在异构铁 (II) 复合体中依赖溶剂和替代剂的晶格旋转交叉
Senthil Kumar Kuppusamy1, Asato Mizuno2, Lea Kämmerer3
1Institute of Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany. senthil.kuppusamy2@kit.edu.
Dalton transactions (Cambridge, England : 2003)
|June 3, 2024
概括
在铁 (II) 复合体中,旋转状态的切换受到连接物替代物的影响. 乙基2,6-bis(1H-pyrazol-1-yl) isonicotinate连接物能够实现双稳定切换,而其他连接物则会捕获高旋转状态或显示逐渐转换.
科学领域:
- 协调化学 协调化学
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
背景情况:
- 对于分子开关来说,铁 (II) 复合体中的旋转状态切换 (SCO) 是至关重要的.
- 连接物设计显著影响SCO特性,包括歇斯底里和合作性.
- 了解替代物效应是调整单核铁 (II) 复合体中SCO行为的关键.
研究的目的:
- 调查异构铁 (II) 复合体中替代物对SCO的影响.
- 为了比较复合物中的SCO行为与乙2,6-bis(1H-pyrazol-1-yl) isonicotinate (L1) 和 (2,6-di(1H-pyrazol-1-yl) pyridin-4-yl) methylacetate (L2) 连接物.
- 探索分子结构,SCO和分子设备中的潜在应用之间的关系.
主要方法:
- 铁 (II) 复合物的合成与基于BPP的配体 (L1和L2).
- 使用温度依赖的磁感应度测量对旋转状态切换的表征.
- 低旋转和高旋转形式的结构分析,以了解上合组织机制.
- 研究光引起的旋转状态切换 (LIESST效应).
主要成果:
- 复杂的1·CH3CN (L1联体) 呈现出双稳定的SCO,具有广泛的歇斯底里 (44K) 和室温切换 (298K).
- 复合物2a (L2联体) 保持在高旋转状态,而复合物2b·CH3CN-Y则呈现逐渐的,非歇斯底里的SCO.
- 两种复合体1·CH3CN和2b·CH3CN-Y都通过LIESST在5K时显示出光感应的旋转状态切换.
- 结构分析显示,复合物1·CH3CN的低旋转形式中的跨-N{pyridyl}-Fe-N{pyridyl}角度明显扭曲,与歇斯底里的SCO相关.
结论:
- 连接物替代剂在铁 (II) 复合体中批判性地控制了自旋状态切换行为.
- 在室温复合物1·CH3CN中观察到的双稳定SCO突出了其在分子开关应用中的潜力.
- 结构性扭曲在使歇性旋转状态在固态中切换成为可能方面发挥着重要作用.
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