A theoretical prediction on CN6O: structure, stability and performance
The potential energy surfaces of CN6O isomers were calculated at the B3LYP/aug-cc-pVDZ level and the key decomposition pathways were calculated at the G3B3 level. The optimum pathway for the decomposition of carbonyl diazide to OCN4 and N2 has a barrier of about 30 kcal mol−1. Except for carbonyl diazide, no isomer of CN6O crosses a higher decomposition barrier than 20 kcal mol−1. The specific impulse of carbonyl diazide is close to those of RDX (cyclotrimethylene trinitramine), HMX (cyclotetramethylene tetranitramine) and CL-20 (hexanitrohexaazaisowurtzitane), and the specific impulses of many other CN6O isomers are greater than that of FTDO ([1,2,5]oxadizolo[3,4-4][1,2,3,4]tetrazine-4,6-di-N-dioxide). The CN6O system has a higher combustion temperature than RDX, HMX, CL-20 and FTDO at comparable specific impulses. The detonation velocity and pressure of most of CN6O isomers are lower than that of CL-20.