Investigation Of spectroscopic and some electronic properties Of (E)-4-((P-Tolylimino)methyl)phenol Schiff base By DFT method

Schiff' base is an organic compound consisting of the union of nitrogen atom in the primary amines with the carbonyl group in various aldehydes or ketones to form the group of azomethin. The usage area of Schiff bases and metal complexes is quite wide. Schiff bases; They are compounds that are important in various branches such as pharmacy, medicine, biological systems, cosmetics, agriculture, dyestuff production, plastic industry, aircraft industry, liquid crystal technology, electronics industry and analytical chemistry. In addition to the properties of these compounds such as synthetic oxygen carriers, intermediate product creators in enzymatic reactions, and antitumor effects, their use in analytical chemistry as spectrophotometric reagents by giving selective and specific reactions to some metal ions is also important. Schiff Bases are generally colored solids. By taking advantage of these features, it can also be used widely in the paint industry. Apart from these, it can also be used as a liquid crystal in electronic display systems and as a polymer formation accelerator. This study aims to the toretically investigate the spectroscopic and electronic properties of (E)-4-((p-tolylimino)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 dby FT-IR, 1H-NMR and 13C-NMR spectroscopy. Thestructure 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-((p-tolylimino)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 assigned 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. Theresults of this study provide valuable insights into the spectroscopic and electronic properties of the (E)-4-((p-tolylimino)methyl)phenol Schiff base and could be useful in designing novel organic materials with promising optical and electronic properties.