineering (BK21 four), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Hyun S Park
- Center for Hydrogen and Fuel Cell Research, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Yousung Jung
- Department of Chemical and Biomolecular Engineering (BK21 four), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
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33
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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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34
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Singh B, Sharma V, Gaikwad RP, Fornasiero P, Zbořil R, Gawande MB. Single-Atom Catalysts: A Sustainable Pathway for the Advanced Catalytic Applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2006473. [PMID: 33624397 DOI: 10.1002/smll.202006473] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/29/2020] [Indexed: 06/12/2023]
Abstract
A heterogeneous catalyst is a backbone of modern sustainable green industries; and understanding the relationship between its structure and properties is the key for its advancement. Recently, many upscaling synthesis strategies for the development of a variety of respectable control atomically precise heterogeneous catalysts are reported and explored for various important applications in catalysis for energy and environmental remediation. Precise atomic-scale control of catalysts has allowed to significantly increase activity, selectivity, and in some cases stability. This approach has proved to be relevant in various energy and environmental related technologies such as fuel cell, chemical reactors for organic synthesis, and environmental remediation. Therefore, this review aims to critically analyze the recent progress on single-atom catalysts (SACs) application in oxygen reduction reaction, oxygen evolution reaction, hydrogen evolution reaction, and chemical and/or electrochemical organic transformations. Finally, opportunities that may open up in the future are summarized, along with suggesting new applications for possible exploitation of SACs.
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Affiliation(s)
- Baljeet Singh
- CICECO-Aveiro Institute of Materials, University of Aveiro, Department of Chemistry, Aveiro, 3810-193, Portugal
| | - Vikas Sharma
- Centre for Converging Technologies, University of Rajasthan, Jaipur, 302004, India
| | - Rahul P Gaikwad
- Department of Industrial and Engineering Chemistry, Institute of Chemical Technology, Mumbai-Marathwada Campus, Jalna, Maharashtra, 431213, India
| | - Paolo Fornasiero
- Department of Chemical and Pharmaceutical Sciences, INSTM Trieste Research Unit and ICCOM-CNR Trieste Research Unit, University of Trieste, Trieste, I-34127, Italy
| | - Radek Zbořil
- Regional Centre of Advanced Technologies and Materials, Palacky University, Šlechtitelů 27, Olomouc, 783 71, Czech Republic
- Nanotechnology Centre, VŠB-Technical University of Ostrava, 17. listopadu 2172/15, Ostrava-Poruba, 708 00, Czech Republic
| | - Manoj B Gawande
- Department of Industrial and Engineering Chemistry, Institute of Chemical Technology, Mumbai-Marathwada Campus, Jalna, Maharashtra, 431213, India
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35
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Yi J, Zhan S, Chen L, Tian Q, Wang N, Li J, Xu W, Zhang B, Ahlquist MSG. Electrostatic Interactions Accelerating Water Oxidation Catalysis via Intercatalyst O-O Coupling. J Am Chem Soc 2021; 143:2484-2490. [PMID: 33538597 DOI: 10.1021/jacs.0c07103] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Intercatalyst coupling has been widely applied in the functional mimics for binuclear synergy in natural metal enzymes. Herein, we introduce two facile and effective design strategies, which facilitate the coupling of two catalytic units via electrostatic interactions. The first system is based on a catalyst molecule functionalized with both a positively charged and a negatively charged group in the structure being able to pair with each other in an antiparallel manner arranged by electrostatic interactions. The other system consists of a mixture of two different of catalysts modified with either positively or negatively charged groups to generate intermolecular electrostatic interactions. Applying these designs to Ru(bda) (H2bda = 2,2'-bipyridine-6,6'-dicarboxylic acid) water-oxidation catalysts improved the catalytic performance by more than an order of magnitude. The intermolecular electrostatic interactions in these two systems were fully identified by 1H NMR, TEM, SAXS, and electrical conductivity experiments. Molecular dynamics simulations further verified that electrostatic interactions contribute to the formation of prereactive dimers, which were found to play a key role in dramatically improving the catalytic performance. The successful strategies demonstrated here can be used in designing other intercatalyst coupling systems for activation and formation of small molecules and organic synthesis.
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Affiliation(s)
- Jiajia Yi
- Key Laboratory of Synthetic and Natural Functional Molecule of Ministry of Education, College of Chemistry & Materials Science, Northwest University, 710069 Xi'an, China
| | - Shaoqi Zhan
- Department of Theoretical Chemistry & Biology, School of Engineering Sciences in Chemistry Biotechnology and Health, KTH Royal Institute of Technology, 10691 Stockholm, Sweden
| | - Lin Chen
- State Key Laboratory of Environment-Friendly Energy Material, School of Materials Science and Engineering, Southwest University of Science and Technology, 621010 Mianyang, China
| | - Qiang Tian
- State Key Laboratory of Environment-Friendly Energy Material, School of Materials Science and Engineering, Southwest University of Science and Technology, 621010 Mianyang, China
| | - Ning Wang
- Key Laboratory of Synthetic and Natural Functional Molecule of Ministry of Education, College of Chemistry & Materials Science, Northwest University, 710069 Xi'an, China
| | - Jun Li
- Key Laboratory of Synthetic and Natural Functional Molecule of Ministry of Education, College of Chemistry & Materials Science, Northwest University, 710069 Xi'an, China
| | - Wenhua Xu
- Key Laboratory of Synthetic and Natural Functional Molecule of Ministry of Education, College of Chemistry & Materials Science, Northwest University, 710069 Xi'an, China
| | - Biaobiao Zhang
- Department of Chemistry, KTH Royal Institute of Technology, 10044 Stockholm, Sweden
| | - Mårten S G Ahlquist
- Department of Theoretical Chemistry & Biology, School of Engineering Sciences in Chemistry Biotechnology and Health, KTH Royal Institute of Technology, 10691 Stockholm, Sweden
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36
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Fajardo J, Peters JC. Tripodal P 3XFe-N 2 Complexes (X = B, Al, Ga): Effect of the Apical Atom on Bonding, Electronic Structure, and Catalytic N 2-to-NH 3 Conversion. Inorg Chem 2021; 60:1220-1227. [PMID: 33410667 PMCID: PMC8279418 DOI: 10.1021/acs.inorgchem.0c03354] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Terminal dinitrogen complexes of iron ligated by tripodal, tetradentate P3X ligands (X = B, C, Si) have previously been shown to mediate catalytic N2-to-NH3 conversion (N2RR) with external proton and electron sources. From this set of compounds, the tris(phosphino)borane (P3B) system is most active under all conditions canvassed thus far. To further probe the effects of the apical Lewis acidic atom on structure, bonding, and N2RR activity, Fe-N2 complexes supported by analogous group 13 tris(phosphino)alane (P3Al) and tris(phosphino)gallane (P3Ga) ligands are synthesized. The series of P3XFe-N2[0/1-] compounds (X = B, Al, Ga) possess similar electronic structures, degrees of N2 activation, and geometric flexibility as determined from spectroscopic, structural, electrochemical, and computational (DFT) studies. However, treatment of [Na(12-crown-4)2][P3XFe-N2] (X = Al, Ga) with excess acid/reductant in the form of HBArF4/KC8 generates only 2.5 ± 0.1 and 2.7 ± 0.2 equiv of NH3 per Fe, respectively. Similarly, the use of [H2NPh2][OTf]/Cp*2Co leads to the production of 4.1 ± 0.9 (X = Al) and 3.6 ± 0.3 (X = Ga) equiv of NH3. Preliminary reactivity studies confirming P3XFe framework stability under pseudocatalytic conditions suggest that a greater selectivity for hydrogen evolution versus N2RR may be responsible for the attenuated yields of NH3 observed for P3AlFe and P3GaFe relative to P3BFe.
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Affiliation(s)
- Javier Fajardo
- 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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37
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Gu Z, Chen Y, Wei Z, Qian L, Al-Enizi AM, Ma J, Zhou G, Zheng G. Precise tuning of heteroatom positions in polycyclic aromatic hydrocarbons for electrocatalytic nitrogen fixation. J Colloid Interface Sci 2020; 580:623-629. [PMID: 32711210 DOI: 10.1016/j.jcis.2020.07.046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 07/10/2020] [Accepted: 07/10/2020] [Indexed: 01/25/2023]
Abstract
The electrochemical dinitrogen reduction represents an attractive approach of converting N2 and water into ammonia, while the rational design of catalytic active centers remains challenging. Investigating model molecular catalysts with well-tuned catalytic sites should help to develop a clear structure-activity relationship for electrochemical N2 reduction. Herein, we designed several polycyclic aromatic hydrocarbon (PAH) molecules with well-defined positions of boron and nitrogen atoms. Theoretical calculations revealed that the boron atoms possess high local positive charge densities as Lewis acid sites, which are beneficial for N2 adsorption and activation, thus serving as major catalytic active sites for N2 electrochemical reduction. Furthermore, the close vicinity of two boron atoms can further enhance the local positive density and subsequent catalytic activity. Using the PAH molecule with two boron atoms separated by two carbon atoms (B-2C-B), a high NH3 production rate of 34.58 μg·h-1·cm-2 and a corresponding Faradaic efficiency (5.86%) were achieved at -0.7 V versus reversible hydrogen electrode, substantially exceeding the other PAHs with single boron or nitrogen-containing molecular structures.
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Affiliation(s)
- Zhengxiang Gu
- Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, China
| | - Yijing Chen
- Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, China
| | - Zengxi Wei
- School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Linping Qian
- Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, China
| | - Abdullah M Al-Enizi
- Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Jianmin Ma
- School of Physics and Electronics, Hunan University, Changsha 410082, China.
| | - Gang Zhou
- Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, China.
| | - Gengfeng Zheng
- Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, China.
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38
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Benedek Z, Papp M, Oláh J, Szilvási T. Demonstrating the Direct Relationship between Hydrogen Evolution Reaction and Catalyst Deactivation in Synthetic Fe Nitrogenases. ACS Catal 2020. [DOI: 10.1021/acscatal.0c02315] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Zsolt Benedek
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4, 1111 Budapest, Hungary
| | - Marcell Papp
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4, 1111 Budapest, Hungary
| | - Julianna Oláh
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4, 1111 Budapest, Hungary
| | - Tibor Szilvási
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
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39
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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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Kim S, Loose F, Chirik PJ. Beyond Ammonia: Nitrogen–Element Bond Forming Reactions with Coordinated Dinitrogen. Chem Rev 2020; 120:5637-5681. [DOI: 10.1021/acs.chemrev.9b00705] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sangmin Kim
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Florian Loose
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Paul J. Chirik
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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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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Chalkley MJ, Peters JC. Relating N-H Bond Strengths to the Overpotential for Catalytic Nitrogen Fixation. Eur J Inorg Chem 2020; 2020:1353-1357. [PMID: 33071628 DOI: 10.1002/ejic.202000232] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Nitrogen (N2) fixation to produce bio-available ammonia (NH3) is essential to all life but is a challenging transformation to catalyse owing to the chemical inertness of N2. Transition metals can, however, bind N2 and activate it for functionalization. Significant opportunities remain in developing robust and efficient transition metal catalysts for the N2 reduction reaction (N2RR). One opportunity to target in catalyst design concerns the stabilization of transition metal diazenido species (M-NNH) that result from the first N2 functionalization step. Well-characterized M-NNH species remain very rare, likely a consequence of their low N-H bond dissociation free energies (BDFEs). In this essay, we discuss the relationship between the BDFEN-H of a given M-NNH species to the observed overpotential and selectivity for N2RR catalysis with that catalyst system. We note that developing strategies to either increase the N-H BDFEs of M-NNH species, or to avoid M-NNH intermediates altogether, are potential routes to improved N2RR efficiency.
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Affiliation(s)
- Matthew J Chalkley
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
| | - Jonas C Peters
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
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43
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García-Romero Á, Plajer AJ, Miguel D, Wright DS, Bond AD, Álvarez CM, García-Rodríguez R. Tris(2-pyridyl) Bismuthines: Coordination Chemistry, Reactivity, and Anion-Triggered Pyridyl Coupling. Inorg Chem 2020; 59:7103-7116. [DOI: 10.1021/acs.inorgchem.0c00579] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Álvaro García-Romero
- GIR MIOMeT-IU, Cinquima, Quı́mica Inorgánica, Facultad de Ciencias, Universidad de Valladolid, Campus Miguel Delibes, 47011 Valladolid, Spain
| | - Alex J. Plajer
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Daniel Miguel
- GIR MIOMeT-IU, Cinquima, Quı́mica Inorgánica, Facultad de Ciencias, Universidad de Valladolid, Campus Miguel Delibes, 47011 Valladolid, Spain
| | - Dominic S. Wright
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Andrew D. Bond
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Celedonio M. Álvarez
- GIR MIOMeT-IU, Cinquima, Quı́mica Inorgánica, Facultad de Ciencias, Universidad de Valladolid, Campus Miguel Delibes, 47011 Valladolid, Spain
| | - Raúl García-Rodríguez
- GIR MIOMeT-IU, Cinquima, Quı́mica Inorgánica, Facultad de Ciencias, Universidad de Valladolid, Campus Miguel Delibes, 47011 Valladolid, Spain
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44
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Kadassery KJ, Crawley MR, MacMillan SN, Lacy DC. A hemilabile manganese(i)–phenol complex and its coordination induced O–H bond weakening. Dalton Trans 2020; 49:16217-16225. [DOI: 10.1039/d0dt00973c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Synthesis and characterization of [(HPO)(PO)Mn(CO)2 (H1), a phenol bound first-row transition metal complex, is reported. Thermochemical analysis of H1 indicated the presence of coordination induced O–H bond weakening.
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Affiliation(s)
| | - Matthew R. Crawley
- Department of Chemistry
- University at Buffalo
- State University of New York
- Buffalo
- USA
| | | | - David C. Lacy
- Department of Chemistry
- University at Buffalo
- State University of New York
- Buffalo
- USA
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45
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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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46
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Dorantes MJ, Moore JT, Bill E, Mienert B, Lu CC. Bimetallic iron–tin catalyst for N2 to NH3 and a silyldiazenido model intermediate. Chem Commun (Camb) 2020; 56:11030-11033. [DOI: 10.1039/d0cc04563b] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A new tin-supported iron complex catalyzes N2 fixation. The role of this heavy main group element in the catalysis is evaluated.
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Affiliation(s)
| | - James T. Moore
- Department of Chemistry
- University of Minnesota
- Minneapolis
- USA
| | - Eckhard Bill
- Max Planck Institut für Chemische Energiekonversion
- 45470 Mülheim an der Ruhr
- Germany
| | - Bernd Mienert
- Max Planck Institut für Chemische Energiekonversion
- 45470 Mülheim an der Ruhr
- Germany
| | - Connie C. Lu
- Department of Chemistry
- University of Minnesota
- Minneapolis
- USA
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47
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Lohrey TD, Fostvedt JI, Bergman RG, Arnold J. Electron acceptors promote proton–hydride tautomerism in low valent rhenium β-diketiminates. Chem Commun (Camb) 2020; 56:3761-3764. [DOI: 10.1039/c9cc09475j] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report a series of β-diketiminate (BDI) complexes in which tautomeric rhenium(iii) hydride and rhenium(i) protio-BDI species readily interconvert between the solid and solution states.
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Affiliation(s)
- Trevor D. Lohrey
- Department of Chemistry
- University of California
- Berkeley
- USA
- Chemical Sciences Division
| | | | | | - John Arnold
- Department of Chemistry
- University of California
- Berkeley
- USA
- Chemical Sciences Division
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48
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Schluschaß B, Abbenseth J, Demeshko S, Finger M, Franke A, Herwig C, Würtele C, Ivanovic-Burmazovic I, Limberg C, Telser J, Schneider S. Selectivity of tungsten mediated dinitrogen splitting vs. proton reduction. Chem Sci 2019; 10:10275-10282. [PMID: 32110313 PMCID: PMC6984443 DOI: 10.1039/c9sc03779a] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 09/19/2019] [Indexed: 01/12/2023] Open
Abstract
An N2-bridged ditungsten complex is presented that undergoes N2-splitting or hydrogen evolution upon protonation depending on the acid and reaction conditions. Spectroscopic, kinetic and computational results emphasize the impact of hydrogen bonding on the reaction selectivity.
Mo complexes are currently the most active catalysts for nitrogen fixation under ambient conditions. In comparison, tungsten platforms are scarcely examined. For active catalysts, the control of N2vs. proton reduction selectivities remains a difficult task. We here present N2 splitting using a tungsten pincer platform, which has been proposed as the key reaction for catalytic nitrogen fixation. Starting from [WCl3(PNP)] (PNP = N(CH2CH2PtBu2)2), the activation of N2 enabled the isolation of the dinitrogen bridged redox series [(N2){WCl(PNP)}2]0/+/2+. Protonation of the neutral complex results either in the formation of a nitride [W(N)Cl(HPNP)]+ or H2 evolution and oxidation of the W2N2 core, respectively, depending on the acid and reaction conditions. Examination of the nitrogen splitting vs. proton reduction selectivity emphasizes the role of hydrogen bonding of the conjugate base with the protonated intermediates and provides guidelines for nitrogen fixation.
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Affiliation(s)
- Bastian Schluschaß
- Georg-August-Universität , Institut für Anorganische Chemie , Tammannstrasse 4 , 37077 Göttingen , Germany .
| | - Josh Abbenseth
- Georg-August-Universität , Institut für Anorganische Chemie , Tammannstrasse 4 , 37077 Göttingen , Germany .
| | - Serhiy Demeshko
- Georg-August-Universität , Institut für Anorganische Chemie , Tammannstrasse 4 , 37077 Göttingen , Germany .
| | - Markus Finger
- Georg-August-Universität , Institut für Anorganische Chemie , Tammannstrasse 4 , 37077 Göttingen , Germany .
| | - Alicja Franke
- Lehrstuhl für Bioanorganische Chemie , Department Chemie und Pharmazie , Friedrich-Alexander-Universität Erlangen , Egerlandstrasse 3 , 91058 Erlangen , Germany
| | - Christian Herwig
- Institut für Chemie , Humboldt Universität zu Berlin , Brook-Taylor-Strasse 2 , 12489 Berlin , Germany
| | - Christian Würtele
- Georg-August-Universität , Institut für Anorganische Chemie , Tammannstrasse 4 , 37077 Göttingen , Germany .
| | - Ivana Ivanovic-Burmazovic
- Lehrstuhl für Bioanorganische Chemie , Department Chemie und Pharmazie , Friedrich-Alexander-Universität Erlangen , Egerlandstrasse 3 , 91058 Erlangen , Germany
| | - Christian Limberg
- Institut für Chemie , Humboldt Universität zu Berlin , Brook-Taylor-Strasse 2 , 12489 Berlin , Germany
| | - Joshua Telser
- Department of Biological, Physical and Health Sciences , Roosevelt University , 430 S. Michigan Avenue , Chicago , Illinois 60605 , USA
| | - Sven Schneider
- Georg-August-Universität , Institut für Anorganische Chemie , Tammannstrasse 4 , 37077 Göttingen , Germany .
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Salazar-Díaz JJ, Muñoz-Hernández MA, Rufino-Felipe E, Flores-Alamo M, Ramírez-Solís A, Montiel-Palma V. Bi- and tridentate stannylphosphines and their coordination to low-valent platinum. Dalton Trans 2019; 48:15896-15905. [PMID: 31552976 DOI: 10.1039/c9dt03317c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Semirigid bifunctional tin-substituted o-tolylphosphines of general formulae [Ph2P(o-C6H4CH2)SnR3] (R = Ph, 1; R = Me, 2) and [{Ph2P(o-C6H4CH2)}2SnPh2] (3) were synthesized and isolated in good yields. The new compounds were fully characterized by single-crystal X-ray diffraction and multinuclear solution NMR spectroscopic techniques. The observed J(119Sn,31P) values in solution NMR spectroscopy as well as the PSn distances in the solid state and DFT calculations (B3LYP) on compounds 1 and 3 do not support the existence of intramolecular P → Sn bond interactions in either of the three compounds. 1 and 2 reacted with stoichiometric amounts of tristriphenylphosphine platinum(0) [Pt(PPh3)3] under toluene refluxing conditions leading to formation of Pt(ii) distorted square-planar complexes [Ph2P(o-C6H4CH2)Pt(SnR3)(PPh3)], (R = Ph, 4; R = Me, 5), each bearing a five-membered carbometallated ring resulting from Pt coordination to P and the benzylic C sp3 atom of the ligand architecture rather than from activation of the terminal Sn-C carbon bonds of the phenyl or methyl substituents which would have rendered six-membered rings. Additionally, the fragment SnR3 also binds to the metal centre disposing cis to the cyclometalated carbon atom and to the single remaining PPh3. This carbometallation takes place affecting the integrity of the ligand skeleton. NBO calculations show the Sn fragment coordinates to the metal as X-type stannyl, SnR3. The analogous reaction of [Pt(PPh3)3] towards the stannyldiphosphine 3 leads to the quantitative formation of complex [(Ph2P-o-C6H4CH2)Pt(Ph2P-o-C6H4CH2SnPh3)], 6, which exhibits five- and six-membered metallacycles at the expense of the ligand frame. All compounds were characterized exhaustively by solution spectroscopic measurements and by single crystal X-ray diffraction analysis. DFT computations corroborate the higher stability of the observed products over those resulting from preservation of the ligand backbone.
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Affiliation(s)
- J Jacobo Salazar-Díaz
- Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos 62209, Mexico.
| | - Miguel A Muñoz-Hernández
- Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos 62209, Mexico. and Department of Chemistry, Mississippi State University, Box 9573, Mississippi State, Mississippi 39762, USA
| | - Ernesto Rufino-Felipe
- Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos 62209, Mexico.
| | - Marcos Flores-Alamo
- Facultad de Química, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Alejandro Ramírez-Solís
- Centro de Investigación en Ciencias-IICBA, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos 62209, Mexico
| | - Virginia Montiel-Palma
- Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos 62209, Mexico. and Department of Chemistry, Mississippi State University, Box 9573, Mississippi State, Mississippi 39762, USA
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