1
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Singh KK, Gerke CS, Saund SS, Zito AM, Siegler MA, Thoi VS. CO 2 Activation with Manganese Tricarbonyl Complexes through an H-Atom Responsive Benzimidazole Ligand. Chemistry 2023; 29:e202300796. [PMID: 37519094 DOI: 10.1002/chem.202300796] [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: 03/11/2023] [Revised: 07/20/2023] [Accepted: 07/27/2023] [Indexed: 08/01/2023]
Abstract
Herein, we report the synthesis and characterization of two manganese tricarbonyl complexes, MnI (HL)(CO)3 Br (1 a-Br) and MnI (MeL)(CO)3 Br (1 b-Br) (where HL=2-(2'-pyridyl)benzimidazole; MeL=1-methyl-2-(2'-pyridy)benzimidazole) and assayed their electrocatalytic properties for CO2 reduction. A redox-active pyridine benzimidazole ancillary ligand in complex 1 a-Br displayed unique hydrogen atom transfer ability to facilitate electrocatalytic CO2 conversion at a markedly lower reduction potential than that observed for 1 b-Br. Notably, a one-electron reduction of 1 a-Br yields a structurally characterized H-bonded binuclear Mn(I) adduct (2 a') rather than the typically observed Mn(0)-Mn(0) dimer, suggesting a novel method for CO2 activation. Combining advanced electrochemical, spectroscopic, and single crystal X-ray diffraction techniques, we demonstrate the use of an H-atom responsive ligand may reveal an alternative, low-energy pathway for CO2 activation by an earth-abundant metal complex catalyst.
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Affiliation(s)
- Kundan K Singh
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, United States
| | - Carter S Gerke
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, United States
| | - Simran S Saund
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, United States
| | - Alessandra M Zito
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, United States
| | - Maxime A Siegler
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, United States
| | - V Sara Thoi
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, 21218, United States
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, 21218, United States
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2
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Capulín Flores L, Paul LA, Siewert I, Havenith R, Zúñiga-Villarreal N, Otten E. Neutral Formazan Ligands Bound to the fac-(CO) 3Re(I) Fragment: Structural, Spectroscopic, and Computational Studies. Inorg Chem 2022; 61:13532-13542. [PMID: 35969867 PMCID: PMC9438031 DOI: 10.1021/acs.inorgchem.2c02168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Metal complexes with ligands that coordinate via the nitrogen atom of azo (N═N) or imino (C═N) groups are of interest due to their π-acceptor properties and redox-active nature, which leads to interesting (opto)electronic properties and reactivity. Here, we describe the synthesis and characterization of rhenium(I) tricarbonyl complexes with neutral N,N-bidentate formazans, which possess both N═N and C═N fragments within the ligand backbone (Ar1-NH-N═C(R3)-N═N-Ar5). The compounds were synthesized by reacting equimolar amounts of [ReBr(CO)5] and the corresponding neutral formazan. X-ray crystallographic and spectroscopic (IR, NMR) characterization confirmed the generation of formazan-type species with the structure fac-[ReBr(CO)3(κ2-N2,N4(Ar1-N1H-N2═C(R3)-N3═N4-Ar5))]. The formazan ligand coordinates the metal center in the 'open' form, generating a five-membered chelate ring with a pendant NH arm. The electronic absorption and emission properties of these complexes are governed by the presence of low-lying π*-orbitals on the ligand as shown by DFT calculations. The high orbital mixing between the metal and ligand results in photophysical properties that contrast to those observed in fac-[ReBr(CO)3(L,L)] species with α-diimine ligands.
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Affiliation(s)
- Liliana Capulín Flores
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Circuito Exterior, 04510 México, D.F., México
| | - Lucas A Paul
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstraße 4, D-37077 Göttingen, Germany
| | - Inke Siewert
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstraße 4, D-37077 Göttingen, Germany
| | - Remco Havenith
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Noé Zúñiga-Villarreal
- Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Circuito Exterior, 04510 México, D.F., México
| | - Edwin Otten
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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3
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Siewert I. Electrochemical CO 2 Reduction Catalyzed by Binuclear LRe 2(CO) 6Cl 2 and LMn 2(CO) 6Br 2 Complexes with an Internal Proton Source. Acc Chem Res 2022; 55:473-483. [PMID: 35077152 DOI: 10.1021/acs.accounts.1c00609] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of certain commodity chemicals, e.g., methanol and acetic acid, relies on CO, which is currently mainly produced by the combustion of carbon or natural gas. Photo- or electrochemical conversion of atmospheric CO2 to CO represents an attractive alternative strategy as this approach is carbon-neutral. Such photo- or electrochemically formed CO can also be used in the Fischer-Tropsch process forming liquid hydrocarbons for energy storage applications. The multiple electroreduction of CO2 is preferably coupled with proton transfer steps as this requires less energy than the single outer-sphere 1e- reduction of CO2.In 1984 and 2011, it was shown that [(Lbpy)Re(CO)3Cl] (1) and [(Lbpy)Mn(CO)3Br] (2), respectively, mediate the electrochemical 2e-/2H+ reduction of CO2 forming CO and water (Lbpy = 2,2'-bipyridine). Since proton management is crucial for catalysis, recently the impact of internal proton sources close to the axial position in such complexes has been investigated. However, binuclear complexes have been used rarely as mediators although it has been shown very early for 1 that electron management is also important: the 2e-/2H+ reduction pathway with 1 exhibits a higher reaction rate than going via the singly reduced species, though the pathway requires a higher overpotential. In this Account, we focus on recent developments of binuclear LMn2(CO)6 and LRe2(CO)6 mediators with an internal phenol group in the electroreduction of CO2. In contrast to mononuclear derivatives, for which the impact of the internal proton source on catalysis is very diverse, we always observed a higher reaction rate and for the Mn complexes also a lower overpotential with the binuclear complexes compared to the mononuclear variants. Spectroscopic, electrochemical, and computational studies on the mono- and binuclear complexes shed light on their reactivity under reductive conditions, elucidated the structure of reduced species, unraveled the kinetics for catalytically productive and unproductive (side) reactions, and allowed us to derive some hypothesis on the CO2 reduction mechanism. Finally, I emphasize that the electrohydrogenation of the polar double bonds by the binuclear complex LMn2(CO)6 with a central phenol unit is not restricted to CO2 but is also applicable to organic compounds with C═O bonds.
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Affiliation(s)
- Inke Siewert
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstr. 4, 37077 Göttingen, Germany
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4
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Aleksanyan DV, Churusova SG, Yu. Rybalkina E, Klemenkova ZS, Denisov GL, Kozlov VA. Dinucleating ligands based on functionalized oxalamides: lability of Re(I) coordination with the phosphorus pendant arms. Polyhedron 2022. [DOI: 10.1016/j.poly.2022.115742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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5
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Polyansky DE, Grills DC, Ertem MZ, Ngo KT, Fujita E. Role of Bimetallic Interactions in the Enhancement of Catalytic CO2 Reduction by a Macrocyclic Cobalt Catalyst. ACS Catal 2022. [DOI: 10.1021/acscatal.1c05043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dmitry E. Polyansky
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - David C. Grills
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Mehmed Z. Ertem
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Ken T. Ngo
- Department of Chemistry, University of Massachusetts, Boston, 100 Morrissey Boulevard, Boston, Massachusetts 02125, United States
| | - Etsuko Fujita
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
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6
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7
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Kinzel NW, Werlé C, Leitner W. Transition Metal Complexes as Catalysts for the Electroconversion of CO 2 : An Organometallic Perspective. Angew Chem Int Ed Engl 2021; 60:11628-11686. [PMID: 33464678 PMCID: PMC8248444 DOI: 10.1002/anie.202006988] [Citation(s) in RCA: 111] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/11/2020] [Indexed: 12/17/2022]
Abstract
The electrocatalytic transformation of carbon dioxide has been a topic of interest in the field of CO2 utilization for a long time. Recently, the area has seen increasing dynamics as an alternative strategy to catalytic hydrogenation for CO2 reduction. While many studies focus on the direct electron transfer to the CO2 molecule at the electrode material, molecular transition metal complexes in solution offer the possibility to act as catalysts for the electron transfer. C1 compounds such as carbon monoxide, formate, and methanol are often targeted as the main products, but more elaborate transformations are also possible within the coordination sphere of the metal center. This perspective article will cover selected examples to illustrate and categorize the currently favored mechanisms for the electrochemically induced transformation of CO2 promoted by homogeneous transition metal complexes. The insights will be corroborated with the concepts and elementary steps of organometallic catalysis to derive potential strategies to broaden the molecular diversity of possible products.
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Affiliation(s)
- Niklas W. Kinzel
- Max Planck Institute for Chemical Energy ConversionStiftstr. 34–3645470Mülheim an der RuhrGermany
- Institut für Technische und Makromolekulare Chemie (ITMC)RWTH Aachen UniversityWorringer Weg 252074AachenGermany
| | - Christophe Werlé
- Max Planck Institute for Chemical Energy ConversionStiftstr. 34–3645470Mülheim an der RuhrGermany
- Ruhr University BochumUniversitätsstr. 15044801BochumGermany
| | - Walter Leitner
- Max Planck Institute for Chemical Energy ConversionStiftstr. 34–3645470Mülheim an der RuhrGermany
- Institut für Technische und Makromolekulare Chemie (ITMC)RWTH Aachen UniversityWorringer Weg 252074AachenGermany
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8
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Gerschel P, Cordes AL, Bimmermann S, Siegmund D, Metzler‐Nolte N, Apfel U. Investigation of Cyclam Based Re‐Complexes as Potential Electrocatalysts for the CO
2
Reduction Reaction. Z Anorg Allg Chem 2021. [DOI: 10.1002/zaac.202000450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Philipp Gerschel
- Inorganic Chemistry I Ruhr-Universität Bochum Universitätsstraße 150 44801 Bochum Germany
| | - Anna L. Cordes
- Inorganic Chemistry I Ruhr-Universität Bochum Universitätsstraße 150 44801 Bochum Germany
| | - Sarah Bimmermann
- Inorganic Chemistry I Ruhr-Universität Bochum Universitätsstraße 150 44801 Bochum Germany
| | - Daniel Siegmund
- Department of Electrosynthesis Fraunhofer UMSICHT Osterfelder Straße 3 46047 Oberhausen Germany
| | - Nils Metzler‐Nolte
- Inorganic Chemistry I Ruhr-Universität Bochum Universitätsstraße 150 44801 Bochum Germany
| | - Ulf‐Peter Apfel
- Inorganic Chemistry I Ruhr-Universität Bochum Universitätsstraße 150 44801 Bochum Germany
- Department of Electrosynthesis Fraunhofer UMSICHT Osterfelder Straße 3 46047 Oberhausen Germany
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9
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Kinzel NW, Werlé C, Leitner W. Übergangsmetallkomplexe als Katalysatoren für die elektrische Umwandlung von CO
2
– eine metallorganische Perspektive. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202006988] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Niklas W. Kinzel
- Max-Planck-Institut für Chemische Energiekonversion Stiftstraße 34–36 45470 Mülheim an der Ruhr Deutschland
- Institut für Technische und Makromolekulare Chemie (ITMC) RWTH Aachen University Worringer Weg 2 52074 Aachen Deutschland
| | - Christophe Werlé
- Max-Planck-Institut für Chemische Energiekonversion Stiftstraße 34–36 45470 Mülheim an der Ruhr Deutschland
- Ruhr-Universität Bochum Universitätsstraße 150 44801 Bochum Deutschland
| | - Walter Leitner
- Max-Planck-Institut für Chemische Energiekonversion Stiftstraße 34–36 45470 Mülheim an der Ruhr Deutschland
- Institut für Technische und Makromolekulare Chemie (ITMC) RWTH Aachen University Worringer Weg 2 52074 Aachen Deutschland
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10
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Fokin I, Siewert I. Chemoselective Electrochemical Hydrogenation of Ketones and Aldehydes with a Well-Defined Base-Metal Catalyst. Chemistry 2020; 26:14137-14143. [PMID: 32497312 PMCID: PMC7702145 DOI: 10.1002/chem.202002075] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/02/2020] [Indexed: 01/06/2023]
Abstract
Hydrogenation reactions are fundamental functional group transformations in chemical synthesis. Here, we introduce an electrochemical method for the hydrogenation of ketones and aldehydes by in situ formation of a Mn-H species. We utilise protons and electric current as surrogate for H2 and a base-metal complex to form selectively the alcohols. The method is chemoselective for the hydrogenation of C=O bonds over C=C bonds. Mechanistic studies revealed initial 3 e- reduction of the catalyst forming the steady state species [Mn2 (H-1 L)(CO)6 ]- . Subsequently, we assume protonation, reduction and internal proton shift forming the hydride species. Finally, the transfer of the hydride and a proton to the ketone yields the alcohol and the steady state species is regenerated via reduction. The interplay of two manganese centres and the internal proton relay represent the key features for ketone and aldehyde reduction as the respective mononuclear complex and the complex without the proton relay are barely active.
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Affiliation(s)
- Igor Fokin
- Institut für Anorganische ChemieUniversität GöttingenTammannstr. 437077GöttingenGermany
| | - Inke Siewert
- Institut für Anorganische ChemieUniversität GöttingenTammannstr. 437077GöttingenGermany
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11
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Mukherjee J, Siewert I. Manganese and Rhenium Tricarbonyl Complexes Equipped with Proton Relays in the Electrochemical CO
2
Reduction Reaction. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000738] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jyotima Mukherjee
- Institut für Anorganische Chemie Universität Göttingen Tammannstr. 4 37077 Göttingen Germany
| | - Inke Siewert
- Institut für Anorganische Chemie Universität Göttingen Tammannstr. 4 37077 Göttingen Germany
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12
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Rotundo L, Polyansky DE, Gobetto R, Grills DC, Fujita E, Nervi C, Manbeck GF. Molecular Catalysts with Intramolecular Re-O Bond for Electrochemical Reduction of Carbon Dioxide. Inorg Chem 2020; 59:12187-12199. [PMID: 32804491 PMCID: PMC8009525 DOI: 10.1021/acs.inorgchem.0c01181] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
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A new Re bipyridine-type complex,
namely, fac-Re(pmbpy)(CO)3Cl (pmbpy =
4-phenyl-6-(2-hydroxy-phenyl)-2,2′-bipyridine), 1, carrying a single OH moiety as local proton source, has
been synthesized, and its electrochemical behavior under Ar and under
CO2 has been characterized. Two isomers of 1, namely, 1-cis characterized by the
proximity of Cl to OH and 1-trans, are
identified. The interconversion between 1-cis and 1-trans is clarified by DFT calculations,
which reveal two transition states. The energetically lower pathway
displays a non-negligible barrier of 75.5 kJ mol–1. The 1e– electrochemical reduction of 1 affords the neutral intermediate 1-OPh, formally derived
by reductive deprotonation and loss of Cl– from 1. 1-OPh, which exhibits an entropically favored
intramolecular Re–O bond, has been isolated and characterized.
The detailed electrochemical mechanism is demonstrated by combined
chemical reactivity, spectroelectrochemistry, spectroscopic (IR and
NMR), and computational (DFT) approaches. Comparison with previous
Re and Mn derivatives carrying local proton sources highlights that
the catalytic activity of Re complexes is more sensitive to the presence
of local OH groups. Similar to Re-2OH (2OH = 4-phenyl-6-(phenyl-2,6-diol)-2,2′-bipyridine), 1 and Mn-1OH display a selective reduction of
CO2 to CO. In the case of the Re bipyridine-type complex,
the formation of a relatively stable Re–O bond and a preference
for phenolate-based reactivity with CO2 slightly inhibit
the electrocatalytic reduction of CO2 to CO, resulting
in a low TON value of 9, even in the presence of phenol as a proton
source. A new Re bipyridine-type complex, namely, fac-Re(pmbpy)(CO)3Cl (pmbpy = 4-phenyl-6-(2-hydroxy-phenyl)-2,2′-bipyridine), 1, carrying a single OH moiety as local proton source, has
been synthesized, and its electrochemical behavior under Ar and under
CO2 has been characterized. Two isomers of 1, namely, 1-cis characterized by the
proximity of Cl to OH and 1-trans, are
identified.
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Affiliation(s)
- Laura Rotundo
- Chemistry Department, University of Torino, Via P. Giuria 7, 10125 Torino, Italy.,CIRCC (Bari), University of Bari, Via Celso Ulpiani 27, 70126 Bari, Italy
| | - Dmitry E Polyansky
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Roberto Gobetto
- Chemistry Department, University of Torino, Via P. Giuria 7, 10125 Torino, Italy.,CIRCC (Bari), University of Bari, Via Celso Ulpiani 27, 70126 Bari, Italy
| | - David C Grills
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Etsuko Fujita
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Carlo Nervi
- Chemistry Department, University of Torino, Via P. Giuria 7, 10125 Torino, Italy.,CIRCC (Bari), University of Bari, Via Celso Ulpiani 27, 70126 Bari, Italy
| | - Gerald F Manbeck
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
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13
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Paul LA, Röttcher NC, Zimara J, Borter JH, Du JP, Schwarzer D, Mata RA, Siewert I. Photochemical Properties of Re(CO)3 Complexes with and without a Local Proton Source and Implications for CO2 Reduction Catalysis. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00240] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lucas A. Paul
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Nico C. Röttcher
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Jennifer Zimara
- Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Jan-Hendrik Borter
- Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Jia-Pei Du
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Dirk Schwarzer
- Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Ricardo A. Mata
- Universität Göttingen, Institut für Physikalische Chemie, Tammannstrasse 6, 37077 Göttingen, Germany
| | - Inke Siewert
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
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14
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Isolating substituent effects in Re(I)-phenanthroline electrocatalysts for CO2 reduction. Inorganica Chim Acta 2020. [DOI: 10.1016/j.ica.2019.119397] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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15
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Daryanavard M, Masoumpour MS. A new polypyridyl‐based Ru (II) complex as a highly efficient electrocatalyst for CO
2
reduction. Appl Organomet Chem 2020. [DOI: 10.1002/aoc.5389] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Marzieh Daryanavard
- Department of ChemistryEstahban Higher Education Center Estahban 74519‐44655 Iran
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16
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Paul LA, Rajabi S, Jooss C, Meyer F, Ebrahimi F, Siewert I. A dinuclear rhenium complex in the electrochemically driven homogeneous and heterogeneous H +/CO 2-reduction. Dalton Trans 2020; 49:8367-8374. [PMID: 32520049 DOI: 10.1039/d0dt00381f] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A dinculear Re(CO)3 complex with a proton responsive phenol unit and a pyrene anchor in the ligand backbone was investigated in the electrochemical CO2/H+ conversion in solution and adsorbed on multi walled carbon nanotubes (MWCNT) on an GC electrode surface. The pyrene group unit is introduced at the end of the ligand synthesis via a coupling reaction, which allows for a versatile ligand modification in order to tune the electronic properties or to introduce various anchor groups for heterogenisation at a late stage. The redox chemistry of the pyrene-α-diimine-Re(CO)3 complex, 1, was investigated in N,N-dimethylformamide (dmf), including IR-spectroelectrochemical (IR-SEC) characterisation of the short lived, reduced species. Subsequently, the electrochemical H+/CO2-reduction catalysis in dmf/water was investigated. The complex catalyses syngas formation yielding CO and H2 with similar rates, namely in Faraday yields of 45% and 35%, respectively. Since the similar complex without the pyrene anchor in the backbone, I, prefers CO2 over H+ reduction, the formation of syngas was rationalised by the small differences in the redox properties and pKa values of the phenol-pyrene unit in regard to phenol unit as in I. Subsequently, the complex was adsorbed on multi walled carbon nanotubes (MWCNT) on a GC electrode surface. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) confirmed coating of the electrode. The immobilised complex was utilised in the electrochemical CO2/H+ reduction in dmf/water, however, the complex quickly desorbed under reductive conditions, likely due to the good solubility of the reduced species. Water as a solvent prevents desorption as confirmed by XPS, however, then a preference for H2 formation over syngas formation was observed under electrocatalytic conditions. Thus, these experiments show, that the results obtained in aqueous organic solution are not easily transferable to the heterogeneous systems operating in water due to changes in the reaction rates for competing pathways.
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Affiliation(s)
- Lucas A Paul
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstr. 4, 37077 Göttingen, Germany.
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17
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Sinha S, Sonea A, Gibbs CA, Warren JJ. Heterogeneous aqueous CO2 reduction by rhenium(i) tricarbonyl diimine complexes with a non-chelating pendant pyridyl group. Dalton Trans 2020; 49:7078-7083. [DOI: 10.1039/d0dt01300e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A graphite-adsorbed tricarbonylrhenium(i) terpyridine complex supports CO2 reduction electrocatalysis over a wide range of pH values.
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Affiliation(s)
- Soumalya Sinha
- Department of Chemistry
- Simon Fraser University
- Burnaby BC V5A 1S6
- Canada
| | - Ana Sonea
- Department of Chemistry
- Simon Fraser University
- Burnaby BC V5A 1S6
- Canada
| | - Curtis A. Gibbs
- Department of Chemistry
- Simon Fraser University
- Burnaby BC V5A 1S6
- Canada
| | - Jeffrey J. Warren
- Department of Chemistry
- Simon Fraser University
- Burnaby BC V5A 1S6
- Canada
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18
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Fokin I, Denisiuk A, Würtele C, Siewert I. The Impact of a Proton Relay in Binuclear α-Diimine-Mn(CO)3 Complexes on the CO2 Reduction Catalysis. Inorg Chem 2019; 58:10444-10453. [DOI: 10.1021/acs.inorgchem.9b00992] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Igor Fokin
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstr. 4, 37077 Göttingen, Germany
| | - Alisa Denisiuk
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstr. 4, 37077 Göttingen, Germany
| | - Christian Würtele
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstr. 4, 37077 Göttingen, Germany
| | - Inke Siewert
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstr. 4, 37077 Göttingen, Germany
- Universität Göttingen, International Center for Advanced Studies of Energy Conversion, 37077 Göttingen, Germany
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Antoni PW, Bruckhoff T, Hansmann MM. Organic Redox Systems Based on Pyridinium–Carbene Hybrids. J Am Chem Soc 2019; 141:9701-9711. [DOI: 10.1021/jacs.9b04249] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Patrick W. Antoni
- Georg-August Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
| | - Tim Bruckhoff
- Georg-August Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
| | - Max M. Hansmann
- Georg-August Universität Göttingen, Tammannstraße 2, 37077 Göttingen, Germany
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