Investigation of spectroscopic and some electronic properties of (e)-4-((4-chlorophenylimino) methyl) phenol schiff base by dft method

Schiff bases were first synthesized in 1864 by German chemist H. Schiff. It was used as a ligand by Pfeiffer in 1933. Schiff base complexes are substances of increasing importance in various branches such as the preparation of some drugs, the production of dyestuffs, the electronics industry, the plastics industry, agriculture, cosmetics and polymer production, analytical chemistry and liquid crystal technology. In recent years, the importance of Schiff base complexes in the medical world has been increasing due to their anticancer activity and they have been used as reagents in the fight against cancer. This study aims to theoretically investigate the spectroscopic and electronic properties of (E)-4-((4-chlorophenylimino)methyl)phenol Schiff base using density functional theory (DFT) and the 6-311++G(d,p) basis set. . The structure of the Schiff base compound was theoretically elucidated by FT-IR, 1H-NMR and 13C-NMR spectroscopy. The structure of the compound was optimized at the B3LYP/6-311++G(d,p) theory level. After the optimization calculation, the harmonic frequency calculation was made and it was understood that the molecule was in a stable structure since no negative frequency was observed as a result of the calculation. Since the (E)-4-((4-chlorophenylimino)methyl)phenol Schiff base does not have crystal data in the literature, it was compared with the structural parameters of similar molecules and it was seen that the results were compatible with the experimental data. The vibration frequencies were marked and it was seen that the calculated theoretical frequency values were in good agreement with the experimental spectra. The calculated NMR chemical shifts were also found to be in good agreement with the experimental values. Also, nonlinear optical (NLO) properties of Schiff base with HOMO-LUMO molecular orbital energies were calculated and found to have significant NLO activity. Finally, the molecular electrostatic potential (MEP) analysis was performed to study the reactivity and potential sites of electrophilic and nucleophilic attacks. The results of this study provide valuable insights into the spectroscopic and electronic properties of the (E)-4-((4-chlorophenylimino)methyl)phenyl acrylate Schiff base and could be useful in designing novel organic materials with promising optical and electronic properties.