Explanation of the colossal detonation sensitivity of silicon pentaerythritol tetranitrate (Si-PETN) explosive
Wei-Guang Liu, Sergey V. Zybin, Siddharth Dasgupta, Thomas M. Klaptke, William A. Goddard III
Abstract
DFT calculations have identified the novel rearrangement shown here for decomposition of the Si derivative of the PETN explosive [pentaerythritol tetranitrate (PETN), C(CH_2ONO_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 (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.
Group Members
Liu, W., Zybin, S. V., Dasgupta, S., Klaptke, T. M., & III, W. A. G. (2009). Explanation of the colossal detonation sensitivity of silicon pentaerythritol tetranitrate (Si-PETN) explosive. *J. Am. Chem. Soc.*, *131*(22), 7490-7491. https://doi.org/10.1021/ja809725p