Insight for the synthesis and crystal structure of diazatetraasterane derivatives: Experimental and theoretical studies

Abstract

3,6-diazatetraasterane and 3,9-diazatetraasterane are diazatetraasterane derivatives and cage-dimers of 1,4-dihydropyridine in head-to-head or head-to-tail manner by the regioselective [2+2] photocycloaddition. They were synthesized and their structures were verified by NMR spectra, high-resolution mass spectrometry, and Single-crystal X-ray diffraction. The results showed that the molecular structure of 3,6-diazatetraasterane with a C1 symmetric property and the 3,9-diazatetraasterane with a C2 symmetric property. The molecular packing arrangement of 3,6-diazatetraasterane was in the zigzag-shape, and the 3,9-diazatetraasterane was in layer-like architecture. The non-covalent interaction (NCI) and Hirshfeld surface analysis were conducted to characterize and visualize the intramolecular and intermolecular interactions. The molecular electrostatic potential (MEP) was calculated to predict electrophilic and nucleophilic regions. The results will provide a theoretical basis for further studies on chemical properties and pharmacological application of the azatetraasterane derivatives.