A series of halogen-substituted phenylpyrazinamides have been synthesized and crystallographically characterized in order to investigate the effect of halogen bonding interaction on supramolecular assembly of N-phenylpyrazine-2-carboxamide derivatives. The notable feature in crystal structures of meta- and para-iodinated, brominated and chlorinated compounds is that there is a tendency to form a halogen bonding synthon between adjacent halophenyl and prazine/halophenyl rings. Influence of these halogen bonding interactions on supramolecular assemblies have been discussed with the help of geometrical analysis and theoretical calculations. The X⋯N halogen bonding distances are 2.2–7.7% shorter than the sum of the van der Waals radii of the nitrogen and halogen atoms. Also, theoretical methods show the N⋯X halogen bonding energies within a range of −9.43 to −23.67 kJ mol−1. Our studies show that the selection of halogen atom as well as the position of substitution on phenylpyrazinamide compound may be important for crystal design based on halogen bonding.
合成了一系列卤素取代的苯基
吡嗪氨基酸酰胺,并进行了晶体学表征,以研究卤素键相互作用对N-苯基
吡嗪-2-羧酰胺衍
生物超分子组装的影响。meta-和para-
碘化、
溴化及
氯化化合物的晶体结构中的一个显著特征是,邻近的卤素苯基和
吡嗪/卤素苯基环之间有形成卤素键合成体的趋势。利用几何分析和理论计算,讨论了这些卤素键相互作用对超分子组装的影响。X⋯N卤素键距比氮和卤素原子的范德华半径之和短2.2%–7.7%。此外,理论方法显示N⋯X卤素键能量在−9.43到−23.67 kJ mol−1之间。我们的研究表明,卤素原子的选择以及在苯基
吡嗪氨基酸酰胺化合物上的取代位置可能对基于卤素键的晶体设计至关重要。