含能共晶堆积结构的理论研究

Theoretical Research on Packing Structures of Energetic Cocrystals

采用Hirshfeld面、指纹图的方法,从密度、堆积系数、分子间相互作用的相对贡献方面,研究了已报道的六硝基六氮杂异伍兹烷(CL-20)、环四甲撑四硝胺(HMX)、苯并三呋咱氮氧化物(BTF)及2,4,6-三硝基甲苯(TNT)基含能共晶的堆积结构。结果发现,绝大部分含能共晶的堆积系数处于两组分之间。不同含能共晶中的相同含能分子与周围分子间相互作用的方向和大小不同。CL-20共晶中O…H、O…O作用所占比例之和大于70%,说明它们是晶体稳定的主导作用。HMX共晶中O…H作用所占比例大于50%,说明弱氢键占主导地位。与CL-20共晶和HMX共晶相比,BTF和TNT共晶中,C…O和C…C作用占较高比例,说明π堆积作用明显。

Packing structures of the reported CL-20, HMX, BTF and TNT cocrystals were studied by Hirshfeld surface and fingerprint plot from densities, packing coefficients and molecular interaction contributions. Results show that the packing coefficients of most energetic cocrystals are between their conformers. Energetic molecules in different energetic cocrystals possess different intermolecular interactions with neighboring molecules. The total percentage of O... H and O...O in CL-20 cocrystals are more than 70%, indicating the two interactions making cocrystals stable. O...H in HMX cocrystals plays an dominant role with the amount of more than 50%. C...O and C...C in BTF cocrystals and TNT cocrystals are more than that in CL-20 cocrystals and HMX cocrystals, which proves π packing is obvious in BTF cocrystals and TNT cocrystals.