Chemical insight on decreased sensitivity of CL-20/TNT co-crystal revealed by ReaxFF MD simulations

Understanding the underlying mechanisms on sensitivity-decrease of the CL-20/TNT co-crystal is essential for wide applications of the promising high-energetic CL-20. This work presents the chemical scenario of CL-20/TNT thermolysis obtained from ReaxFF molecular dynamics simulations. Facilitated by the unique VARxMD for reaction analysis, the interplay reactions between CL-20 and TNT responsible for the sensitivity-decrease of CL-20/TNT was first revealed. The early response of CL-20/TNT to thermal stimulus is dominated by N―NO2 bond cleavage for NO2 formation and C―N bond scission leading to ring-opening of CL-20. The kinetics of N―NO2 and C―N bond cleavage as well as the followed oxygen-abstraction of NO2 are significantly slowed in the CL-20/TNT thermolysis against β-CL-20, which are responsible for the low sensitivity at the stage of active intermediate generation. The early formed active intermediates of NO2, NO3, NO and N2O are confined and consumed by the reactions of the surrounding TNT or ring in...