Nano Silica as a Catalyst for Efficient and Green Synthesis of Imidazole Derivatives: Exploring Catalytic, Photophysical, and Nonlinear Optical Properties

This manuscript presents a comprehensive investigation into the catalytic efficiency of nano silica (SiO₂) in the synthesis of imidazole derivatives, showcasing its ability to enhance reaction efficiency, yield, and product purity. Employing nano SiO₂ as a catalyst in multi-component reactions, we achieved significant improvements over conventional methods. Detailed characterization of the synthesized imidazoles using NMR spectroscopy provided insights into molecular structures, atom numbering, and proton assignments. Solvent studies revealed that polarity influences absorption and emission spectra, resulting in bathochromic shifts attributed to electronic transitions and solvent interactions. Second harmonic generation (SHG) analysis demonstrated the nonlinear optical (NLO) properties of the derivatives, emphasizing their potential in NLO material applications. Quantum yield measurements, emission kinetics, and density functional theory (DFT) analyses—including HOMO–LUMO energies and molecular electrostatic potential (MEP) mapping—highlighted the compounds’ electronic properties and charge distributions. These findings underscore the effectiveness of nano SiO₂ as a catalyst for sustainable, high-yield imidazole synthesis, with far-reaching implications for materials science and pharmaceutical applications.