在离子电荷转移复合体中,单键 (C(60) (((-)) ((2) 双质体的可逆形成:Cp*(2) Cr.C(60) (((C(6) H(4) Cl(2)) (((2). (C(60) (((-)) ((2) 的分子结构
Dmitri V Konarev1, Salavat S Khasanov, Akihiro Otsuka
1Division of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan. konarev@icp.ac.ru
Journal of the American Chemical Society
|July 18, 2002
概括
一个新的C60富勒烯与十甲基基烯的离子复合体在低温下表现出可逆的二分化. 这种结构变化会影响磁性,X射线衍射研究证实了这一点.
科学领域:
- 超分子化学 超分子化学
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
背景情况:
- 富勒,特别是C60,是材料科学中的多功能构建块.
- 涉及富勒的离子复合体具有独特的电子和结构性质.
- 十甲基 (Cp*2Cr) 是一种已知的有机金属化合物,具有形成电荷转移复合物的潜力.
研究的目的:
- 为了合成和表征一种新型的C60离子复合物与十甲基基烯.
- 调查该综合体的结构和磁性特性,特别是在低温下.
- 了解与富勒烯二元化相关的相位过渡.
主要方法:
- 在100K的单晶X射线衍射以确定低温结构.
- 对磁感应度的测量,以监测磁矩的变化.
- 电子磁共振 (EPR) 光谱检测磁共振物种.电子磁共振 (EPR) 光谱检测磁共振物种.
主要成果:
- 形成一个新的离子复合物:十甲基烯-C60 (二二) 2.
- 在室温下观察单体C60和在低温下观察单结合 (C60-) 2二极体的形成.
- X射线衍射揭示了二次体的C-C键长度为1.597(7) Å和9.28 Å的interfullerene距离.
- 在200-220K之间发生了可逆相变,标志着单元细胞参数的变化.
- 磁矩从4.20μB下降到3.88μB,并出现了来自Cp*2Cr+的EPR信号.
结论:
- 合成的复合物表现出温度依赖的富勒二元化.
- 观察到的相变归因于 (C60-) 2二次体的可逆形成.
- 结构和磁性变化为可逆二极化和相关的电子重组提供了证据.
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