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Tomoda M, Kondo M, Izu H, Masaoka S. Brønsted Acid/Base Site Isolated in a Pentanuclear Scaffold. Chemistry 2023; 29:e202203253. [PMID: 36507625 DOI: 10.1002/chem.202203253] [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: 10/18/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 12/14/2022]
Abstract
The concept of Brønsted-Lowry acids and bases is long and widely recognized as the most reasonable theory to explain the behavior of H+ ions. Here, we report a Brønsted acid/base pair that does not follow this theory. Two heteronuclear metal complexes, in which Brønsted acid/base sites are sterically isolated, were synthesized and characterized. These sterically isolated sites exhibited anomalous behavior, wherein the H+ species encapsulated in the Brønsted acid site did not undergo a deprotonation reaction, and the corresponding protonation reaction at the Brønsted base site failed to proceed. As a result, two states that are in a relationship of a Brønsted acid/base pair stably exist over a wide pH range without any interconversion, generating a thermodynamically metastable state. Additionally, these two states exhibited distinct electron transfer abilities and reactivities. The system presented in this study is in sharp contrast with the traditional concept of Brønsted-Lowry acids and bases.
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Affiliation(s)
- Misa Tomoda
- Division of Applied Chemistry Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science (IMS), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.,Department of Structural Molecular Sciences, SOKENDAI [The Graduate University for Advanced Studies] Shonan Village, Hayama, Kanagawa, 240-0193, Japan
| | - Mio Kondo
- Division of Applied Chemistry Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Innovative Catalysis Science Division Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Suita, Osaka, 565-0871, Japan.,JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Hitoshi Izu
- Division of Applied Chemistry Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science (IMS), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan
| | - Shigeyuki Masaoka
- Division of Applied Chemistry Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Innovative Catalysis Science Division Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Suita, Osaka, 565-0871, Japan
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Kondo M, Masaoka S. Function-Integrated Catalytic Systems for Small-Molecule Conversion: Advances and Perspectives. J SYN ORG CHEM JPN 2022. [DOI: 10.5059/yukigoseikyokaishi.80.1055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Mio Kondo
- Division of Applied Chemistry, Graduate School of Engineering, Osaka University
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