Dithiocarbazate Ligand-Based Cu(II), Ni(II), and Zn(II) Complexes: Synthesis, Structural Investigations, Cytotoxicity, DNA Binding, and Molecular Docking Studies.

S-4-methylbenzyl- β -N-(2-methoxybenzylmethylene)dithiocarbazate ligand, 1, prepared from S-(4-methylbenzyl)dithiocarbazate, was used to produce a novel series of transition metal complexes of the type, [M (L) 2 ] [M = Cu(II) ( 2 ), Ni(II) ( 3 ), and Zn(II) ( 4 ), L =  1 ]. The ligand and its complexes were investigated by elemental analysis, FTIR, 1 H and 13 C-NMR, MS spectrometry, and molar conductivity. In addition, single X-ray crystallography was also performed for ligand, 1 , and complex 3 . The Hirshfeld surface analyses were also performed to know about various bonding interactions in the ligand, 1 , and complex 3 . The investigated compounds were also tested to evaluate their cytotoxic behaviour. However, complex 2 showed promising results against MCF-7 and MDA-MB-213 cancer cell lines. Furthermore, the interaction of CT-DNA with ligand, 1, and complex 2 was also studied using the electronic absorption method, revealing that the compounds have potential DNA-binding ability via hydrogen bonding and hydrophobic and van der Waals interactions. A molecular docking study of complex 2 was also carried out, which revealed that free binding free energy value was -7.39 kcal mol -1 .