Chemical insights into the initial thermolysis reactions of [2,2’-bi(1,3,4-oxadiazole)]-5,5’-dinitramide (ICM-101) from quantum chemical modeling

Abstract

ICM-101 exhibits the density and detonation performance comparable to CL-20, however the atomistic details of its decomposition still remain lacking. Density functional theory and coupled-cluster theory were utilized to study the unimolecular decomposition of ICM-101 in this work. The detailed primary decay reactions map was presented, and results of thermochemistry calculations showed that the preferred decomposition path of ICM-101 is the oxidation of C atom by nitro group, which is a universal decay path in a range of energetic molecules. Furthermore, we found the reversible H transfer and bond rotation reactions for ICM-101 decay, in which bond rotation reaction was proposed as a new sensitivity mechanism. The bond rotation reaction takes place with a low energy barrier, and the product could return back to original molecule with a low barrier. Those findings could contribute to a deep understating of the sensitivity and safety of energetic materials.