CL-20/FOX-7共晶的理论研究
Theoretical Research on CL-20/FOX-7 cocrystal

采用分子动力学（MD）模拟和DFT-B3LYP/6-311++G**理论研究了2,4,6,8-六硝基-2,4,6,8,10,12-六氮杂异伍兹烷(CL-20)与1,1-二氨基-2,2-二硝基乙烯（FOX-7）的共晶结构.其中，共晶的不同摩尔配比用MD模拟实现，CL-20和FOX-7结构借助B3LYP/6-311++G**最优化，并计算了单体的表面静电势.在此基础上，结合总配位能量（ISPE）预测共晶的相互结合位点.结果表明，只有当化学计量比为1:1时才可以生成CL-20/FOX-7的共晶，与MD方法的结论一致.CL-20/FOX-7共晶的结合位点的顺序依次是：F5-C9(19.82kJ/mol)＞F5-C3(15.07kJ/mol)＞F5-C4(14.84kJ/mol)＞F5-C1(14.67kJ/mol).
Low sensitive high energeticmaterials can be prepared by cocrystallization. Theoretical methods including Molecular Dynamics (MD) simulation and DFT-B3LYP/6-311++G** methods were employed to investigate 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (CL-20) and 1,1-diamino-2,2-dinitroethylene (FOX-7) co-crystal. Different molar ratios of co-formers were studied by MD simulation method.CL-20 and FOX-7 were optimized at B3LYP/6-311++G** level. Molecular electrostatic potential surfaces of the monomer were also calculated at the same level. Based on this study, we estimated the cocrystallized intermolecular pairing site according to the total intermolecular site pairing energy (ISPE). The results indicate that CL-20/FOX-7 cocrystal can only be prepared in the molar 1:1, which is well in accordance with the result from MD analysis. Intermolecular pairing sites of CL-20/FOX-7 cocrystal are in descending order: F5-C9(19.82kJ/mol)＞F5-C3(15.07kJ/mol)＞F5-C4(14.84kJ/mol)＞F5-C1(14.67kJ/mol)