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Okude S, Koizumi K, Sakamoto Y, Hatakeyama M, Wakabayashi M, Yokojima S, Nishimura R, Hattori Y, Uchida K, Nakamura S. Spontaneous Combustion of 2-Bromo-3-Methoxythiophene: A Study on Reaction Pathways and Energetics by Quantum Chemical Calculations. J Phys Chem A 2021; 125:5615-5625. [PMID: 34137622 DOI: 10.1021/acs.jpca.1c01569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reaction pathways and energetics for the dimerization and trimerization reactions of 2-bromo-3-methoxythiophene (2Br-3Met) molecules are investigated using hybrid density functional theory (DFT) calculations to obtain insight into the oligomerization reaction observed in the spontaneous combustion of pure liquid 2Br-3Met. The calculations show that the carbon-bromine bond in a 2Br-3Met molecule elongates easily, and the trans addition of this C-Br bond to a double bond in the neighboring 2Br-3Met molecule occurs easily at room temperature, reflecting the evaluated activation energy of ΔHa = 12.46 kcal/mol (enthalpy) or ΔGa = 35.68 kcal/mol (Gibbs free energy, 298.150 K and 1 atm). The formation process of trimers is calculated in a similar way. A model for the explanation of spontaneous combustion is proposed; large oligomers of the 2Br-3Met molecule are produced spontaneously following the initial formation of dimers or trimers. UV-vis spectra and vibration spectra are obtained for related molecular species, which show reasonable agreement with the experimental results.
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Affiliation(s)
- Shin'ichiro Okude
- Cluster for Science, Technology and Innovation Hub, Nakamura Laboratory, RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kenichi Koizumi
- Cluster for Science, Technology and Innovation Hub, Nakamura Laboratory, RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yuki Sakamoto
- Cluster for Science, Technology and Innovation Hub, Nakamura Laboratory, RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - Makoto Hatakeyama
- Cluster for Science, Technology and Innovation Hub, Nakamura Laboratory, RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - Masamitsu Wakabayashi
- Cluster for Science, Technology and Innovation Hub, Nakamura Laboratory, RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - Satoshi Yokojima
- Cluster for Science, Technology and Innovation Hub, Nakamura Laboratory, RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan.,Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Ryo Nishimura
- Department of Materials Chemistry, Faculty of Science and Technology, Ryukoku University, Seta, Otsu, Shiga 520-2194, Japan
| | - Yohei Hattori
- Department of Materials Chemistry, Faculty of Science and Technology, Ryukoku University, Seta, Otsu, Shiga 520-2194, Japan
| | - Kingo Uchida
- Department of Materials Chemistry, Faculty of Science and Technology, Ryukoku University, Seta, Otsu, Shiga 520-2194, Japan
| | - Shinichiro Nakamura
- Cluster for Science, Technology and Innovation Hub, Nakamura Laboratory, RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
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