在有机溶剂中,H2和H2@C60的核放松
Elena Sartori1, Marco Ruzzi, Nicholas J Turro
1Department of Chemistry, Columbia University, New York, NY 10027, USA.
Journal of the American Chemical Society
|November 16, 2006
概括
溶剂显著影响-1核旋网放松时间 (T1) 对H2和H2@C60. 类似的温度依赖放松行为表明共享的潜在机制.
科学领域:
- 物理化学 物理化学
- 材料科学 材料科学 材料科学
- 核磁共振光谱学 核磁共振光谱学
背景情况:
- 核自旋晶格放松时间 (T1) 是一个反映分子动态的基本属性.
- 了解放松机制对于解释NMR数据和描述分子系统至关重要.
- 在富勒伦C60 (H2@C60) 中封装的分子 (H2) 提供了一个独特的系统,用于研究分子动力学上的限制效应.
研究的目的:
- 调查有机溶剂对H2和H2@C60.0的1H核自旋放松时间 (T1) 的影响.
- 阐明控制溶液中的H2和H2@C60的主导放松机制.
- 为了比较T1对自由H2和封装H2.2的溶剂和温度的依赖性.
主要方法:
- 在各种有机溶剂中测量H2和H2@C60的1H核自旋放松时间 (T1).
- 系统的温度变化,以研究T1的温度依赖性.
- 对放松数据的分析,以确定不同放松机制的贡献.
主要成果:
- 无论是H2还是H2@C60的1H T1都表现出与选择有机溶剂的比例变化.
- 排除了分子间磁相互作用作为一个重要的因素.
- 对于H2和H2@C60,观察到类似的T1的温度依赖,T1通过最大.
- 这种行为归因于双极和旋转旋转放松机制的相互作用,它们具有相反的温度依赖性.
结论:
- 有机溶剂在调节H2的放松过程中发挥着至关重要的作用,无论是在自由溶液中还是被封装在C60中.
- 与自由H2.2相比,被C60封闭并没有从根本上改变主要的放松机制.
- 观察到的温度依赖性支持温度依赖的双极和自旋旋转放松机制的同时贡献.
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