Synthesis And Properties Of Energetic Compounds Based On Aza Fused Rings And Tetrazinetriazole

In the development of energetic compounds in recent years,people are pursuing high explosive heat,density and enthalpy of formation while seeking low-sensitivity compounds.Among them,the aza-fused ring has a dense structure,high decomposition temperature and high density,which is popular in new energetic materials.At the same time,nitrogen content is also an important basis for the performance pursuit of energy-containing compounds.Due to the high enthalpy of formation of high nitrogen compounds,the decomposition products are mainly water and N₂,they have become a favorite target for researchers of energetic materials.In this paper,by optimizing the molecular structure,a class of energetic compounds based on pyrazinooxadiazole and s-tetrazine bi(1,2,4-triazole)were designed and prepared.Their structures and performances were further studied.The research content was mainly divided into the following three parts:1.Studies of synthesis and properties on the energetic compounds based on pyrazinooxadiazole:Using 3,4-diaminofuran as a substrate,an aza-fused fused ring is obtained through the aldol condensation reaction with glyoxal.Through nitration,the nitro groups are introduced at the N-position of pyrazine to increase its density.The structure of the tetracyclic compound was characterized by ¹H NMR,¹³C NMR,IR and DSC,and the single crystal structure of the compound was intuitively obtained by X-ray single crystal diffraction.Using the method of quantum chemistry calculation,their detonation performance was predicted by EXPOL5.2.Studies of synthesis and properties on the energetic compounds based on s-tetrazine bi(1,2,4-triazole):The symmetrical structure tricyclic compound 1,4-dihydro-1,2,4,5-tetrazine-3,5-bis(1H-1,2,4-triazole-3-amino)was successfully prepared in four steps using cheap and easily available ethyl diazoacetate as raw material.The test results show that such energetic compounds are at low density(IS>20 J,FS>270 N)and excellent detonation performance(8898-9267 m·s^-1).The reaction mechanism of esters and aminoguanidine salt to construct 1,2,4-triazole ring was proposed,and the low sensitivity of compounds 8 and 9 was reasonably explained by two-dimensional fingerprint and Hirshfeld surfaces.3.Studies and synthesis of the nitrogen-rich energetic salts based on s-tetrazine bi(1,2,4-triazole):A series of new nitrogen-rich energetic ion salts(11-19)featuring 1,2,4,5-tetrazine-3,5bis(1H-1,2,4-triazol-3-nitramino)were synthesized by facile deprotonation or metathesis reactions with different nitrogen-rich bases or salts.Structural characterization,safety performance testing and theoretical calculation of detonation performance were performed on these ionic salts.The results show that the thermal stabilities have been greatly improved after the formation of energetic salts.Among them,the hydroxylammonium salt 12 has the most outstanding comprehensive properties.These compounds have a great application prospect in the field of high-energy and insensitive explosive materials.