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Uniaxial negative thermal expansion induced by molecular rotation in a one-dimensional supramolecular assembly with associated peculiar magnetic behavior
| Title: | Uniaxial negative thermal expansion induced by molecular rotation in a one-dimensional supramolecular assembly with associated peculiar magnetic behavior |
| Authors: | Takahashi, Kiyonori Browse this author | | Shirakawa, Yuki Browse this author | | Sakai, Hiroki Browse this author | | Hisaki, Ichiro Browse this author | | Noro, Shin-ichiro Browse this author | | Akutagawa, Tomoyuki Browse this author | | Nakano, Motohiro Browse this author | | Nakamura, Takayoshi Browse this author →KAKEN DB |
| Issue Date: | 7-Feb-2023 |
| Publisher: | Royal Society of Chemistry |
| Journal Title: | Journal of materials chemistry C |
| Volume: | 11 |
| Issue: | 5 |
| Start Page: | 1891 |
| End Page: | 1898 |
| Publisher DOI: | 10.1039/d2tc04874d |
| Abstract: | In general, negative thermal expansion (NTE) is entropy-driven. We have developed the alternative approach for achieving uniaxial NTE in a molecular crystal induced by supramolecular deformation and molecular rotation, along with peculiar magnetic responses. In the crystal of (pyridazinium(+))(2)(dibenzo[24]crown-8)(3)[Ni(dmit)(2)](-)(2) (1) (dmit = 1,3-dithiole-2-thione-4,5-dithiolate), pyridazinium was included within the dibenzo[24]crown-8, and formed a one-dimensional columnar structure parallel to the a-axis. This column elongates along the a-axis, and shrinks along the b-axis. This provides space for the pyridazinium to rotate, which promotes further NTE above 183 K. In addition, the [Ni(dmit)(2)](-) forms a dimer, where the intradimer magnetic exchange interaction (J) increases with increasing temperature. The modified singlet-triplet thermal excitation model, where J increased with increasing temperature, can be fitted to the temperature-dependent magnetic susceptibility of 1. A deviation from the model was observed above 180 K, which is attributed to the structural changes within the [Ni(dmit)(2)](-) dimer, caused by the molecular rotation of the pyridazinium moiety. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/91222 |
| Appears in Collections: | 電子科学研究所 (Research Institute for Electronic Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 高橋 仁徳
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