Computational Design of High Energy RDX-Based Derivatives: Property Prediction, Intermolecular Interactions, and Decomposition Mechanisms

A series of new high-energy insensitive compounds were designed based on 1,3,5-trinitro-1,3,5-triazinane (RDX) skeleton through incorporating -N(NO2)-CH2-N(NO2)-, -N(NH2)-, -N(NO2)-, and -O- linkages. Then, their electronic structures, heats of formation, detonation properties, and impact sensitivities were analyzed and predicted using DFT. The types of intermolecular interactions between their bimolecular assemble were analyzed. The thermal decomposition of one compound with excellent performance was studied through ab initio molecular dynamics simulations. All the designed compounds exhibit excellent detonation properties superior to 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), and lower impact sensitivity than CL-20. Thus, they may be viewed as promising candidates for high energy density compounds. Overall, our design strategy that the construction of bicyclic or cage compounds based on the RDX framework through incorporating the intermolecular linkages is very beneficial for developing novel energetic compounds with excellent detonation performance and low sensitivity.

Computational study of energetic derivatives of 3,3′-bridged ditriazoles

A series of energetic bridged ditriazole was designed by incorporating different bridges and substituents into 4H-1,2,4-triazole ring. The geometrical structures, heats of formation, detonation properties, electronic structures, thermodynamic properties, free spaces, impact sensitivities, and thermal stabilities of the designed compounds were evaluated by employing density functional theory. The results elucidate that the –N3 substituent and –N=N– bridge can sufficiently increase their heats of formation. The calculated values of detonation properties show that –NF2, –ONO2, –O–, and –N=N(O)– are useful structural fragments to improve their detonation performance. The incorporation of the oxy (–O–) bridge increases their HOMO–LUMO energy gaps. An analysis of h50 values indicate that most of the designed compounds are less sensitive. The N(ring)-NO2 bond in the majority of the derivatives may be a possible trigger bond in thermal decomposition process. The incorporation of –CH2–CH2– and –O– is helpful to enhance their thermal stabilities. Based on appropriate thermal stabilities and superb detonation properties, six compounds were screened as promising high energy density compounds.