Studies and Theoretical Optimization of CL-20 : RDX Cocrystal

Abstract

CL-20 among other nitramines is highly energetic along with the high positive heat of formation, and is a green energetic material employed as solid propellant [1–3]. However, it suffers basically from mechanical sensitivity and cost of synthesis. Cocrystallization of CL-20 with other suitable HEMs and LEMs is considered as the best crystal engineering technique to reduce its sensitivity [2, 4–6] as it masks crystal defects which in turn are responsible for mechanical sensitivity. The present investigation reports on the scale up process for the synthesis of Energy-Energy Cocrystallization (EECC) of ?-CL-20 and RDX and focus on the process to optimize the structure and energetics of thus formed cocrystal (CRCC) through DFT study. In our study CL-20 and RDX are taken in 1 : 1 molar ratio as suggested by Gui-yun Hang [7]. We claim successful scale up of cocrystallization to the earlier report [4] employing a more user friendly solvent (acetone) in the present study and the cocrystal formed was through ultra centrifugation. During the course of the cocrystal formation a phase transition from ?- to ? took place. The Trauzl lead block tests on CRCC support the better performance of the synthesised EECC. Introducing shock tube test as the parameter to claim the strength of HEMs enhances the comparability [8]. The present report envisages and collaborates the synthesised CRCC through the theoretical study in arriving at the spatial conformation leading to optimization in structure and energy of the synthesized EECC. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim