Evident Hydrogen Bonded Chains Building CL-20-Based Cocrystals

We report two kinds of evident hydrogen bonded chains constructing two binary cocrystals of 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (CL-20) with para-benzoquinone (1) and 1,4-naphthoquinone (2): one kind is the CL-20 molecule chains linked by R22(6) hydrogen bonds, and the other is connected by CL-20 and coformer (1 or 2) molecules alternately through R21(5) hydrogen bonds. All chains extend to the entire cocrystals CL-20/1 and CL-20/2 with crossing points of CL-20 molecules. In contrast to the unremarkable intermolecular interactions in observed CL-20 polymorphs and cocrystals, these two kinds of chains in CL-20/1 and CL-20/2 are evident and can be readily understood using the definition of supramolecular synthons. Moreover, the thermal behaviors, impact sensitivity, and detonation properties of these two energetic cocrystals are reported.

本工作报道了两种清晰可辨的氢键链结构，它们分别构筑了六硝基六氮杂异伍兹烷（2,4,6,8,10,12-hexanitrohexaazaisowurtzitane，CL-20）与对苯醌（para-benzoquinone，1）、1,4-萘醌（1,4-naphthoquinone，2）形成的两类二元共晶体：其中一类为由R22(6)型氢键连接的CL-20分子链，另一类则是CL-20与共晶组分（1或2）分子通过R21(5)型氢键交替连接形成的分子链。所有分子链均贯穿整个CL-20/1与CL-20/2共晶体，并存在CL-20分子的交叉结点。相较于已报道的CL-20多晶型及共晶体中相对微弱的分子间相互作用，CL-20/1与CL-20/2中的这两类氢键链结构特征显著，且可通过超分子合成子的定义得到合理解释。此外，本工作还报道了这两种含能共晶体的热行为、撞击感度与爆轰性能。