Kawasaki Tadashi, Hori Akiko
Department of Applied Chemistry, Graduate School of Engineering & Science, 307 Fukasaku, Minuma-ku, Saitama-shi, Saitama 337-8570, Japan.
Acta Crystallogr E Crystallogr Commun. 2025 Mar 6;81(Pt 4):289-295. doi: 10.1107/S205698902500194X. eCollection 2025 Apr 1.
The title compound, tetra-oxa[2]perfluoro-arene[2]triazine (CHFNO), composed of two tetra-fluoro-phenyl-ene and two triazine moieties connected by four oxygen atoms, was crystallized slow evaporation of a di-chloro-methane solution, yielding two polymorphs: block- () and plate-shaped () crystals. Polymorph (triclinic, 1, = 516 Å at 173 K) was previously reported by Yang [(2015. , 4414-4417] whereas the newly identified polymorph (triclinic, 1, = 1085 Å at 100 K) shares the same space group but has a unit-cell volume twice as large, accommodating two symmetrically distinct mol-ecules, and , with a different mol-ecular arrangement. Since these crystals are expected to exhibit the characteristics of non-porous adaptive crystals, detailed analyses of inter-molecular inter-actions were conducted, revealing that C-F⋯π-hole inter-actions are more pronounced in than in . Hirshfeld surface analysis at 100 K revealed that the primary contributions to the crystal packing in polymorph were F⋯F (17.1%), F⋯H/H⋯F (21.5%), C⋯H/H⋯C (6.3%), C⋯F/F⋯C (4.5%) and C⋯O/O⋯C (9.2%) inter-actions, whereas in polymorph , these inter-actions were F⋯F (9.9% and 10.0%), F⋯H/H⋯F (20.9% and 26.5%), C⋯H/H⋯C (6.3% and 2.9%), C⋯F/F⋯C (8.5% and 10.0%) and C⋯O/O⋯C (4.9% and 4.6%) for and , respectively. Powder X-ray diffraction analysis indicates that polymorph is the more stable crystalline form, predominantly obtained through rapid precipitation or by grinding the crystals.
标题化合物四氧杂[2]全氟芳烃[2]三嗪（CHFNO）由两个四氟亚苯基和两个通过四个氧原子相连的三嗪部分组成，通过二氯甲烷溶液的缓慢蒸发结晶，得到两种多晶型物：块状（）和板状（）晶体。多晶型物（三斜晶系，1，173 K时 = 516 Å）先前已由Yang报道[（2015. ，4414 - 4417]，而新鉴定的多晶型物（三斜晶系，1，100 K时 = 1085 Å）具有相同的空间群，但晶胞体积是其两倍大，容纳两个对称不同的分子，和，具有不同的分子排列。由于预计这些晶体将表现出无孔自适应晶体的特性，因此对分子间相互作用进行了详细分析，结果表明C - F⋯π - 空穴相互作用在中比在中更明显。100 K时的 Hirshfeld表面分析表明，多晶型物中晶体堆积的主要贡献来自F⋯F（17.1%）、F⋯H/H⋯F（21.5%）、C⋯H/H⋯C（6.3%）、C⋯F/F⋯C（4.5%）和C⋯O/O⋯C（9.2%）相互作用，而在多晶型物中，这些相互作用对于和分别为F⋯F（9.9%和10.0%）、F⋯H/H⋯F（20.9%和26.5%）、C⋯H/H⋯C（6.3%和2.9%）、C⋯F/F⋯C（8.5%和10.0%）和C⋯O/O⋯C（4.9%和4.6%）。粉末X射线衍射分析表明多晶型物是更稳定的晶型，主要通过快速沉淀或研磨晶体获得。
