Synthesis And Properties Research Of The Energetic Compounds Of Nitrogen-rich Fused Heterocyclic

The requirement of new high-energy high-density materials(HEDMs)is to find energetic materials with thermal stability and good mechanical sensitivity on the basis of high energy.Because high energy usually comes at the expense of molecular stability.How to achieve in-sensitivity on the basis of high energy has always been the direction of research and explora-tion.Aza-fused ring energetic compounds have large conjugated structures and can form mol-ecules with good planarity,thereby improving the sensitivity of explosives,and have attracted widespread attention from scientists at home and abroad.This thesis mainly includes con-structing a new type of Nitrogen-rich fused heterocyclic energetic compound,exploring its synthesis method,and characterizing the molecules by means of infrared spectroscopy(IR),nuclear magnetic resonance(NMR),mass spectrometry(MS),elemental analysis,and single crystal diffraction.The energy and stability of the molecule were studied by a combination of actual tests and theoretical calculations.(1)Using 2-aminobenzimidazole as a raw material,3,7,9-trinitrobenzo[4,5]imidazo[2,1-c][1,2,4]triazine-4(10H)-one was synthesized through diazotization reaction,addition reaction,cyclization reaction,and nitration reaction.The compounds were characterized by infrared spectroscopy,nuclear magnetic resonance,mass spectrometry,and elemental analysis.The single crystal was cultured with ethyl acetate as a crystallization solvent,and its structure was confirmed again by X-ray single crystal diffraction.The results show that at 25°C,with helium as the atmosphere,the density of 3,7,9-trinitrobenzo[4,5]imidazo[2,1-c][1,2,4]tria-zine-4(10H)-one is 1.78 g/cm~3.The BAM mechanical sensitivity test shows that the impact sensitivity is 20J and the friction sensitivity is 324 N.Differential scanning calorimetry anal-ysis showed that its initial decomposition temperature was 258°C.Using Mercury 4.3.0 to measure its interlayer distance(2.980?),which is closer than the typical set parameter of aromatic?-?interactions:3.65-4.00?.It is proved that there is a strong?-?interaction be-tween the layers.At the same time,intermolecular/intramolecular hydrogen bonding is used to enhance stability,which may be the reason for its good mechanical sensitivity and thermal stability.The EXPLO5(V6.02)program was used to predict its detonation performance:the detonation speed(D)was 7672 m/s and the detonation pressure(P)was 23.56 GPa.In the synthesis of 3,7,9-trinitrobenzo[4,5]imidazo[2,1-c][1,2,4]triazine-4(10H)-one,the cycliza-tion reaction was innovative The use of triethylamine as a catalyst enables the reaction in this step to obtain a product in a higher yield,which has certain reference value for similar cycliza-tion reactions.(2)Synthesis of 1H-imidazo[4,5-d]pyridazin-2,4,7-triamine and its hydrochloride,Chlorate,and its structure was characterized.1H-imidazo[4,5-d]pyridazin-2,4,7-triamine shows a high degree of planarity.When synthesizing its perchlorate,different crystal forms were obtained by changing the reaction solvent.The?-type shows high density(1.93 g/cm~3),high detonation speed,pressure(8437 m/s,32.86 GPa),good thermal stability(289°C),and better than RDX(IS:7.5 J,FS:120 N)mechanical sensitivity(IS:14 J,FS:168 N);beta type has relatively low density(1.88 g/cm~3)and detonation pressure(8128 m/s,29.4 GPa),but it Has better impact sensitivity(IS:20 J).This study provides a new aza-fused ring energetic compound as a cation to synthesize various new energetic ionic salts.The good performance of perchlorate confirms this from one aspect.1H-imidazo[4,5-d]pyridazin-2,4,7-triamine is a simple and convenient synthesis method with good yield(100%),which makes the com-pound practical value for scale-up production.