Desensitizing high energy materials HMX and CL-20 by the smallest all carbon compound cyclo[18]carbon: a DFT study

The safety of energetic materials is very important to reduce accidents. Thus, for the first time, the smallest all carbon compound cyclo[18]carbon (C18) was used to develop new energetic composite materials to desensitize two most powerful energetic materials (HMX and CL-20). Based on the designed composites, the structures, interaction and binding strength, and safety performance of them were studied using DFT and ESP methods. The desensitizing mechanism was explored also. The results showed that the binding process of C18 with HMX or CL-20 was exothermic and spontaneous thermodynamically, and the binding energy of HMX/C18 and CL-20/C18 composites was negative, showing the high possibility of binding C18 with HMX or CL-20 to form energetic composite materials. The impact sensitivity of HMX and CL-20 could be reduced more than 40% through shortening the N-NO2 bonds, decreasing the number of positive ESP values and dispersing the region with high ESP values. C18 could also reduce the electrostatic sensitivity of them by decreasing the ability to electron withdrawing, enhancing the ability to electron donating and transition, and changing the electron-induced reaction sites from HMX or CL-20 to C18. In all, it is worth to form new HMX/C18 and CL-20/C18 energetic composite materials with superior safety performance.