Analysis of Vibrational Properties of Dimethylaniline–Dimethyl Sulfoxide Mixtures Using IR Spectroscopy and Molecular Docking Study of Dimethylaniline
Abstract
Abstract— Intermolecular interactions in a binary dimethylaniline (DMA)‒dimethyl sulfoxide (DMSO) system are investigated systematically based on infrared absorption spectroscopy and molecular docking analysis. The FTIR spectra recorded in the 600–1700 cm–1 range exhibit consistent vibrational shifts within 1–13 cm–1 as a function of the DMA mole fraction. Particularly, frequency shifts in aromatic-ring and C–N vibrational modes indicate the electron-density redistribution induced by the dipolar solvent environment. The relatively small amplitude shifts of spectral parameters suggest that noncovalent interactions, primarily of dipole–dipole and donor–acceptor character, predominate over strong covalent complexes in the system. Probable binding characteristics of dimethylaniline with biological systems are evaluated using molecular docking based on the cytochrome P450 2A6 (CYP2A6) enzyme model. Computational results show that the ligand is energetically favorably positioned within the active site of the enzyme and that complex stability is governed primarily by hydrophobic and aromatic π–π interactions. The consistency between experimental spectral data and computational results indicates a close relationship between solvent-induced electronic effects and the protein–ligand binding mechanism. These results provide a theoretical basis for explaining the behavior of small aromatic amines in solutions and biological media at the molecular level, as well as for predicting their metabolic properties.