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Askins EJ, Sarkar A, Navabi P, Kumar K, Finkelmeyer SJ, Presselt M, Cabana J, Glusac KD. Interfacial Electrochemistry of Catalyst-Coordinated Graphene Nanoribbons. J Am Chem Soc 2024; 146:22360-22373. [PMID: 39087647 DOI: 10.1021/jacs.4c05250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2024]
Abstract
The immobilization of molecular electrocatalysts on conductive electrodes is an appealing strategy for enhancing their overall activity relative to those of analogous molecular compounds. In this study, we report on the interfacial electrochemistry of self-assembled two-dimensional nanosheets of graphene nanoribbons (GNR-2DNS) and analogs containing a Rh-based hydrogen evolution reaction (HER) catalyst (RhGNR-2DNS) immobilized on conductive electrodes. Proton-coupled electron transfer (PCET) taking place at N-centers of the nanoribbons was utilized as an indirect reporter of the interfacial electric fields experienced by the monolayer nanosheet located within the electric double layer. The experimental Pourbaix diagrams were compared with a theoretical model, which derives the experimental Pourbaix slopes as a function of parameter f, a fraction of the interfacial potential drop experienced by the redox-active group. Interestingly, our study revealed that GNR-2DNS was strongly coupled to glassy carbon electrodes (f = 1), while RhGNR-2DNS was not (f = 0.15). We further investigated the HER mechanism by RhGNR-2DNS using electrochemical and X-ray absorption spectroelectrochemical methods and compared it to homogeneous molecular model compounds. RhGNR-2DNS was found to be an active HER electrocatalyst over a broader set of aqueous pH conditions than its molecular analogs. We find that the improved HER performance in the immobilized catalyst arises due to two factors. First, redox-active bipyrimidine-based ligands were shown to dramatically alter the activity of Rh sites by increasing the electron density at the active Rh center and providing RhGNR-2DNS with improved catalysis. Second, catalyst immobilization was found to prevent catalyst aggregation that was found to occur for the molecular analog in the basic pH. Overall, this study provides valuable insights into the mechanism by which catalyst immobilization can affect the overall electrocatalytic performance.
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Affiliation(s)
- Erik J Askins
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, United States
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Abdul Sarkar
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, United States
| | - Pouyan Navabi
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, United States
| | - Khagesh Kumar
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, United States
| | - Sarah Jasmin Finkelmeyer
- Leibniz Institute of Photonic Technology (IPHT), Jena 07745, Germany
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Jena 07743, Germany
| | - Martin Presselt
- Leibniz Institute of Photonic Technology (IPHT), Jena 07745, Germany
- SciClus GmbH & Co. KG, Jena 07745, Germany
- Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Jena 07743, Germany
| | - Jordi Cabana
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, United States
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Ksenija D Glusac
- Department of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, United States
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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2
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Sanderson HJ, Kociok-Köhn G, McMullin CL, Hintermair U. Twinned versus linked organometallics - bimetallic "half-baguette" pentalenide complexes of Rh(I). Dalton Trans 2024; 53:5881-5899. [PMID: 38446046 DOI: 10.1039/d3dt04325h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
The application of Mg[Ph4Pn] and Li·K[Ph4Pn] in transmetalation reactions to a range of Rh(I) precursors led to the formation of "half-baguette" anti-[RhI(L)n]2[μ:η5:η5Ph4Pn] (L = 1,5-cyclooctadiene, norbornadiene, ethylene; n = 1, 2) and syn-[RhI(CO)2]2[μ:η5:η5Ph4Pn] complexes as well as the related iridium complex anti-[IrI(COD)]2[μ:η5:η5Ph4Pn]. With CO exclusive syn metalation was obtained even when using mono-nuclear Rh(I) precursors, indicating an electronic preference for syn metalation. DFT analysis showed this to be the result of π overlap between the adjacent M(CO)2 units which overcompensates for dz2 repulsion of the metals, an effect which can be overridden by steric clash of the auxiliary ligands to yield anti-configuration as seen in the larger olefin complexes. syn-[RhI(CO)2]2[μ:η5:η5Ph4Pn] is a rare example of a twinned organometallic where the two metals are held flexibly in close proximity, but the two d8 Rh(I) centres did not show signs of M-M bonding interactions or exhibit Lewis basic behaviour as in some related mono-nuclear Cp complexes due to the acceptor properties of the ligands. The ligand substitution chemistry of syn-[RhI(CO)2]2[μ:η5:η5Ph4Pn] was investigated with a series of electronically and sterically diverse donor ligands (P(OPh)3, P(OMe)3, PPh3, PMe3, dppe) yielding new mono- and bis-substituted complexes, with E-syn-[RhI(CO)(P{OR})3]2[μ:η5:η5Ph4Pn] (R = Me, Ph) characterised by XRD.
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Affiliation(s)
- Hugh J Sanderson
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.
| | - Gabriele Kociok-Köhn
- Material and Chemical Characterisation Facility, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Claire L McMullin
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.
| | - Ulrich Hintermair
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.
- Institute for Sustainability, University of Bath, Claverton Down, Bath, BA2 7AY, UK
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3
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Boyd EA, Leseberg JAH, Cosner EL, Lionetti D, Henke WC, Day VW, Blakemore JD. Remote Oxidative Activation of a [Cp*Rh] Monohydride. Chemistry 2022; 28:e202104389. [PMID: 35038188 PMCID: PMC8891045 DOI: 10.1002/chem.202104389] [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: 12/08/2021] [Indexed: 11/09/2022]
Abstract
Half-sandwich rhodium monohydrides are often proposed as intermediates in catalysis, but little is known regarding the redox-induced reactivity accessible to these species. Herein, the bis(diphenylphosphino)ferrocene (dppf) ligand has been used to explore the reactivity that can be induced when a [Cp*Rh] monohydride undergoes remote (dppf-centered) oxidation by 1e- . Chemical and electrochemical studies show that one-electron redox chemistry is accessible to Cp*Rh(dppf), including a unique quasi-reversible RhII/I process at -0.96 V vs. ferrocenium/ferrocene (Fc+/0 ). This redox manifold was confirmed by isolation of an uncommon RhII species, [Cp*Rh(dppf)]+ , that was characterized by electron paramagnetic resonance (EPR) spectroscopy. Protonation of Cp*Rh(dppf) with anilinium triflate yielded an isolable and inert monohydride, [Cp*Rh(dppf)H]+ , and this species was found to undergo a quasireversible electrochemical oxidation at +0.41 V vs. Fc+/0 that corresponds to iron-centered oxidation in the dppf backbone. Thermochemical analysis predicts that this dppf-centered oxidation drives a dramatic increase in acidity of the Rh-H moiety by 23 pKa units, a reactivity pattern confirmed by in situ 1 H NMR studies. Taken together, these results show that remote oxidation can effectively induce M-H activation and suggest that ligand-centered redox activity could be an attractive feature for the design of new systems relying on hydride intermediates.
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Affiliation(s)
- Emily A. Boyd
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Julie A. Hopkins Leseberg
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Emma L. Cosner
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Davide Lionetti
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Wade C. Henke
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Victor W. Day
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - James D. Blakemore
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States,To whom correspondence should be addressed.
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4
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Henke WC, Stiel JP, Day VW, Blakemore JD. Evidence for Charge Delocalization in Diazafluorene Ligands Supporting Low-Valent [Cp*Rh] Complexes. Chemistry 2022; 28:e202103970. [PMID: 35006643 PMCID: PMC8857064 DOI: 10.1002/chem.202103970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Indexed: 12/14/2022]
Abstract
Ligands based upon the 4,5-diazafluorene core are an important class of emerging ligands in organometallic chemistry, but the structure and electronic properties of these ligands have received less attention than they deserve. Here, we show that 9,9'-dimethyl-4,5-diazafluorene (Me2 daf) can stabilize low-valent complexes through charge delocalization into its conjugated π-system. Using a new platform of [Cp*Rh] complexes with three accessible formal oxidation states (+III, +II, and +I), we show that the methylation in Me2 daf is protective, blocking Brønsted acid-base chemistry commonly encountered with other daf-based ligands. Electronic absorption spectroscopy and single-crystal X-ray diffraction analysis of a family of eleven new compounds, including the unusual Cp*Rh(Me2 daf), reveal features consistent with charge delocalization driven by π-backbonding into the LUMO of Me2 daf, reminiscent of behavior displayed by the workhorse 2,2'-bipyridyl ligand. Taken together with spectrochemical data demonstrating clean conversion between oxidation states, our findings show that 9,9'-dialkylated daf-type ligands are promising building blocks for applications in reductive chemistry and catalysis.
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Affiliation(s)
- Wade C. Henke
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Jonah P. Stiel
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Victor W. Day
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - James D. Blakemore
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
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Suhr S, Walter R, Beerhues J, Albold U, Sarkar B. Rhodium Diamidobenzene Complexes: A Tale of Different Substituents on the Diamidobenzene Ligand. Chem Sci 2022; 13:10532-10545. [PMID: 36277629 PMCID: PMC9473529 DOI: 10.1039/d2sc03227a] [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: 06/08/2022] [Accepted: 07/15/2022] [Indexed: 11/21/2022] Open
Abstract
Diamidobenzene ligands are a prominent class of redox-active ligands owing to their electron reservoir behaviour, as well as the possibility of tuning the steric and the electronic properties of such ligands through the substituents on the N-atoms of the ligands. In this contribution, we present Rh(iii) complexes with four differently substituted diamidobenzene ligands. By using a combination of crystallography, NMR spectroscopy, electrochemistry, UV-vis-NIR/EPR spectroelectrochemistry, and quantum chemical calculations we show that the substituents on the ligands have a profound influence on the bonding, donor, electrochemical and spectroscopic properties of the Rh complexes. We present, for the first time, design strategies for the isolation of mononuclear Rh(ii) metallates whose redox potentials span across more than 850 mV. These Rh(ii) metallates undergo typical metalloradical reactivity such as activation of O2 and C–Cl bond activations. Additionally, we also show that the substituents on the ligands dictate the one versus two electron nature of the oxidation steps of the Rh complexes. Furthermore, the oxidative reactivity of the metal complexes with a [CH3]+ source leads to the isolation of a unprecedented, homobimetallic, heterovalent complex featuring a novel π-bonded rhodio-o-diiminoquionone. Our results thus reveal several new potentials of the diamidobenzene ligand class in organometallic reactivity and small molecule activation with potential relevance for catalysis. Diamidobenzene ligands are versatile platforms in organometallic Rh-chemistry. They allow the isolation of tunable mononuclear ate-complexes, and the formation of a unprecedented homobimetallic, heterovalent complex.![]()
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Affiliation(s)
- Simon Suhr
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Robert Walter
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Julia Beerhues
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Uta Albold
- Institut für Chemie und Biochemie, Freie Universität Berlin Fabeckstr. 34-36 14195 Berlin Germany
| | - Biprajit Sarkar
- Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
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6
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Kuvshinova SS, Nelyubina YV, Larionov VA, Vorobyeva DV, Osipov SN, Loginov DA. Half-sandwich complexes of group 9 metals with N,Nʹ-ligands for CF3-carbenoid alkylation of N-(pyrimidin-2-yl)indole. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2021.121899] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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7
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Hopkins Leseberg JA, Lionetti D, Day VW, Blakemore JD. Electrochemical Kinetic Study of [Cp*Rh] Complexes Supported by Bis(2-pyridyl)methane Ligands. Organometallics 2021. [DOI: 10.1021/acs.organomet.0c00747] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Julie A. Hopkins Leseberg
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Davide Lionetti
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Victor W. Day
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - James D. Blakemore
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
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8
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9
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Malenov DP, Blagojević Filipović JP, Zarić SD. Stacking interactions of the methylated cyclopentadienyl ligands in the crystal structures of transition metal complexes. ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2020; 76:252-258. [PMID: 32831227 DOI: 10.1107/s2052520620002206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 02/17/2020] [Indexed: 06/11/2023]
Abstract
In the crystal structures of methylated cyclopentadienyl (Cp) complexes (MeCp, Me4Cp and Me5Cp) deposited in the Cambridge Structural Database, certain orientation types of stacked contacts can be noted as the most frequent. These orientation preferences can be well explained by the matching of oppositely charged regions of electrostatic potential. Parallel displaced stacking, large offset stacking and C-H...π interactions are the dominant interaction types that are responsible for the arrangement in the crystal structures of stacked methylated Cp complexes.
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Affiliation(s)
- Dušan P Malenov
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade 11000, Serbia
| | | | - Snežana D Zarić
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade 11000, Serbia
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10
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Wu Y, Shi J, Li D, Zhang S, Gu B, Qiu Q, Sun Y, Zhang Y, Cai Z, Jiang Z. Synergy of Electron Transfer and Electron Utilization via Metal–Organic Frameworks as an Electron Buffer Tank for Nicotinamide Regeneration. ACS Catal 2020. [DOI: 10.1021/acscatal.9b05240] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Yizhou Wu
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P. R. China
| | - Jiafu Shi
- Tianjin Engineering Center of Biomass-derived Gas and Oil, School of Environmental Science & Engineering, Tianjin University, Tianjin 300072, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P. R. China
| | - Donglin Li
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P. R. China
| | - Shaohua Zhang
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P. R. China
| | - Bo Gu
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P. R. China
| | - Qian Qiu
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P. R. China
| | - Yiying Sun
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P. R. China
| | - Yishan Zhang
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P. R. China
| | - Ziyi Cai
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P. R. China
| | - Zhongyi Jiang
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P. R. China
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City 350207, Fuzhou, P. R. China
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11
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Wang Q, Guo CH, Zhang X, Zhu M, Jiao H, Wu HS. Mechanisms and Activity of 1-Phenylethanol Dehydrogenation Catalyzed by Bifunctional NHC-Ir III
Complex. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900377] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Qiong Wang
- Key Laboratory of Magnetic Molecules; Magnetic Information Materials Ministry of Education; The School of Chemical and Material Science; Shanxi Normal University; 041004 Linfen China
| | - Cai-Hong Guo
- Key Laboratory of Magnetic Molecules; Magnetic Information Materials Ministry of Education; The School of Chemical and Material Science; Shanxi Normal University; 041004 Linfen China
| | - Xiang Zhang
- Key Laboratory of Magnetic Molecules; Magnetic Information Materials Ministry of Education; The School of Chemical and Material Science; Shanxi Normal University; 041004 Linfen China
| | - Mi Zhu
- Key Laboratory of Magnetic Molecules; Magnetic Information Materials Ministry of Education; The School of Chemical and Material Science; Shanxi Normal University; 041004 Linfen China
| | - Haijun Jiao
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock; Albert-Einstein Straße 29a 18059 Rostock Germany
| | - Hai-Shun Wu
- Key Laboratory of Magnetic Molecules; Magnetic Information Materials Ministry of Education; The School of Chemical and Material Science; Shanxi Normal University; 041004 Linfen China
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12
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Todorova TK, Huan TN, Wang X, Agarwala H, Fontecave M. Controlling Hydrogen Evolution during Photoreduction of CO 2 to Formic Acid Using [Rh(R-bpy)(Cp*)Cl] + Catalysts: A Structure-Activity Study. Inorg Chem 2019; 58:6893-6903. [PMID: 31050296 DOI: 10.1021/acs.inorgchem.9b00371] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The photochemical reduction of CO2 to formic acid catalyzed by a series of [Rh(4,4'-R-bpy)(Cp*)Cl]+ and [Rh(5,5'-COOH-bpy)(Cp*)Cl]+ complexes (Cp* = pentamethylcyclopentadienyl, bpy = 2,2'-bipyridine, and R = OCH3, CH3, H, COOC2H5, CF3, NH2, or COOH) was studied to assess how modifications in the electronic structure of the catalyst affect its selectivity, defined as the HCOOH:H2 product ratio. A direct molecular-level influence of the functional group on the initial reaction rate for CO2 versus proton reduction reactions was established. Density functional theory computations elucidated for the first time the respective role of the [RhH] and [Cp*H] tautomers, recognizing rhodium hydride as the key player for both reactions. In particular, our calculations explain the observed tendency of electron-donating substituents to favor CO2 reduction by means of decreasing the hydricity of the Rh-H bond, resulting in a lower hydride transfer barrier toward formic acid production as compared to substituents with an electron-withdrawing nature that favor more strongly the reduction of protons to hydrogen.
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Affiliation(s)
- Tanya K Todorova
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France , Université Paris 6 , 11 Place Marcelin Berthelot , 75231 Paris Cedex 05, France
| | - Tran Ngoc Huan
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France , Université Paris 6 , 11 Place Marcelin Berthelot , 75231 Paris Cedex 05, France
| | - Xia Wang
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France , Université Paris 6 , 11 Place Marcelin Berthelot , 75231 Paris Cedex 05, France
| | - Hemlata Agarwala
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France , Université Paris 6 , 11 Place Marcelin Berthelot , 75231 Paris Cedex 05, France
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France , Université Paris 6 , 11 Place Marcelin Berthelot , 75231 Paris Cedex 05, France
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13
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Boyd EA, Lionetti D, Henke WC, Day VW, Blakemore JD. Preparation, Characterization, and Electrochemical Activation of a Model [Cp*Rh] Hydride. Inorg Chem 2019; 58:3606-3615. [PMID: 30256096 DOI: 10.1021/acs.inorgchem.8b02160] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Monomeric half-sandwich rhodium hydride complexes are often proposed as intermediates in catalytic cycles, but relatively few such compounds have been isolated and studied, limiting understanding of their properties. Here, we report preparation and isolation of a monomeric rhodium(III) hydride complex bearing the pentamethylcyclopentadienyl (Cp*) and bis(diphenylphosphino)benzene (dppb) ligands. The hydride complex is formed rapidly upon addition of weak acid to a reduced precursor complex, Cp*Rh(dppb). Single-crystal X-ray diffraction data for the [Cp*Rh] hydride, which were previously unavailable for this class of compounds, provide evidence of the direct Rh-H interaction. Complementary infrared spectra show the Rh-H stretching frequency at 1986 cm-1. In contrast to results with other [Cp*Rh] complexes bearing diimine ligands, treatment of the isolated hydride with strong acid does not result in H2 evolution. Electrochemical studies reveal that the hydride complex can be reduced only at very negative potentials (ca. -2.5 V vs ferrocenium/ferrocene), resulting in Rh-H bond cleavage and H2 generation. These results are discussed in the context of catalytic H2 generation, and development of design rules for improved catalysts bearing the [Cp*] ligand.
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Affiliation(s)
- Emily A Boyd
- Department of Chemistry , University of Kansas , 1251 Wescoe Hall Drive , Lawrence , Kansas 66045 , United States
| | - Davide Lionetti
- Department of Chemistry , University of Kansas , 1251 Wescoe Hall Drive , Lawrence , Kansas 66045 , United States
| | - Wade C Henke
- Department of Chemistry , University of Kansas , 1251 Wescoe Hall Drive , Lawrence , Kansas 66045 , United States
| | - Victor W Day
- Department of Chemistry , University of Kansas , 1251 Wescoe Hall Drive , Lawrence , Kansas 66045 , United States
| | - James D Blakemore
- Department of Chemistry , University of Kansas , 1251 Wescoe Hall Drive , Lawrence , Kansas 66045 , United States
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14
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Nandanwar SK, Kim HJ. Anticancer and Antibacterial Activity of Transition Metal Complexes. ChemistrySelect 2019. [DOI: 10.1002/slct.201803073] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Sondavid K. Nandanwar
- Department of Marine Convergence ProgramPukyong National University Busan 48513 Republic of Korea
| | - Hak Jun Kim
- Department of ChemistryPukyong National University Busan 48513 Republic of Korea
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15
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Qiu Y, Scheremetjew A, Ackermann L. Electro-Oxidative C-C Alkenylation by Rhodium(III) Catalysis. J Am Chem Soc 2019; 141:2731-2738. [PMID: 30636408 DOI: 10.1021/jacs.8b13692] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Electrochemical C-C activations were accomplished by expedient oxidative rhodium(III) catalysis. Thus, oxidative C-C alkenylations proved viable with the aid of electricity, avoiding the use of toxic and/or expensive transition-metal oxidants. The chelation-assisted C-C functionalizations proceeded with ample scope and excellent levels of chemo- and position selectivities within an organometallic C-C activation manifold. Detailed mechanistic studies provided support for a kinetically relevant C-C scission, and a well-defined organometallic rhodium(III) complex was identified as a catalytically competent intermediate. The electrochemical C-C functionalization was devoid of additional electrolytes, could be conducted on a gram scale, and provided position-selective access to densely 1,2,3-substituted arenes, which are not viable by C-H activation.
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Affiliation(s)
- Youai Qiu
- Institut für Organische und Biomolekulare Chemie , Georg-August-Universität Göttingen , Tammannstrasse 2 , 37077 Göttingen , Germany
| | - Alexej Scheremetjew
- Institut für Organische und Biomolekulare Chemie , Georg-August-Universität Göttingen , Tammannstrasse 2 , 37077 Göttingen , Germany
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare Chemie , Georg-August-Universität Göttingen , Tammannstrasse 2 , 37077 Göttingen , Germany
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16
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Sobottka S, van der Meer MB, Glais E, Albold U, Suhr S, Su CY, Sarkar B. A coordinatively unsaturated iridium complex with an unsymmetrical redox-active ligand: (spectro)electrochemical and reactivity studies. Dalton Trans 2019; 48:13931-13942. [DOI: 10.1039/c9dt01597c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Metal–ligand cooperativity can be used in iridium complexes with an unsymmetrically substituted redox-active diamidobenzene ligand for bond activation reactions.
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Affiliation(s)
- Sebastian Sobottka
- Institut für Chemie und Biochemie
- Anorganische Chemie
- Freie Universität Berlin
- Berlin
- Germany
| | | | - Estelle Glais
- Institut für Chemie und Biochemie
- Anorganische Chemie
- Freie Universität Berlin
- Berlin
- Germany
| | - Uta Albold
- Institut für Chemie und Biochemie
- Anorganische Chemie
- Freie Universität Berlin
- Berlin
- Germany
| | - Simon Suhr
- Institut für Chemie und Biochemie
- Anorganische Chemie
- Freie Universität Berlin
- Berlin
- Germany
| | - Cheng-Yong Su
- School of Chemistry and Chemical Engineering
- Sun Yat-Sen University
- Guangzhou,510275
- China
| | - Biprajit Sarkar
- Institut für Chemie und Biochemie
- Anorganische Chemie
- Freie Universität Berlin
- Berlin
- Germany
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17
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Moore WNG, Henke WC, Lionetti D, Day VW, Blakemore JD. Single-Electron Redox Chemistry on the [Cp*Rh] Platform Enabled by a Nitrated Bipyridyl Ligand. Molecules 2018; 23:E2857. [PMID: 30400193 PMCID: PMC6278249 DOI: 10.3390/molecules23112857] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 10/23/2018] [Accepted: 11/01/2018] [Indexed: 11/16/2022] Open
Abstract
[Cp*Rh] complexes (Cp* = pentamethylcyclopentadienyl) are attracting renewed interest in coordination chemistry and catalysis, but these useful compounds often undergo net two-electron redox cycling that precludes observation of individual one-electron reduction events. Here, we show that a [Cp*Rh] complex bearing the 4,4'-dinitro-2,2'-bipyridyl ligand (dnbpy) (3) can access a distinctive manifold of five oxidation states in organic electrolytes, contrasting with prior work that found no accessible reductions in aqueous electrolyte. These states are readily generated from a newly isolated and fully characterized rhodium(III) precursor complex 3, formulated as [Cp*Rh(dnbpy)Cl]PF₆. Single-crystal X-ray diffraction (XRD) data, previously unavailable for the dnbpy ligand bound to the [Cp*Rh] platform, confirm the presence of both [η⁵-Cp*] and [κ²-dnbpy]. Four individual one-electron reductions of 3 are observed, contrasting sharply with the single two-electron reductions of other [Cp*Rh] complexes. Chemical preparation and the study of the singly reduced species with electronic absorption and electron paramagnetic resonance spectroscopies indicate that the first reduction is predominantly centered on the dnbpy ligand. Comparative cyclic voltammetry studies with [NBu₄][PF₆] and [NBu₄][Cl] as supporting electrolytes indicate that the chloride ligand can be lost from 3 by ligand exchange upon reduction. Spectroelectrochemical studies with ultraviolet (UV)-visible detection reveal isosbestic behavior, confirming the clean interconversion of the reduced forms of 3 inferred from the voltammetry with [NBu₄][PF₆] as supporting electrolyte. Electrochemical reduction in the presence of triethylammonium results in an irreversible response, but does not give rise to catalytic H₂ evolution, contrasting with the reactivity patterns observed in [Cp*Rh] complexes bearing bipyridyl ligands with less electron-withdrawing substituents.
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Affiliation(s)
- William N G Moore
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS 66045, USA.
| | - Wade C Henke
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS 66045, USA.
| | - Davide Lionetti
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS 66045, USA.
| | - Victor W Day
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS 66045, USA.
| | - James D Blakemore
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS 66045, USA.
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18
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Qiu Y, Stangier M, Meyer TH, Oliveira JCA, Ackermann L. Iridium-Catalyzed Electrooxidative C−H Activation by Chemoselective Redox-Catalyst Cooperation. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201809611] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Youai Qiu
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstrasse 2 37077 Göttingen Germany
| | - Maximilian Stangier
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstrasse 2 37077 Göttingen Germany
| | - Tjark H. Meyer
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstrasse 2 37077 Göttingen Germany
| | - João C. A. Oliveira
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstrasse 2 37077 Göttingen Germany
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstrasse 2 37077 Göttingen Germany
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19
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Qiu Y, Stangier M, Meyer TH, Oliveira JCA, Ackermann L. Iridium-Catalyzed Electrooxidative C-H Activation by Chemoselective Redox-Catalyst Cooperation. Angew Chem Int Ed Engl 2018; 57:14179-14183. [PMID: 30199130 DOI: 10.1002/anie.201809611] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Indexed: 01/17/2023]
Abstract
Iridium-catalyzed electrochemical C-H activation was accomplished within a cooperative catalysis manifold, setting the stage for electrooxidative C-H alkenylations through weak O-coordination. The iridium-electrocatalyzed C-H activation featured high functional-group tolerance through assistance of a metal-free redox mediator through indirect electrolysis. Detailed mechanistic insights provided strong support for an organometallic C-H cleavage and a synergistic iridium(III/I)/redox catalyst regime, enabling the use of sustainable electricity as the terminal oxidant with improved selectivity features.
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Affiliation(s)
- Youai Qiu
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077, Göttingen, Germany
| | - Maximilian Stangier
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077, Göttingen, Germany
| | - Tjark H Meyer
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077, Göttingen, Germany
| | - João C A Oliveira
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077, Göttingen, Germany
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077, Göttingen, Germany
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20
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Qiu Y, Kong WJ, Struwe J, Sauermann N, Rogge T, Scheremetjew A, Ackermann L. Electrooxidative Rhodium-Catalyzed C−H/C−H Activation: Electricity as Oxidant for Cross-Dehydrogenative Alkenylation. Angew Chem Int Ed Engl 2018; 57:5828-5832. [DOI: 10.1002/anie.201803342] [Citation(s) in RCA: 143] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Indexed: 12/31/2022]
Affiliation(s)
- Youai Qiu
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
| | - Wei-Jun Kong
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
| | - Julia Struwe
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
| | - Nicolas Sauermann
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
| | - Torben Rogge
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
| | - Alexej Scheremetjew
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
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21
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Qiu Y, Kong WJ, Struwe J, Sauermann N, Rogge T, Scheremetjew A, Ackermann L. Electrooxidative Rhodium-Catalyzed C−H/C−H Activation: Electricity as Oxidant for Cross-Dehydrogenative Alkenylation. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201803342] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Youai Qiu
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
| | - Wei-Jun Kong
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
| | - Julia Struwe
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
| | - Nicolas Sauermann
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
| | - Torben Rogge
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
| | - Alexej Scheremetjew
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare Chemie; Georg-August-Universität Göttingen; Tammannstraße 2 37077 Göttingen Germany
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22
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Lionetti D, Day VW, Lassalle-Kaiser B, Blakemore JD. Multiple binding modes of an unconjugated bis(pyridine) ligand stabilize low-valent [Cp*Rh] complexes. Chem Commun (Camb) 2018; 54:1694-1697. [DOI: 10.1039/c7cc09164h] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
An unconjugated bis(pyridine) ligand enables sequential one-electron reductions of a [Cp*Rh] complex, revealing the ligand's ability to stabilize low-valent species.
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Affiliation(s)
| | - Victor W. Day
- Department of Chemistry
- University of Kansas
- Lawrence
- USA
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23
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Henke WC, Lionetti D, Moore WNG, Hopkins JA, Day VW, Blakemore JD. Ligand Substituents Govern the Efficiency and Mechanistic Path of Hydrogen Production with [Cp*Rh] Catalysts. CHEMSUSCHEM 2017; 10:4589-4598. [PMID: 29024563 DOI: 10.1002/cssc.201701416] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/01/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate that [Cp*Rh] complexes bearing substituted 2,2'-bipyridyl ligands are effective hydrogen evolution catalysts (Cp*=η5 -pentamethylcyclopentadienyl). Disubstitution (at the 4 and 4' positions) of the bipyridyl ligand (namely -tBu, -H, and -CF3 ) modulates the catalytic overpotential, in part due to involvement of the reduced ligand character in formally rhodium(I) intermediates. These reduced species are synthesized and isolated here; protonation results in formation of complexes bearing the unusual η4 -pentamethylcyclopentadiene ligand, and the properties of these protonated intermediates further govern the catalytic performance. Electrochemical studies suggest that multiple mechanistic pathways are accessible, and that the operative pathway depends on the applied potential and solution conditions. Taken together, these results suggest synergy in metal-ligand cooperation that modulates the mechanisms of fuel-forming catalysis with organometallic compounds bearing multiple non-innocent ligands.
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Affiliation(s)
- Wade C Henke
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS, 66045, USA
| | - Davide Lionetti
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS, 66045, USA
| | - William N G Moore
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS, 66045, USA
| | - Julie A Hopkins
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS, 66045, USA
| | - Victor W Day
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS, 66045, USA
| | - James D Blakemore
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS, 66045, USA
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24
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Johnson SI, Gray HB, Blakemore JD, Goddard WA. Role of Ligand Protonation in Dihydrogen Evolution from a Pentamethylcyclopentadienyl Rhodium Catalyst. Inorg Chem 2017; 56:11375-11386. [DOI: 10.1021/acs.inorgchem.7b01698] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Samantha I. Johnson
- Center for Chemical
Innovation in Solar Fuels, California Institute of Technology, Pasadena, California 91125, United States
- Materials Research Center, California Institute of Technology, Pasadena, California 91125, United States
| | - Harry B. Gray
- Center for Chemical
Innovation in Solar Fuels, California Institute of Technology, Pasadena, California 91125, United States
| | - James D. Blakemore
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045-7582, United States
| | - William A. Goddard
- Materials Research Center, California Institute of Technology, Pasadena, California 91125, United States
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25
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Peng Y, Ramos-Garcés MV, Lionetti D, Blakemore JD. Structural and Electrochemical Consequences of [Cp*] Ligand Protonation. Inorg Chem 2017; 56:10824-10831. [PMID: 28832122 DOI: 10.1021/acs.inorgchem.7b01895] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yun Peng
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045-7582, United States
| | - Mario V. Ramos-Garcés
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045-7582, United States
| | - Davide Lionetti
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045-7582, United States
| | - James D. Blakemore
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045-7582, United States
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