Structural elucidation, spectroscopic profile, and nonlinear optical properties of 1-ethoxy-2-methoxy-4-(2-nitroethenyl) benzene: A DFT approach

An organic compound, 1-ethoxy-2-methoxy-4-(2-nitroethenyl) benzene (EMNB), was investigated using experimental and density functional theory (DFT) methods. The optimized geometry at the B3LYP/6–311++G(d,p) level shows good agreement with experimental observations. Frontier molecular orbital and TD-DFT analysis indicate significant intramolecular charge transfer, supported by UV –vis spectral behavior. The calculated first-order hyperpolarizability suggests that EMNB exhibits enhanced nonlinear optical (NLO) properties, making it a promising candidate for optical applications. Molecular electrostatic potential and NBO analyses further confirm strong donor–acceptor interactions and reactive sites within the molecule. Topological studies illustrated electron localization and delocalization regions and confirmed the presence of van der Waals interactions and hydrogen bonding within the molecular framework. Thermal analysis reveals good stability, while other complementary studies support its structural and electronic properties relevant to NLO behavior.