Synthesis, Characterization and DFT Calculation of Naphthalene-Based Crystal Structure with Pyridylimine-Binding Units

This study focuses on the synthesis, characterization, and properties of a yellowish, prism-shaped ligand, N,N′-(naphthalene-1,5-diyl) bis(1-(pyridin-2-yl) methanimine). The ligand was synthesized through refluxing 1,5-diaminonaphthalene and pyridine-2-carbaldehyde in extra-pure ethanol, employing X-ray diffraction on single crystal. The crystal is structured with two pyridylimine-binding units linked to a naphthalene. The crystal has a P21/c space group in a monoclinic system. The structure was confirmed through an infrared examination. Computational spectroscopy and theoretical methods were used to investigate the ligand HOMO, LUMO, and charge distribution. Additionally, a Hirshfeld analysis was performed to investigate noncovalent interactions in the crystalline form. The results showed that dispersion forces (H···H) were the primary factor contributing to the arrangement of the ligand molecule, accounting for 45.3% of the total interactions in the absence of hydrogen bonding. Overall, this study provides valuable insights into the synthesis, characterization, and properties of this unique ligand.