Layered crystal structure of bicyclic aziridines as revealed by analysis of intermolecular interactions energy

An X-ray diffraction study of three bicyclic aziridines (2,2-dimethyl-4,6-diaryl-1,3-diazabicyclo-[3.1.0]hex-3-enes) reveals the absence of strong specific intermolecular interactions in the crystals. Therefore, crystal packing has been analyzed on the basis of quantum-chemical calculations of energy of intermolecular interactions between basic molecules located in the asymmetric part of the unit cell and molecules belonging to its first coordination sphere in the crystal. The analysis of the energy of intermolecular interactions indicates that the crystal structures of bicyclic aziridines are layered. The total energy of the interactions between the basic molecule and other molecules belonging to the layer is significantly higher as compared to the energy of the interactions with molecules of two neighbouring layers.