Abstract

Carboxylic acid supramolecular synthon exhibited dimer or catemer motifs in the crystal lattice depend on the substituent and other functional groups present in the structure. In general, presence of other competing functional groups produced catemer motifs, whereas unsubstituted acids showed dimer. In this manuscript, we have synthesized a new aryl ether amine-based Schiff base with carboxylic acid functionality (1) and demonstrated polymorphic structure via catemer (1a) and dimer (1 b) motifs in the solid state. In both the structure, carboxylic acid group adopted different orientation in the crystal lattice. The different H-bonding lead to modulation of optical properties that was further supported highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) calculation. Further the stability calculation indicates that dimer (1 b) structure was more stable by 8.54 kcal/mole relative to catemer (1a) motifs. Further, the supramolecular interactions in catemer (1a) and dimer (1 b) motifs was studied by Hirshfeld surface and fingerprint plots to gain insight and compare the different functional groups contribution for intermolecular interactions in the polymorphic crystals which clearly showed different intermolecular interactions in polymorphs.

摘要

羧酸超分子合成子在晶格中表现出二聚体或多聚体基序，这取决于结构中存在的取代基和其他官能团。一般来说，其他竞争性官能团的存在会产生多聚体基序，而未取代的酸则表现出二聚体。在这篇手稿中，我们合成了一种新的芳基醚胺基席夫碱，具有羧酸官能团 ( 1 )，并通过多聚体 ( 1a ) 和二聚体 ( 1b )证明了多晶型结构) 固态的图案。在这两种结构中，羧酸基团在晶格中采用不同的取向。不同的氢键导致光学性质的调制，这进一步支持最高占据分子轨道 (HOMO) 和最低未占据分子轨道 (LUMO) 计算。此外，稳定性计算表明二聚体 ( 1b ) 结构相对于多聚体 ( 1a ) 基序更稳定 8.54 kcal/mole 。此外，多聚体(1a)和二聚体( 1b)中的超分子相互作用通过 Hirshfeld 表面和指纹图研究基序，以深入了解并比较不同官能团对多晶型晶体中分子间相互作用的贡献，这清楚地显示了多晶型物中不同的分子间相互作用。