Intermolecular Interaction of Tetrabutylammonium and Tetrabutylphosphonium Salt Hydrates by Low-Frequency Raman Observation
Semi-clathrate hydrates are attractive heat storage materials because the equilibrium temperatures, located above 0 °C in most cases, can be changed by selecting guest cations and anions. The equilibrium temperatures are influenced by the size and hydrophilicity of guest ions, hydration number, crys...
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| Format: | Article |
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MDPI AG
2022-07-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/27/15/4743 |
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| author | Yasuhiro Miwa Tomoki Nagahama Harumi Sato Atsushi Tani Kei Takeya |
| author_facet | Yasuhiro Miwa Tomoki Nagahama Harumi Sato Atsushi Tani Kei Takeya |
| author_sort | Yasuhiro Miwa |
| collection | DOAJ |
| description | Semi-clathrate hydrates are attractive heat storage materials because the equilibrium temperatures, located above 0 °C in most cases, can be changed by selecting guest cations and anions. The equilibrium temperatures are influenced by the size and hydrophilicity of guest ions, hydration number, crystal structure, and so on. This indicates that intermolecular and/or interionic interaction in the semi-clathrate hydrates may be related to the variation of the equilibrium temperatures. Therefore, intermolecular and/or interionic interaction in semi-clathrate hydrates with quaternary onium salts was directly observed using low-frequency Raman spectroscopy, a type of terahertz spectroscopy. The results show that Raman peak positions were mostly correlated with the equilibrium temperatures: in the semi-clathrate hydrates with higher equilibrium temperatures, Raman peaks around 65 cm<sup>−1</sup> appeared at a higher wavenumber and the other Raman peaks at around 200 cm<sup>−1</sup> appeared at a lower wavenumber. Low-frequency Raman observation is a valuable tool with which to study the equilibrium temperatures in semi-clathrate hydrates. |
| first_indexed | 2024-03-09T05:11:14Z |
| format | Article |
| id | doaj.art-9cdd57953bc241a1ab4cce29a2f478c9 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-09T05:11:14Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-9cdd57953bc241a1ab4cce29a2f478c92023-12-03T12:49:23ZengMDPI AGMolecules1420-30492022-07-012715474310.3390/molecules27154743Intermolecular Interaction of Tetrabutylammonium and Tetrabutylphosphonium Salt Hydrates by Low-Frequency Raman ObservationYasuhiro Miwa0Tomoki Nagahama1Harumi Sato2Atsushi Tani3Kei Takeya4Graduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada, Kobe 657-8501, JapanGraduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada, Kobe 657-8501, JapanGraduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada, Kobe 657-8501, JapanGraduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada, Kobe 657-8501, JapanInstitute for Molecular Science (IMS), 38 Nishigonaka, Myodaiji, Okazaki 444-8585, JapanSemi-clathrate hydrates are attractive heat storage materials because the equilibrium temperatures, located above 0 °C in most cases, can be changed by selecting guest cations and anions. The equilibrium temperatures are influenced by the size and hydrophilicity of guest ions, hydration number, crystal structure, and so on. This indicates that intermolecular and/or interionic interaction in the semi-clathrate hydrates may be related to the variation of the equilibrium temperatures. Therefore, intermolecular and/or interionic interaction in semi-clathrate hydrates with quaternary onium salts was directly observed using low-frequency Raman spectroscopy, a type of terahertz spectroscopy. The results show that Raman peak positions were mostly correlated with the equilibrium temperatures: in the semi-clathrate hydrates with higher equilibrium temperatures, Raman peaks around 65 cm<sup>−1</sup> appeared at a higher wavenumber and the other Raman peaks at around 200 cm<sup>−1</sup> appeared at a lower wavenumber. Low-frequency Raman observation is a valuable tool with which to study the equilibrium temperatures in semi-clathrate hydrates.https://www.mdpi.com/1420-3049/27/15/4743semi-clathrate hydrateintermolecular interactioninterionic interactionlow-frequency Ramanequilibrium temperature |
| spellingShingle | Yasuhiro Miwa Tomoki Nagahama Harumi Sato Atsushi Tani Kei Takeya Intermolecular Interaction of Tetrabutylammonium and Tetrabutylphosphonium Salt Hydrates by Low-Frequency Raman Observation Molecules semi-clathrate hydrate intermolecular interaction interionic interaction low-frequency Raman equilibrium temperature |
| title | Intermolecular Interaction of Tetrabutylammonium and Tetrabutylphosphonium Salt Hydrates by Low-Frequency Raman Observation |
| title_full | Intermolecular Interaction of Tetrabutylammonium and Tetrabutylphosphonium Salt Hydrates by Low-Frequency Raman Observation |
| title_fullStr | Intermolecular Interaction of Tetrabutylammonium and Tetrabutylphosphonium Salt Hydrates by Low-Frequency Raman Observation |
| title_full_unstemmed | Intermolecular Interaction of Tetrabutylammonium and Tetrabutylphosphonium Salt Hydrates by Low-Frequency Raman Observation |
| title_short | Intermolecular Interaction of Tetrabutylammonium and Tetrabutylphosphonium Salt Hydrates by Low-Frequency Raman Observation |
| title_sort | intermolecular interaction of tetrabutylammonium and tetrabutylphosphonium salt hydrates by low frequency raman observation |
| topic | semi-clathrate hydrate intermolecular interaction interionic interaction low-frequency Raman equilibrium temperature |
| url | https://www.mdpi.com/1420-3049/27/15/4743 |
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