Supramolecular Assembly of Tris(4-carboxyphenyl)arenes: Relationship between Molecular Structure and Solid-State Catenation Motifs
作者:Holden W. H. Lai、Ren A. Wiscons、Cassandra A. Zentner、Matthias Zeller、Jesse L. C. Rowsell
DOI:10.1021/acs.cgd.5b01416
日期:2016.2.3
The crystal structures of seven 1,3,5-tris(4-carboxyphenyl)arenes with functionalized central arene rings are reported. The formation of (6,3) hcb hexagonal sheets as a result of carboxylic acid dimer formation was observed in most of the crystal structures, with the exception of two compounds with functional groups capable of forming hydrogen bonds, namely, 2,4,6-tris(4-carboxyphenyl)-1,3-diaminobenzene and 2,4,6-tris(4-carboxyphenyl)-3-methylaniline. These structures were found to incorporate THF solvent molecules in their hydrogen-bonding motif, giving rise to distorted pseudohexagonal arrays. Functional groups on the central ring were found to influence stacking distances, stacking offsets, inclination angles, degree of catenation, and dimensions of solvent-occupied channels. To better understand and appreciate these complicated crystal structures, they were categorized into four distinct stacking/catenation families: simple stacking, single-layer offset catenation, double-layer offset catenation, and rotated-layer catenation. The unique structure of the unfunctionalized parent compound 1,3,5-tris(4-carboxyphenyl)benzene is rationalized in light of the structural behavior of its derivatives.
报告了七种具有官能化中央炔环的 1,3,5-三(4-羧基苯基)炔的晶体结构。在大多数晶体结构中都观察到了由于羧酸二聚体的形成而形成的 (6,3) hcb 六边形薄片,但有两种化合物除外,它们的官能团能够形成氢键,这两种化合物是 2,4,6- 三(4-羧基苯基)-1,3-二氨基苯和 2,4,6- 三(4-羧基苯基)-3-甲基苯胺。研究发现,这些结构的氢键基团中含有四氢呋喃溶剂分子,从而形成了扭曲的假六边形阵列。研究发现,中心环上的官能团会影响堆叠距离、堆叠偏移、倾斜角度、斤化程度以及溶剂占据通道的尺寸。为了更好地理解和认识这些复杂的晶体结构,我们将它们分为四个不同的堆叠/卡氏化系列:简单堆叠、单层偏移卡氏化、双层偏移卡氏化和旋转层卡氏化。根据 1,3,5-三(4-羧基苯基)苯衍生物的结构行为,合理解释了未官能化母体化合物 1,3,5-三(4-羧基苯基)苯的独特结构。