Synthesis, DFT calculations and optical nonlinear properties of two derived Schiff base compounds from ethyl-4-amino benzoate

Abstract

Two Schiff base compounds viz., Ethyl (E)-4-((3-ethoxy-2-hydroxybenzylidene)amino)benzoate(EHB) and Ethyl (E)-4-(((2-hydroxynaphthalen-1-yl)methylene)amino)benzoate(ENB) are synthesized by condensation of ethyl-4-amino benzoate with 2-hydroxy-3-ethoxy benzaldehyde and 2-hydroxy-1-naphthaldehyde. The two compounds are studied and identified by FT-IR, UV-visible, Mass, 1H-NMR, and 13C-NMR spectroscopies. The nonlinear refractive index (NRI) of the two compounds are determined, for ENB compound via the diffraction ring patterns (DRPs) and the Z-scan and via Z-scan for the EHB compound, using continuous wave (CW) low power laser beam, and founds of the order of 10−7 cm2 W−1 due to the first technique and 10−8 cm2 W−1 due to the second technique. The optical limiting (OL) property of both compounds is studied too with OLg thresholds of 16.5 mW and 11 mW for the compounds EHB and ENB respectively, which makes these two compounds as candidates to be used as an optical limiter (OLr). The DRPs are numerically simulated based on the theory of Fresnel-Kirchhoff with reasonable agreement compared to the experimental findings.