凝聚相能材料的分解:单分子和双分子机制之间的相互作用
David Furman1, Ronnie Kosloff, Faina Dubnikova
1Fritz Haber Research Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem , Jerusalem 91904, Israel.
Journal of the American Chemical Society
|February 6, 2014
概括
爆炸性分解的激活能量在凝结阶段显著降低,这是由于从单分子到双分子激素反应的转变. 这项研究解释了像TNT这样的酸芳香爆炸物中能量屏障的降低.
科学领域:
- 化学 化学 化学
- 材料科学 材料科学 材料科学
- 计算化学计算化学
背景情况:
- 激活能量对于爆炸性能至关重要.
- 凝聚相亚酸盐中减少的激活能量是一个长期存在的难题.
- 气相分解在机械上不同于爆炸物中缩相分解.
研究的目的:
- 为了合理化缩相酸芳香爆炸物中减少的激活能量.
- 研究从气相单分子分解向凝聚相双分子分解的机械转变.
- 为了阐明2,4,6-三二 (TNT) 的气相和冷凝相之间的激活能差异的起源.
主要方法:
- 使用电子结构计算.
- 采用了反应分子动力学 (ReaxFF-lg) 模拟.
- 在极端的温度和压力条件下探测了冷凝相化学.
主要成果:
- 在凝结阶段确定了从单分子到激进双分子反应的机制变化.
- 确定了负责低激活能量路径的关键双分子激素反应.
- 解释了TNT的气相 (~62 kcal/mol) 和凝聚相 (~35 kcal/mol) 激活能量之间的显著差异.
结论:
- 凝聚相亚酸盐的激活能量的减少归因于转换到双分子基路径.
- 这与胺和酸盐相反,它们在两个阶段均以单分子分解.
- 基爆炸物的反应性可以通过单分子和双分子过程的相互作用来理解.
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