4-叠氮基-2,2,6,6-四硝基金刚烷的合成与热稳定性

Synthesis and Thermal Stability of 4-Azido-2,2,6,6-tetranitroadamantane

多硝基金刚烷是一类结构稳定、具有良好应用前景的笼形含能材料。以丙二酸二乙酯和多聚甲醛为原料经过环合,脱羧,甲酰化,Aldol缩合,O-甲磺酰化,叠氮化,肟化和偕二硝化等步骤,以9.8%的总产率合成了4-叠氮基-2,2,6,6-四硝基金刚烷。用热重分析(TG)和差示扫描量热法(DSC)研究了其热性能,21℃开始分解,251℃时达到峰值,表明具有良好的热稳定性。与2,2,6,6-四硝基金刚烷和2,2,4,4,6,6-六硝基金刚烷比较发现,用叠氮基取代2,2,6,6-四硝基金刚烷4-位上的氢,可降低热稳定性;用叠氮基取代偕二硝基,可提高其稳定性。利用密度泛函理论计算4-叠氮基-2,2,6,6-四硝基金刚烷的密度为1.79 g·cm^-3,爆速为7770 m·s^-1,爆压为26.68 GPa,表明4-叠氮基-2,2,6,6-四硝基金刚烷是一种高能化合物。

Polynitroadamantanes are a class of stable and prospective cage-like energetic compounds.4-Azido-2,2,6,6-tetranitroadamantane was synthesized from diethyl malonate and paraformaldehyde via cyclization,decarboxylation,formylation,Aldol condensation,O-sulfonylation,azidation,oximation and gem-dinitration reactions with a total yield of 9.8%.The thermal stability of 4-azido-2,2,6,6-tetranitroadamantane was investigated through differential scanning calorimetry(DSC)and thermogravimetry(TG)methods.The onset decomposition temperature and the decomposition peak temperature were located at219℃and 251℃,respectively,indicating a good thermal stability.Compared with 2,2,6,6-tetranitroadamantane and 2,2,4,4,6,6-hexanitroadamantane,the replacement of hydrogen in C-4 by azido group resulted in decreased thermal stability,in contrast,the thermal stability was improved by replacing the gem-dinitro group in C-4 by azido group.By using desity functional theory,4-azido-2,2,6,6-tetranitroadamantane showed a density of 1.79 g·cm^-3,a detonation velocity of 7770 m·s^-1,and a detonation pressure of 26.68 GPa.Results indicate that 4-azido-2,2,6,6-tetranitroadamantane is a high-energy compound.