(E)-2-((4-tert-butylbenzylimino)methyl)-4-methoxyphenol is synthesized by the reaction of 4-tert-buthylbenzylamine with 5-methoxysalicylaldehyde. The structure of the Schiff base is investigated by FT-IR, UV-visible, and H-1 NMR, C-13 NMR, and X-ray data. Moreover, the molecular structure, molecular electrostatic potential surfaces (MEP), frontier molecular orbitals, and nonlinear optical properties (NLO) are also investigated by density functional theory (DFT) calculations. The experimental and calculated results show that the phenol-imine form of the compound is more favoured than the keto-amine form. The most energy favourable docked structures are obtained from the rigid molecular docking of the compound with DNA. The compound binds at the active site of DNA proteins by weak non-covalent interactions. UV-Vis spectroscopy studies of the interactions between the compounds and calf thymus DNA (CT-DNA) show that the compounds interact with CT-DNA via the electrostatic and intercalative binding. The compound inhibits the frameshift and base pair mutations in the absence of S9 mix with a high inhibition rate. Also, the molecular docking is made to identify the interaction between the ligand and DNA.