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Wegener D, Pérez-Bitrián A, Limberg N, Wiesner A, Hoffmann KF, Riedel S. A Highly Sterically Encumbered Boron Lewis Acid Enabled by an Organotellurium-Based Ligand. Chemistry 2024; 30:e202401231. [PMID: 38625061 DOI: 10.1002/chem.202401231] [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: 04/06/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/17/2024]
Abstract
Lewis acidic boron compounds are ubiquitous in chemistry due to their numerous applications, yet tuning and optimizing their properties towards different purposes is still a challenging field of research. In this work, the boron-based Lewis acid B[OTeF3(C6F5)2]3 was synthesized by reaction of the teflate derivative HOTeF3(C6F5)2 with BCl3 or BCl3 ⋅ SMe2. This new compound presents a remarkably high thermal stability up to 300 °C, as well as one of the most sterically encumbered boron centres known in the literature. Theoretical and experimental methods revealed that B[OTeF3(C6F5)2]3 exhibits a comparable Lewis acidity to that of the well-known B(C6F5)3. The affinity of B[OTeF3(C6F5)2]3 towards pyridine was accessed by Isothermal Titration Calorimetry (ITC) and compared to that of B(OTeF5)3 and B(C6F5)3. The ligand-transfer reactivity of this new boron compound towards different fluorides was demonstrated by the formation of an anionic Au(III) complex and a hypervalent iodine(III) species.
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Affiliation(s)
- Daniel Wegener
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, 14195, Berlin, Germany
| | - Alberto Pérez-Bitrián
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, 14195, Berlin, Germany
- Current address: Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin, Germany
| | - Niklas Limberg
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, 14195, Berlin, Germany
| | - Anja Wiesner
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, 14195, Berlin, Germany
| | - Kurt F Hoffmann
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, 14195, Berlin, Germany
| | - Sebastian Riedel
- Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, 14195, Berlin, Germany
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Mondal H, Chattaraj PK. Unraveling Reactivity Pathways: Dihydrogen Activation and Hydrogenation of Multiple Bonds by Pyramidalized Boron-Based Frustrated Lewis Pairs. ChemistryOpen 2024; 13:e202300179. [PMID: 38117941 PMCID: PMC11004477 DOI: 10.1002/open.202300179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/24/2023] [Indexed: 12/22/2023] Open
Abstract
The activation of H2 by pyramidalized boron-based frustrated Lewis Pairs (FLPs) (B/E-FLP systems where "E" refers to N, P, As, Sb, and Bi) have been explored using density functional theory (DFT) based computational study. The activation pathway for the entire process is accurately characterized through the utilization of the activation strain model (ASM) of reactivity, shedding light on the underlying physical factors governing the process. The study also explores the hydrogenation process of multiple bonds with the help of B/N-FLP. The research findings demonstrate that the liberation of activated dihydrogen occurs in a synchronized, albeit noticeably asynchronous, fashion. The transformation is extensively elucidated using the activation strain model and the energy decomposition analysis. This approach suggests a co-operative double hydrogen-transfer mechanism, where the B-H hydride triggers a nucleophilic attack on the carbon atom of the multiple bonds, succeeded by the migration of the protic N-H.
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Affiliation(s)
- Himangshu Mondal
- Department of ChemistryIndian Institute of TechnologyKharagpur721302India
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Timoshkin AY. The Field of Main Group Lewis Acids and Lewis Superacids: Important Basics and Recent Developments. Chemistry 2024; 30:e202302457. [PMID: 37752859 DOI: 10.1002/chem.202302457] [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: 07/30/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 09/28/2023]
Abstract
New developments in the field of Lewis acidity are highlighted, with the focus of novel Lewis acids and Lewis superacids of group 2, 13, 14, and 15 elements. Several important basics, illustrated by modern examples (classification of Donor-Acceptor (DA) complexes, amphoteric nature of any compound in terms of DA interactions, reorganization energies of main group Lewis acids and the role of the energies of frontier orbitals) are presented and discussed. It is emphasized that the Lewis acidity phenomena are general and play vital role in different areas of chemistry: from weak "atomophilic" interactions to the complexes of Lewis superacids.
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Affiliation(s)
- Alexey Y Timoshkin
- Institute of Chemistry, St. Petersburg State University, 199034, Universitetskaya emb. 7/9, St. Petersburg, Russia
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Pomogaeva AV, Timoshkin AY. Hydrogen Activation by Frustrated and Not So Frustrated Lewis Pairs Based on Pyramidal Lewis Acid 9-Boratriptycene: A Computational Study. ACS OMEGA 2022; 7:48493-48505. [PMID: 36591180 PMCID: PMC9798527 DOI: 10.1021/acsomega.2c06836] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Structural features and reactivity of frustrated Lewis pairs (FLPs) formed by pyramidal group 13 Lewis acids based on 9-bora and 9-alatriptycene and bulky phosphines P t Bu3, PPh3, and PCy3 are considered at the M06-2X/def2-TZVP level of theory. Classic FLP is formed only in the B(C6Me4)3CH/P t Bu3 system, while both FLP and donor-acceptor (DA) complex are observed in the B(C6F4)3CF/P t Bu3 system. Formation of DA complexes was observed in other systems; the B(C6H4)3CH·P t Bu3 complex features an elongated DA bond and can be considered a "latent" FLP. Transition states and reaction pathways for molecular hydrogen activation have been obtained. Processes of heterolytic hydrogen splitting are energetically more favored in solution compared to the gas phase, while activation energies in the gas phase and in solution are close. The alternative processes of hydrogenation of B-C or Al-C bonds in the source pyramidal Lewis acids in the absence of a Lewis base are exergonic but have larger activation energies than those for heterolytic hydrogen splitting. The tuning of Lewis acidity of 9-boratriptycene by changing the substituents allows one to control its reactivity with respect to hydrogen activation. Interestingly, the most promising system from the practical point of view is the DA complex B(C6H4)3CH·P t Bu3, which is predicted to provide both low activation energy and thermodynamic reversibility of the heterolytic hydrogen splitting process. It appears that such "not so frustrated" or "latent" FLPs are the best candidates for reversible heterolytic hydrogen splitting.
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Pomogaeva AV, Timoshkin AY. Influence of the solvent on the Lewis acidity of antimony pentahalides and group 13 Lewis acids toward acetonitrile and pyridine. J Comput Chem 2021; 42:1792-1802. [PMID: 34227137 DOI: 10.1002/jcc.26713] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 11/05/2022]
Abstract
Energetic effects of solvation of SbF5 , SbCl5 , and 21 group 13 Lewis acids (LA) and their molecular complexes with acetonitrile and pyridine are evaluated using SMD approach. Compared to the gas phase, solvation increases the stability of boron- and aluminum-containing complexes but decreases the stability of gallium and indium-containing homologs due to larger solation energies of free LA. New Lewis acidity scales, based on the Gibbs energy of dissociation of the molecular complexes LA·pyridine and LA·acetonitrile in the gas phase, in benzene and acetonitrile solutions, are proposed.
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Affiliation(s)
- Anna V Pomogaeva
- Institute of Chemistry, St. Petersburg State University, St. Petersburg, Russian Federation
| | - Alexey Y Timoshkin
- Institute of Chemistry, St. Petersburg State University, St. Petersburg, Russian Federation
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Katzman BD, Maar RR, Cappello D, Sattler MO, Boyle PD, Staroverov VN, Gilroy JB. A strongly Lewis-acidic and fluorescent borenium cation supported by a tridentate formazanate ligand. Chem Commun (Camb) 2021; 57:9530-9533. [PMID: 34546239 DOI: 10.1039/d1cc03873g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Lewis acids are highly sought after for their applications in sensing, small-molecule activation, and catalysis. When combined with π-conjugated molecular frameworks, Lewis acids with unique optoelectronic properties can be realized. Here, we use a tridentate formazanate ligand to create a planar, redox-active, fluorescent, and strongly Lewis-acidic borenium cation. We also demonstrate that this compound can act as a colourimetric probe for reactivity.
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Affiliation(s)
- Benjamin D Katzman
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
| | - Ryan R Maar
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
| | - Daniela Cappello
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
| | - Madeleine O Sattler
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
| | - Paul D Boyle
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
| | - Viktor N Staroverov
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
| | - Joe B Gilroy
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario, Canada.
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Stoian C, Olaru M, Cucuiet TA, Kegyes KT, Sava A, Timoshkin AY, Raţ CI, Beckmann J. Bulky Polyfluorinated Terphenyldiphenylboranes: Water Tolerant Lewis Acids. Chemistry 2021; 27:4327-4331. [PMID: 33368648 PMCID: PMC7986919 DOI: 10.1002/chem.202005367] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Indexed: 11/23/2022]
Abstract
Protocols for the synthesis of the bulky polyfluorinated triarylboranes 2,6‐(C6F5)2C6F3B(C6F5)2 (1), 2,6‐(C6F5)2C6F3B[3,5‐(CF3)2C6H3] (2), 2,4,6‐(C6F5)3C6H2B(C6F5)2 (3), 2,4,6‐(C6F5)3C6H2B[3,5‐(CF3)2C6H3] (4) were developed. All boranes are water tolerant and according to the Gutmann‐Beckett method, 1–3 display Lewis acidities larger than that of the prominent B(C6F5)3.
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Affiliation(s)
- Corina Stoian
- Institut für Anorganische Chemie und Kristallographie, Universität Bremen, Leobener Straße 7, 28359, Bremen, Germany.,Department of Chemistry, Supramolecular Organic and Organometallic Chemistry Centre (SOOMCC), Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, Arany János Steet 11, 400028, Cluj-Napoca, Romania
| | - Marian Olaru
- Institut für Anorganische Chemie und Kristallographie, Universität Bremen, Leobener Straße 7, 28359, Bremen, Germany
| | - Teodor A Cucuiet
- Department of Chemistry, Supramolecular Organic and Organometallic Chemistry Centre (SOOMCC), Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, Arany János Steet 11, 400028, Cluj-Napoca, Romania
| | - Krisztina T Kegyes
- Department of Chemistry, Supramolecular Organic and Organometallic Chemistry Centre (SOOMCC), Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, Arany János Steet 11, 400028, Cluj-Napoca, Romania
| | - Alexandru Sava
- Department of Chemistry, Supramolecular Organic and Organometallic Chemistry Centre (SOOMCC), Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, Arany János Steet 11, 400028, Cluj-Napoca, Romania
| | - Alexey Y Timoshkin
- Institute of Chemistry, St. Petersburg State University, Universitetskaya emb. 7/9, 199034, St. Petersburg, Russia
| | - Ciprian I Raţ
- Department of Chemistry, Supramolecular Organic and Organometallic Chemistry Centre (SOOMCC), Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, Arany János Steet 11, 400028, Cluj-Napoca, Romania
| | - Jens Beckmann
- Institut für Anorganische Chemie und Kristallographie, Universität Bremen, Leobener Straße 7, 28359, Bremen, Germany
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