Theoretical Studies on PNMFIW by AM1 and PM3 Methods

AM1 and PM3 semi‐empirical methods were used to conduct theoretical studies on possible polymorphs of pentanitromonoformylhexaazaisowurtzitane (PNMFIW), and a close link between PNMFIW and Hexanitrohexaazaisowurtzitane (HNIW), especially in sensitivity, is shown. The optimized geometries of possible polymorphs of PNMFIW are similar to those of HNIW. PNMFIW in ε‐HNIW prepared from tetraacetyldiformylhexaazaisowurtzitane is predicted to have a D‐form. The average N N bond lengths of PNMFIW computed by AM1 and PM3 methods are shorter than those of HNIW. The differences in energy and thermochemistry values between PNMFIW and HNIW are insignificant except molecular energies 255.75 kJ⋅mol⁻¹ for D‐form PNMFIW and 460.36 kJ⋅mol⁻¹ for ε‐HNIW. Based on a Mulliken population analysis of the N N bonds, the impact sensitivities of A‐, B‐, C‐ and D‐forms of PNMFIW are estimated to be lower than those of the corresponding polymorphs of HNIW. Taking into account all N N bond lengths and overall molecule size, the shock sensitivities of all forms PNMFIW are predicted to be almost the same, and lower than those of HNIW.     

六硝基六氮杂异伍兹烷中杂质的结构表征及热分解研究

分别以四乙酰基二苄基六氮杂异伍兹烷( TADBIW)为硝解基质通过亚硝解／硝解一锅法和四乙酰基二甲酰基六氮杂异伍兹烷( TADFIW)为硝解基质通过硝硫混酸法制备六硝基六氮杂异伍兹烷(HNIW)．用柱色谱对HNIW的主要杂质进行分离,以FTIR、1H NMR、MS、元素分析确定主要杂质为五硝基一乙酰基六氮杂异伍兹烷( PNMAIW)和五硝基一甲酰基六氮杂异伍兹烷(PNMFIW)．PNMFIW与PNMAIW的DSC分析和动力学参数计算表明,前者的初始分解温度和分解峰温均比后者的高,且前者的分解表观活化能约为后者的2倍,这可能是因为,对于一取代基的五硝基六氮杂异伍兹烷六元环上的甲酰基比五元环上的乙酰基有助于笼型结构的稳定。