Advancement in explosive systems toward miniaturization and enhanced safety has prompted the development of primary explosives with powerful detonation performance and relatively low sensitivities. Energetic coordination polymers (ECPs) as a new type of energetic materials have attracted wide attention. However, regulating the energetic characters of ECPs and establishing the relationship between structure and energetic property remains great challenges. In this study, two isomorphic 2D π-stacked solvent-free coordination polymers, [M(N₃)₂(atrz)]_n (M = Co 1, Cd 2; atrz = 4,4′-azo-1,2,4-triazole), were hydrothermally prepared and structurally characterized by X-ray diffraction. The two compounds exhibit reliable stabilities, remarkable positive enthalpies of formation, and prominent heats of detonation. The enthalpy of formation of 1 is 4.21 kJ·g^–1, which is higher than those of all hitherto known primary explosives. Repulsive steric clashes between the sensitive azide ions in 1 and 2 influence the mechanical sensitivities deduced from the calculated noncovalent interaction domains. The two energetic π-stacked ECPs 1 and 2 can serve as candidates for primary explosives with an approved level of safety.

中文翻译：

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金属叠氮化物和强大的富氮配体向具有优异能量性能的一次炸药的配位聚合

炸药系统朝着小型化和增强安全性的发展，已促使开发具有强大爆炸性能和较低敏感性的初级炸药。高能配位聚合物（ECPs）作为一种新型的高能材料受到了广泛的关注。然而，调节ECP的能量特性并建立结构与能量性质之间的关系仍然是巨大的挑战。在这项研究中，两种同构2Dπ堆积的无溶剂配位聚合物[M（N ₃）₂（atrz）] _n（M = Co 1，Cd 2; 进行水热制备，并通过X射线衍射对其结构进行表征。这两种化合物显示出可靠的稳定性，显着的正焓形成和显着的爆炸热。1的形成焓为4.21 kJ·g ^–1，比迄今所有已知的初级炸药的焓高。1和2中敏感的叠氮化物离子之间的排斥性空间碰撞会影响从计算的非共价相互作用域推导出的机械敏感性。两个高能π堆积的ECP 1和2可以用作具有安全等级的初级炸药的候选物。