1
|
Depenbrock F, Limpke T, Stammler A, Oldengott J, Bögge H, Glaser T. Increasing the electron donation in a dinucleating ligand family: molecular and electronic structures in a series of Co IICo II complexes. Dalton Trans 2024; 53:9554-9567. [PMID: 38771300 DOI: 10.1039/d4dt00877d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
We have developed a family of dinucleating ligands with varying terminal donors to generate dinuclear peroxo and high-valent complexes and to correlate their stabilities and reactivities with their molecular and electronic structures as a function of the terminal donors. It appears that the electron-donating ability of the terminal donors is an important handle for controlling these stabilities and reactivities. Here, we present the synthesis of a new dinucleating ligand with potentially strong donating terminal imidazole donors. As CoII ions are sensitive to variations in donor strength in terms of coordination number, magnetism, UV-Vis-NIR spectra, redox potentials, we probe the electron donation ability of this new ligand in CoIICoII complexes in comparison to the parent CoIICoII complexes with terminal pyridine donors and we synthesize the analogous CoIICoII complexes with terminal 6-methylpyridines and methoxy-substituted pyridines. The molecular structures show indeed strong variations in coordination numbers and bond lengths. These differences in the molecular structures are reflected in the magnetic properties and in the d-d transitions demonstrating that the molecular structures remain intact upon dissolution. The redox potentials are analyzed with respect to the electron donation ability and are the only handle to observe an effect of the methoxy-substituted pyridines. All data taken together show the following order of electron donating ability for the terminal donors: 6-methylpyridines ≪ pyridines < methoxy-substituted pyridines ≪ imidazoles.
Collapse
Affiliation(s)
- Felix Depenbrock
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
| | - Thomas Limpke
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
| | - Anja Stammler
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
| | - Jan Oldengott
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
| | - Hartmut Bögge
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
| | - Thorsten Glaser
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
| |
Collapse
|
2
|
Malik DD, Ryu W, Kim Y, Singh G, Kim JH, Sankaralingam M, Lee YM, Seo MS, Sundararajan M, Ocampo D, Roemelt M, Park K, Kim SH, Baik MH, Shearer J, Ray K, Fukuzumi S, Nam W. Identification, Characterization, and Electronic Structures of Interconvertible Cobalt-Oxygen TAML Intermediates. J Am Chem Soc 2024; 146:13817-13835. [PMID: 38716885 DOI: 10.1021/jacs.3c14346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Abstract
The reaction of Li[(TAML)CoIII]·3H2O (TAML = tetraamido macrocyclic tetraanionic ligand) with iodosylbenzene at 253 K in acetone in the presence of redox-innocent metal ions (Sc(OTf)3 and Y(OTf)3) or triflic acid affords a blue species 1, which is converted reversibly to a green species 2 upon cooling to 193 K. The electronic structures of 1 and 2 have been determined by combining advanced spectroscopic techniques (X-band electron paramagnetic resonance (EPR), electron nuclear double resonance (ENDOR), X-ray absorption spectroscopy/extended X-ray absorption fine structure (XAS/EXAFS), and magnetic circular dichroism (MCD)) with ab initio theoretical studies. Complex 1 is best represented as an S = 1/2 [(Sol)(TAML•+)CoIII---OH(LA)]- species (LA = Lewis/Brønsted acid and Sol = solvent), where an S = 1 Co(III) center is antiferromagnetically coupled to S = 1/2 TAML•+, which represents a one-electron oxidized TAML ligand. In contrast, complex 2, also with an S = 1/2 ground state, is found to be multiconfigurational with contributions of both the resonance forms [(H-TAML)CoIV═O(LA)]- and [(H-TAML•+)CoIII═O(LA)]-; H-TAML and H-TAML•+ represent the protonated forms of TAML and TAML•+ ligands, respectively. Thus, the interconversion of 1 and 2 is associated with a LA-associated tautomerization event, whereby H+ shifts from the terminal -OH group to TAML•+ with the concomitant formation of a terminal cobalt-oxo species possessing both singlet (SCo = 0) Co(III) and doublet (SCo = 1/2) Co(IV) characters. The reactivities of 1 and 2 at different temperatures have been investigated in oxygen atom transfer (OAT) and hydrogen atom transfer (HAT) reactions to compare the activation enthalpies and entropies of 1 and 2.
Collapse
Affiliation(s)
- Deesha D Malik
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Wooyeol Ryu
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| | - Yujeong Kim
- Western Seoul Center, Korea Basic Science Institute, Seoul 03759, Korea
| | - Gurjot Singh
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Jun-Hyeong Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science, Daejeon 34141, Korea
| | | | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Mi Sook Seo
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Mahesh Sundararajan
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science, Daejeon 34141, Korea
- Theoretical Chemistry Section, Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
| | - Daniel Ocampo
- Department of Chemistry, Trinity University, San Antonio, Texas 78212-7200, United States
| | - Michael Roemelt
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Kiyoung Park
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| | - Sun Hee Kim
- Western Seoul Center, Korea Basic Science Institute, Seoul 03759, Korea
- Department of Chemistry, Chung-Ang University, Seoul 06974, Korea
| | - Mu-Hyun Baik
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science, Daejeon 34141, Korea
| | - Jason Shearer
- Department of Chemistry, Trinity University, San Antonio, Texas 78212-7200, United States
| | - Kallol Ray
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| |
Collapse
|
3
|
Uhlig F, Stammler MB, Meurer F, Shenderovich IG, Blahut J, Wisser FM. Monitoring structure and coordination chemistry of Co 4O 4-based oxygen evolution catalysts by nitrogen-14/-15 and cobalt-59 NMR spectroscopy. Dalton Trans 2024; 53:8541-8545. [PMID: 38712528 DOI: 10.1039/d4dt01273a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
The structural features of cobalt-based oxygen evolution catalysts are elucidated by combining high-field MAS NMR spectroscopy and DFT calculations. The superior photocatalytic activity of the heterogeneous system over its homogeneous counterpart is rationalised by the structural features. The higher activity is caused by a more favourable electron-withdrawing character of the framework.
Collapse
Affiliation(s)
- Felix Uhlig
- University of Regensburg, Institute of Inorganic Chemistry, Universitätsstraße 31, 93053 Regensburg, Germany.
| | - Michael B Stammler
- University of Regensburg, Institute of Inorganic Chemistry, Universitätsstraße 31, 93053 Regensburg, Germany.
| | - Florian Meurer
- University of Regensburg, Institute of Inorganic Chemistry, Universitätsstraße 31, 93053 Regensburg, Germany.
- Rossendorf Beamline, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Ilya G Shenderovich
- University of Regensburg, Institute of Organic Chemistry, Universitätsstraße 31, 93040 Regensburg, Germany
| | - Jan Blahut
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 166 10, Prague 6, Czech Republic.
| | - Florian M Wisser
- University of Regensburg, Institute of Inorganic Chemistry, Universitätsstraße 31, 93053 Regensburg, Germany.
- Erlangen Center for Interface Research and Catalysis, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
| |
Collapse
|
4
|
Depenbrock F, Limpke T, Bill E, SantaLucia DJ, van Gastel M, Walleck S, Oldengott J, Stammler A, Bögge H, Glaser T. Reactivities and Electronic Structures of μ-1,2-Peroxo and μ-1,2-Superoxo Co IIICo III Complexes: Electrophilic Reactivity and O 2 Release Induced by Oxidation. Inorg Chem 2023; 62:17913-17930. [PMID: 37838986 DOI: 10.1021/acs.inorgchem.3c02782] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Peroxo complexes are key intermediates in water oxidation catalysis (WOC). Cobalt plays an important role in WOC, either as oxides CoOx or as {CoIII(μ-1,2-peroxo)CoIII} complexes, which are the oldest peroxo complexes known. The oxidation of {CoIII(μ-1,2-peroxo)CoIII} complexes had usually been described to form {CoIII(μ-1,2-superoxo)CoIII} complexes; however, recently the formation of {CoIV(μ-1,2-peroxo)CoIII} species were suggested. Using a bis(tetradentate) dinucleating ligand, we present here the synthesis and characterization of {CoIII(μ-1,2-peroxo)(μ-OH)CoIII} and {CoIII(μ-OH)2CoIII} complexes. Oxidation of {CoIII(μ-1,2-peroxo)(μ-OH)CoIII} at -40 °C in CH3CN provides the stable {CoIII(μ-1,2-superoxo)(μ-OH)CoIII} species and activates electrophilic reactivity. Moreover, {CoIII(μ-1,2-peroxo)(μ-OH)CoIII} catalyzes water oxidation, not molecularly but rather via CoOx films. While {CoIII(μ-1,2-peroxo)(μ-OH)CoIII} can be reversibly deprotonated with DBU at -40 °C in CH3CN, {CoIII(μ-1,2-superoxo)(μ-OH)CoIII} undergoes irreversible conversions upon reaction with bases to a new intermediate that is also the decay product of {CoIII(μ-1,2-superoxo)(μ-OH)CoIII} in aqueous solution at pH > 2. Based on a combination of experimental methods, the new intermediate is proposed to have a {CoII(μ-OH)CoIII} core formed by the release of O2 from {CoIII(μ-1,2-superoxo)(μ-OH)CoIII} confirmed by a 100% yield of O2 upon photocatalytic oxidation of {CoIII(μ-1,2-peroxo)(μ-OH)CoIII}. This release of O2 by oxidation of a peroxo intermediate corresponds to the last step in molecular WOC.
Collapse
Affiliation(s)
- Felix Depenbrock
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, Bielefeld D-33615, Germany
| | - Thomas Limpke
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, Bielefeld D-33615, Germany
| | - Eckhard Bill
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstr. 34-36, Mülheim an der Ruhr D-45470, Germany
| | - Daniel J SantaLucia
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr D-45470, Germany
| | - Maurice van Gastel
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr D-45470, Germany
| | - Stephan Walleck
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, Bielefeld D-33615, Germany
| | - Jan Oldengott
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, Bielefeld D-33615, Germany
| | - Anja Stammler
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, Bielefeld D-33615, Germany
| | - Hartmut Bögge
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, Bielefeld D-33615, Germany
| | - Thorsten Glaser
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, Bielefeld D-33615, Germany
| |
Collapse
|
5
|
Montgomery CL, Amtawong J, Jordan AM, Kurtz DA, Dempsey JL. Proton transfer kinetics of transition metal hydride complexes and implications for fuel-forming reactions. Chem Soc Rev 2023; 52:7137-7169. [PMID: 37750006 DOI: 10.1039/d3cs00355h] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Proton transfer reactions involving transition metal hydride complexes are prevalent in a number of catalytic fuel-forming reactions, where the proton transfer kinetics to or from the metal center can have significant impacts on the efficiency, selectivity, and stability associated with the catalytic cycle. This review correlates the often slow proton transfer rate constants of transition metal hydride complexes to their electronic and structural descriptors and provides perspective on how to exploit these parameters to control proton transfer kinetics to and from the metal center. A toolbox of techniques for experimental determination of proton transfer rate constants is discussed, and case studies where proton transfer rate constant determination informs fuel-forming reactions are highlighted. Opportunities for extending proton transfer kinetic measurements to additional systems are presented, and the importance of synergizing the thermodynamics and kinetics of proton transfer involving transition metal hydride complexes is emphasized.
Collapse
Affiliation(s)
- Charlotte L Montgomery
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA.
| | - Jaruwan Amtawong
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA.
| | - Aldo M Jordan
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA.
| | - Daniel A Kurtz
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA.
| | - Jillian L Dempsey
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA.
| |
Collapse
|
6
|
Xiong G, Feng C, Chen HC, Li J, Jiang F, Tao S, Wang Y, Li Y, Pan Y. Atomically Dispersed Pt-Doped Co 3 O 4 Spinel Nanoparticles Embedded in Polyhedron Frames for Robust Propane Oxidation at Low Temperature. SMALL METHODS 2023:e2300121. [PMID: 37002182 DOI: 10.1002/smtd.202300121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/04/2023] [Indexed: 06/19/2023]
Abstract
This study adopts a facile and effective in situ encapsulation-oxidation strategy for constructing a coupling catalyst composed of atomically dispersed Pt-doped Co3 O4 spinel nanoparticles (NPs) embedded in polyhedron frames (PFs) for robust propane total oxidation. Benefiting from the abundant oxygen vacancies and more highly valent active Co3+ species caused by the doping of Pt atoms as well as the confinement effect, the optimized 0.2Pt-Co3 O4 NPs/PFs catalyst exhibits excellent propane catalytic activity with low T90 (184 °C), superior apparent reaction rate (21.62×108 (mol gcat -1 s-1 )), low apparent activation energy (Ea = 17.89 kJ mol-1 ), high turnover frequency ( 811×107 (mol gcat -1 s-1 )) as well as good stability. In situ diffuse reflectance infrared Fourier transform spectroscopy and density functional theory calculations indicate that the doping of Pt atoms enhances the oxygen activation ability, and decreases the energy barrier required for CH bond breaking, thus improving the deep oxidation process of the intermediate species. This study opens up new ideas for constructing coupling catalysts from atomic scale with low cost to enhance the activation of oxygen molecules and the deep oxidation of linear short chain alkanes at low temperature.
Collapse
Affiliation(s)
- Gaoyan Xiong
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Chao Feng
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Hsiao-Chien Chen
- Center for Reliability Science and Technologies, Center for Green Technology, Chang Gung University, Taoyuan, 33302, Taiwan
- Kidney Research Center, Department of Nephrology, Chang Gung Memorial Hospital, Linkou, Taoyuan, 33305, Taiwan
| | - Junxi Li
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Fei Jiang
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Shu Tao
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Yunxia Wang
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Yichuan Li
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Yuan Pan
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| |
Collapse
|
7
|
Zhao Y, Adiyeri Saseendran DP, Huang C, Triana CA, Marks WR, Chen H, Zhao H, Patzke GR. Oxygen Evolution/Reduction Reaction Catalysts: From In Situ Monitoring and Reaction Mechanisms to Rational Design. Chem Rev 2023; 123:6257-6358. [PMID: 36944098 DOI: 10.1021/acs.chemrev.2c00515] [Citation(s) in RCA: 50] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
The oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are core steps of various energy conversion and storage systems. However, their sluggish reaction kinetics, i.e., the demanding multielectron transfer processes, still render OER/ORR catalysts less efficient for practical applications. Moreover, the complexity of the catalyst-electrolyte interface makes a comprehensive understanding of the intrinsic OER/ORR mechanisms challenging. Fortunately, recent advances of in situ/operando characterization techniques have facilitated the kinetic monitoring of catalysts under reaction conditions. Here we provide selected highlights of recent in situ/operando mechanistic studies of OER/ORR catalysts with the main emphasis placed on heterogeneous systems (primarily discussing first-row transition metals which operate under basic conditions), followed by a brief outlook on molecular catalysts. Key sections in this review are focused on determination of the true active species, identification of the active sites, and monitoring of the reactive intermediates. For in-depth insights into the above factors, a short overview of the metrics for accurate characterizations of OER/ORR catalysts is provided. A combination of the obtained time-resolved reaction information and reliable activity data will then guide the rational design of new catalysts. Strategies such as optimizing the restructuring process as well as overcoming the adsorption-energy scaling relations will be discussed. Finally, pending current challenges and prospects toward the understanding and development of efficient heterogeneous catalysts and selected homogeneous catalysts are presented.
Collapse
Affiliation(s)
- Yonggui Zhao
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | | | - Chong Huang
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Carlos A Triana
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Walker R Marks
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Hang Chen
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Han Zhao
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Greta R Patzke
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| |
Collapse
|
8
|
Shiau AA, Lee HB, Oyala PH, Agapie T. Mn IV4O 4 Model of the S 3 Intermediate of the Oxygen-Evolving Complex: Effect of the Dianionic Disiloxide Ligand. Inorg Chem 2023; 62:1791-1796. [PMID: 35829634 DOI: 10.1021/acs.inorgchem.2c01612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Synthetic complexes provide useful models to study the interplay between the structure and spectroscopy of the different Sn-state intermediates of the oxygen-evolving complex (OEC) of photosystem II (PSII). Complexes containing the MnIV4 core corresponding to the S3 state, the last observable intermediate prior to dioxygen formation, remain very rare. Toward the development of synthetic strategies to stabilize highly oxidized tetranuclear complexes, ligands with increased anion charge were pursued. Herein, we report the synthesis, electrochemistry, SQUID magnetometry, and electron paramagnetic resonance spectroscopy of a stable MnIV4O4 cuboidal complex supported by a disiloxide ligand. The substitution of an anionic acetate or amidate ligand with a dianionic disiloxide ligand shifts the reduction potential of the MnIIIMnIV3/MnIV4 redox couple by up to ∼760 mV, improving stability. The S = 3 spin ground state of the siloxide-ligated MnIV4O4 complex matches the acetate and amidate variants, in corroboration with the MnIV4 assignment of the S3 state of the OEC.
Collapse
Affiliation(s)
- Angela A Shiau
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States
| | - Heui Beom Lee
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States
| | - Paul H Oyala
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States
| | - Theodor Agapie
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States
| |
Collapse
|
9
|
Cooney SE, Fertig AA, Buisch MR, Brennessel WW, Matson EM. Coordination-induced bond weakening of water at the surface of an oxygen-deficient polyoxovanadate cluster. Chem Sci 2022; 13:12726-12737. [PMID: 36519047 PMCID: PMC9645371 DOI: 10.1039/d2sc04843d] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/10/2022] [Indexed: 10/19/2023] Open
Abstract
Hydrogen-atom (H-atom) transfer at the surface of heterogeneous metal oxides has received significant attention owing to its relevance in energy conversion and storage processes. Here, we present the synthesis and characterization of an organofunctionalized polyoxovanadate cluster, (calix)V6O5(OH2)(OMe)8 (calix = 4-tert-butylcalix[4]arene). Through a series of equilibrium studies, we establish the BDFE(O-H)avg of the aquo ligand as 62.4 ± 0.2 kcal mol-1, indicating substantial bond weaking of water upon coordination to the cluster surface. Subsequent kinetic isotope effect studies and Eyring analysis indicate the mechanism by which the hydrogenation of organic substrates occurs proceeds through a concerted proton-electron transfer from the aquo ligand. Atomistic resolution of surface reactivity presents a novel route of hydrogenation reactivity from metal oxide surfaces through H-atom transfer from surface-bound water molecules.
Collapse
Affiliation(s)
- Shannon E Cooney
- Department of Chemistry, University of Rochester Rochester NY 14627 USA
| | - Alex A Fertig
- Department of Chemistry, University of Rochester Rochester NY 14627 USA
| | | | | | - Ellen M Matson
- Department of Chemistry, University of Rochester Rochester NY 14627 USA
| |
Collapse
|
10
|
Skjelstad BB, Helgaker T, Maeda S, Balcells D. Oxyl Character and Methane Hydroxylation Mechanism in Heterometallic M( O)Co 3O 4 Cubanes (M = Cr, Mn, Fe, Mo, Tc, Ru, and Rh). ACS Catal 2022. [DOI: 10.1021/acscatal.2c03748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Bastian Bjerkem Skjelstad
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, 0315 Oslo, Norway
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Trygve Helgaker
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, 0315 Oslo, Norway
| | - Satoshi Maeda
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan
| | - David Balcells
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, 0315 Oslo, Norway
| |
Collapse
|
11
|
Wang K, Li SS, Wang J, He ZH, Wang D, Zhang RR, Wang W, Yang Y, Liu ZT. Photothermal oxidation of cyclohexane over CoLaOx/WO3 Z-scheme composites with p-n heterojunction in solvent-free conditions. Catal Today 2022. [DOI: 10.1016/j.cattod.2022.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
12
|
Resorcin[4]arene-based [Co12] supermolecule cage functionalized by bio-inspired [Co4O4] cubanes for visible light-driven water oxidation. INORG CHEM COMMUN 2022. [DOI: 10.1016/j.inoche.2022.109514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|