Construction Of Nitrogen Heterocyclic Energetic Compounds Using Fluorodinitroethanol And Nitroacetonitrile As Building Blocks

The white paper of Chineses Defense in the New Era states that“The world today is undergoing profound changes unseen in a century.Peace,development and win-win cooperation remain the irreversible trends of the times.Nonetheless,there are prominent destabilizing factors and uncertainties in international security.”Under such a situation,in order to strengthen China’s defense capabilities,it is urgent to develop a new generation of energetic materials to improve the damage of modern weapons.The difficulty of energetic materials research lies in how to ensure high detonation performance while maintaining the characteristics of low sensitivity.To solve this problem,this paper adopts fluorodinitroethanol and nitroacetonitrile as raw materials to construct novel insensitive energetic compounds.Firstly,the simultaneous introduction of a fluorine atom and a nitro functional group to a nitrogen heterocyclic ring can not only increase its stability but also improve its detonation performance to a certain extent.Therefore,a fluorodinitroethyl group is connected to various nitrogen heterocyclic rings.Through“one-pot method”by treating Ionic liquid as reaction medium,to synthesize three bisfurazan energetic compounds including 3,3’-bis(2-fluoro-2,2-dinitroethylamino)-4,4’-bifurazanyl(41),3,3’-bis(2-fluoro-2,2-dinitroethylamino)-4,4’-bisfuroxane(44)and 4,4’-bis(2-fluoro-2,2-Dinitroethylamino)-3,3’-bisfuroxane(46).Subsequently,a high yield of 5,6-Di(2-uoro-2,2-dinitroethoxy)furazano[3,4-b]pyrazine(55)was obtained in a two-step process at room temperature.The structure and properties of the synthesized energetic compounds were characterized by NMR,DSC,X-ray single crystal diffraction,etc.Among them,Compound55 has a crystal density of 1.899 g/cm~3 and a thermal decomposition temperature of 250.47°C,compared with the traditional energetic material RDX,it has good thermal stability.Secondly,the presence of nitro and amino groups in the fused heterocyclic ring system can improve the density and stability of the molecule through hydrogen bonding interactions.Therefore,in this thesis,fused ring energetic compounds are formed by the ring-forming reaction between nitroacetonitrile and aminoazoles simultaneous introduction of nitro and amino.5-amino-3,4-dinitropyrazole(59)and 3-nitro-5-amino-1,2,4-triazole(63)are treated as the matrix.Through a ring-forming reaction between the Sodium nitroacetonitrile and the two matrix respectively,two fused ring energetic compounds named4-amino-3,7,8-trinitropyrazolo[5,1-c][1,2,4]triazine(60)and 4-amino-3,7-dinitro-[1,2,4]triazole[5,1-c][1,2,4]triazine(65)are synthesized.The structure and properties of the synthesized energetic compounds were characterized by NMR,DSC,X-ray single crystal diffraction,etc.The crystal densities of compounds 60 and 65 are 1.98 g/cm~3 and 1.81 g/cm~3,respectively,and the thermal decomposition temperatures are 281.91°C and 278.37°C,respectively,and both have good stability.The impact sensitivities of the two compounds were measured.Among them,the insensitivity of compound 60 is 19 J,and the insensitivity of compound 65 is greater than 80 J.It is a very insensitive energetic compound,and its performance is much better than traditional energetic materials.