1
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Newman PD, Platts JA, Alrashidi B, Pope SJA, Kariuki BM. A noble nexus: a phosphino-phen ligand for tethering precious metals. Dalton Trans 2024; 53:15539-15550. [PMID: 39229681 DOI: 10.1039/d4dt02130d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Controlled formation of mixed-metal bimetallics was achieved via two derivatised 1,10-phenanthroline ligands bearing an imino- or amino-phosphine appendage at the 5-position. Selective coordination of the phen group to the [Re(CO)3Cl] core was achieved enabling precise construction of bimetallic complexes with a second rhenium centre or with gold. The mixed Ru/Au complex was similarly obtained with the imino-phosphine but access to the heterobimetallic iridium systems required prior formation of the P-bound gold complexes subsequent to the introduction of the [Ir(Ppy)2]+ fragment. The Re/Pd, Re/Pt, Ir/Pd and Ir/Pt compounds were prepared from the combination of κ-N'',P-Pd(Pt)Cl2 and the appropriate rhenium or iridium precursors. Spectroscopic and theoretical analyses have been employed to investigate the structural and electronic impact of the second metal.
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Affiliation(s)
- Paul D Newman
- School of Chemistry, Cardiff University, Cardiff, Wales, UK, CF10 3AT.
| | - James A Platts
- School of Chemistry, Cardiff University, Cardiff, Wales, UK, CF10 3AT.
| | - Basheer Alrashidi
- School of Chemistry, Cardiff University, Cardiff, Wales, UK, CF10 3AT.
| | - Simon J A Pope
- School of Chemistry, Cardiff University, Cardiff, Wales, UK, CF10 3AT.
| | - Benson M Kariuki
- School of Chemistry, Cardiff University, Cardiff, Wales, UK, CF10 3AT.
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2
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Chen Y, Zhou MJ, Hu Y, Xie Y. Direct hydrogenation of natural oils to fatty alcohols enabled by an alcoholysis/hydrogenation relay strategy and two-phase solvent system. Org Biomol Chem 2024; 22:6703-6707. [PMID: 39115549 DOI: 10.1039/d4ob00822g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
Direct hydrogenation of natural oils to fatty alcohols was achieved via a relay strategy involving alcoholysis of natural oils followed by hydrogenation of fatty acid esters. A two-phase system was used to avoid catalyst poisoning by glycerol. This protocol is suitable for plant oils, animal fats and waste cooking oil.
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Affiliation(s)
- Ying Chen
- School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211, P. R. China
- Materials Tech Laboratory for Hydrogen & Energy Storage, Ningbo Institute of Materials Technology and Engineering of the Chinese Academy of Sciences (CAS), Ningbo, 315201, P. R. China.
| | - Min-Jie Zhou
- Materials Tech Laboratory for Hydrogen & Energy Storage, Ningbo Institute of Materials Technology and Engineering of the Chinese Academy of Sciences (CAS), Ningbo, 315201, P. R. China.
| | - Yue Hu
- Materials Tech Laboratory for Hydrogen & Energy Storage, Ningbo Institute of Materials Technology and Engineering of the Chinese Academy of Sciences (CAS), Ningbo, 315201, P. R. China.
| | - Yinjun Xie
- Materials Tech Laboratory for Hydrogen & Energy Storage, Ningbo Institute of Materials Technology and Engineering of the Chinese Academy of Sciences (CAS), Ningbo, 315201, P. R. China.
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3
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Keil P, Ezendu S, Schulz A, Kubisz M, Szilvási T, Hadlington TJ. Thermodynamic Modulation of Dihydrogen Activation Through Rational Ligand Design in Ge II-Ni 0 Complexes. J Am Chem Soc 2024; 146:23606-23615. [PMID: 39106297 PMCID: PMC11345810 DOI: 10.1021/jacs.4c08297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 07/19/2024] [Accepted: 07/22/2024] [Indexed: 08/09/2024]
Abstract
A family of chelating aryl-functionalized germylene ligands has been developed and employed in the synthesis of their corresponding 16-electron Ni0 complexes (PhiPDippGeAr·Ni·IPr; PhiPDipp = {[Ph2PCH2Si(iPr)2](Dipp)N}-; IPr = [{(H)CN(Dipp)}2C:]; Dipp = 2,6-iPr2C6H3). These complexes demonstrate the ability to cooperatively and reversibly activate dihydrogen at the germylene-nickel interface under mild conditions (1.5 atm H2, 298 K). We show that the thermodynamics of the dihydrogen activation process can be modulated by tuning the electronic nature of the germylene ligands, with an increase in the electron-withdrawing character displaying more exergonic ΔG298 values, as ascertained through NMR spectroscopic Van't Hoff analyses for all systems. This is also shown to correlate with experimental 31P NMR and UV/vis absorption data as well as with computationally derived parameters such as Ge-Ni bond order and Ni/Ge NPA charge, giving a thorough understanding of the modulating effect of ligand design on this reversible, cooperative bond activation reaction. Finally, the utility of this modulation was demonstrated in the catalytic dehydrocoupling of phenylsilane, whereby systems that disfavor dihydrogen activation are more efficient catalysts, aligning with H2-elimination being the rate-limiting step. A density functional theory analysis supports cooperative activation of the Si-H moiety in PhSiH3.
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Affiliation(s)
- Philip
M. Keil
- Fakultät
für Chemie, Technische Universität
München, Lichtenbergstraße 4, 85748 Garching bei München, Germany
| | - Sophia Ezendu
- Department
of Chemical and Biological Engineering, University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Annika Schulz
- Fakultät
für Chemie, Technische Universität
München, Lichtenbergstraße 4, 85748 Garching bei München, Germany
| | - Malte Kubisz
- Fakultät
für Chemie, Technische Universität
München, Lichtenbergstraße 4, 85748 Garching bei München, Germany
| | - Tibor Szilvási
- Department
of Chemical and Biological Engineering, University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Terrance J. Hadlington
- Fakultät
für Chemie, Technische Universität
München, Lichtenbergstraße 4, 85748 Garching bei München, Germany
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4
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Mahawar P, Rajeshkumar T, Spaniol TP, Maron L, Okuda J. Hydrogenolysis of Cationic Half-Sandwich Zinc Complexes Containing a Chelating Amine: Facile Cleavage of Zinc-Carbon Bond by Dihydrogen to Give Zinc Hydride Cations. Chemistry 2024; 30:e202401262. [PMID: 38777793 DOI: 10.1002/chem.202401262] [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: 03/29/2024] [Revised: 05/22/2024] [Accepted: 05/22/2024] [Indexed: 05/25/2024]
Abstract
Cationic half-sandwich zinc complexes containing chelating amines [Cp*Zn(Ln)][BAr4 F] (2 a, Cp*=η3-C5Me5, Ln=N,N,N',N'-tetramethylethylenediamine, TMEDA; 2 b, Ln=N,N,N',N'-tetraethylethylenediamine, TEEDA; 2 c, Cp*=η1-C5Me5, Ln=N,N,N',N'',N''-pentamethyldiethylenetriamine, PMDTA; Ar4 F=(3,5-(CF3)2C6H3)4) reacted with dihydrogen (ca. 2 bar) in THF at 80 °C to give molecular zinc hydride cations [(Ln)ZnH(thf)m][BAr4 F] (3 a,b, m=1; 3 c, m=0) previously reported along with Cp*H. Pseudo first-order kinetics with respect to the concentration of 2 b suggests heterolytic cleavage of dihydrogen by the Zn-Cp* bond, reminiscent of σ-bond metathesis. Hydrogenolysis of the zinc cation 2 b in the presence of benzophenone gave the zinc alkoxide [(TEEDA)Zn(OCHPh2)(thf)][BAr4 F] (5 b). Cation 2 b was shown to catalytically hydrogenate N-benzylideneaniline. The PMDTA complex 2 c underwent C-H bond activation in acetonitrile to give a dinuclear μ-κC,κN-cyanomethyl zinc complex [(PMDTA)Zn(CH2CN)]2[BAr4 F]2 (6 c).
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Affiliation(s)
- Pritam Mahawar
- Institute of Inorganic Chemistry, RWTH Aachen University, Aachen, 52062, Germany
| | - Thayalan Rajeshkumar
- CNRS, INSA, UPS, UMR 5215, LPCNO, Université de Toulouse, 135 Avenue de Rangueil, Toulouse, 31077, France
| | - Thomas P Spaniol
- Institute of Inorganic Chemistry, RWTH Aachen University, Aachen, 52062, Germany
| | - Laurent Maron
- CNRS, INSA, UPS, UMR 5215, LPCNO, Université de Toulouse, 135 Avenue de Rangueil, Toulouse, 31077, France
| | - Jun Okuda
- Institute of Inorganic Chemistry, RWTH Aachen University, Aachen, 52062, Germany
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5
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Escomel L, Martins FF, Vendier L, Coffinet A, Queyriaux N, Krewald V, Simonneau A. Coordination of Al(C 6F 5) 3 vs. B(C 6F 5) 3 on group 6 end-on dinitrogen complexes: chemical and structural divergences. Chem Sci 2024; 15:11321-11336. [PMID: 39055009 PMCID: PMC11268509 DOI: 10.1039/d4sc02713b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 06/14/2024] [Indexed: 07/27/2024] Open
Abstract
The coordination of the Lewis superacid tris(pentafluorophenyl)alane (AlCF) to phosphine-supported, group 6 bis(dinitrogen) complexes [ML2(N2)2] is explored, with M = Cr, Mo or W and L = dppe (1,2-bis(diphenylphosphino)ethane), depe (1,2-bis(diethylphosphino)ethane), dmpe (1,2-bis(dimethylphosphino)ethane) or 2 × PMe2Ph. Akin to tris(pentafluorophenyl)borane (BCF), AlCF can form 1 : 1 adducts by coordination to one distal nitrogen of general formula trans-[ML2(N2){(μ-η1:η1-N2)Al(C6F5)3}]. The boron and aluminium adducts are structurally similar, showing a comparable level of N2 push-pull activation. A notable exception is a bent (BCF adducts) vs. linear (AlCF adducts) M-N-N-LA motif (LA = Lewis acid), explained computationally as the result of steric repulsion. A striking difference arose when the formation of two-fold adducts was conducted. While in the case of BCF the 2 : 1 Lewis pairs could be observed in equilibrium with the 1 : 1 adduct and free borane but resisted isolation, AlCF forms robust 2 : 1 adducts trans-[ML2{(μ-η1:η1-N2)Al(C6F5)3}2] that isomerise into a more stable cis configuration. These compounds could be isolated and structurally characterized, and represent the first examples of trinuclear heterometallic complexes formed by Lewis acid-base interaction exhibiting p and d elements. Calculations also demonstrate that from the bare complex to the two-fold aluminium adduct, substantial decrease of the HOMO-LUMO gap is observed, and, unlike the trans adducts (1 : 1 and 1 : 2) for which the HOMO was computed to be a pure d orbital, the one of the cis-trinuclear compounds mixes a d orbital with a π* one of each N2 ligands. This may translate into a more favourable electrophilic attack on the N2 ligands instead of the metal centre, while a stabilized N2-centered LUMO should ease electron transfer, suggesting Lewis acids could be co-activators for electro-catalysed N2 reduction. Experimental UV-vis spectra for the tungsten family of compounds were compared with TD-DFT calculations (CAM-B3LYP/def2-TZVP), allowing to assign the low extinction bands found in the visible spectrum to unusual low-lying MLCT involving N2-centered orbitals. As significant red-shifts are observed upon LA coordination, this could have important implications for the development of visible light-driven nitrogen fixation.
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Affiliation(s)
- Léon Escomel
- LCC-CNRS, Université de Toulouse, CNRS UPS 205 Route de Narbonne, BP44099 F-31077 Toulouse Cedex 4 France
| | - Frederico F Martins
- Department of Chemistry, Quantum Chemistry, TU Darmstadt Peter-Grünberg-Str. 4, 6 4287 Darmstadt Germany
| | - Laure Vendier
- LCC-CNRS, Université de Toulouse, CNRS UPS 205 Route de Narbonne, BP44099 F-31077 Toulouse Cedex 4 France
| | - Anaïs Coffinet
- LCC-CNRS, Université de Toulouse, CNRS UPS 205 Route de Narbonne, BP44099 F-31077 Toulouse Cedex 4 France
| | - Nicolas Queyriaux
- LCC-CNRS, Université de Toulouse, CNRS UPS 205 Route de Narbonne, BP44099 F-31077 Toulouse Cedex 4 France
| | - Vera Krewald
- Department of Chemistry, Quantum Chemistry, TU Darmstadt Peter-Grünberg-Str. 4, 6 4287 Darmstadt Germany
| | - Antoine Simonneau
- LCC-CNRS, Université de Toulouse, CNRS UPS 205 Route de Narbonne, BP44099 F-31077 Toulouse Cedex 4 France
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6
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Kumar S, Singh D, Rit A. Cooperativity between metal centers in homobimetallic Pd II-NHC complexes: catalytic potential towards hydrodefluorination. Chem Commun (Camb) 2024; 60:7761-7764. [PMID: 38973622 DOI: 10.1039/d4cc02185a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
Among the several unsymmetrical bis-NHC derived distinct homo-bimetallic and mono-NHC supported PdII complexes studied here (1-5), the bimetallic complex 1 was noted to be the most effective catalyst for the challenging hydrodefluorination. The electron richness of the metal centers and the synergistic cooperation between the PdII centers (cooperativity index, ɑ = 8.67) have been recognized to be the deciding factor for its better activity.
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Affiliation(s)
- Shashi Kumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
| | - Dushyant Singh
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
| | - Arnab Rit
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
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7
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Becker S. Understanding Cooperativity in Homo- and Heterometallic Complexes: From Basic Concepts to Design. Chempluschem 2024; 89:e202300619. [PMID: 38317458 DOI: 10.1002/cplu.202300619] [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: 10/28/2023] [Revised: 12/12/2023] [Accepted: 02/05/2024] [Indexed: 02/07/2024]
Abstract
Cooperative effects have attracted considerable attention in recent years. These effects are ubiquitous in chemistry and biology and can govern interactions of proteins with other biomolecules, mechanisms of supramolecular recognition and polymerization, catalysis, assembly of compounds on surfaces, and physical properties such as magnetic, electronic or optical properties, e. g. Consequently, the understanding of cooperative effects can lead to a structure-property relation that can pave the way to future applications in various research areas; however, with regard to cooperative effects in homo- and heterometallic complexes, we still are at the beginning of understanding. Nevertheless, concepts to describe cooperativity of metal centers as well as methodologies to investigate and model these effects have emerged over the last years. This concept article gives an overview of these existing concepts, approaches, and strategies to understand cooperative effects in homo- and heterometallic complexes. Special emphasis is put on concepts to define cooperative effects, their quantification, as well as methods to investigate cooperative effects.
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Affiliation(s)
- Sabine Becker
- Fachbereich Chemie, RPTU Kaiserslautern-Landau, Erwin-Schroedinger-Str. 54, 67663, Kaiserslautern, Germany
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8
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Mahawar P, Rajeshkumar T, Spaniol TP, Maron L, Okuda J. Dihydrogen Cleavage by a Zinc-Zinc Bond of a Heteroleptic Dizinc(I) Cation. Inorg Chem 2024; 63:8493-8501. [PMID: 38651332 DOI: 10.1021/acs.inorgchem.4c01116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Oxidative addition of dihydrogen across a metal-metal bond to form reactive metal hydrides in homogeneous catalysis is known for transition metals but not for zinc(I)-zinc(I) bond as found in Carmona's eponymous dizinconene [Zn2Cp*2] (Cp* = η5-C5Me5). Dihydrogen reacted with the heteroleptic zinc(I)-zinc(I) bonded cation [(L2)Zn-ZnCp*][BAr4F] (L2 = TMEDA, N,N,N',N'-tetramethylethylenediamine, TEEDA, N,N,N',N'-tetraethylethylenediamine; ArF = 3,5-(CF3)2C6H3) under 2 bar at 80 °C to give the zinc(II) hydride cation [(L2)ZnH(thf)][BAr4F] along with zinc metal and Cp*H derived from the intermediate [Cp*ZnH]. DFT calculations show that the cleavage of dihydrogen occurs through a highly unsymmetrical transition state. Mechanistic studies agree with a heterolytic cleavage of dihydrogen as a result of the cationic charge and unsymmetrical ligand coordination. To explore the existence of zinc(I) hydride, thermally unstable hydridotriphenylborate complexes of zinc(I) [(L2)Zn(HBPh3)-ZnCp*] (L2 = TMEDA, TEEDA; TMPDA, N,N,N',N'-tetramethyl-1,3-propylenediamine) have been prepared by salt metathesis and were shown to undergo fast exchange with both BPh3 and [HBPh3]-.
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Affiliation(s)
- Pritam Mahawar
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany
| | - Thayalan Rajeshkumar
- CNRS, INSA, UPS, UMR 5215, LPCNO, Université de Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Thomas P Spaniol
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany
| | - Laurent Maron
- CNRS, INSA, UPS, UMR 5215, LPCNO, Université de Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Jun Okuda
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany
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9
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Li J, Yin H, Liu S, Xu C, Cai Z. Significantly enhanced catalytic performance of Pd nanocatalyst on AlOOH featuring abundant solid surface frustrated Lewis pair for improved hydrogen activation. RSC Adv 2024; 14:12593-12599. [PMID: 38638811 PMCID: PMC11024899 DOI: 10.1039/d4ra01852d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Accepted: 04/11/2024] [Indexed: 04/20/2024] Open
Abstract
The catalytic performance of a catalyst is significantly influenced by its ability to activate hydrogen. Constructing frustrated Lewis pairs (FLPs) with the capacity for hydrogen dissociation on non-reducible supports remains a formidable challenge. Herein, we employed a straightforward method to synthesize a layered AlOOH featuring abundant OH defects suitable for constructing solid surface frustrated Lewis pair (ssFLP). The results indicated that the AlOOH-80 (synthesized at 80 °C) possessed an appropriate crystalline structure conducive to generating numerous OH defects, which facilitated the formation of ssFLP. This was further evidenced by the minimal water adsorption in the AlOOH-80, inversely correlated with the quantity of defects in the catalyst. As expected, the Pd loaded onto AlOOH (Pd/AlOOH-80) exhibited excellent catalytic activity in hydrogenation reactions, attributed to abundant defects available for constructing ssFLP. Remarkably, the Pd/AlOOH-80 catalyst, with larger-sized Pd nanoparticles, displayed notably superior activity compared to commercial Pd/Al2O3 and Pd/C, both featuring smaller-sized Pd nanoparticles. Evidently, under the influence of ssFLP, the size effect of Pd nanoparticles did not dominate, highlighting the pivotal role of ssFLP in enhancing catalytic performance. This catalyst also exhibited exceptionally high stability, indicating its potential for industrial applications.
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Affiliation(s)
- Junwei Li
- College of Chemistry, Chemical Engineering and Environment, Minnan NormalUniversity Zhangzhou 363000 China
| | - Hongshuai Yin
- College of Chemistry, Chemical Engineering and Environment, Minnan NormalUniversity Zhangzhou 363000 China
| | - Sisi Liu
- College of Chemistry, Chemical Engineering and Environment, Minnan NormalUniversity Zhangzhou 363000 China
| | - Chaofa Xu
- College of Chemistry, Chemical Engineering and Environment, Minnan NormalUniversity Zhangzhou 363000 China
- Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University Zhangzhou 363000 China
| | - Zhixiong Cai
- College of Chemistry, Chemical Engineering and Environment, Minnan NormalUniversity Zhangzhou 363000 China
- Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University Zhangzhou 363000 China
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10
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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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11
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Platts JA, Kariuki BM, Newman PD. Welcoming Neighbour or Inhospitable Host? Selective Second Metal Binding in 5- and 6-Phospha-Substituted Bpy Ligands. Molecules 2024; 29:1150. [PMID: 38474663 DOI: 10.3390/molecules29051150] [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: 01/26/2024] [Revised: 02/29/2024] [Accepted: 03/01/2024] [Indexed: 03/14/2024] Open
Abstract
The controlled formation of mixed-metal bimetallics was realised through use of a fac-[Re(CO)3(N,N'-bpy-P)Cl] complex bearing an exogenous 2,4,6-trioxa-1,3,5,7-tetramethyl-8-phosphaadamantane donor at the 5-position of the bpy. The introduction of gold, silver, and rhodium with appropriate secondary ligands was readily achieved from established starting materials. Restricted rotation about the C(bpy)-P bond was observed in several of the bimetallic complexes and correlated with the relative steric bulk of the second metal moiety. Related chemistry with the 6-substituted derivative proved more limited in scope with only the bimetallic Re/Au complex being isolated.
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Affiliation(s)
- James A Platts
- School of Chemistry, Cardiff University, Cardiff CF10 3AT, UK
| | | | - Paul D Newman
- School of Chemistry, Cardiff University, Cardiff CF10 3AT, UK
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12
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Jalwal S, Regina A, Atreya V, Paranjothy M, Chakraborty S. NNN manganese complex-catalyzed α-alkylation of methyl ketones using alcohols: an experimental and computational study. Dalton Trans 2024. [PMID: 38251673 DOI: 10.1039/d3dt04321e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
We present here a phosphine-free, quinoline-based pincer Mn catalyst for α-alkylation of methyl ketones using primary alcohols as alkyl surrogates. The C-C bond formation reaction proceeds via a hydrogen auto-transfer methodology. The sole by-product formed is water, rendering the protocol atom efficient. Electronic structure theory studies corroborated the proposed mechanism.
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Affiliation(s)
- Sachin Jalwal
- Department of Chemistry, Indian Institute of Technology Jodhpur, Karwar, Jodhpur, 342030, Rajasthan, India.
| | - Anitta Regina
- Department of Chemistry, Indian Institute of Technology Jodhpur, Karwar, Jodhpur, 342030, Rajasthan, India.
| | - Vaishnavi Atreya
- Department of Chemistry, Indian Institute of Technology Jodhpur, Karwar, Jodhpur, 342030, Rajasthan, India.
| | - Manikandan Paranjothy
- Department of Chemistry, Indian Institute of Technology Jodhpur, Karwar, Jodhpur, 342030, Rajasthan, India.
| | - Subrata Chakraborty
- Department of Chemistry, Indian Institute of Technology Jodhpur, Karwar, Jodhpur, 342030, Rajasthan, India.
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13
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Stevens MA, Lim LF, Pham LN, Cox N, Coote ML, Colebatch AL. A one-pot reduction route to bimetallic manganese 1,8-naphthyridine complexes. Dalton Trans 2024; 53:1284-1294. [PMID: 38112500 DOI: 10.1039/d3dt03709f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Reaction of the dinucleating ligand 2,7-bis(6-methyl-2-pyridyl)-1,8-naphthyridine (MeL) with the MnI and MnII precursors MnBr(CO)5 and MnCl2 resulted in the formation of the monometallic complexes [MnBr(CO)3(MeL)] (1) and [MnCl2(MeL)] (3). In both cases, formation of bimetallic manganese complexes could be achieved by reduction with KC8, yielding the carbonyl-bridged complex [Mn2(CO)6(MeL)] (2) and the helicate complex [Mn2(MeL)2] (4), respectively. EPR results demonstrate that 4 represents a novel, weakly antiferromagnetically coupled homovalent dimer (J = -0.85 cm-1). The two formally Mn0 ions are both high spin (S = 3/2) and exhibit a zero-field splitting of ≈1 cm-1, suggesting reduction of the complex is substantially ligand centered, and may be better described as a MnII complex coupled to two open shell singlet ligands [MnII2(MeL2-)2]. X-ray crystallography, UV-Vis spectroscopy and DFT analysis support this finding.
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Affiliation(s)
- Michael A Stevens
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia.
| | - Li Feng Lim
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia.
| | - Le Nhan Pham
- Institute for Nanoscale Science & Technology, Flinders University, Adelaide, South Australia, 5042, Australia.
| | - Nicholas Cox
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia.
| | - Michelle L Coote
- Institute for Nanoscale Science & Technology, Flinders University, Adelaide, South Australia, 5042, Australia.
| | - Annie L Colebatch
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia.
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14
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Multem AJH, Delaney AR, Kroeger AA, Coote ML, Colebatch AL. Utilising a Proton-Responsive 1,8-Naphthyridine Ligand for the Synthesis of Bimetallic Palladium and Platinum Complexes. Chem Asian J 2023:e202301071. [PMID: 38161148 DOI: 10.1002/asia.202301071] [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: 11/29/2023] [Revised: 12/20/2023] [Accepted: 12/25/2023] [Indexed: 01/03/2024]
Abstract
We present four proton-responsive palladium and platinum complexes, [MCl2 (R PONNHO)] (M=Pd, Pt; R=i Pr, t Bu) synthesised by complexation of PdCl2 or PtCl2 (COD) with the 1,8-naphthyridine ligand R PONNHO. Deprotonation of [MCl2 (tBu PONNHO)] switches ligand coordination from mono- to dinucleating, offering a synthetic pathway to bimetallic PdII and PtII complexes [M2 Cl2 (tBu PONNO)2 ]. Two-electron reduction gives planar MI -MI complexes [M2 (tBu PONNO)2 ] (M=Pd, Pt) containing a metal-metal bond. In contrast to the related nickel system that forms a metallophosphorane [Ni2 (tBu PONNOPONNO)], an unusual phosphinite binding mode is observed in [M2 (tBu PONNO)2 ] containing close phosphinite-naphthyridinone P⋅⋅⋅O interactions, which is investigated spectroscopically, crystallographically and computationally. The presented proton-responsive and structurally-responsive R PONNHO and bimetallic R PONNO complexes offer a novel platform for future explorations of metal-ligand and metal-metal cooperativity with palladium and platinum.
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Affiliation(s)
- Arie J H Multem
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Andie R Delaney
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Asja A Kroeger
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
- Institute for Nanoscale Science & Technology, Flinders University, Adelaide, South Australia, 5042, Australia
| | - Michelle L Coote
- Institute for Nanoscale Science & Technology, Flinders University, Adelaide, South Australia, 5042, Australia
| | - Annie L Colebatch
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
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15
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Singh T, Atreya V, Jalwal S, Anand A, Chakraborty S. Advances in Group VI Metal-Catalyzed Homogeneous Hydrogenation and Dehydrogenation Reactions. Chem Asian J 2023; 18:e202300758. [PMID: 37815164 DOI: 10.1002/asia.202300758] [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: 08/29/2023] [Revised: 10/10/2023] [Accepted: 10/10/2023] [Indexed: 10/11/2023]
Abstract
Transition metal-catalyzed homogeneous hydrogenation and dehydrogenation reactions for attaining plethora of organic scaffolds have evolved as a key domain of research in academia and industry. These protocols are atom-economic, greener, in line with the goal of sustainability, eventually pave the way for numerous novel environmentally benign methodologies. Appealing progress has been achieved in the realm of homogeneous catalysis utilizing noble metals. Owing to their high cost, less abundance along with toxicity issues led the scientific community to search for sustainable alternatives. In this context, earth- abundant base metals have gained substantial attention culminating enormous progress in recent years, predominantly with pincer-type complexes of nickel, cobalt, iron, and manganese. In this regard, group VI chromium, molybdenum and tungsten complexes have been overlooked and remain underdeveloped despite their earth-abundance and bio-compatibility. This review delineates a comprehensive overview in the arena of homogeneously catalysed (de)hydrogenation reactions using group VI base metals chromium, molybdenum, and tungsten till date. Various reactions have been described; hydrogenation, transfer hydrogenation, dehydrogenation, acceptorless dehydrogenative coupling, hydrogen auto transfer, along with their scope and brief mechanistic insights.
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Affiliation(s)
- Tushar Singh
- Department of Chemistry, Indian Institute of Technology Jodhpur, Karwar, Jodhpur, 342037, Rajasthan
| | - Vaishnavi Atreya
- Department of Chemistry, Indian Institute of Technology Jodhpur, Karwar, Jodhpur, 342037, Rajasthan
| | - Sachin Jalwal
- Department of Chemistry, Indian Institute of Technology Jodhpur, Karwar, Jodhpur, 342037, Rajasthan
| | - Aman Anand
- Department of Chemistry, Indian Institute of Technology Jodhpur, Karwar, Jodhpur, 342037, Rajasthan
| | - Subrata Chakraborty
- Department of Chemistry, Indian Institute of Technology Jodhpur, Karwar, Jodhpur, 342037, Rajasthan
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16
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Nath S, Yadav E, Raghuvanshi A, Singh AK. Ru(II) Complexes with Protic- and Anionic-Naked-NHC Ligands for Cooperative Activation of Small Molecules. Chemistry 2023; 29:e202301971. [PMID: 37377294 DOI: 10.1002/chem.202301971] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 06/29/2023]
Abstract
A set of ruthenium(II)-protic-N-heterocyclic carbene complexes, [Ru(NNCH )(PPh3 )2 (X)]Cl (1, X=Cl and 2, X=H) and their deprotonated forms [Ru(NNC)(PPh3 )2 (X)] (1', X=Cl and 2', X=H), in which NNC is a new unsymmetrical pincer ligand, are reported. The four complexes are interconvertible by simple acid-base chemistry. The combined theoretical and spectroscopic investigations indicate charge segregation in anionic-NHC complexes (1' and 2') and can be described from a Lewis pair perspective. The chemical reactivity of deprotonated complex 1' shows cooperative small molecule activation. Complex 1' activates H-H bond of hydrogen, C(sp3 )-I bond of iodomethane, and C(sp)-H bond of phenylacetylene. The activation of CO2 using anionic NHC complex 1' at moderate temperature and ambient pressure and subsequent conversion to formate is also described. All the new compounds have been characterized using ESI-MS, 1 H, 13 C, and 31 P NMR spectroscopy. Molecular structures of 1, 2, and 2' have also been determined with single-crystal X-ray diffraction. The cooperative small molecule activation perspective broadens the scope of potential applications of anionic-NHC complexes in small molecule activation, including the conversion of carbon dioxide to formate, a much sought after reaction in the renewable energy and sustainable development domains.
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Affiliation(s)
- Shambhu Nath
- Department of Chemistry, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Ekta Yadav
- Department of Chemistry, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Abhinav Raghuvanshi
- Department of Chemistry, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Amrendra K Singh
- Department of Chemistry, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
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17
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Wei D, Shi X, Junge H, Du C, Beller M. Carbon neutral hydrogen storage and release cycles based on dual-functional roles of formamides. Nat Commun 2023; 14:3726. [PMID: 37349304 DOI: 10.1038/s41467-023-39309-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 06/07/2023] [Indexed: 06/24/2023] Open
Abstract
The development of alternative clean energy carriers is a key challenge for our society. Carbon-based hydrogen storage materials are well-suited to undergo reversible (de)hydrogenation reactions and the development of catalysts for the individual process steps is crucial. In the current state, noble metal-based catalysts still dominate this field. Here, a system for partially reversible and carbon-neutral hydrogen storage and release is reported. It is based on the dual-functional roles of formamides and uses a small molecule Fe-pincer complex as the catalyst, showing good stability and reusability with high productivity. Starting from formamides, quantitative production of CO-free hydrogen is achieved at high selectivity ( > 99.9%). This system works at modest temperatures of 90 °C, which can be easily supplied by the waste heat from e.g., proton-exchange membrane fuel cells. Employing such system, we achieve >70% H2 evolution efficiency and >99% H2 selectivity in 10 charge-discharge cycles, avoiding undesired carbon emission between cycles.
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Affiliation(s)
- Duo Wei
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China
- Leibniz-Institut für Katalyse e.V, 18059, Rostock, Germany
| | - Xinzhe Shi
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China
- Leibniz-Institut für Katalyse e.V, 18059, Rostock, Germany
| | - Henrik Junge
- Leibniz-Institut für Katalyse e.V, 18059, Rostock, Germany.
| | - Chunyu Du
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China.
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18
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Fickenscher Z, Hey-Hawkins E. Added Complexity!-Mechanistic Aspects of Heterobimetallic Complexes for Application in Homogeneous Catalysis. Molecules 2023; 28:4233. [PMID: 37241974 PMCID: PMC10224482 DOI: 10.3390/molecules28104233] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 05/16/2023] [Accepted: 05/17/2023] [Indexed: 05/28/2023] Open
Abstract
Inspired by multimetallic assemblies and their role in enzyme catalysis, chemists have developed a plethora of heterobimetallic complexes for application in homogeneous catalysis. Starting with small heterobimetallic complexes with σ-donating and π-accepting ligands, such as N-heterocyclic carbene and carbonyl ligands, more and more complex systems have been developed over the past two decades. These systems can show a significant increase in catalytic activity compared with their monometallic counterparts. This increase can be attributed to new reaction pathways enabled by the presence of a second metal center in the active catalyst. This review focuses on mechanistic aspects of heterobimetallic complexes in homogeneous catalysis. Depending on the type of interaction of the second metal with the substrates, heterobimetallic complexes can be subdivided into four classes. Each of these classes is illustrated with multiple examples, showcasing the versatility of both, the types of interactions possible, and the reactions accessible.
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Affiliation(s)
| | - Evamarie Hey-Hawkins
- Institute of Inorganic Chemistry, Universität Leipzig, Johannisallee 29, D-04103 Leipzig, Germany;
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19
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Geer AM, Navarro J, Alamán-Valtierra P, Coles NT, Kays DL, Tejel C. Homotropic Cooperativity in Iron-Catalyzed Alkyne Cyclotrimerizations. ACS Catal 2023; 13:6610-6618. [PMID: 37229435 PMCID: PMC10204060 DOI: 10.1021/acscatal.3c00764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/18/2023] [Indexed: 05/27/2023]
Abstract
Enhancing catalytic activity through synergic effects is a current challenge in homogeneous catalysis. In addition to the well-established metal-metal and metal-ligand cooperation, we showcase here an example of self-activation by the substrate in controlling the catalytic activity of the two-coordinate iron complex [Fe(2,6-Xyl2C6H3)2] (1, Xyl = 2,6-Me2C6H3). This behavior was observed for aryl acetylenes in their regioselective cyclotrimerization to 1,2,4-(aryl)-benzenes. Two kinetically distinct regimes are observed dependent upon the substrate-to-catalyst ratio ([RC≡CH]0/[1]0), referred to as the low ([RC≡CH]0/[1]0 < 40) and high ([RC≡CH]0/[1]0 > 40) regimes. Both showed sigmoidal kinetic response, with positive Hill indices of 1.85 and 3.62, respectively, and nonlinear Lineweaver-Burk replots with an upward curvature, which supports positive substrate cooperativity. Moreover, two alkyne molecules participate in the low regime, whereas up to four are involved in the high regime. The second-order rate dependence on 1 indicates that binuclear complexes are the catalytically competent species in both regimes, with that in the high one being 6 times faster than that involved in the low one. Moreover, Eyring plot analyses revealed two different catalytic cycles, with a rate-determining step more endergonic in the low regime than in the high one, but with a more ordered transition state in the high regime than in the low one.
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Affiliation(s)
- Ana M. Geer
- Instituto
de Síntesis Química y Catálisis Homogénea
(ISQCH), Departamento de Química Inorgánica, Facultad
de Ciencias, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Janeth Navarro
- Instituto
de Síntesis Química y Catálisis Homogénea
(ISQCH), Departamento de Química Inorgánica, Facultad
de Ciencias, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Pablo Alamán-Valtierra
- Instituto
de Síntesis Química y Catálisis Homogénea
(ISQCH), Departamento de Química Inorgánica, Facultad
de Ciencias, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Nathan T. Coles
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - Deborah L. Kays
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - Cristina Tejel
- Instituto
de Síntesis Química y Catálisis Homogénea
(ISQCH), Departamento de Química Inorgánica, Facultad
de Ciencias, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
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20
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Shelte AR, Patil RD, Karan S, Bhadu GR, Pratihar S. Nanoscale Ni-NiO-ZnO Heterojunctions for Switchable Dehydrogenation and Hydrogenation through Modulation of Active Sites. ACS APPLIED MATERIALS & INTERFACES 2023; 15:24329-24345. [PMID: 37186804 DOI: 10.1021/acsami.3c00985] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Catalysts consisting of metal-metal hydroxide/oxide interfaces are highly in demand for advanced catalytic applications as their multicomponent active sites will enable different reactions to occur in close proximity through synergistic cooperation when a single component fails to promote it. To address this, herein we disclosed a simple, scalable, and affordable method for synthesizing catalysts consisting of nanoscale nickel-nickel oxide-zinc oxide (Ni-NiO-ZnO) heterojunctions by a combination of complexation and pyrolytic reduction. The modulation of active sites of catalysts was achieved by varying the reaction conditions of pyrolysis, controlling the growth, and inhibiting the interlayer interaction and Ostwald ripening through the efficient use of coordinated acetate and amide moieties of Zn-Ni materials (ZN-O), produced by the reaction between hydrazine hydrate and Zn-Ni-acetate complexes. We found that the coordinated organic moieties are crucial for forming heterojunctions and their superior catalytic activity. We analyzed two antagonistic reactions to evaluate the performance of the catalysts and found that while the heterostructure of Ni-NiO-ZnO and their cooperative synergy were crucial for managing the effectiveness and selectivity of the catalyst for dehydrogenation of aryl alkanes/alkenes, they failed to enhance the hydrogenation of nitro arenes. The hydrogenation reaction was influenced by the shape, surface properties, and interaction of the hydroxide and oxide of both zinc and nickel, particularly accessible Ni(0). The catalysts showed functional group tolerance, multiple reusabilities, broad substrate applicability, and good activity for both reactions.
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Affiliation(s)
- Amishwar Raysing Shelte
- Inorganic Materials and Catalysis Division, CSIR-Central Salt & Marine Chemicals Research Institute, Gijubhai Badheka Marg, Bhavnagar, Gujarat 364002, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Rahul Daga Patil
- Inorganic Materials and Catalysis Division, CSIR-Central Salt & Marine Chemicals Research Institute, Gijubhai Badheka Marg, Bhavnagar, Gujarat 364002, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Santanu Karan
- Membrane Science and Separation Technology Division, CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), Gijubhai Badheka Marg, Bhavnagar, Gujarat 364002, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Gopala R Bhadu
- Analytical and Environmental Science Division & Centralized Instrument Facility, Central Salt & Marine Chemicals Research Institute, Gijubhai Badheka Marg, Bhavnagar, Gujarat 364002, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Sanjay Pratihar
- Inorganic Materials and Catalysis Division, CSIR-Central Salt & Marine Chemicals Research Institute, Gijubhai Badheka Marg, Bhavnagar, Gujarat 364002, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
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21
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Li B, Weinert HM, Wölper C, Schulz S. Reactions of Zinc Hydride with Silylenes: From Oxidative Addition to Ligand Exchange Reactions. Organometallics 2023. [DOI: 10.1021/acs.organomet.3c00006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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22
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Kumar R, Pandey MK, Bhandari A, Choudhury J. Balancing the Seesaw in Mn-Catalyzed N-Heteroarene Hydrogenation: Mechanism-Inspired Catalyst Design for Simultaneous Taming of Activation and Transfer of H 2. ACS Catal 2023. [DOI: 10.1021/acscatal.2c06405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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23
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Malakar S, Gordon BM, Mandal S, Emge TJ, Goldman AS. Ruthenium Complexes of a Triphosphorus-Coordinating Pincer Ligand: Ru-P Ligand-Substituent Exchange Reactions Driven by Large Variations of Bond Energies. Inorg Chem 2023; 62:4525-4532. [PMID: 36881741 DOI: 10.1021/acs.inorgchem.2c04416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
The reaction of [(p-cymene)RuCl2]2 with the triphosphine ligand bis(2-di-tert-butylphosphinophenyl)phosphine (tBuPHPP) results in an unusual exchange reaction in which a chloride ligand and a phosphorus-bound H atom are exchanged ("H-P/Ru-Cl exchange") to give the (chlorophosphine)ruthenium hydride complex (tBuPClPP)RuHCl [1Cl-HCl; tBuPClPP = bis(2-di-tert-butylphosphinophenyl)chlorophosphine]. Density functional theory calculations indicate that the presumed initial product of metalation, (tBuPHPP)RuCl2 (1H-Cl2), undergoes an H-P/Ru-Cl exchange via sequential P-to-Ru α-H migration to give the intermediate (tBuPPP)RuHCl2, followed by Ru-to-P α-Cl migration to give the observed product 1Cl-HCl (crystallographically characterized). Dehydrochlorination of 1Cl-HCl under a H2 atmosphere gives (tBuPClPP)RuH4 (1Cl-H4), which then can undergo a second dehydrochlorination and addition of H2 to give (tBuPHPP)RuH4 (1H-H4). This reaction may proceed via the reverse of the intramolecular exchange by 1H-Cl2, i.e., loss of H2 from 1Cl-H4 to give 1Cl-H2, which could undergo Cl-P/Ru-H exchange to give (tBuPHPP)RuHCl (1H-HCl). Accordingly, the thermodynamics of Cl-P/Ru-H exchange are found to be highly dependent on the nature of the ancillary anionic ligand (H or Cl), which is not directly involved in the exchange. The origin of this thermodynamic dependence can be explained in terms of the high stability of complexes (RPXPP)RuHCl (X = H, Cl; R = Me, tBu), in which the hydride is approximately trans to a vacant coordination site and the central phosphine group is approximately trans to the weak-trans-influence chloride ligand. This conclusion has general implications for five-coordinate d6 complexes, both pincer- and nonpincer-ligated.
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Affiliation(s)
- Santanu Malakar
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Benjamin M Gordon
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Souvik Mandal
- 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
| | - Alan S Goldman
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
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24
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Delaney AR, Yu LJ, Doan V, Coote ML, Colebatch AL. Bimetallic Nickel Complexes Supported by a Planar Macrocyclic Diphosphoranide Ligand. Chemistry 2023; 29:e202203940. [PMID: 36545819 DOI: 10.1002/chem.202203940] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 12/20/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022]
Abstract
Metal-metal cooperativity is emerging as an important strategy in catalysis. This requires appropriate ligand scaffolds that can support two metals in close proximity. Here we report nickel-promoted formation of a dinucleating planar macrocyclic ligand that can support bimetallic dinickel(II) and dinickel(I) complexes. Reaction outcomes can be tuned by variation of the substituents and reaction conditions to favour dinucleating macrocyclic, mononucleating macrocyclic or conventional pincer architectures.
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Affiliation(s)
- Andie R Delaney
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Li-Juan Yu
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Vincent Doan
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Michelle L Coote
- Institute for Nanoscale Science & Technology, Flinders University, Adelaide, South Australia, 5042, Australia
| | - Annie L Colebatch
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
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25
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Garçon M, Phanopoulos A, White AJP, Crimmin MR. Reversible Dihydrogen Activation and Catalytic H/D Exchange with Group 10 Heterometallic Complexes. Angew Chem Int Ed Engl 2023; 62:e202213001. [PMID: 36350647 PMCID: PMC10107683 DOI: 10.1002/anie.202213001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Indexed: 11/10/2022]
Abstract
Reaction of a hexagonal planar palladium complex featuring a [PdMg3 H3 ] core with H2 is reversible and leads to the formation of a new [PdMg2 H4 ] tetrahydride species alongside an equivalent of a magnesium hydride co-product [MgH]. While the reversibility of this process prevented isolation of [PdMg2 H4 ], analogous [PtMg2 H4 ] and [PtZn2 H4 ] complexes could be isolated and characterised through independent syntheses. Computational analysis (DFT, AIM, NCIPlot) of the bonding in a series of heterometallic tetrahydride compounds (Ni-Pt; Mg and Zn) suggests that these complexes are best described as square planar with marginal metal-metal interactions; the strength of which increases slightly as group 10 is descended and increases from Mg to Zn. DFT calculations support a mechanism for H2 activation involving a ligand-assisted oxidative addition to Pd. These findings were exploited to develop a catalytic protocol for H/D exchange into magnesium hydride and zinc hydride bonds.
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Affiliation(s)
- Martí Garçon
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, London, W12 0BZ, UK
| | - Andreas Phanopoulos
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, London, W12 0BZ, UK
| | - Andrew J P White
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, London, W12 0BZ, UK
| | - Mark R Crimmin
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, London, W12 0BZ, UK
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26
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Hall PD, Stevens MA, Wang JYJ, Pham LN, Coote ML, Colebatch AL. Copper and Zinc Complexes of 2,7-Bis(6-methyl-2-pyridyl)-1,8-naphthyridine─A Redox-Active, Dinucleating Bis(bipyridine) Ligand. Inorg Chem 2022; 61:19333-19343. [DOI: 10.1021/acs.inorgchem.2c03126] [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)
- Peter D. Hall
- Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory2601, Australia
| | - Michael A. Stevens
- Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory2601, Australia
| | - Jiao Yu J. Wang
- Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory2601, Australia
| | - Le Nhan Pham
- Institute for Nanoscale Science & Technology, Flinders University, Adelaide, South Australia5042, Australia
| | - Michelle L. Coote
- Institute for Nanoscale Science & Technology, Flinders University, Adelaide, South Australia5042, Australia
| | - Annie L. Colebatch
- Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory2601, Australia
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27
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Morris LJ, Rajeshkumar T, Maron L, Okuda J. Reversible Oxidative Addition of Zinc Hydride at a Gallium(I)-Centre: Labile Mono- and Bis(hydridogallyl)zinc Complexes. Chemistry 2022; 28:e202201480. [PMID: 35819049 PMCID: PMC9804236 DOI: 10.1002/chem.202201480] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Indexed: 01/05/2023]
Abstract
In the presence of TMEDA (N,N,N',N'-tetramethylethylenediamine), partially deaggregated zinc dihydride as hydrocarbon suspensions react with the gallium(I) compound [(BDI)Ga] (I, BDI={HC(C(CH3 )N(2,6-iPr2 -C6 H3 ))2 }- ) by formal oxidative addition of a Zn-H bond to the gallium(I) centre. Dissociation of the labile TMEDA ligand in the resulting complex [(BDI)Ga(H)-(H)Zn(tmeda)] (1) facilitates insertion of a second equiv. of I into the remaining Zn-H to form a thermally sensitive trinuclear species [{(BDI)Ga(H)}2 Zn] (2). Compound 1 exchanges with polymeric zinc dideuteride [ZnD2 ]n in the presence of TMEDA, and with compounds I and 2 via sequential and reversible ligand dissociation and gallium(I) insertion. Spectroscopic and computational studies demonstrate the reversibility of oxidative addition of each Zn-H bond to the gallium(I) centres.
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Affiliation(s)
- Louis J. Morris
- Institute for Inorganic ChemistryRWTH Aachen University52062AachenGermany
- Chemistry Research LaboratoryUniversity of OxfordOxfordOX1 3TAUnited Kingdom
| | | | - Laurent Maron
- CNRSINSAUPSUMR 5215LPCNOUniversité de Toulouse31077ToulouseFrance
| | - Jun Okuda
- Institute for Inorganic ChemistryRWTH Aachen University52062AachenGermany
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Cesari C, Bortoluzzi M, Forti F, Gubbels L, Femoni C, Iapalucci MC, Zacchini S. 2-D Molecular Alloy Ru-M (M = Cu, Ag, and Au) Carbonyl Clusters: Synthesis, Molecular Structure, Catalysis, and Computational Studies. Inorg Chem 2022; 61:14726-14741. [PMID: 36069711 PMCID: PMC9490753 DOI: 10.1021/acs.inorgchem.2c02099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Indexed: 11/28/2022]
Abstract
The reactions of [HRu3(CO)11]- (1) with M(I) (M = Cu, Ag, and Au) compounds such as [Cu(CH3CN)4][BF4], AgNO3, and Au(Et2S)Cl afford the 2-D molecular alloy clusters [CuRu6(CO)22]- (2), [AgRu6(CO)22]- (3), and [AuRu5(CO)19]- (4), respectively. The reactions of 2-4 with PPh3 result in mixtures of products, among which [Cu2Ru8(CO)26]2- (5), Ru4(CO)12(CuPPh3)4 (6), Ru4(CO)12(AgPPh3)4 (7), Ru(CO)3(PPh3)2 (8), and HRu3(OH)(CO)7(PPh3)3 (9) have been isolated and characterized. The molecular structures of 2-6 and 9 have been determined by single-crystal X-ray diffraction. The metal-metal bonding within 2-5 has been computationally investigated by density functional theory methods. In addition, the [NEt4]+ salts of 2-4 have been tested as catalyst precursors for transfer hydrogenation on the model substrate 4-fluoroacetophenone using iPrOH as a solvent and a hydrogen source.
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Affiliation(s)
- Cristiana Cesari
- Dipartimento
di Chimica Industriale “Toso Montanari”, Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy
- Center
for Chemical Catalysis—C3, University
of Bologna, Viale Risorgimento
4, 40136 Bologna, Italy
| | - Marco Bortoluzzi
- Dipartimento
di Scienze Molecolari e Nanosistemi, Ca’
Foscari University of Venice, Via Torino 155, 30175 Mestre (Ve), Italy
| | - Francesca Forti
- Dipartimento
di Chimica Industriale “Toso Montanari”, Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy
- Center
for Chemical Catalysis—C3, University
of Bologna, Viale Risorgimento
4, 40136 Bologna, Italy
| | - Lisa Gubbels
- Dipartimento
di Chimica Industriale “Toso Montanari”, Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy
| | - Cristina Femoni
- Dipartimento
di Chimica Industriale “Toso Montanari”, Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy
| | - Maria Carmela Iapalucci
- Dipartimento
di Chimica Industriale “Toso Montanari”, Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy
| | - Stefano Zacchini
- Dipartimento
di Chimica Industriale “Toso Montanari”, Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy
- Center
for Chemical Catalysis—C3, University
of Bologna, Viale Risorgimento
4, 40136 Bologna, Italy
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29
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Heterogeneous Transition-Metal Catalyst for Fine Chemical Synthesis Hydrogen Auto-transfer Reaction. Top Catal 2022. [DOI: 10.1007/s11244-022-01694-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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