Impact of external electric field on the physical and chemical properties of aniline

Abstract Aniline, having the molecular formula C 6 H 5 NH 2 , contains a phenyl group (C 6 H 5 ) connected to an amino group (NH 2 ). Aniline is a multifunctional solvent used in variousfields, such as pharmaceutical industries, although it’s toxic and has a detrimental effect on human health. Using density functional theory (DFT) with the B3LYP/6-311 g(d) basis set, the physical and chemical properties of aniline, such as total energy, dipole moment, bond length, infrared (IR) absorption spectra, frontier orbital energy and Raman spectra are computed under an external electric field (EEF) ranging from 0 to 15.427 V·nm −1 . The calculated results indicate that when the external field becomes stronger, the most prominent IR absorption curve exhibits a blue shift and a corresponding variation in intensity. Meanwhile, when an electric field is applied, many absorption peaks appear within the Raman spectrum while an EEF is applied. Furthermore, the distinctive Raman Spectral peaks for aniline were identified using a self-constructed Raman spectrometer. The potential energy variation curves corresponding to the rising of EEF were derived by examining the single-point energy across the C-N bond using the same approach. It was estimated by performing a linear curve fitting within the potential energy barrier. The outcomes provide significant, considerable theoretical predictions for future investigations into aniline’s chemical and physical properties and reveal that the molecular structure and other aspects undergo observable changes. Furthermore, Aniline’s ultraviolet-visible (UV–vis) spectrum exhibits a redshift, and the excitation energy gradually reduces in response to the EEF.