Benzylidenemalononitrile Derivatives as a New Class of Materials: Third‐Order Nonlinear Optical Properties and Pharmacological Aspects via Molecular Docking and Admet Analysis

ABSTRACT This study reports on the synthesis, characterization, screening experimentally and theoretically for their third‐order nonlinear optical (NLO) properties, and bioactivity of four organic compounds derived from malononitrile [(E)‐2‐(3‐phenylallylidene)malononitrile ( 1 ); 2‐(2,4‐dichlorobenzylidene)malononitrile ( 2 ); 2‐(4‐nitrobenzylidene)malononitrile ( 3 ); 2,2'‐(1,4 phenylenebis(methanylylidene))dimalononitrile ( 4 )]. Structures were characterized by IR, UV‐Vis, and NMR spectroscopy, and the third‐order polarizability (γ) was experimentally determined by the third‐harmonic generation (THG) technique. The third‐susceptibility χ(3) is maximum for the compound 1 , showing that it could be a promising high‐power NLO material. To support experimental NLO data, density functional theory (DFT) and time‐dependent (TD‐DFT) calculations were performed using two basis sets: B3LYP/6–311++G(d,p) and B3LYP/6–31G(d,p). The analysis of the electronic structures, HOMO–LUMO energy gaps, dipole moments, polarizability, and hyperpolarizability highlights the crucial influence of structural and electronic properties on NLO behavior, that is, extended π‐conjugation and orbital contributions, contributing significantly to increasing nonlinear responses. Molecules 1 and 4 stand out as the most conjugated with the strongest transitions, while molecules 2 and 3 display weaker transitions. Molecular docking and ADMET predictions reveal potent anticancer inhibition, with molecule 4 being the best‐scoring ligand toward the oxidoreductase protein (PDB ID: 2XFU). Furthermore, almost all the compounds ( 1 ‐ 4 ) exhibit promising pharmacokinetic profiles for oral drug development, and could be good candidates for in‐vitro and in‐vivo assays. The results also suggest that the compounds ( 1 ‐ 4 ) have the potential to serve as multi‐functional compounds in optoelectronics and biomedicine.