Insight Into The Thermostability And Low Sensitivity Of Energetc Salts Based On3,6-diamine-[1,2,4]triazolo[4,3-b][1,2,4]triazole

From the first synthesized 2,4,6-trinitrotoluene(TNT)to the pentaazole anion salt,the development of energetic materials has always been a research topic in academic technology and industrial practice.The design and synthesis of new nitrogen-rich heterocyclic compounds have always been at the forefront of high-energy research,because they usually have green decomposition products and consist of a large number of N-C/N single and double bonds,especially the high-energy fused heterocyclic groups with coplanar polycyclic structures.Materials have relatively high heat generation and ring strain energy stored in molecules,making them have good energy characteristics.In addition,the intramolecular/intermolecular hydrogen bonds formed in nitrogen-rich compounds increase the density and reduce the sensitivity.These properties all increase the safety of the synthesis,transfer and storage of high energy density compounds.In this paper,3,6-diamino-1H-[1,2,4]triazole[4,3-b][1,2,4]triazole(DATT)was synthesized for the first time in the laboratory,and DATT was used as the parent,7 kinds of energetic ion salts were synthesized.The structure was confirmed by single crystal X-ray diffraction analysis of DATT(compound 2),DATT 3,4,5-trinitropyrazole salt(compound 3),DATT perchlorate(compound 6)and DATT 3-nitro-1,2,4-triazol-5-ketone salt(compound 8),and a comprehensive analysis of its crystal structure.Infrared spectroscopy(IR),¹H and ¹³C nuclear magnetic resonance,elemental analysis,differential scanning calorimetry(DSC),etc.were used to comprehensively characterize the structure of the synthesized series of compounds.All new compounds show good thermal stability(T_d>205°C)and low sensitivity to external mechanical stimuli.The actual density of these salts is 1.72 g cm^-3 to 1.93 g cm^-3.Theoretical performance calculations(Gaussian 09 and EXPLO 5)respectively calculated the explosion pressure to be 20.8 GPa to 32.9 GPa and the detonation velocity to be 7599 m s^-1 to 8719 m s^-1.Perchlorate 6 has the highest density(d=1.93g cm^-3)and the best oxygen balance(-30.0%),good thermal stability(T_d=258?),and low sensitivity(IS>40 J,FS=216 N)and excellent detonation velocity(v _D=8719 m s^-1)and explosion pressure(P=32.9 GPa),indicating that it has the potential to be used as high energy density materials(HEDMs).