We designed four bicyclic nitramines and three cage nitramines by incorporating −N(NO₂)–CH₂–N(NO₂)–, −N(NO₂)–, and −O– linkages based on the HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazocane) framework. Then, their electronic structure, heats of formation, energetic properties, strain energy, thermal stability, and impact sensitivity were systematically studied using density functional theory (DFT). Compared to the parent compound HMX, all the title compounds have much higher density, better detonation properties, and better oxygen balance. Among them, four compounds have extraordinary high detonation properties (D > 9.70 km/s and P > 44.30 GPa). Moreover, most of the title compounds exhibit better thermal stability and lower impact sensitivity than CL-20 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane) or HNHAA (hexanitrohexaazaadamantane). Thus, all of the seven new nitramine compounds are promising candidates for high energy density compounds. In particular, five compounds exhibit a best combination of better oxygen balance, good thermal stability, excellent detonation properties superior to or comparable to CL-20 or HNHAA, and lower impact sensitivity than CL-20 or HNHAA. The results indicate that our unusual design strategy that constructing bicyclic or cage nitramines based on the HMX framework by incorporating the intramolecular linkages is very useful for developing novel energetic compounds with excellent detonation performance and low sensitivity.

中文翻译：

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一系列新型双环和笼式硝胺为高能量密度化合物的理论设计

我们设计了四个双环硝胺和三个轿厢硝胺通过掺入-N（NO ₂）-CH ₂ -N（NO ₂） - ， - N（NO ₂） - ，和-O-键基于所述HMX（1,3， 5,7-tetranitro-1,3,5,7-tetrazocane）骨架。然后，使用密度泛函理论（DFT）系统地研究了它们的电子结构，形成热，高能性质，应变能，热稳定性和冲击敏感性。与母体化合物HMX相比，所有标题化合物均具有更高的密度，更好的爆轰特性和更好的氧平衡。其中，四种化合物具有极高的爆震性能（D > 9.70 km / s和P> 44.30 GPa）。此外，大多数标题化合物比CL-20 2,4,6,8,10,12-六硝基-2,4,6,8,10,12-六氮杂异纤锌矿型结构烷烃或HNHAA（）表现出更好的热稳定性和更低的冲击敏感性。六硝基六氮杂金刚烷）。因此，所有七个新的硝胺化合物都是高能量密度化合物的有前途的候选者。尤其是，五种化合物的最佳组合是氧平衡更好，热稳定性好，比CL-20或HNHAA更好的爆轰性能以及比CL-20或HNHAA更低的冲击敏感性。结果表明，我们不寻常的设计策略是通过结合分子内键，基于HMX框架构建双环或笼型硝胺，对于开发具有出色爆震性能和低灵敏度的高能化合物非常有用。