Synthesis, Characterizations of New Schiff Base Heterocyclic Derivatives and their Density Functional Theory (DFT) and Nonlinear Optical (NLO) Studies
摘要
The synthesis of novel Schiff base heterocyclic compounds, along with their structural, electronic, and optical properties, is presented, highlighting their significance for potential applications in optoelectronic devices. Derivatives of 4-methylpyridin-2-amine and 4-hydroxybenzaldehyde which comprises of the condensation reactions by the help of ethanol and catalysed by a small amount of sulfuric acid. Thin Layer Chromatography (TLC) was employed to monitor and confirm the formation of the Schiff base. After performing the FTIR spectroscopy, the functional groups are important and feature an intense CN stretching frequency at 1650 cm⁻1 for the Schiff base. UV–Vis spectra such as π to π* transition at 290 nm, n to π* transition at 350 nm, and charge transfer band approximately at 450 nm were identified. The XRD analysis also revealed that all the synthesized compounds had high crystalline nature from their diffraction pattern of peaks. Density Functional Theory(DFT) estimated and indicated a HOMO–LUMO energy difference of 4.168. Hence, the energy spectrum of the source LMC X-3 at 25 eV is relatively highly populated and therefore the source is comparatively less electronically excited/radioactively unstable. The previous charge distribution analysis has helped to conclude that the electron density region is more concentrated on the oxygen and nitrogen atoms than the others. These NLO properties were calculated by employing the finite filed method. Second order hyperpolarizability values were in the range of 2.90 × 10–30 to 4.25 × 10–30 esu. This systematic study evidently demonstrates the potential of these Schiff base derivatives for optoelectronics application due to their reasonably good structural, electronic, and NLO properties.