Sonication-assisted synthesis of new Schiff bases derived from 3-ethoxysalicylaldehyde: Crystal structure determination, Hirshfeld surface analysis, theoretical calculations and spectroscopic studies

Abstract

• A novel series of the Schiff bases have been synthesized by treating substituted aminopyridines with 3-ethoxysalicylaldehyde with the help of ultrasonic irradiations. • Single crystals of the two compounds were screened via X-ray diffraction analysis. • Hirshfeld surface (HS) analysis was conducted by using crystal explorer software. • Electronic and structural parameters of all prepared compounds were investigated by employing the B3LYP/Def2-TZVP method. A rapid and efficient preparation of a new series of the Schiff bases (Pn) by the reaction of 2-aminopyridine derivatives with 3-ethoxysalicylaldehyde under ultrasonic irradiation is reported. Sono-chemical synthesis is the safest and greener method for the preparation of Schiff bases in the shorter period of time with higher yield as compared to traditional methods. The synthesized compounds have been characterized by 1 H NMR spectroscopic technique and elemental analyses. Furthermore, the crystal structures of two compounds ( P0 and P6 ) were determined by single crystal X-ray diffraction studies. Hirshfeld surface analysis showed that H…H interatomic contact is the most significant contributor in crystal packing of both compounds with percentage contribution of 53.7% and 57.7% for P0 and P6 , respectively. Theoretical calculations of the synthesized compounds were carried out by DFT using B3LYP method with the help of Def2-TZVP basis set, indicating that the results of calculation are in accordance with the experimental findings. The synthesis, crystal structure, Hirshfeld surface analysis, theoretical calculation and spectroscopic studies of new Schiff bases derived from 3-ethoxysalicylaldehyde have been reported.