通过化学修饰和外部刺激,在化物桥梁分子正方形中进行受控的分子内电子转移
Masayuki Nihei1, Yoshihiro Sekine, Naoki Suganami
1Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8571, Japan.
Journal of the American Chemical Society
|February 24, 2011
概括
这项研究详细介绍了铁分子正方形的合成,这些正方形表现出独特的旋转过渡. 化合物1显示了两步电荷转移诱导自旋转换 (CTIST) 和光诱导转换,而化合物2和3则没有.
科学领域:
- 协调化学 协调化学
- 材料科学 材料科学 材料科学
- 磁电化学 磁电化学 磁电化学
背景情况:
- 由化物联体桥接交替的Fe-Co离子组成的分子正方形因其独特的磁性特性而引起人们的兴趣.
- 电荷转移诱导自旋转换 (CTIST) 是这种材料中的一个关键现象,使其在分子开关和内存设备中具有潜在的应用.
研究的目的:
- 为了合成和描述一系列化物桥接的Fe-Co分子正方形.
- 为了研究这些分子方块的自旋过渡行为,包括温度依赖和光感应的效应.
- 阐明影响观察到的旋转转变的结构和电子因素.
主要方法:
- 使用[Fe(CN) 3(L) ]-前体和Co(II) 盐与双联体合成四核Fe-Co分子正方形.
- 可变温度X射线结构分析和磁感应度测量以确定结构和磁性质.
- 光磁实验和UV-vs-NIR吸收光谱学用于研究光诱导的过渡和电子状态.
主要成果:
- 三个化物桥接的Fe-Co分子正方形,化合物1,2和3已成功合成.
- 化合物1在固态和光感应CTIST中表现出两步电荷转移诱导的自旋转变 (CTIST),从低温 (LT) 阶段到高温 (HT) 阶段.
- 化合物2和3分别保持在HT或LT阶段,但没有表现出CTIST,这归因于影响d轨道能量的连接物修饰 (甲基和三基).
结论:
- 通过修改辅助连接体,可以调整Fe-Co分子方块的电子和结构性质.
- 复合物1通过温度和光来展示可切换的自旋状态,突出显示其用于分子设备应用的潜力.
- 这项研究提供了对CTIST的机制和多核协调复合体中旋转过渡的因素的洞察.
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