Exploring packing features of N-substituted acridone derivatives: Synthesis and X-ray crystallography studies

The title compounds include an acridone as a parent molecule in which nitrogen is linked to other nitrogen-containing heterocyclic molecules through two carbon chain alkyl linkers connected by a C—N single bond. These acridone derivatives crystallized as Triclinic, Monoclinic, Tetragonal, and Orthorhombic having space group P1, P2<inf>1</inf>/c, I4<inf>1</inf>/a, Pca2<inf>1</inf>, respectively at T = 273 K. In the present work, synthesis and single-crystal X-ray crystallographic study of four novel acridone derivatives are reported from the perspective of crystal engineering. This work is based on the comprehensive analysis of Hirshfeld surfaces, 2D fingerprint plots, and DFT studies. The single-crystal structure analysis showed that compounds are connected by various intermolecular interactions such as C – H⋯O, C – H⋯C/π, and π⋯π (C⋯C) stacking interactions, which are accountable for the arrangement and amplification of molecular assembly. The DFT studies using the B3LYP functional with the 6-311++ G (d,p) basis set are employed to compare the experimental results with theoretically obtained molecular parameters. The HOMO and LUMO analyzes were used to elucidate information regarding molecular reactivity and charge transfer within the molecule.