Abstract For energetic compounds, a slight difference in their molecular structures can result in a tremendous difference in their properties. Compounds with similar structures but exhibiting big difference in their physicochemical properties (such as density and detonation properties) are of interest to the researchers. The understanding of the reason causes the difference in their properties is important for designing new energetic compounds with improved performances. In this study, the structural and physicochemical properties of 3,3′-bis-1,2,4-oxadiazole-5,5′-dione (1) and 3,3′-azo-1,2,4-oxadiazole-5,5′-dione (2) and their derivatives were presented. All of the synthesized compounds were fully characterized, the comparative studies showed that 1 and its ionic derivatives were found to exhibit higher detonation velocities and pressures as well as higher densities than their corresponding azo linkage analogs. The crystal structures for the two neutral compounds were compared by Hirshfeld surface and non-covalent interaction analyses. The results indicate that a high packing coefficient and extensive π-π stacking interactions are two major reasons for 1 exhibiting better physicochemical and energetic properties.

中文翻译：

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桥接的1,2,4-恶唑酮及其衍生物的比较研究

摘要对于高能化合物，其分子结构上的微小差异会导致其性质上的巨大差异。具有相似结构但在物理化学性质（例如密度和爆轰性质）上表现出很大差异的化合物引起了研究人员的兴趣。了解原因会导致其性能差异对于设计性能改善的新型含能化合物很重要。在这项研究中，3,3'-双-1,2,4-恶二唑-5,5'-二酮（1）和3,3'-偶氮-1,2,4-恶二唑-的结构和理化性质介绍了5,5'-二酮（2）及其衍生物。所有合成的化合物均经过充分表征，比较研究表明，与它们相应的偶氮键类似物相比，发现1及其离子衍生物具有更高的爆炸速度和压力以及更高的密度。通过Hirshfeld表面和非共价相互作用分析比较了两种中性化合物的晶体结构。结果表明，高堆积系数和广泛的π-π堆积相互作用是1表现出更好的理化和能量特性的两个主要原因。