The crystal structures of 8-phenoxycarbonyl-1,8-diazabicyclo[5.4.0]undec-7-enium chloride, C16H21N2O2+·Cl−, (I), and 8-methoxycarbonyl-1,8-diazabicyclo[5.4.0]undec-7-enium chloride monohydrate, C11H19N2O2+·Cl−·H2O, (II), recently reported by Carafa, Mesto & Quaranta [Eur. J. Org. Chem.(2011), pp. 2458–2465], are analysed and discussed with a focus on crystal interaction assembly. Both compounds crystallize in the space groupP21/c. The crystal packings are characterized by dimers linked through π–π stacking interactions and intermolecular nonclassical hydrogen bonds, respectively. Additional intermolecular C—H...Cl interactions [in (I) and (II)] and classical O—H...Cl hydrogen bonds [in (II)] are also evident and contribute to generating three-dimensional hydrogen-bonded networks.
8-phenoxycarbonyl-1,8-diazabicyclo[5.4.0]undec-7-enium chloride, C16H21N2O2+-Cl-, (I)和 8-methoxycarbonyl-1,8-diazabicyclo[5.4.0]undec-7-enium chloride, C11H19N2O2+-Cl--H2O, (II) [Eur. J. Org. Chem.(2011), pp.这两种化合物都在空间群 P21/c 中结晶。晶体组装的特点是分别通过 π-π 堆积相互作用和分子间非经典氢键连接的二聚体。其他分子间 C-H...Cl 相互作用[在 (I) 和 (II) 中]和经典 O-H...Cl 氢键[在 (II) 中]也很明显,并有助于生成三维氢键网络。