Photoinduced macroscopic polarization change with long-lived metastable state

具有长寿命亚稳态的光致宏观偏振变化

• 批准号: 21K05085
• 负责人: SU SHENGQUN
• 金额: $ 2.66万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2021
• 资助国家: 日本
• 起止时间: 2021-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-21K05085/
• 关键词: polarization change; spin transition; photoexcitation; ion displacement; photo effect

The purpose of this research project is to realize the photoinduced persistent polarization change in spin crossover crystals attained by Light-Induced Excited Spin-State Trapping (LIESST) effect. After we obtained a Fe(II) spin transition complex with photoinduced polarization change in the first year, we mainly focused on exploring the factors induced the polarization change. Considering the structure of the excited state is difficult to analysis due to the low structural conversion ratio after irradiation, we confirmed that 24% of Fe(II) changes from the low spin state of the ground state to the high spin state of the excited state through variable temperature Mossbauer spectra before and after irradiation. In addition, the variable temperature IR spectra have also afforded the evidence for this result. The structure data during the spin transition from 273 K to 393 K were determined by the variable temperature single structure analysis. Combined the point charge calculation and the theoretic calculation, the calculated result indicates that the large polarization change originates from the off-centering ion displacement because of the shrinkage or expansion of cations due to the spin transition. It also shows that light-induced ion movement in a polar crystal is realized. To improve this work, the other spin crossover complex that exhibited photoinduced polarization change and complete spin transition was developed. It is a better model to study the mechanism of photoinduced polarization change and then to improve the polarization change.

本研究的目的是利用光诱导激发自旋态俘获（LIESST）效应实现自旋交叉晶体的光诱导持续极化变化。在第一年我们得到了一个具有光致极化变化的Fe（II）自旋跃迁配合物后，我们主要集中在探索引起极化变化的因素上。考虑到辐照后结构转换率低，激发态的结构难以分析，我们通过变温穆斯堡尔谱证实了辐照前后有24%的Fe（II）从基态的低自旋态转变为激发态的高自旋态。此外，变温红外光谱也为这一结果提供了证据。用变温单结构分析方法测定了273 ~ 393 K自旋转变过程中的结构数据。结合点电荷计算和理论计算，计算结果表明，大的极化变化是由于自旋跃迁引起的阳离子收缩或膨胀而引起的离子偏心位移。实验还表明，光致离子在极性晶体中的运动是可以实现的。为了改进这一工作，开发了另一种表现出光致极化变化和完全自旋转变的自旋交叉复合物。这是研究光致偏振变化机理进而改善偏振变化的较好模型。

项目成果

Macroscopic Polarization Change of Mononuclear Valence Tautomeric Cobalt Complexes Through the Use of Enantiopure Ligand

通过使用对映体纯配体改变单核价互变钴配合物的宏观偏振

• DOI: 10.1002/chem.202202161
• 发表时间: 2022
• 期刊: Chemistry ? A European Journal
• 作者: Cheng Feng;Wu Shuqi;Zheng Wenwei;Su Shengqun;Nakanishi Takumi;Xu Wenhuang;Sadhukhan Pritam;Sejima Hibiki;Ikenaga Shimon;Yamamoto Kaoru;Gao Kaige;Kanegawa Shinji;Sato Osamu
• 通讯作者: Sato Osamu

Yangzhou University(中国)

扬州大学（中国）

Photoinduced Persistent Polarization Change in a Spin Transition Crystal

• DOI: 10.1002/anie.202208771
• 发表时间: 2022-08-18
• 期刊: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
• 影响因子: 16.6
• 作者: Su, Sheng-Qun;Wu, Shu-Qi;Sato, Osamu
• 通讯作者: Sato, Osamu