季戊四醇四硝酸酯（Si-PETN）炸药巨大爆轰敏感性的解释。
Explanation of the colossal detonation sensitivity of silicon pentaerythritol tetranitrate (Si-PETN) explosive.
作者信息
Liu Wei-Guang, Zybin Sergey V, Dasgupta Siddharth, Klapötke Thomas M, Goddard William A
机构信息
Materials and Process Simulation Center, 139-74, California Institute of Technology, Pasadena, California 91125, USA.
出版信息
J Am Chem Soc. 2009 Jun 10;131(22):7490-1. doi: 10.1021/ja809725p.
DFT calculations have identified the novel rearrangement shown here for decomposition of the Si derivative of the PETN explosive [PentaErythritol TetraNitrate (PETN), C(CH(2)ONO(2))(4)] that explains the very dramatic increase in sensitivity observed experimentally. The critical difference is that Si-PETN allows a favorable five-coordinate transition state in which the new Si-O and C-O bonds form simultaneously, leading to a transition state barrier of 33 kcal/mol (it is 80 kcal/mol for PETN) and much lower than the normal O-NO(2) bond fission observed in other energetic materials (approximately 40 kcal/mol). In addition this new mechanism is very exothermic (45 kcal/mol) leading to a large net energy release at the very early stages of Si-PETN decomposition that facilitates a rapid temperature increase and expansion of the reaction zone.
密度泛函理论（DFT）计算已经确定了此处所示的新型重排反应，该反应可用于解释季戊四醇四硝酸酯（PETN，C(CH(2)ONO(2))(4)）的硅衍生物分解情况，这也解释了实验中观察到的灵敏度急剧增加的现象。关键的区别在于，硅代PETN允许形成一个有利的五配位过渡态，在此过渡态中，新的Si-O键和C-O键同时形成，导致过渡态能垒为33千卡/摩尔（PETN的能垒为80千卡/摩尔），且远低于其他含能材料中观察到的正常O-NO(2)键裂变能垒（约40千卡/摩尔）。此外，这种新机制是非常放热的（45千卡/摩尔），导致在硅代PETN分解的早期阶段有大量的净能量释放，这有利于温度快速升高和反应区的扩展。
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