通过AFM对四重H键二次体的力谱:动态键断裂和分子时间-温度叠加
Shan Zou1, Holger Schönherr, G Julius Vancso
1Materials Science and Technology of Polymers, MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede, The Netherlands.
Journal of the American Chemical Society
|August 11, 2005
概括
我们将时间-温度叠加原理应用于单分子键断裂力. 这种方法扩展了可访问的负载率,允许在不平衡状态和平衡状态下研究超分子复合物.
科学领域:
- 超分子化学 超分子化学
- 物理化学 物理化学
- 材料科学 材料科学 材料科学
背景情况:
- 在单个分子水平上了解超分子键的机械性质对于设计先进材料至关重要.
- 现有的实验技术往往在可访问的强力加载率范围内面临局限性,这阻碍了对键动态的全面分析.
研究的目的:
- 应用时间-温度叠加原理来分析超分子键断裂力.
- 为了扩大单分子力光谱 (SMFS) 实验的实验可访问的强力加载速率范围.
- 在不同的热力学条件下研究四重键复合物的解结行为.
主要方法:
- 利用基于原子力显微镜 (AFM) 的单分子力光谱 (SMFS) 与现场可变温度实验.
- 采用时间-温度叠加原理来构建力-负载率主曲线.
- 在有机介质 (六甲) 中研究了四重H键的尿素-4[1H]-胺 (UPy) 2复合体.
主要成果:
- 证明了时间-温度叠加原理对超分子键断裂力的应用.
- 构建了强力加载率主曲线,将可访问范围从5nN/s扩展到500nN/s.
- 在301K时观察到依赖加载速度的解束力和在330K时观察到依赖加载速度的解束力,表明非平衡和准平衡状态之间的过渡.
- 对于 (UPy) 2 复合体,在负载率为 5.6 nN/s 的情况下,确定了约 145 pN 的交叉力.
结论:
- 时间-温度叠加原理有效地扩大了SMFS实验中可访问的加载率范围.
- 这种方法可以获得超分子复合体潜在能量景观的细节.
- 能够在热力学不平衡和准平衡条件下直接探测解结行为.
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