Theoretical investigation of spectroscopic and some electronic properties of (E)-4-((P-tolylimino) methyl) phenyl acrylate Schiff base by DFT method

Schiff bases; They are compounds that have importance in various branches such as pharmacy, medicine, biological systems, cosmetics, agriculture, production of dyes, plastics industry, aircraft industry, liquid crystal technology, electronics industry and analytical chemistry. The present study aims to theoretically investigate the spectroscopic and electronic properties of (E)-4-((P-tolylimino) methyl) phenyl acrylate Schiff base using the Density Functional Theory (DFT) method. The structure of Schiff base molecule was theoretically elucidated by FT-IR and NMR spectroscopy. The molecular geometry of the Schiff base was drawn with the Gauss View 5.0 program and its structure was optimized using the B3LYP/6-311++G(d,p) theory level DFT method. 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 studied 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.