Noncovalent Interactions and Crystal Packing Chromono-3-carboxylic Acid Esters and Their Triazole Derivatives: A Combined Experimental and Theoretical Study

A comprehensive analysis of noncovalent interactions has been carried out focusing on their role in building the supramolecular networks in four newly synthesized and characterized compounds (two chromone esters and two chromone analogues condensed with 1,2,3-triazole). The supramolecular structures of two esters of chromonocarboxylic acids and their analogues condensed with 1,2,3-triazole derivatives were determined by X-ray diffraction. The Hirshfeld surface and its decomposed fingerprint plots were also applied to investigate the substituent effect at the C2 position of the benzopyran moiety (−CH3 vs –Ph) and different conformations of the ethylamine–triazole substituent on the contributions of intermolecular interactions to crystal packing. The contribution of O···H contacts in the HS changes from 39.5% to 23.6% (for compound I and II, respectively) and the contribution of N···H contacts in the HS changes from 15.7% to 11.3% (for compound III and IV, respectively). The crystal packing analysis reveals the formation chains and rings in 24 different motifs. The intermolecular interaction energies for motifs calculated by the CrystalExplorer program (Etot) and using DFT methods (Eint) are comparable. Additionally, all noncovalent interactions have been studied by QTAIM topological analysis suggesting that all of intermolecular interactions are closed-shell, which was further confirmed by NCI index analysis.