Exploring the nonlinear optical properties of 6-ethoxy-2-aminobenzothiazolium-4-methoxyphenyl acetate: Experimental and computational insights into a monoclinic single crystal

The study aims to investigate the third-order nonlinear optical properties of a single crystal of 6-ethoxy-2-aminobenzothiazolium-4-methoxyphenylacetate (EABT), which is synthesized via solvent evaporation. The X-ray structural analysis revealed that the crystal possesses a monoclinic structure, characterized by a centrosymmetric P21/c space group. Various analytical methods were employed to study the existence of various functional groups, crystallinity, thermal stability, and the solubility of the crystal. Optical absorption, transmittance, and emission behavior of the crystal were examined by UV–Vis–NIR and photoluminescence spectroscopy. The third harmonic generation (THG) studies were conducted on well-polished single crystals using the Z-scan method. In addition to experimental investigations, computational calculations were conducted to assess the properties of the molecular structure. The geometry optimization of the molecule was performed using Density Functional Theory (DFT) methods, specifically employing the B3LYP 6-311G level of theory. •6-ethoxybenzo [d]thiazol-2-aminium-2-(4-methoxyphenyl) acetate (BTPA) single crystal was grown and characterized.•Comprehensive investigation of optical behavior was studied using UV-Vis, and NIR transmittance.•The efficiency of third harmonic generation (THG) was assessed using the Z-scan technique.•Hirshfeld analysis provides a graphic representation and intermolecular interactions of the synthesized crystals.•Quantum chemical methods were utilized to investigate the properties of the BTPA molecule.