Exploring non-covalent interactions in oxazolidine derivatives: Synthesis, X-ray diffraction, and quantum chemical studies

In this work, two oxazolidine derivatives 4 and 5 were conveniently prepared in high yields via the reaction of pseudoephedrine 1 with the corresponding bis(methythio)yledinenitriles 2 and/or 3, respectively using both ultrasonic and microwave irradiation techniques. The yields of oxazolidines 4 and 5 were summarized and compared with their preparation by traditional methods. X-ray diffraction analysis uncovers that a multitude of non-covalent interactions collaborate to establish the arrangement of crystals and the behavior of supramolecular assemblies in the solid state. The quantification of all intermolecular interactions is achieved through Hirshfeld surface analysis and fingerprint plots, while energy frameworks are constructed to examine the predominant energy interactions that contribute to the strength of molecular packing. In the experimental investigation, we conducted a thorough theoretical analysis employing quantum chemical techniques to ascertain the characteristics of the derivatives. The comparison of geometrical parameters revealed a strong agreement with the experimental findings. QTAIM has been used to analyze and characterize both covalent and non-covalent bonds. The closed-shell interactions at the bond critical point confirm the presence of non-covalent interactions.