Czapik Agnieszka, Gdaniec Maria
Faculty of Chemistry, Adam Mickiewicz University, 60-780 Poznań, Poland.
Acta Crystallogr C. 2011 Sep;67(Pt 9):o341-5. doi: 10.1107/S0108270111027843. Epub 2011 Aug 5.
2,3,4,5,6-Pentafluorophenol (pFp), unlike phenol, forms cocrystals with the weak heteroaromatic base phenazine (phz). Two types of cocrystals were prepared, (I) with a high content of pFp, 2,3,4,5,6-pentafluorophenol-phenazine (5/1), 5C(6)HF(5)O·C(12)H(8)N(2), and (II) with a 2:1 pFp-phz molar ratio, 2,3,4,5,6-pentafluorophenol-phenazine (2/1), 2C(6)HF(5)O·C(12)H(8)N(2). In both forms, homostacks are formed by the heterocyclic base and phenol molecules and no aryl-perfluoroaryl stacking interactions occur. The arrangement of the molecules in the crystal of (I) is determined by strong O-H···N and O-H···O hydrogen bonds, weak O-H···F, C-H···F and C-H···O interactions, π-π stacking interactions between the phz molecules and C-F···π(F) interactions within the pFp stacks. Among the specific interactions in (II) are a strong O-H···N hydrogen bond, weak C-H···F interactions and π-π stacking interactions between the phz molecules. In (I) and (II), the heterocyclic molecules are located around inversion centres and one of the symmetry-independent pFp molecules in (I) is disordered about an inversion centre. Remarkably, similar structural fragments consisting of six pFp stacks can be identified in cocrystal (I) and in the known orthorhombic polymorph of pFp with Z' = 3 [Gdaniec (2007). CrystEngComm, 9, 286-288].
与苯酚不同，2,3,4,5,6 - 五氟苯酚（pFp）能与弱杂芳族碱吩嗪（phz）形成共晶体。制备了两种类型的共晶体，（I）pFp含量高的2,3,4,5,6 - 五氟苯酚 - 吩嗪（5/1），5C(6)HF(5)O·C(12)H(8)N(2)，以及（II）pFp与phz摩尔比为2:1的2,3,4,5,6 - 五氟苯酚 - 吩嗪（2/1），2C(6)HF(5)O·C(12)H(8)N(2)。在这两种形式中，杂环碱和苯酚分子形成了同型堆积，且不存在芳基 - 全氟芳基堆积相互作用。（I）的晶体中分子排列由强O - H···N和O - H···O氢键、弱O - H···F、C - H···F和C - H···O相互作用、phz分子之间的π - π堆积相互作用以及pFp堆积内的C - F···π(F)相互作用决定。（II）中的特定相互作用包括强O - H···N氢键、弱C - H···F相互作用以及phz分子之间的π - π堆积相互作用。在（I）和（II）中，杂环分子位于反演中心周围，（I）中一个与对称无关的pFp分子围绕一个反演中心无序排列。值得注意的是，在共晶体（I）和已知的Z' = 3的pFp正交多晶型物中可以识别出由六个pFp堆积组成 的相似结构片段[Gdaniec（2007年）。《晶体工程通讯》，9，286 - 288]。
