An investigation into the substituent effect of halogen atoms (F, Cl, Br) on the crystal structure of indole-3-carboxylic acid (ICA) was prepared in this work. The investigation was done through the aspect of crystal structure, intermolecular interactions and π⋯π stacking motifs with the assistance of infrared spectra, elemental analyses, NMR spectra, differential scanning calorimetry (DSC), thermogravimetric analyses (TGA) and hot stage microscopy (HSM) measurements. The results revealed that the different kinds of halogen atoms and the different substituted positions have a significant effect on the crystal structures, molecular π⋯π stacking motifs and the kinds of intermolecular interactions. We further correlated the melting points of the ICAs with the H–H, O–H and X–H (X = F, Cl, Br) interactions, and found a positive correlation between them.
本工作中对卤素原子(F,Cl,Br)取代
吲哚-3-
羧酸(ICA)的取代基效应对晶体结构进行了研究。通过晶体结构、分子间相互作用和π⋯π堆积模式,结合红外光谱、元素分析、核磁共振谱、差示扫描量热(
DSC)、热重分析(TGA)和热台显微镜(HSM)测量进行了研究。结果表明,不同种类的卤素原子和不同取代位置对晶体结构、分子π⋯π堆积模式和分子间相互作用类型有显著影响。我们进一步将ICA的熔点与H–H、O–H和X–H(X = F,Cl,Br)相互作用相关联,并发现它们之间存在正相关关系。