Designing and looking for novel cage compounds based on bicyclo-HMX as high energy density compounds

Abstract

We designed four novel cage compounds 2,4,6,8,9-pentanitro-2,4,6,8,9-pentaazatricyclo[3.3.1.0^3,7]nonane (PATN), 2,4,6,8,9,9-hexanitro-2,4,6,8-tetraazatricyclo[3.3.1.0^3,7]nonane (HNTATN), 2,4,6,8,9-pentanitro-2,4,6,8-tetraazatricyclo[3.3.1.0^3,7]nonane (PNTATN), and 2,4,6,8-tetranitro-2,4,6,8-tetraaza-9-oxatricyclo[3.3.1.0^3,7]nonane (TAOTN) by introducing the intramolecular –N(NO₂)–, –C(NO₂)₂–, –CH(NO₂)–, or –O– linkage into the bicyclo-HMX framework. Then, their molecular and electronic structures, energetic properties, thermal stability, and impact sensitivity were investigated using density functional theory. We discussed the effects of molecular geometry and electronic structure on their detonation properties. Their thermal stability was discussed based on bond dissociation energies and strain energies. We evaluated their impact sensitivity compared with known energetic compounds. Because of their detonation performance, thermal stability, and impact sensitivity, the potential candidates for high energy density compounds were selected. Our design strategy, constructing the novel cage skeleton by introducing a intramolecular linkage, may offer another way to obtain potential energetic compounds with outstanding energetic performance and low sensitivity.