多硝基3,3,7,7-四(三氟甲基)-2,4,6,8-四氮杂双环[3.3.0]辛烷的合成与性能

Synthesis and Properties of Polynitro 3,3,7,7-Tetra(trifluoromethyl)-2,4,6,8-tetraazabicyclo[3.3.0]octane

为了探索三氟甲基对含能材料性能的影响,以偕二氨基六氟丙烷和乙二醛为原料构建了氮杂稠环类含能材料的硝化前体——3,3,7,7-四(三氟甲基)-2,4,6,8-四氮杂双环[3.3.0]辛烷,通过改进的合成路线,用发烟硝酸多步硝化分别得到2,6-二硝基-3,3,7,7-四(三氟甲基)-2,4,6,8-四氮杂双环[3.3.0]辛烷(4)、2,4,6-三硝基-3,3,7,7-四(三氟甲基)-2,4,6,8-四氮杂双环[3.3.0]辛烷(5)和2,4,6,8-四硝基6-3,3,7,7-四(三氟甲基)-2,4,6,8-四氮杂双环[3.3.0]辛烷(6)。利用核磁共振氢谱、碳谱和氮谱表征了产物结构;采用排惰性气体法测试了三种硝化产物的密度,其中6的密度最大,高达2.08 g·cm^-3;分别用落锤升降法和BAM法测得三种产物的撞击感度均大于30 J、摩擦感度均大于360 N;热重-微商热重(TG-DTG)分析发现三种产物的质量损失均大于90%,其热稳定性随硝基的增加而下降;利用Gaussian 09计算包,通过Monte-Carlo统计学方法以及Kamlet-Jacbos方程和VLW爆轰产物状态方程等理论模型预估了产物的爆速、爆压,其中化合物6的爆速为11937 m·s^-1,爆压为74.3 GPa。与四硝基甘脲(TNGU)的性能及感度对比发现,在含能材料的分子结构中引入具有更高密度和更大电负性的三氟甲基,可在维持较高密度和良好爆轰性能的同时降低感度。

In order to explore the effect of trifluoromethyl group on the performance of energetic materials,2,6-dinitrate-3,3,7,7-tetra-trifluoromethyl-2,4,6,8-tetraazabicyclo[3.3.0]octane(4),2,4,6-trinitro-3,3,7,7-tetra-trifluoromethyl-2,4,6,8-tetraazabicyclo[3.3.0]octane(5)and 2,4,6,8-tetranitrate-3,3,7,7-tetra-trifluoromethyl-2,4,6,8-tetraazabicyclo[3.3.0]octane(6)were synthesized from the aza-fused ring precursor(3,3,7,7-tetra-trifluoromethyl-2,4,6,8-tetraazabicyclo[3.3.0]octane)through improved multi-step nitration in fuming nitric acid.The precursor was obtained from condensation of diaminohexafluoropropane and glyoxal.The structure of all nitration products were characterized by^1H,^13C and^15N NMR.The density of compound 6 is the highest(up to 2.08 g·cm^-3)by testing with exhaust gas method.For all three compounds,the impact sensitivity measured by the dropping hammer lift is greater than 30 J,and the friction sensitivity based on BAM method is greater than360 N.The TG-DTG analysis shows that the mass loss of all three products is more than 90%and their thermal stability decrease with the increase of nitro group.The detonation properties were estimated by Monte-Carlo statistical methods and theoretical models using Gaussian 09 calculation package.The detonation velocity and detonation pressure of com pou nd 6 are 11937 m·s^-1and 74.3 GPa,respectively.Due to the high density and greater electronegativity,the introduction of CF3 group reduces the sensitivity while maintaining higher density and good detonation performance compared with that of tetranitroglycoluril(TNGU).It also opens up new ideas for the research of energetic materials.