压缩和扩展格子 - - 在Mn3+复合体中旋转状态切换的障碍
Michelle M Harris1, Irina A Kühne1,2, Conor T Kelly1
1School of Chemistry, University College Dublin, Belfield, Dublin, D04 V1W8, Ireland.
Crystal growth & design
|June 12, 2023
概括
我们探索了对复合物的化学修改如何影响它们的自旋状态. 配体上的不同替代物影响了离子是否保持在低旋转或高旋转状态,影响了它们的磁性.
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:
- 旋转交叉 (SCO) 复合体根据其旋转状态 (例如,旋转三重组,旋转五重组) 呈现出不同的磁性特性.
- [Mn(R-sal2323) ]+系列为研究复合体中SCO现象提供了一个平台.
- 调连接物替代剂是控制金属复合物的自旋状态和SCO行为的一个关键策略.
研究的目的:
- 在[Mn(R-sal2323) ]+家族中合成和表征新的Mn3+复合.
- 为了研究电子捐赠和电子吸收组对联体的酸盐捐赠者对Mn3+旋转状态的影响.
- 为了将结构性和磁性特性与连接体替代模式及其对旋转交叉行为的影响相关联.
主要方法:
- 合成两种新的六基希夫基联体 (L1和L2) 与多种类型的酸盐替代物 (3-nitro-5-methoxy和3-methoxy-5-nitro).
- 复合Mn3+与这些连接体形成[MnL1]+和[MnL2]+复杂.
- 由此产生的14种具有不同 counterions 的新化合物的结构特征 (例如,X射线衍射) 和磁性特性测量 (例如,温度依赖的磁性易感性).
主要成果:
- 具有3--5-甲基酸盐供体 ([MnL1]+,化合物1a-7a) 的复合物在室温下主要采用了旋转三重体 (低旋转) 状态.
- 复合物中含有3-甲基-5-酸联体同位素 ([MnL2]+,化合物1b-7b) 的复合物表现出旋转三重组,旋转五重组 (高旋转) 和热旋转交叉行为.
- 结构数据显示了与纽带长度和角扭曲相关的趋势,这表明在某些复合体中,切换到高旋转状态的潜在障碍.
结论:
- 连接体设计,特别是酸盐替代物的电子性质和同位素排列,显著影响Mn3+复合物的自旋状态和SCO行为.
- 在确定观察到的磁性特性时,几何和硬质因素起着至关重要的作用.
- 该研究提供了有关Mn3+ SCO系统中旋转状态转换的因素的见解,这对设计新的磁性材料有潜在的影响.
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