Investigation On Synthsis Of Energetic Compounds:Rich Nitrogen Azoles And Trinitro-substituted Azoles

Energetic materials containing triazoles and tetrazoles have excellent properties such as high heat of formation due to the C=N and N=N in the moleculars and combustion products mostly being nitrogen. Combination of oxygen-containing groups into triazoles and tetrazoles attributes greatly to oxygen balance (OB),density and thermal stability, thus these compounds have extensive research prospect.1,5-diaminotetrazole (DAT) was synthesized through substitution reaction, dehydration and ring-closure of thiosemicarbazide. Then DAT was used as the substrate to synthesize4-methyl-1,5-diaminotetrazole by a two-step reaction procedure using iodomethane as methylation agent, and the purification condition for the first step was optimized.4-amino-1,2,4-triazole was synthesized by one-step method using glyoxal and hydrazine hydrate as raw material.The mechanism for the synthetic of route was investigated. Different amine derivatives, such as1,5-diaminotetrazole,4-methyl-1,5-diaminotetrazole,1-amino-1,2,3-triazole and4-amino-1,2,4-triazole were synthesized from4-amino-1,2,4-triazole as the diazotization substrates. Finally eight compounds with N-N structure were obtained. Effect of the concentration of hydrochloric acid on the reaction was discussed. Mechanism for the synthesis of1,5-diaminotetrazole (DAT),4-amino-1,2,4-triazole and1-amino-1,2,3-triazole was proposed.In order to increase oxygen balance (OB), density and thermal stability, polynitro was introduced into azole compounds by nitration of acetoxy in azole compounds in this thesis.5-amino-3-acetoxy-1,2,4-triazole was synthesized through condensation and ring-closure by using malonic acid and aminoguanidine bicarbonate as the substrates. And the acetoxy in5-amino-3-acetoxy-1,2,4-triazole was further nitrated using a series of nitrating agents to obtain3,3’-trinitromethyl-5,5’-azo-1H-triazole.5-amino-1H-tetrazole was synthesized through diazotization and intramolecular ring-closure of aminoguanidine nitrate, and then reacted with chloroacetic acid to afford2-(5-amino-1H-tetrazol-l-yl)acetic acid. Furthermore, the product was oxidated by acidic potassium permanganate to form azo compounds, and then the azo compounds were further converted ionic salt by reacting with triazoles.Also different nitrating agents were investigated in the nitration of acetoxy in tetrazoles. N-(2,2,2-trinitroethyl)-4-amino-1,2,4-triazole was synthesized by the mannich reaction of4-amino-1,2,4-triazole with2,2,2-trinitroethanol.The target compounds were characterized by IR,1H NMR and13C NMR, and meanwhile density functional theory DFT/B3LYP was adopted in the determination of explosive performance, such as detonation pressure, detonation velocity, heat of formation, density and so on. The results show combination of triazene and polynitro into the moleculars promote the detonation performance.