1
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Beagan DM, Rivera C, Szymczak NK. Appended Lewis Acids Enable Dioxygen Reactivity and Catalytic Oxidations with Ni(II). J Am Chem Soc 2024; 146:12375-12385. [PMID: 38661576 PMCID: PMC11148854 DOI: 10.1021/jacs.3c12399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
We disclose a suite of Ni(II) complexes featuring secondary sphere Lewis acids of varied Lewis acidity and tether lengths. Several of these complexes feature atypical behavior of Ni(II): reactivity with O2 that occurs only in the presence of a tethered Lewis acid. In situ UV-vis spectroscopy revealed that, although adducts are stable at -40 °C, complexes containing 9-borabicyclo[3.3.1]nonane (9-BBN) Lewis acids underwent irreversible oxidative deborylation when warmed to room temperature. We computationally and experimentally identified that oxidative instability of appended 9-BBN moieties can be mitigated using weaker Lewis acids such as pinacolborane (BPin). These insights enabled the realization of catalytic reactions: hydrogen atom abstraction from phenols and room temperature oxygen atom transfer to PPh3.
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Affiliation(s)
- Daniel M Beagan
- University of Michigan, 930 N. University Ave., Ann Arbor, Michigan 48109, United States
| | - Carolina Rivera
- University of Michigan, 930 N. University Ave., Ann Arbor, Michigan 48109, United States
| | - Nathaniel K Szymczak
- University of Michigan, 930 N. University Ave., Ann Arbor, Michigan 48109, United States
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2
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Nath S, Yadav E, Raghuvanshi A, Singh AK. Ru(II) Complexes with Protic- and Anionic-Naked-NHC Ligands for Cooperative Activation of Small Molecules. Chemistry 2023; 29:e202301971. [PMID: 37377294 DOI: 10.1002/chem.202301971] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 06/29/2023]
Abstract
A set of ruthenium(II)-protic-N-heterocyclic carbene complexes, [Ru(NNCH )(PPh3 )2 (X)]Cl (1, X=Cl and 2, X=H) and their deprotonated forms [Ru(NNC)(PPh3 )2 (X)] (1', X=Cl and 2', X=H), in which NNC is a new unsymmetrical pincer ligand, are reported. The four complexes are interconvertible by simple acid-base chemistry. The combined theoretical and spectroscopic investigations indicate charge segregation in anionic-NHC complexes (1' and 2') and can be described from a Lewis pair perspective. The chemical reactivity of deprotonated complex 1' shows cooperative small molecule activation. Complex 1' activates H-H bond of hydrogen, C(sp3 )-I bond of iodomethane, and C(sp)-H bond of phenylacetylene. The activation of CO2 using anionic NHC complex 1' at moderate temperature and ambient pressure and subsequent conversion to formate is also described. All the new compounds have been characterized using ESI-MS, 1 H, 13 C, and 31 P NMR spectroscopy. Molecular structures of 1, 2, and 2' have also been determined with single-crystal X-ray diffraction. The cooperative small molecule activation perspective broadens the scope of potential applications of anionic-NHC complexes in small molecule activation, including the conversion of carbon dioxide to formate, a much sought after reaction in the renewable energy and sustainable development domains.
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Affiliation(s)
- Shambhu Nath
- Department of Chemistry, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Ekta Yadav
- Department of Chemistry, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Abhinav Raghuvanshi
- Department of Chemistry, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Amrendra K Singh
- Department of Chemistry, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
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3
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Beagan DM, Kiernicki JJ, Zeller M, Szymczak NK. A Bidentate Ligand Featuring Ditopic Lewis Acids in the Second Sphere for Selective Substrate Capture and Activation. Angew Chem Int Ed Engl 2023; 62:e202218907. [PMID: 36720708 PMCID: PMC10023486 DOI: 10.1002/anie.202218907] [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: 12/21/2022] [Revised: 01/30/2023] [Accepted: 01/31/2023] [Indexed: 02/02/2023]
Abstract
We present a ligand platform featuring appended ditopic Lewis acids to facilitate capture/activation of diatomic substrates. We show that incorporation of two 9-borabicyclo[3.3.1]nonane (9-BBN) units on a single carbon tethered to a pyridine pyrazole scaffold maintains a set of unquenched nitrogen donors available to coordinate FeII , ZnII , and NiII . Using hydride ion affinity and competition experiments, we establish an additive effect for ditopic secondary sphere boranes, compared to the monotopic analogue. These effects are exploited to achieve high selectivity for binding NO2 - in the presence of competitive anions such as F- and NO3 - . Finally, we demonstrate hydrazine capture within the second-sphere of metal complexes, followed by unique activation pathways to generate hydrazido and diazene ligands on Zn and Fe, respectively.
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Affiliation(s)
- Daniel M Beagan
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, MI 48109, USA
| | - John J Kiernicki
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, MI 48109, USA
- Present address: Drury University, Department of Chemistry and Physics, 900 North Benton Ave., Springfield, MO 65802, USA
| | - Matthias Zeller
- H.C. Brown Laboratory, Department of Chemistry, Purdue University, 560 Oval Dr., West Lafayette, IN 47907, USA
| | - Nathaniel K Szymczak
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, MI 48109, USA
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4
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Zurakowski JA, Austen BJ, Drover MW. Exterior decorating: Lewis acid secondary coordination spheres for cooperative reactivity. TRENDS IN CHEMISTRY 2022. [DOI: 10.1016/j.trechm.2022.01.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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5
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Spielvogel KD, Stumme NC, Fetrow TV, Wang L, Luna JA, Keith JM, Shaw SK, Daly SR. Quantifying Variations in Metal–Ligand Cooperative Binding Strength with Cyclic Voltammetry and Redox-Active Ligands. Inorg Chem 2022; 61:2391-2401. [DOI: 10.1021/acs.inorgchem.1c03014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Kyle D. Spielvogel
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Nathan C. Stumme
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Taylor V. Fetrow
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Li Wang
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Javier A. Luna
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Jason M. Keith
- Department of Chemistry, Colgate University, 13 Oak Drive, Hamilton, New York 13346, United States
| | - Scott K. Shaw
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
| | - Scott R. Daly
- Department of Chemistry, The University of Iowa, E331 Chemistry Building, Iowa City, Iowa 52242, United States
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6
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Elsby MR, Kim SYH, Steinmann SN, Baker RT. Same ligand, three first-row metals: comparing M-amido bifunctional reactivity (Mn, Fe, Co). Dalton Trans 2021; 50:14542-14546. [PMID: 34661593 DOI: 10.1039/d1dt02637b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The bifunctional reactivity of three metal SNS (bis)amido complexes was computationally assessed by comparing the nucleophilicity of the M-Namido donor (Mn, Fe, Co). Hirshfeld charges identified the Mn-Namido donor as most nucleophilic and Fe as most electrophilic metal. Reaction energy profiles of a model bifunctional H2 activation showed Mn with the lowest reaction barrier (17 kcal mol-1), followed by Fe and Co (21 and 29 kcal mol-1).
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Affiliation(s)
- Matthew R Elsby
- Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario, K1N 6N5 Canada.
| | - Scott Y H Kim
- Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario, K1N 6N5 Canada.
| | | | - R Tom Baker
- Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario, K1N 6N5 Canada.
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7
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Kiernicki JJ, Norwine EE, Zeller M, Szymczak NK. Substrate Specific Metal-Ligand Cooperative Binding: Considerations for Weak Intramolecular Lewis Acid/Base Pairs. Inorg Chem 2021; 60:13806-13810. [PMID: 34242009 DOI: 10.1021/acs.inorgchem.1c01382] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Metal-ligand cooperative binding modes were interrogated in a series of zinc bis(thiophenoxide) complexes. A weak B-S binding interaction is observed in solution between the weakly Lewis basic thiophenoxide ligands and an appended trialkylborane. The energy of this binding event is dependent upon the strength of the Lewis acid and its proximity to the zinc thiophenoxide.
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Affiliation(s)
- John J Kiernicki
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Emily E Norwine
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Matthias Zeller
- H. C. Brown Laboratory, Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Nathaniel K Szymczak
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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8
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Kiernicki JJ, Norwine EE, Lovasz MA, Zeller M, Szymczak NK. Mobility of Lewis acids within the secondary coordination sphere: toward a model for cooperative substrate binding. Chem Commun (Camb) 2020; 56:13105-13108. [PMID: 33016291 PMCID: PMC7606458 DOI: 10.1039/d0cc05121g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Distance dependence of appended Lewis acids in N2H4 binding and deprotonation was evaluated within a series of zinc complexes. Variation of spacer-length to a tethered trialkylborane Lewis acid revealed distinct preferences for binding and stabilization of the resulting deprotonated N2H3- unit.
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Affiliation(s)
- John J Kiernicki
- University of Michigan, 930 N. University, Ann Arbor, MI 48109, USA.
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9
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Carter C, Kratish Y, Jurca T, Gao Y, Marks TJ. Bis-Ferrocenyl-Pyridinediimine Trinuclear Mixed-Valent Complexes with Metal-Binding Dependent Electronic Coupling: Synthesis, Structures, and Redox-Spectroscopic Characterization. J Am Chem Soc 2020; 142:18715-18729. [DOI: 10.1021/jacs.0c10015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Cole Carter
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208−3113, United States
| | - Yosi Kratish
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208−3113, United States
| | - Titel Jurca
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208−3113, United States
| | - Yanshan Gao
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208−3113, United States
| | - Tobin J. Marks
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208−3113, United States
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10
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Elsby MR, Baker RT. Strategies and mechanisms of metal–ligand cooperativity in first-row transition metal complex catalysts. Chem Soc Rev 2020; 49:8933-8987. [DOI: 10.1039/d0cs00509f] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The use of metal–ligand cooperation (MLC) by transition metal bifunctional catalysts has emerged at the forefront of homogeneous catalysis science.
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Affiliation(s)
- Matthew R. Elsby
- Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation
- University of Ottawa
- Ottawa
- Canada
| | - R. Tom Baker
- Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation
- University of Ottawa
- Ottawa
- Canada
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