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Morris RH. Reactivity umpolung (reversal) of ligands in transition metal complexes. Chem Soc Rev 2024; 53:2808-2827. [PMID: 38353155 DOI: 10.1039/d3cs00979c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
The success and power of homogeneous catalysis derives in large part from the wide choice of transition metal ions and their ligands. This tutorial review introduces examples where the reactivity of a ligand is completely reversed (umpolung) from Lewis basic/nucleophilic to acidic/electrophilic or vice versa on changing the metal and co-ligands. Understanding this phenomenon will assist in the rational design of catalysts and the understanding of metalloenzyme mechanisms. Labelling a metal and ligand with Seebach donor and acceptor labels helps to identify whether a reaction involving the intermolecular attack on the ligand is displaying native reactivity or reactivity umpolung. This has been done for complexes of nitriles, carbonyls, isonitriles, dinitrogen, Fischer carbenes, alkenes, alkynes, hydrides, methyls, methylidenes and alkylidenes, silylenes, oxides, imides/nitrenes, alkylidynes, methylidynes, and nitrides. The electronic influence of the metal and co-ligands is discussed in terms of the energy of (HOMO) d electrons. The energy can be related to the pKLACa (LAC is ligand acidity constant) of the theoretical hydride complexes [H-[M]-L]+ formed by the protonation of pair of valence d electrons on the metal in the [M-L] complex. Preliminary findings indicate that a negative pKLACa indicates that nucleophilic attack by a carbanion or amine on the ligand will likely occur while a positive pKLACa indicates that electrophilic attack by strong acids on the ligand will usually occur when the ligand is nitrile, carbonyl, isonitrile, alkene and η6-arene.
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Affiliation(s)
- Robert H Morris
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario, Canada, M5S3H6.
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2
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Montgomery CL, Amtawong J, Jordan AM, Kurtz DA, Dempsey JL. Proton transfer kinetics of transition metal hydride complexes and implications for fuel-forming reactions. Chem Soc Rev 2023; 52:7137-7169. [PMID: 37750006 DOI: 10.1039/d3cs00355h] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Proton transfer reactions involving transition metal hydride complexes are prevalent in a number of catalytic fuel-forming reactions, where the proton transfer kinetics to or from the metal center can have significant impacts on the efficiency, selectivity, and stability associated with the catalytic cycle. This review correlates the often slow proton transfer rate constants of transition metal hydride complexes to their electronic and structural descriptors and provides perspective on how to exploit these parameters to control proton transfer kinetics to and from the metal center. A toolbox of techniques for experimental determination of proton transfer rate constants is discussed, and case studies where proton transfer rate constant determination informs fuel-forming reactions are highlighted. Opportunities for extending proton transfer kinetic measurements to additional systems are presented, and the importance of synergizing the thermodynamics and kinetics of proton transfer involving transition metal hydride complexes is emphasized.
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Affiliation(s)
- Charlotte L Montgomery
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA.
| | - Jaruwan Amtawong
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA.
| | - Aldo M Jordan
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA.
| | - Daniel A Kurtz
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA.
| | - Jillian L Dempsey
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA.
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3
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Bhatti T, Kumar A, Parihar A, Moncy HK, Emge TJ, Waldie KM, Hasanayn F, Goldman AS. Metal-Ligand Proton Tautomerism, Electron Transfer, and C(sp 3)-H Activation by a 4-Pyridinyl-Pincer Iridium Hydride Complex. J Am Chem Soc 2023; 145:18296-18306. [PMID: 37552857 PMCID: PMC10450815 DOI: 10.1021/jacs.3c03376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Indexed: 08/10/2023]
Abstract
The para-N-pyridyl-based PCP pincer proligand 3,5-bis(di-tert-butylphosphinomethyl)-2,6-dimethylpyridine (pN-tBuPCP-H) was synthesized and metalated to give the iridium complex (pN-tBuPCP)IrHCl (2-H). In marked contrast with its phenyl-based congeners, e.g., (tBuPCP)IrHCl and derivatives, 2-H is highly air-sensitive and reacts with oxidants such as ferrocenium, trityl cation, and benzoquinone. These oxidations ultimately lead to intramolecular activation of a phosphino-t-butyl C(sp3)-H bond and cyclometalation. Considering the greater electronegativity of N than C, 2-H is expected to be less easily oxidized than simple PCP derivatives; cyclic voltammetry and DFT calculations support this expectation. However, 2-H is calculated to undergo metal-ligand-proton tautomerism (MLPT) to give an N-protonated complex that can be described with resonance forms representing a zwitterionic complex (with a negative charge on Ir) and a p-N-pyridylidene (a remote N-heterocyclic carbene) Ir(I) complex. One-electron oxidation of this tautomer is calculated to be dramatically more favorable than direct oxidation of 2-H (ΔΔG° = -31.3 kcal/mol). The resulting Ir(II) oxidation product is easily deprotonated to give metalloradical 2• which is observed by NMR spectroscopy. 2• can be further oxidized to give cationic Ir(III) complex, 2+, which can oxidatively add a phosphino-t-butyl C-H bond and undergo deprotonation to give the observed cyclometalated product. DFT calculations indicate that less sterically hindered analogues of 2+ would preferentially undergo intermolecular addition of C(sp3)-H bonds, for example, of n-alkanes. The resulting iridium alkyl complexes could undergo facile β-H elimination to afford olefin, thereby completing a catalytic cycle for alkane dehydrogenation driven by one-electron oxidation and deprotonation, enabled by MLPT.
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Affiliation(s)
- Tariq
M. Bhatti
- Department
of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Akshai Kumar
- Centre
for Nanotechnology, Indian Institute of
Technology Guwahati, Guwahati 781039, Assam, India
| | - Ashish Parihar
- Department
of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Hellan K. Moncy
- Department
of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Thomas J. Emge
- Department
of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Kate M. Waldie
- Department
of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Faraj Hasanayn
- Department
of Chemistry, American University of Beirut, Beirut 1107 2020, Lebanon
| | - Alan S. Goldman
- Department
of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
- Centre
for Nanotechnology, Indian Institute of
Technology Guwahati, Guwahati 781039, Assam, India
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4
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Evans RM, Beaton SE, Rodriguez Macia P, Pang Y, Wong KL, Kertess L, Myers WK, Bjornsson R, Ash PA, Vincent KA, Carr SB, Armstrong FA. Comprehensive structural, infrared spectroscopic and kinetic investigations of the roles of the active-site arginine in bidirectional hydrogen activation by the [NiFe]-hydrogenase 'Hyd-2' from Escherichia coli. Chem Sci 2023; 14:8531-8551. [PMID: 37592998 PMCID: PMC10430524 DOI: 10.1039/d2sc05641k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 07/01/2023] [Indexed: 08/19/2023] Open
Abstract
The active site of [NiFe]-hydrogenases contains a strictly-conserved pendant arginine, the guanidine head group of which is suspended immediately above the Ni and Fe atoms. Replacement of this arginine (R479) in hydrogenase-2 from E. coli results in an enzyme that is isolated with a very tightly-bound diatomic ligand attached end-on to the Ni and stabilised by hydrogen bonding to the Nζ atom of the pendant lysine and one of the three additional water molecules located in the active site of the variant. The diatomic ligand is bound under oxidising conditions and is removed only after a prolonged period of reduction with H2 and reduced methyl viologen. Once freed of the diatomic ligand, the R479K variant catalyses both H2 oxidation and evolution but with greatly decreased rates compared to the native enzyme. Key kinetic characteristics are revealed by protein film electrochemistry: most importantly, a very low activation energy for H2 oxidation that is not linked to an increased H/D isotope effect. Native electrocatalytic reversibility is retained. The results show that the sluggish kinetics observed for the lysine variant arise most obviously because the advantage of a more favourable low-energy pathway is massively offset by an extremely unfavourable activation entropy. Extensive efforts to establish the identity of the diatomic ligand, the tight binding of which is an unexpected further consequence of replacing the pendant arginine, prove inconclusive.
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Affiliation(s)
- Rhiannon M Evans
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
| | - Stephen E Beaton
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
| | | | - Yunjie Pang
- College of Chemistry, Beijing Normal University 100875 Beijing China
- Department of Inorganic Spectroscopy, Max Planck Institute for Chemical Energy Conversion Stiftstraße 34-36 45470 Mülheim an der Ruhr Germany
| | - Kin Long Wong
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
- Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus Didcot UK
| | - Leonie Kertess
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
| | - William K Myers
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
| | - Ragnar Bjornsson
- Department of Inorganic Spectroscopy, Max Planck Institute for Chemical Energy Conversion Stiftstraße 34-36 45470 Mülheim an der Ruhr Germany
- Univ Grenoble Alpes, CNRS, CEA, IRIG, Laboratoire Chimie et Biologie des Métaux 17 Rue Des Martyrs F-38054 Grenoble Cedex France
| | - Philip A Ash
- School of Chemistry, The University of Leicester University Road Leicester LE1 7RH UK
| | - Kylie A Vincent
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
| | - Stephen B Carr
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
- Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus Didcot UK
| | - Fraser A Armstrong
- University of Oxford, Department of Chemistry South Parks Road Oxford UK
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Kuehn MA, Fernandez W, Zall CM. Structure and Thermodynamic Hydricity in Cobalt(triphosphine)(monophosphine) Hydrides. Inorg Chem 2023. [PMID: 37216471 DOI: 10.1021/acs.inorgchem.2c04124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The mononuclear cobalt hydride complex [HCo(triphos)(PMe3)], in which triphos = PhP(CH2CH2PPh2)2, was synthesized and characterized by X-ray crystallography and by 1H and 31P NMR spectroscopy. The geometry of the compound is a distorted trigonal bipyramid in which the axial positions are occupied by the hydride and the central phosphorus atom of the triphos ligand, while the PMe3 and terminal triphos donor atoms occupy the equatorial positions. Protonation of [HCo(triphos)(PMe3)] generates H2 and the Co(I) cation, [Co(triphos)(PMe3)]+, and this reaction is reversible under an atmosphere of H2 when the proton source is weakly acidic. The thermodynamic hydricity of HCo(triphos)(PMe3) was determined to be 40.3 kcal/mol in MeCN from measurements of these equilibria. The reactivity of the hydride is, therefore, well suited to CO2 hydrogenation catalysis. Density functional theory (DFT) calculations were performed to evaluate the structures and hydricities of a series of analogous cobalt(triphosphine)(monophosphine) hydrides where the phosphine substituents are systematically changed from Ph to Me. The calculated hydricities range from 38.5 to 47.7 kcal/mol. Surprisingly, the hydricities of the complexes are generally insensitive to substitution at the triphosphine ligand, as a result of competing structural and electronic trends. The DFT-calculated geometries of the [Co(triphos)(PMe3)]+ cations are more square planar when the triphosphine ligand possesses bulkier phenyl groups and more tetrahedrally distorted when the triphosphine ligand has smaller methyl substituents, reversing the trend observed for [M(diphosphine)2]+ cations. More distorted structures are associated with an increase in ΔGH-°, and this structural trend counteracts the electronic effect in which methyl substitution at the triphosphine is expected to yield smaller ΔGH-° values. However, the steric influence of the monophosphine follows the normal trend that phenyl substituents give more distorted structures and increased ΔGH-° values.
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Affiliation(s)
- Makenzie A Kuehn
- Department of Chemistry, Sam Houston State University, 1003 Bowers Boulevard, Huntsville, Texas 77341, United States
| | - William Fernandez
- Department of Chemistry, Sam Houston State University, 1003 Bowers Boulevard, Huntsville, Texas 77341, United States
| | - Christopher M Zall
- Department of Chemistry, Sam Houston State University, 1003 Bowers Boulevard, Huntsville, Texas 77341, United States
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6
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Rennie BE, Price JS, Emslie DJH, Morris RH. Trans Ligand Determines the Stability of Paramagnetic Manganese(II) Hydrides of the Type trans-[MnH(L)(dmpe) 2] + Where L is PMe 3, C 2H 4, or CO. Inorg Chem 2023; 62:8123-8135. [PMID: 36812512 DOI: 10.1021/acs.inorgchem.2c04432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Paramagnetic metal hydride (PMH) complexes play important roles in catalytic applications and bioinorganic chemistry. 3d PMH chemistry has largely focused on Ti, Mn, Fe, and Co. Various MnII PMHs have been proposed as intermediates in catalysis, but isolated MnII PMHs are limited to dimeric high-spin MnII structures with bridging hydrides. In this paper, a series of the first low-spin monomeric MnII PMH complexes are generated by chemical oxidation of their MnI analogues. This series is of the type trans-[MnH(L)(dmpe)2]+/0 where the trans ligand L is PMe3, C2H4, or CO [dmpe is 1,2-bis(dimethylphosphino)ethane], and the thermal stability of the MnII hydride complexes was found to be strongly dependent on the identity of the trans ligand. When L is PMe3, the complex is the first example of an isolated monomeric MnII hydride complex. In contrast, when L is C2H4 or CO, the complexes are only stable at low temperatures; upon warming to room temperature, the former decomposed to afford [Mn(dmpe)3]+, accompanied by ethane and ethylene, whereas the latter eliminated H2, generating [Mn(MeCN)(CO)(dmpe)2]+ or a mixture of products including [Mn(κ1-PF6)(CO)(dmpe)2], depending on the reaction conditions. All PMHs were characterized by low-temperature electron paramagnetic resonance (EPR) spectroscopy, and stable [MnH(PMe3)(dmpe)2]+ was further characterized by UV-vis and IR spectroscopy, Superconducting Quantum Interference Device magnetometry, and single-crystal X-ray diffraction. Noteworthy spectral properties are the significant EPR superhyperfine coupling to the hydride (∼85 MHz) and an increase (+33 cm-1) in the Mn-H IR stretch upon oxidation. Density functional theory calculations were also employed to gain insights into the acidity and bond strengths of the complexes. MnII-H bond dissociation free energies are estimated to decrease in the series of complexes from 60 (L = PMe3) to 47 kcal/mol (L = CO).
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Affiliation(s)
- Benjamin E Rennie
- Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S3H6, Canada
| | - Jeffrey S Price
- Department of Chemistry, McMaster University, Hamilton, Ontario L8S4M1, Canada
| | - David J H Emslie
- Department of Chemistry, McMaster University, Hamilton, Ontario L8S4M1, Canada
| | - Robert H Morris
- Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S3H6, Canada
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7
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Schlenker K, Casselman LK, VanderLinden RT, Saouma CT. Large changes in hydricity as a function of charge and not metal in (PNP)M–H (de)hydrogenation catalysts that undergo metal–ligand cooperativity. Catal Sci Technol 2023. [DOI: 10.1039/d2cy01349e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Ligand pKa and metal hydricity scale with one another in (de)hydrogenation catalysts that undergo metal–ligand cooperativity, irrespective of metal or ligand identity. Anionic hydrides are significantly more hydridic than their neutral counterparts.
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Affiliation(s)
- Kevin Schlenker
- Department of Chemistry, University of Utah, Salt Lake City, Utah, 84112, USA
| | - Lillee K. Casselman
- Department of Chemistry, University of Utah, Salt Lake City, Utah, 84112, USA
| | | | - Caroline T. Saouma
- Department of Chemistry, University of Utah, Salt Lake City, Utah, 84112, USA
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8
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Kim S, Kim J, Zhong H, Panetti GB, Chirik PJ. Catalytic N–H Bond Formation Promoted by a Ruthenium Hydride Complex Bearing a Redox-Active Pyrimidine-Imine Ligand. J Am Chem Soc 2022; 144:20661-20671. [DOI: 10.1021/jacs.2c07800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sangmin Kim
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Junho Kim
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Hongyu Zhong
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Grace B. Panetti
- 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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9
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Kim YE, Byun MY, Lee KY, Lee MS. Hydrothermal synthesis of mesoporous TiO2 using β-diketonate stabilizing agents for photocatalytic degradation of methyl violet 2B under visible light. Catal Today 2022. [DOI: 10.1016/j.cattod.2022.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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10
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Cypcar AD, Kerr TA, Yang JY. Thermochemical Studies of Nickel Hydride Complexes with Cationic Ligands in Aqueous and Organic Solvents. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00319] [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)
- Andrew D. Cypcar
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Tyler A. Kerr
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Jenny Y. Yang
- Department of Chemistry, University of California, Irvine, California 92697, United States
- Physical Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
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11
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Naik DV, Moehring GA. Dynamic Processes of Rhenium Polyhydride Complexes. Molecules 2022; 27:5017. [PMID: 35956967 PMCID: PMC9370646 DOI: 10.3390/molecules27155017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/19/2022] [Accepted: 07/24/2022] [Indexed: 11/23/2022] Open
Abstract
Studies have demonstrated that high-coordination-number rhenium polyhydride complexes are precursors to catalysts that transform a variety of organic molecules. While rhenium polyhydride complexes lead to active catalysts, little has been reported on the mechanisms for the transformations. High-coordination-number rhenium polyhydride complexes exhibit several dynamic processes that make characterizations of the chemical properties for individual atoms difficult, at best, for room-temperature solutions. This review describes what is known of the dynamic processes that occur at high-coordination-number rhenium polyhydride complexes and how that knowledge may lead to the design of catalytic precursors in which the chemical properties of individual atoms can be more readily identified in room-temperature solutions.
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Affiliation(s)
| | - Gregory A. Moehring
- Department of Chemistry and Physics, Monmouth University, West Long Branch, NJ 07764, USA
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12
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Prat JR, Cammarota RC, Graziano BJ, Moore JT, Lu CC. Toggling the Z-type interaction off-on in nickel-boron dihydrogen and anionic hydride complexes. Chem Commun (Camb) 2022; 58:8798-8801. [PMID: 35838123 DOI: 10.1039/d2cc03219h] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Completing a series of nickel-group 13 complexes, a coordinatively unsaturated nickel-boron complex and its derivatives with a H2, N2, or hydride ligand were synthesized and characterized. The toggling "on" of a Ni(0)-B(III) inverse-dative bond enabled the stabilization of a nickel-bound anionic hydride with a remarkably low thermodynamic hydricity of kcal mol-1 in THF. The flexible topology of the boron metalloligand confers both favorable hydrogen binding affinity and strong hydride donicity, albeit at the cost of high H2 basicity during deprotonation to form the hydride.
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Affiliation(s)
- Jacob R Prat
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, USA
| | - Ryan C Cammarota
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, USA
| | - Brendan J Graziano
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, USA
| | - James T Moore
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, USA
| | - Connie C Lu
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, USA.,Institute of Inorganic Chemistry, University of Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn, Germany.
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13
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Messinis AM, Oliveira JCA, Stückl AC, Ackermann L. Cyclometallated Iron(II) Alkoxides in Iron-Catalyzed C–H Activations by Weak O-Carbonyl Chelation. ACS Catal 2022. [DOI: 10.1021/acscatal.2c00772] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Antonis M. Messinis
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
| | - João C. A. Oliveira
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
| | - A. Claudia Stückl
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraße 4, 37077 Göttingen, Germany
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
- Wöhler-Research Institute for Sustainable Chemistry (WISCh), Georg-August-Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
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14
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Abstract
This tutorial review showcases recent (2015-2021) work describing ligand construction as it relates to the design of secondary coordination spheres (SCSs). Metalloenzymes, for example, utilize SCSs to stabilize reactive substrates, shuttle small molecules, and alter redox properties, promoting functional activity. In the realm of biomimetic chemistry, specific incorporation of SCS residues (e.g., Brønsted or Lewis acid/bases, crown ethers, redox groups etc.) has been shown to be equally critical to function. This contribution illustrates how fundamental advances in organic and inorganic chemistry have been used for the construction of such SCSs. These imaginative contributions have driven exciting findings in many transformations relevant to clean fuel generation, including small molecule (e.g., H+, N2, CO2, NOx, O2) reduction. In most cases, these reactions occur cooperatively, where both metal and ligand are requisite for substrate activation.
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Affiliation(s)
- Marcus W Drover
- Department of Chemistry and Biochemistry, The University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada.
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15
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Zurakowski JA, Austen BJ, Drover MW. Exterior decorating: Lewis acid secondary coordination spheres for cooperative reactivity. TRENDS IN CHEMISTRY 2022. [DOI: 10.1016/j.trechm.2022.01.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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16
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Babón JC, Esteruelas MA, López AM. Homogeneous catalysis with polyhydride complexes. Chem Soc Rev 2022; 51:9717-9758. [DOI: 10.1039/d2cs00399f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This review analyzes the role of transition metal polyhydrides as homogeneous catalysts for organic reactions. Discussed reactions involve nearly every main organic functional group.
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Affiliation(s)
- Juan C. Babón
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
| | - Miguel A. Esteruelas
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
| | - Ana M. López
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
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17
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Toh ZH, Tinnermann H, Do DCH, Huynh HV, Krämer T, Young RD. Gauging the donor strength of iron(0) complexes via their N-heterocyclic carbene gold( i) adducts. Chem Commun (Camb) 2022; 58:12947-12950. [DOI: 10.1039/d2cc05041b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We isolate and characterize the gold(i)–iron(0) adducts [(iPr2-bimy)Au–Fe(CO)3(PMe3)2][BArF4] and [Au–{Fe(CO)3(PMe3)2}2][BArF4] (iPr2-bimy = 1,3-diisopropylbenzimidazolin-2-ylidene, BArF4 = tetrakis(pentafluorophenyl)borate).
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Affiliation(s)
- Zhi Hao Toh
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Hendrik Tinnermann
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Dinh Cao Huan Do
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Han Vinh Huynh
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Tobias Krämer
- Department of Chemistry, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Rowan D. Young
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
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18
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19
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Zurakowski JA, Austen BJH, Dufour MC, Bhattacharyya M, Spasyuk DM, Drover MW. Preparation of a borane-appended Co(III) hydride: evidence for metal-ligand cooperativity in O-H bond activation. Dalton Trans 2021; 50:12440-12447. [PMID: 34397061 DOI: 10.1039/d1dt02331d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cobalt hydrides are known to mediate a number of important chemical transformations including proton (H+), hydride (H-), and hydrogen-atom (H˙) transfer. Central to the tunability of such frameworks is judicious ligand design, which offers the flexibility to alter fundamental properties relevant to reactivity. Herein, we report the preparation of one such cobalt(iii) hydride: [Cp*CoIII(P2BCy4)(H)]BPh4 (Cp* = C5Me5-, P2BCy4 = 1,2-bis(di(3-dicyclohexylborane)propylphosphino)ethane) that is encircled by a boron-based Lewis-acidic secondary coordination sphere. The structure of this species is supported by synchrotron-radiation crystallography, evidencing a terminal Co(iii) hydride with four sp2-hybridized boranes that invite Lewis base coordination. To this end, electrochemical reactivity studies performed using [Cp*CoIII(P2BCy4)Cl]+ or an "all-akyl" model, [Cp*CoIII(dnppe)Cl]+ (dnppe = 1,2-bis(di-n-propylphosphino)ethane) with benzoic or 4-pyridylbenzoic acid show divergent responses for protonation of electrochemically-generated Co(i) to give a Co(iii) hydride. For [Cp*CoIII(P2BCy4)Cl]+, this process is complex, not only involving protonation, but also engagement of the pendant borane moieties in Lewis acid/base interactions. For protonation by benzoic acid, for example, borane-benzoate contacts are substantiated by variable temperature NMR spectroscopic measurements and theoretical calculations, pointing to a cooperative Co-H/B-O bond forming process. These data are discussed in the context of designing new molecular catalysts for ligand-assisted hydrogen evolution reactivity.
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Affiliation(s)
- Joseph A Zurakowski
- Department of Chemistry and Biochemistry, The University of Windsor, 401 Sunset Avenue, Windsor, ON N9B 3P4, Canada.
| | - Brady J H Austen
- Department of Chemistry and Biochemistry, The University of Windsor, 401 Sunset Avenue, Windsor, ON N9B 3P4, Canada.
| | - Maeve C Dufour
- Department of Chemistry and Biochemistry, The University of Windsor, 401 Sunset Avenue, Windsor, ON N9B 3P4, Canada.
| | - Moulika Bhattacharyya
- Department of Chemistry and Biochemistry, The University of Windsor, 401 Sunset Avenue, Windsor, ON N9B 3P4, Canada.
| | - Denis M Spasyuk
- Canadian Light Source Inc., 44 Innovation Blvd., Saskatoon, SK S7N 2V3, Canada
| | - Marcus W Drover
- Department of Chemistry and Biochemistry, The University of Windsor, 401 Sunset Avenue, Windsor, ON N9B 3P4, Canada.
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20
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DiMarco BN, Polyansky DE, Grills DC, Wang P, Kuwahara Y, Zhao X, Fujita E. Structural and Electronic Influences on Rates of Tertpyridine-Amine Co III -H Formation During Catalytic H 2 Evolution in an Aqueous Environment. Chemphyschem 2021; 22:1478-1487. [PMID: 33990996 DOI: 10.1002/cphc.202100295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/13/2021] [Indexed: 01/04/2023]
Abstract
In this work, the differences in catalytic performance for a series of Co hydrogen evolution catalysts with different pentadentate polypyridyl ligands (L), have been rationalized by examining elementary steps of the catalytic cycle using a combination of electrochemical and transient pulse radiolysis (PR) studies in aqueous solution. Solvolysis of the [CoII -Cl]+ species results in the formation of [CoII (κ4 -L)(OH2 )]2+ . Further reduction produces [CoI (κ4 -L)(OH2 )]+ , which undergoes a rate-limiting structural rearrangement to [CoI (κ5 -L)]+ before being protonated to form [CoIII -H]2+ . The rate of [CoIII -H]2+ formation is similar for all complexes in the series. Using E1/2 values of various Co species and pKa values of [CoIII -H]2+ estimated from PR experiments, we found that while the protonation of [CoIII -H]2+ is unfavorable, [CoII -H]+ reacts with protons to produce H2 . The catalytic activity for H2 evolution tracks the hydricity of the [CoII -H]+ intermediate.
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Affiliation(s)
- Brian N DiMarco
- Chemistry Division, Brookhaven National Laboratory Upton, New York, 11973-5000, USA
| | - Dmitry E Polyansky
- Chemistry Division, Brookhaven National Laboratory Upton, New York, 11973-5000, USA
| | - David C Grills
- Chemistry Division, Brookhaven National Laboratory Upton, New York, 11973-5000, USA
| | - Ping Wang
- Department of Chemistry, University of Memphis, Memphis, Tennessee, 38152, USA
| | - Yutaka Kuwahara
- Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto, 860-8555, Japan
| | - Xuan Zhao
- Department of Chemistry, University of Memphis, Memphis, Tennessee, 38152, USA
| | - Etsuko Fujita
- Chemistry Division, Brookhaven National Laboratory Upton, New York, 11973-5000, USA
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21
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Collett JD, Ransohoff RW, Krause JA, Guan H. An Iron‐Hydrogen Bond Resistant to Protonation and Oxidation. Z Anorg Allg Chem 2021. [DOI: 10.1002/zaac.202100066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Joel D. Collett
- Department of Chemistry University of Cincinnati P.O. Box 210172 Cincinnati Ohio 45221-0172 United States
| | - Rebecca W. Ransohoff
- Department of Chemistry University of Cincinnati P.O. Box 210172 Cincinnati Ohio 45221-0172 United States
| | - Jeanette A. Krause
- Department of Chemistry University of Cincinnati P.O. Box 210172 Cincinnati Ohio 45221-0172 United States
| | - Hairong Guan
- Department of Chemistry University of Cincinnati P.O. Box 210172 Cincinnati Ohio 45221-0172 United States
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22
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Pandey I, Agarwal T, Mobin SM, Stein M, Kaur-Ghumaan S. Switching Site Reactivity in Hydrogenase Model Systems by Introducing a Pendant Amine Ligand. ACS OMEGA 2021; 6:4192-4203. [PMID: 33644543 PMCID: PMC7906588 DOI: 10.1021/acsomega.0c04901] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/24/2020] [Indexed: 06/12/2023]
Abstract
Hydrogenases are versatile enzymatic catalysts with an unmet hydrogen evolution reactivity (HER) from synthetic bio-inspired systems. The binuclear active site only has one-site reactivity of the distal Fed atom. Here, binuclear complexes [Fe2(CO)5(μ-Mebdt)(P(4-C6H4OCH3)3)] 1 and [Fe2(CO)5(μ-Mebdt)(PPh2Py)] 2 are presented, which show electrocatalytic activity in the presence of weak acids as a proton source for the HER. Despite almost identical structural and spectroscopic properties (bond distances and angles from single-crystal X-ray; IR, UV/vis, and NMR), introduction of a nitrogen base atom in the phosphine ligand in 2 markedly changes site reactivity. The bridging benzenedithiolate ligand Mebdt interacts with the terminal ligand's phenyl aromatic rings and stabilizes the reduced states of the catalysts. Although 1 with monodentate phosphine terminal ligands only shows a distal iron atom HER activity by a sequence of electrochemical and protonation steps, the lone pair of pyridine nitrogen in 2 acts as the primary site of protonation. This swaps the iron atom catalytic activity toward the proximal iron for complex 2. Density-functional theory (DFT) calculations reveal the role of terminal phosphines ligands without/with pendant amines by directing the proton transfer steps. The reactivity of 1 is a thiol-based protonation of a dangling bond in 1- and distal iron hydride mechanism, which may follow either an ECEC or EECC sequence, depending on the choice of acid. The pendant amine in 2 enables a terminal ligand protonation and an ECEC reactivity. The introduction of a terminal nitrogen atom enables the control of site reactivity in a binuclear system.
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Affiliation(s)
| | - Tashika Agarwal
- Department
of Chemistry, University of Delhi, Delhi 110007, India
| | - Shaikh M. Mobin
- Discipline
of Chemistry, Indian Institute of Technology
Indore, Simrol, Khandwa Road, Indore 453552, India
| | - Matthias Stein
- Max
Planck Institute for Dynamics of Complex Technical Systems, Sandtorstrasse 1, 39106 Magdeburg, Germany
| | - Sandeep Kaur-Ghumaan
- Department
of Chemistry, University of Delhi, Delhi 110007, India
- Max
Planck Institute for Dynamics of Complex Technical Systems, Sandtorstrasse 1, 39106 Magdeburg, Germany
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23
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Morris RH. Focusing on transition metal hydride complexes. CAN J CHEM 2021. [DOI: 10.1139/cjc-2020-0507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Robert H. Morris
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, ON M5S 3H6, Canada
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, ON M5S 3H6, Canada
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24
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Olivares M, Albrecht M. Synthesis, stability, and reactivity of mesoionic carbene iridium dihydride complexes. CAN J CHEM 2021. [DOI: 10.1139/cjc-2020-0390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pyridyl-triazolylidene ligands with variable donor properties were used as tunable ligands at a dihydride iridium (III) center. The straightforward synthesis of this type of ligand allows for an easy incorporation of electron-donating substituents in different positions of the pyridine ring or different functional groups such as esters, alkoxy, or aliphatic chains on the C4 position of the triazole heterocycle. The stability of these hydride metal systems allowed these complexes to be used as models for studying the influence of the ligand modifications on hydride reactivity. Spectroscopic analysis provided unambiguous structural assignment of the dihydride system. Modulation of the electronic properties of the wingtip substituents did not appreciably alter the reactivity of the hydrides. Reactivity studies using acids with a wide range of pK a values indicated a correlation between hydride reactivity and acidity and showed exclusive reactivity towards the less shielded hydride trans to the carbene carbon rather than the more shielded hydride trans to the pyridine ring, suggesting that the trans effect is more relevant in these reactions than the NMR spectroscopically deduced hydridic character.
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Affiliation(s)
- Marta Olivares
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Martin Albrecht
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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25
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Seo CSG, Tsui BTH, Gradiski MV, Smith SAM, Morris RH. Enantioselective direct, base-free hydrogenation of ketones by a manganese amido complex of a homochiral, unsymmetrical P–N–P′ ligand. Catal Sci Technol 2021. [DOI: 10.1039/d1cy00446h] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Base-free direct hydrogenation of ketones using a Mn(PNP′)(CO)2 complex is more enantioselective than that of a related base-activated iron complex.
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26
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Sinha V, Laan JJ, Pidko EA. Accurate and rapid prediction of pKa of transition metal complexes: semiempirical quantum chemistry with a data-augmented approach. Phys Chem Chem Phys 2021; 23:2557-2567. [DOI: 10.1039/d0cp05281g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Data-augmented high-throughput QM approach to compute pKa of transition metal hydride complexes with hDFT accuracy and low cost.
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Affiliation(s)
- Vivek Sinha
- Inorganic Systems Engineering
- Department of Chemical Engineering
- Faculty of Applied Sciences
- Delft University of Technology
- Delft
| | - Jochem J. Laan
- Inorganic Systems Engineering
- Department of Chemical Engineering
- Faculty of Applied Sciences
- Delft University of Technology
- Delft
| | - Evgeny A. Pidko
- Inorganic Systems Engineering
- Department of Chemical Engineering
- Faculty of Applied Sciences
- Delft University of Technology
- Delft
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27
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Wang Y, Zhu J, Guo R, Lindberg H, Wang YM. Iron-catalyzed α-C-H functionalization of π-bonds: cross-dehydrogenative coupling and mechanistic insights. Chem Sci 2020; 11:12316-12322. [PMID: 34094439 PMCID: PMC8163013 DOI: 10.1039/d0sc05091a] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 10/16/2020] [Indexed: 12/02/2022] Open
Abstract
The deprotonation of propargylic C-H bonds for subsequent functionalization typically requires stoichiometric metal alkyl or amide reagents. In addition to the undesirable generation of stoichiometric metallic waste, these conditions limit the functional group compatibility and versatility of this functionalization strategy and often result in regioisomeric mixtures. In this article, we report the use of dicarbonyl cyclopentadienyliron(ii) complexes for the generation of propargylic anion equivalents toward the direct electrophilic functionalization of propargylic C-H bonds under mild, catalytic conditions. This technology was applied to the direct conversion of C-H bonds to C-C bonds for the synthesis of several functionalized scaffolds through a one-pot cross dehydrogenative coupling reaction with tetrahydroisoquinoline and related privileged heterocyclic scaffolds. A series of NMR studies and deuterium-labelling experiments indicated that the deprotonation of the propargylic C-H bond was the rate-determining step when a Cp*Fe(CO)2-based catalyst system was employed.
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Affiliation(s)
- Yidong Wang
- Department of Chemistry, University of Pittsburgh Pittsburgh Pennsylvania 15260 USA
| | - Jin Zhu
- Department of Chemistry, University of Pittsburgh Pittsburgh Pennsylvania 15260 USA
| | - Rui Guo
- Department of Chemistry, University of Pittsburgh Pittsburgh Pennsylvania 15260 USA
| | - Haley Lindberg
- Department of Chemistry, University of Pittsburgh Pittsburgh Pennsylvania 15260 USA
| | - Yi-Ming Wang
- Department of Chemistry, University of Pittsburgh Pittsburgh Pennsylvania 15260 USA
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28
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Rennie BE, Eleftheriades RG, Morris RH. Systematic Trends in the Electrochemical Properties of Transition Metal Hydride Complexes Discovered by Using the Ligand Acidity Constant Equation. J Am Chem Soc 2020; 142:17607-17629. [PMID: 32941024 DOI: 10.1021/jacs.0c08000] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Understanding the thermodynamics of paramagnetic transition metal hydride complexes, especially of the abundant 3d metals, is important in the design of electrocatalysts and organometallic catalysts. The pKaMeCN([MHLn]+/[MLn) of paramagnetic hydrides in MeCN are estimated for the first time using the ligand acidity constant (LAC) equation where contributions to the pKaMeCN from each ligand are simply added together, with the sum corrected for effects of charge and 5d metals. The pKaLAC-MeCN([MHLn]+/MLn) of over 200 hydride complexes MHLn are used, along with their electrochemical potentials from the literature, in an uncommonly applied thermochemical cycle in order to reveal systematic trends in the redox couples MIII/II and MV/IV (M = Cr, Mo, W), MnII/I, ReVI/V and ReIV/III, MIII/II and MIV/III (M = Fe, Ru, Os), and MIII/II and MII/I (M = Co, Rh, and Ir) and allow the estimation of the bond dissociation free energies BDFE(MH) of the unoxidized hydrides MHLn and the prediction of the electrochemical potential for their oxidation. Density functional theory (DFT) calculations are used to validate the pKaLAC-MeCN values of hydrides of WIII, MnII, FeIII, RuIII, CoII, and NiIII. When a pKaLAC-MeCN is less than zero for a given complex [MHLn]+, the oxidation of MHLn is irreversible due to proton loss from the oxidized complex to the solvent. When pKaLAC-MeCN ≫ 0, the oxidation is reversible when there is no gross change in the coordination geometry upon a change in the redox state. Twenty paramagnetic hydrides prepared in bulk all have pKaLAC-MeCN > 8.
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Affiliation(s)
- Benjamin E Rennie
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario M5S3H6, Canada
| | - Renée G Eleftheriades
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario M5S3H6, Canada
| | - Robert H Morris
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario M5S3H6, Canada
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29
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Xue Q, Wu R, Wang D, Zhu M, Zuo W. The Stabilization Effect of π‐Backdonation Ligands on the Catalytic Reactivities of Amido‐Ene(amido) Iron Catalysts in the Asymmetric Transfer Hydrogenation of Ketones. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000470] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Qingquan Xue
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and Engineering Donghua University 2999 North Renmin Road, Songjiang District 201620 Shanghai P. R. China
| | - Rongliang Wu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and Engineering Donghua University 2999 North Renmin Road, Songjiang District 201620 Shanghai P. R. China
| | - Di Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and Engineering Donghua University 2999 North Renmin Road, Songjiang District 201620 Shanghai P. R. China
| | - Meifang Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and Engineering Donghua University 2999 North Renmin Road, Songjiang District 201620 Shanghai P. R. China
| | - Weiwei Zuo
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and Engineering Donghua University 2999 North Renmin Road, Songjiang District 201620 Shanghai P. R. China
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30
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Gradiski MV, Kharat AN, Ong MSE, Lough AJ, Smith SAM, Morris RH. A One-Step Preparation of Tetradentate Ligands with Nitrogen and Phosphorus Donors by Reductive Amination and Representative Iron Complexes. Inorg Chem 2020; 59:11041-11053. [PMID: 32687329 DOI: 10.1021/acs.inorgchem.0c01535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The synthesis and use of the first examples of unsymmetrical, mixed phosphine donor tripodal NPP2' ligands N(CH2CH2PR2)2(CH2CH2PPh2) are presented. The ligands are synthesized via a convenient, one pot reductive amination using 2-(diphenylphosphino)ethylamine and various substituted phosphonium dimers in order to introduce mixed phosphine donors substituted with P/P', those being Ph/Cy (2), Ph/iPr (3), Ph/iBu (4), Ph/o-Tol (5), and Ph/p-Tol (6). Additionally, we have developed the first known synthesis of a symmetrical tripodal NP3 ligand N(CH2CH2PiBu2)3 using bench safe ammonium acetate as the lone nitrogen source (7). This new protocol eliminates the use of extremely dangerous nitrogen mustard reagents typically required to synthesize NP3 ligands. Some of these tetradentate ligands and also P2NN' ligands N(CH2-o-C5H4N)(CH2CH2PR2)2 (P2NN'-Cy, R = Cy; P2NN'-Ph, R = Ph) prepared by reductive amination using 2-picolylamine are used in the synthesis and reactions of iron complexes. FeCl2(P2NN'-Cy) (8) undergoes single halide abstraction with NaBPh4 to give the trigonal bipyramidal complex [FeCl(P2NN'-Cy)][BPh4] (9). Upon exposure to CO(g), complex 9 readily coordinates CO giving [FeCl(P2NN'-Cy)(CO)][BPh4] (10), and further treatment with an excess of NaBH4 results in formation of the hydride complex [Fe(H)(P2NN'-Cy)(CO)][BPh4] (11). Our previously reported complex FeCl2(P2NN'-Ph) undergoes double halide abstraction with NaBPh4 in the presence of the coordinating solvent to give [Fe(NCMe)2(P2NN'-Ph)][BPh4]2 (12). Ligand 3 can be coordinated to FeCl2, and upon sequential halide abstraction, treatment with NaBH4, and exposure to an atmosphere of dinitrogen, the dinitrogen hydride complex [Fe(H)(NPP2'-iPr)(N2)][BPh4] (13) is isolated. Our symmetrical NP3 ligand 7 can also be coordinated to FeCl2 and, upon exposure to an atmosphere of CO(g), selectively forms [FeCl(NP3)(CO)][BPh4] (14) after salt metathesis with NaBPh4. Complex 14 can be treated with an excess of NaBH4 to give the hydride complex [Fe(H)(NP3)(CO)][BPh4] (15), which can further be deprotonated/reduced to the Fe(0) complex Fe(NP3)(CO) (16) upon treatment with an excess of KH.
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Affiliation(s)
- Matthew V Gradiski
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario, Canada, M5S 3H6
| | - Ali Nemati Kharat
- School of Chemistry, College of Science, University of Tehran, Tehran, Iran
| | - Maegan S E Ong
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario, Canada, M5S 3H6
| | - Alan J Lough
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario, Canada, M5S 3H6
| | - Samantha A M Smith
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario, Canada, M5S 3H6
| | - Robert H Morris
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario, Canada, M5S 3H6
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31
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Suslick BA, Tilley TD. Mechanistic Interrogation of Alkyne Hydroarylations Catalyzed by Highly Reduced, Single-Component Cobalt Complexes. J Am Chem Soc 2020; 142:11203-11218. [DOI: 10.1021/jacs.0c04072] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Benjamin A. Suslick
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - T. Don Tilley
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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32
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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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33
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Shimamura T, Maeno Y, Kubo K, Kume S, Greco C, Mizuta T. Protonation and electrochemical properties of a bisphosphide diiron hexacarbonyl complex bearing amino groups on the phosphide bridge. Dalton Trans 2019; 48:16595-16603. [PMID: 31651000 DOI: 10.1039/c9dt03427g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A bisphosphide-bridged diiron hexacarbonyl complex 3 with NEt2 groups on the phosphide bridge was synthesized to examine a new proton relay system from the NEt2 group to the bridging hydride between the two iron centers. As a precursor of the bridging moiety, peri-Et2NP-PNEt2-bridged naphthylene 5 was synthesized by the reaction of 1,8-dilithionaphthylene with two equivalents of Cl2PNEt2 followed by reductive P-P bond formation by magnesium. The reaction of the diphosphine ligand 5 with Fe2(CO)9 gave the diiron hexacarbonyl complex 3, in which the P-P bond of the ligand was cleaved to form the bisphosphide-bridge. The molecular structure of 3 indicated that the trigonal plane of the NEt2 group was forced to face the Fe-Fe bond to avoid steric congestion with the naphthylene group linking the two phosphide groups. The NEt2 group could be protonated by p-toluenesulfonic acid. Density functional theory (DFT) calculations confirmed that the proton of the N(H)Et2 group adopted a position close to the bridging hydride. The DFT results for the ferrocene analogue 1, in which the 1,8-naphthylene group of 3 was replaced with the 1,1'-ferrocenylene group, also revealed that the most stable orientation of the protonated NHEt2 group was that in the protonated 3. As a result, electrochemical proton reduction reactions using complexes 1 and 3 proceeded with similar catalytic efficiencies. Unfortunately, the catalytic efficiencies (CEs) of these complexes were much lower than those of the complexes with a proton relay system of the terminal hydrogen, indicating that the reactive properties of the bridging hydride in the present proton relay system cannot exceed those of the terminal hydride.
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Affiliation(s)
- Takehiko Shimamura
- Department of Chemistry, Graduate School of Science, Hiroshima University, Kagamiyama 1-3-1, Higashi-hiroshima 739-8526, Japan.
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34
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Sung MMH, Prokopchuk DE, Morris RH. Phosphine-free ruthenium NCN-ligand complexes and their use in catalytic CO 2 hydrogenation. Dalton Trans 2019; 48:16569-16577. [PMID: 31560363 DOI: 10.1039/c9dt03143j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This work investigates the hydrogenation of carbon dioxide to formate catalysed by the phosphine-free Ru complexes Ru(OtBu)(κ3-NCN)(tBubpy) and RuH(OtBu)(κ2-NCN)(tBubpy) (OtBu = tert-butoxide, κ2-NCN = 1,3-di(2-methylpyridyl)-4,5-diphenyl-1H-imidazol-2-ylidene, where one pyridyl moiety is not coordinated to Ru, tBubpy = 4,4'-di-tert-butyl-2,2'-dipyridyl). A catalytic cycle is proposed for this reaction, supported by computational studies and the characterization of the hydride and the formate intermediates proposed to be involved. Modest catalytic turnovers are demonstrated at relatively low pressures and temperatures. The proposed rate determining step is heterolytic H2 splitting to regenerate the Ru-H complex, which has an estimated hydricity of approx. 27 kcal mol-1. The κ2-NCN ligand in the hydride complex undergoes a variety of dynamic processes as detected by EXSY spectroscopy including a pyridyl "roll-over" carbon-hydrogen - ruthenium hydride exchange, possibly occuring via a Perutz-Sabo-Etienne CAM mechanism.
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Affiliation(s)
- Molly M H Sung
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto. Ont. M5S3H6, Canada.
| | - Demyan E Prokopchuk
- Department of Chemistry, Rutgers University, 73 Warren Street, Newark, NJ 07102, USA
| | - Robert H Morris
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto. Ont. M5S3H6, Canada.
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35
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Buss JA, Bailey GA, Oppenheim J, VanderVelde DG, Goddard WA, Agapie T. CO Coupling Chemistry of a Terminal Mo Carbide: Sequential Addition of Proton, Hydride, and CO Releases Ethenone. J Am Chem Soc 2019; 141:15664-15674. [DOI: 10.1021/jacs.9b07743] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joshua A. Buss
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard MC 127-72, Pasadena, California 91125, United States
| | - Gwendolyn A. Bailey
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard MC 127-72, Pasadena, California 91125, United States
| | - Julius Oppenheim
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard MC 127-72, Pasadena, California 91125, United States
| | - David G. VanderVelde
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard MC 127-72, Pasadena, California 91125, United States
| | - William A. Goddard
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard MC 127-72, Pasadena, California 91125, United States
| | - Theodor Agapie
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard MC 127-72, Pasadena, California 91125, United States
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36
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Schnieders D, Tsui BTH, Sung MMH, Bortolus MR, Schrobilgen GJ, Neugebauer J, Morris RH. Metal Hydride Vibrations: The Trans Effect of the Hydride. Inorg Chem 2019; 58:12467-12479. [DOI: 10.1021/acs.inorgchem.9b02302] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- David Schnieders
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
- Center for Multiscale Theory and Computation, Corrensstraße 40, 48149 Münster, Germany
| | - Brian T. H. Tsui
- Department of Chemistry, University of Toronto, 80 St. George Street Toronto, Ontario M5S 3H6, Canada
| | - Molly M. H. Sung
- Department of Chemistry, University of Toronto, 80 St. George Street Toronto, Ontario M5S 3H6, Canada
| | - Mark R. Bortolus
- Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Gary J. Schrobilgen
- Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Johannes Neugebauer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
- Center for Multiscale Theory and Computation, Corrensstraße 40, 48149 Münster, Germany
| | - Robert H. Morris
- Department of Chemistry, University of Toronto, 80 St. George Street Toronto, Ontario M5S 3H6, Canada
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37
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Bäcker A, Li Y, Fritz M, Grätz M, Ke Z, Langer R. Redox-Active, Boron-Based Ligands in Iron Complexes with Inverted Hydride Reactivity in Dehydrogenation Catalysis. ACS Catal 2019. [DOI: 10.1021/acscatal.9b00882] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Andreas Bäcker
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straße, 35032 Marburg, Germany
| | - Yinwu Li
- School of Materials Science & Engineering, PCFM Lab, Sun Yat-sen University, Guangzhou 510275, China
| | - Maximilian Fritz
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straße, 35032 Marburg, Germany
| | - Maik Grätz
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straße, 35032 Marburg, Germany
| | - Zhuofeng Ke
- School of Materials Science & Engineering, PCFM Lab, Sun Yat-sen University, Guangzhou 510275, China
| | - Robert Langer
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straße, 35032 Marburg, Germany
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38
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Abstract
In the current manuscript, we describe the reactivity of a series of iridium(III) pincer complexes with the general formulae [(PEP)IrCl(CO)(H)]n (n = +1, +2) towards base, where PEP is a pincer-type ligand with different central donor groups, and E is the ligating atom of this group (E = B, C, N). The donor groups encompass a secondary amine, a phosphine-stabilised borylene and a protonated carbodiphosphorane. As all ligating atoms E exhibit an E–H bond, we addressed the question of wether the coordinated donor group can be deprotonated in competition to the reductive elimination of HCl from the iridium(III) centre. Based on experimental and quantum chemical investigations, it is shown that the ability for deprotonation of the coordinated ligand decreases in the order of (R3P)2CH+ > R2NH > (R3P)2BH. The initial product of the reductive elimination of HCl from [(PBP)IrCl(CO)(H)]n (1c), the square planar iridium(I) complex, [(PBP)Ir(CO)]+ (3c), was found to be unstable and further reacts to [(PBP)Ir(CO)2]+ (5c). Comparing the C–O stretching vibrations of the latter with those of related complexes, it is demonstrated that neutral ligands based on tricoordinate boron are very strong donors.
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Barlow J, Yang JY. Thermodynamic Considerations for Optimizing Selective CO 2 Reduction by Molecular Catalysts. ACS CENTRAL SCIENCE 2019; 5:580-588. [PMID: 31041377 PMCID: PMC6487447 DOI: 10.1021/acscentsci.9b00095] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Indexed: 05/17/2023]
Abstract
Energetically efficient electrocatalysts with high product selectivity are desirable targets for sustainable chemical fuel generation using renewable electricity. Recycling CO2 by reduction to more energy dense products would support a carbon-neutral cycle that mitigates the intermittency of renewable energy sources. Conversion of CO2 to more saturated products typically requires proton equivalents. Complications with product selectivity stem from competitive reactions between H+ or CO2 at shared intermediates. We describe generalized catalytic cycles for H2, CO, and HCO2 - formation that are commonly proposed in inorganic molecular catalysts. Thermodynamic considerations and trends for the reactions of H+ or CO2 at key intermediates are outlined. A quantitative understanding of intermediate catalytic steps is key to designing systems that display high selectivity while promoting energetically efficient catalysis by minimizing the overall energy landscape. For CO2 reduction to CO, we describe how an enzymatic active site motif facilitates efficient and selective catalysis and highlight relevant examples from synthetic systems.
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40
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Vondung L, Jerabek P, Langer R. Ligands Based on Phosphine-Stabilized Aluminum(I), Boron(I), and Carbon(0). Chemistry 2019; 25:3068-3076. [PMID: 30565756 DOI: 10.1002/chem.201805123] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/19/2018] [Indexed: 11/05/2022]
Abstract
A systematic quantum chemical study of the bonding in d6 -transition-metal complexes, containing phosphine-stabilized, main-group-element fragments, (R3 P)2 E, as ligands (E=AlH, BH, CH+ , C), is reported. By using energy decomposition analysis, it is demonstrated that a strong M-E bond is accompanied by weak P-E bonds, and vice versa. Although the Al-M bond is, for example, found to be very strong, the weak Al-P bond suggests that the corresponding metal complexes will not be stable towards phosphine dissociation. The interaction energies for the boron(I)-based ligand are lower, but still higher than those for two-carbon-based ligands. For neutral ligands, electrostatic interactions are the dominating contributions to metal-ligand bonding, whereas for the cationic ligand a significant destabilization, with weak orbital and even weaker electrostatic metal-ligand interactions, is observed. Finally, for iron(II) complexes, it is demonstrated that different reactivity patterns are expected for the four donor groups: the experimentally observed reversible E-H reductive elimination of the borylene-based ligand (E=BH) exhibits significantly higher barriers for the protonated carbodiphosphorane (CDP) ligand (E=CH) and would proceed through different intermediates and transition states. For aluminum, such reaction pathways are not feasible (E=AlH). Moreover, it is demonstrated that the metal hydrido complexes with CDP ligands might not be stable towards reduction and isomerization to a protonated CDP ligand and a reduced metal center.
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Affiliation(s)
- Lisa Vondung
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032, Marburg, Germany.,Centre for Theoretical Chemistry and Physics, The New Zealand Institute for Advanced Study and the Institute for Natural and Mathematical Sciences, Massey University, Albany, New Zealand
| | - Paul Jerabek
- Centre for Theoretical Chemistry and Physics, The New Zealand Institute for Advanced Study and the Institute for Natural and Mathematical Sciences, Massey University, Albany, New Zealand.,Molecular Theory and Spectroscopy, Max-Planck-Institut für Kohlenforschung, 45470, Mülheim an der Ruhr, Germany
| | - Robert Langer
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032, Marburg, Germany
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41
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Ligand acidity constants as calculated by density functional theory for PF3 and N-Heterocyclic carbene ligands in hydride complexes of Iron(II). J Organomet Chem 2019. [DOI: 10.1016/j.jorganchem.2018.10.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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42
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Leon NJ, Yu HC, Mazzacano TJ, Mankad NP. Mixed phosphine/carbonyl derivatives of heterobimetallic copper–iron and copper–tungsten catalysts. Polyhedron 2019. [DOI: 10.1016/j.poly.2018.09.062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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43
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Alig L, Fritz M, Schneider S. First-Row Transition Metal (De)Hydrogenation Catalysis Based On Functional Pincer Ligands. Chem Rev 2018; 119:2681-2751. [PMID: 30596420 DOI: 10.1021/acs.chemrev.8b00555] [Citation(s) in RCA: 497] [Impact Index Per Article: 82.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The use of 3d metals in de/hydrogenation catalysis has emerged as a competitive field with respect to "traditional" precious metal catalyzed transformations. The introduction of functional pincer ligands that can store protons and/or electrons as expressed by metal-ligand cooperativity and ligand redox-activity strongly stimulated this development as a conceptual starting point for rational catalyst design. This review aims at providing a comprehensive picture of the utilization of functional pincer ligands in first-row transition metal hydrogenation and dehydrogenation catalysis and related synthetic concepts relying on these such as the hydrogen borrowing methodology. Particular emphasis is put on the implementation and relevance of cooperating and redox-active pincer ligands within the mechanistic scenarios.
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Affiliation(s)
- Lukas Alig
- Universität Göttingen , Institut für Anorganische Chemie , Tammannstrasse 4 , D-37077 Göttingen , Germany
| | - Maximilian Fritz
- Universität Göttingen , Institut für Anorganische Chemie , Tammannstrasse 4 , D-37077 Göttingen , Germany
| | - Sven Schneider
- Universität Göttingen , Institut für Anorganische Chemie , Tammannstrasse 4 , D-37077 Göttingen , Germany
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44
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Morris RH. Estimating the Wavenumber of Terminal Metal-Hydride Stretching Vibrations of Octahedral d6 Transition Metal Complexes. Inorg Chem 2018; 57:13809-13821. [DOI: 10.1021/acs.inorgchem.8b02314] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Robert H. Morris
- Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario M5S3H6, Canada
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45
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Zhang J, Foley BJ, Bhuvanesh N, Zhou J, Janzen DE, Whited MT, Ozerov OV. Synthesis and Reactivity of Pincer-Type Cobalt Silyl and Silylene Complexes. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00594] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Jia Zhang
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
- Department of Chemistry, Carleton College, Northfield, Minnesota 55057, United States
| | - Bryan J. Foley
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Nattamai Bhuvanesh
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Jia Zhou
- School of Science, Harbin Institute of Technology, Shenzhen 518055, China
| | - Daron E. Janzen
- Department of Chemistry and Biochemistry, St. Catherine University, St. Paul, Minnesota 55105, United States
| | - Matthew T. Whited
- Department of Chemistry, Carleton College, Northfield, Minnesota 55057, United States
| | - Oleg V. Ozerov
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
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46
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Yu X, Pang M, Zhang S, Hu X, Tung CH, Wang W. Terminal Thiolate-Dominated H/D Exchanges and H2 Release: Diiron Thiol–Hydride. J Am Chem Soc 2018; 140:11454-11463. [DOI: 10.1021/jacs.8b06996] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Xin Yu
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, No. 27 South Shanda Road, Jinan, 250100, P. R. China
| | - Maofu Pang
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, No. 27 South Shanda Road, Jinan, 250100, P. R. China
| | - Shengnan Zhang
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, No. 27 South Shanda Road, Jinan, 250100, P. R. China
| | - Xinlong Hu
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, No. 27 South Shanda Road, Jinan, 250100, P. R. China
| | - Chen-Ho Tung
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, No. 27 South Shanda Road, Jinan, 250100, P. R. China
| | - Wenguang Wang
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, No. 27 South Shanda Road, Jinan, 250100, P. R. China
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47
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Omar BS, Mallah J, Ataya M, Li B, Zhou X, Malakar S, Goldman AS, Hasanayn F. H2 Addition to Pincer Iridium Complexes Yielding trans-Dihydride Products: Unexpected Correlations of Bond Strength with Bond Length and Vibrational Frequencies. Inorg Chem 2018; 57:7516-7523. [DOI: 10.1021/acs.inorgchem.7b03086] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Boushra S. Omar
- Department of Chemistry, American University of Beirut, Beirut 1107 2020, Lebanon
| | - Josephina Mallah
- Department of Chemistry, American University of Beirut, Beirut 1107 2020, Lebanon
| | - Mohamad Ataya
- Department of Chemistry, American University of Beirut, Beirut 1107 2020, Lebanon
| | - Bo Li
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08903, United States
| | - Xiaoguang Zhou
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08903, United States
| | - Santanu Malakar
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08903, 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
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48
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Zell T, Langer R. From Ruthenium to Iron and Manganese-A Mechanistic View on Challenges and Design Principles of Base-Metal Hydrogenation Catalysts. ChemCatChem 2018. [DOI: 10.1002/cctc.201701722] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Thomas Zell
- ADAMA Makhteshim Ltd.; PO Box 60, Industrial Zone Beer Sheva 8410001 Israel
| | - Robert Langer
- Department of Chemistry; Philipps-Universität Marburg; Hans-Meerwein-Str. 4 35032 Marburg Germany
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49
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Wan KY, Roelfes F, Lough AJ, Hahn FE, Morris RH. Iridium and Rhodium Complexes Containing Enantiopure Primary Amine-Tethered N-Heterocyclic Carbenes: Synthesis, Characterization, Reactivity, and Catalytic Asymmetric Hydrogenation of Ketones. Organometallics 2018. [DOI: 10.1021/acs.organomet.7b00915] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kai Y. Wan
- Department
of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada
| | - Florian Roelfes
- Institut
für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Alan J. Lough
- Department
of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada
| | - F. Ekkehardt Hahn
- Institut
für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Robert H. Morris
- Department
of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada
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50
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Unsleber JP, Neugebauer J, Morris RH. DFT methods applied to answer the question: how accurate is the ligand acidity constant method for estimating the pKa of transition metal hydride complexes MHXL4 when X is varied? Dalton Trans 2018; 47:2739-2747. [DOI: 10.1039/c7dt03473c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Additive ligand acidity constants AL of anionic ligands are calculated for neutral hydrides of iron(ii), ruthenium(ii) and osmium(ii) with phosphine and carbonyl co-ligands; constant AL in green, more variable AL in red.
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Affiliation(s)
- Jan P. Unsleber
- Theoretische Organische Chemie
- Organisch-Chemisches Institut and Center for Multiscale Theory and Computation
- Westfälische Wilhelms-Universität Münster
- 48149 Münster
- Germany
| | - Johannes Neugebauer
- Theoretische Organische Chemie
- Organisch-Chemisches Institut and Center for Multiscale Theory and Computation
- Westfälische Wilhelms-Universität Münster
- 48149 Münster
- Germany
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