能量转移,展开和碎片化动态在N-质子八素与H-SAM表面碰撞中的能量转移,展开和碎片化动态
George L Barnes1, William L Hase
1Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA.
Journal of the American Chemical Society
|November 26, 2009
概括
模拟表明,与表面的碰撞会导致展开和碎片化. 对的能量转移与实验一致,而表面能量转移随着碰撞能量增加而增加.
科学领域:
- 计算化学是一种计算化学.
- 表面科学是一门科学.
- 生物物理学的生物物理.
背景情况:
- 了解-表面相互作用对于蛋白质组学和材料科学等领域至关重要.
- 直接动力学模拟提供了对碰撞过程中复杂的能量转移和碎片化过程的见解.
研究的目的:
- 通过使用QM+MM模拟,研究N质子八甘氨酸 (gly(8) -H(+)) 与八乙醇自组装单层 (H-SAM) 碰撞的动力学.
- 为了验证和更深入地理解,将模拟结果与实验数据进行比较.
主要方法:
- 进行了PM3和RM1 QM+MM直动力学模拟.
- 计算了8 ps的轨迹,碰撞能量为5到110 eV,撞击角度为0和45度.
- 分析了能量转移,碎片化和形状变化.
主要成果:
- 发现PM3和RM1的能量传输方法之间有很好的一致性,但在碎片化时间尺度上存在差异.
- 观察到对和H-SAM的碰撞能量和内部能量分布之间的线性关系.
- 证明45度的入射角度增加了对的能量转移,并诱导了显著的构造变化,包括展开成β片状结构.
- 在更高的能量下,通过质子转移促进的非破碎碎片,在RM1模拟中观察到更多的碎片.
结论:
- 表面碰撞引发了显著的形状变化和碎片化.
- 模拟结果,特别是在正常发生时的能量转移,与实验结果一致.
- 撞击角度和碰撞能量在决定表面相互作用的结果方面发挥着至关重要的作用.
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