Theoretical investigations of pharmacological activities and solvent effect on structural and nonlinear optical properties of new methyl (E)-3-(2,3,4-trimethoxybenzylidene)dithiocarbazate

A new Schiff base methyl (E)-3-(2,3,4-trimethoxybenzylidene)dithiocarbazate (MTBD) was successfully synthesized by condensation of S-methyldithiocarbazate with 2,3,4-trimethoxybenzaldehyde. The structure of MTBD was confirmed by several spectroscopic techniques such as single crystal X-ray, FTIR, UV–Vis, NMR and mass spectroscopy. To investigate the molecular structure, optoelectronic properties and bioactivity of MTBD, its structure was optimized using the density functional theory (DFT) method on the B3LYP label with a basis set of 6-311++ G (d, p). The optimized structure and the crystal structure showed excellent agreement. Topological studies using a reduced density gradient showed that two monomers are connected by strong hydrogen bonds. Hirshfeld surface analysis revealed the dominance of H⋯H contacts in the molecular system. The solvent effects studied with the IEFPCM model suggested that solvent polarity significantly influences UV absorption, HOMO-LUMO energy level, charge transfer, and nonlinear optical properties. It can be seen that n → π* and π → π* showed a blue shift, and the E_gap and NLO properties increased with increasing solvent polarity. Natural bond orbital analysis revealed that MTBD has a 98.0773 % Lewis structure. Molecular docking against the three different cancer receptors 1H7K (colon cancer), 4FM9 (breast cancer) and 1X2J (lung cancer) examined the MTBD ligand as an efficient ligand for the selected targets and showed maximum binding energy to the lung cancer target. Evaluation of drug-likeness and ADMET properties revealed that MTBD has a safer ADMET profile and good oral bioavailability, indicating its effectiveness as a drug candidate.