在两个复合体中,具有高过渡温度的歇斯底里旋转交叉 (Hysteretic Spin Crossover)
Yu-Chen Sun1, Feng-Li Chen1, Kang-Jie Wang1
1State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
Inorganic chemistry
|September 7, 2023
概括
两个新的 (II) 复合体在高温下表现出歇斯底里旋转交叉 (SCO) 过渡. 这种行为源于连接体功能组的顺序-失序过渡,为SCO材料设计提供了洞察力.
科学领域:
- 协调化学 协调化学
- 材料科学 材料科学 材料科学
- 磁力学 磁力学 是一种
背景情况:
- 过渡金属复合体中的旋转交叉 (SCO) 现象对于开发分子开关和记忆器件至关重要.
- 歇斯底里性SCO过渡,特别是在高温下,很少见,并且在实际应用中非常受欢迎.
- 众所周知, (II) 复合体表现出SCO,但实现具有显著热歇斯底里的合作过渡仍然具有挑战性.
研究的目的:
- 合成和表征具有潜在的歇斯底里旋转交叉的新型单核 ((II) 复合物.
- 调查磁性特性,并确定这些复合体中旋转交叉过渡的结构起源.
- 探索连接物修饰对SCO行为和热歇斯底里的影响.
主要方法:
- 合成了两个单核 (II) 复合物,[Co (terpy-CH2OH) ]·X2 (X=SCN- (1) 和SeCN- (2)).
- 使用X射线衍射进行结构性表征.
- 磁性测量 (取决于温度的磁性易感性),以确定旋转交叉过渡和hysteresis.
- 分析与连接体排序相关的晶体相变的分析.
主要成果:
- 这两种复合体都在高温 (320400 K) 上表现出歇斯底里旋转交叉过渡.
- 综合体1显示了加热时的一步过渡和冷却时的两步过渡.
- 综合体2展示了一个明显的歇斯底里循环,宽度为5K.
- 单晶X射线衍射揭示了歇斯底里性SCO转换与涉及-CH2OH组排序的晶体相转换有关.
结论:
- 特皮里丁配体的修饰显著影响了复合物的磁性特性和SCO行为.
- 观察到的歇斯底里性SCO转换归因于连接体上悬挂氧甲基组的热诱导的顺序-乱序转换.
- 这些发现为设计高温应用可调节歇斯底里的材料提供了一条道路.
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