Fused heterocyclic energetic cation was rarely reported despite the development of energetic cation has attracted increasing attention in recent years. In this work, a new 1H-imidazo[4,5-d]pyridazine-2,4,7-triamine was synthesized in a one-step reaction, which was used as a cation to prepare 1H-imidazo[4,5-d]pyridazine-2,4,7-triamine perchlorate. Interestingly, when the synthesis was accomplished in different conditions, two crystal forms of perchlorate α-4 and β-4 were obtained, which were further confirmed by X-ray single crystal diffraction, X-ray powder diffractograms, infrared and multinuclear NMR spectra. These salts showed high density (1.88–1.93 g cm^–3 at 293(2) K), moderate detonation performance (D, 8128–8437 m s^–1; P, 29.4–32.86 GPa) and good thermal stability (T_d: 272–274 °C). Compared with those known energetic perchlorates, the density and sensitivity (IS, 14–20 J; FS, 144–168 J) of 4 were also significantly improved. Through theoretical calculations and experiment results, the explanations for the differences in physicochemical properties of these two crystal forms were illustrated. Density overlap indicator (DORI) analysis was also employed to perform the necessary visualization and quantification of covalent and noncovalent interactions. It is evident that ionic bonds, hydrogen bonds, and π–π interactions are responsible for the high density and excellent performance of 1H-imidazo[4,5-d]pyridazine-2,4,7-triamine perchlorate, indicating that as-synthesized new material is a very promising cation in the construction of low-sensitivity high-energy compounds.

中文翻译：

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能量1 H-咪唑并[4,5 - d ]哒嗪-2,4,7-三胺：一种新型的高密度富氮熔融杂环阳离子

尽管近年来高能阳离子的发展引起了越来越多的关注，但熔融杂环高能阳离子却鲜有报道。在这项工作中，一步一步合成了一种新的1 H-咪唑并[4,5- d ]哒嗪-2,4,7-三胺，该阳离子用作阳离子制备1 H-咪唑并[4， 5 - d ]哒嗪-2,4,7-三胺高氯酸盐。有趣的是，当在不同条件下完成合成时，获得了高氯酸盐α-4和β-4的两种晶型，这些晶型通过X射线单晶衍射，X射线粉末衍射图，红外光谱和多核NMR光谱进一步证实。这些盐显示出高密度（1.88–1.93 g cm ^–3在293（2）K下），中等的爆震性能（D，8128–8437 ms ^–1 ; P，29.4–32.86 GPa）和良好的热稳定性（T _d：272–274°C）。与这些已知的高能高氯酸盐，密度和灵敏度进行比较（IS，14-20焦耳; FS，144-168 j）的4也有明显改善。通过理论计算和实验结果，解释了这两种晶型的理化性质差异的解释。还使用密度重叠指示剂（DORI）分析来进行共价和非共价相互作用的必要可视化和定量。显然，离子键，氢键和π–π相互作用是1 H-咪唑并[4,5- d ]哒嗪-2,4,7-三胺高氯酸盐的高密度和优异性能的原因，表明-合成的新材料是低灵敏度高能化合物构建中非常有希望的阳离子。