Biological evaluation of dinuclear copper complex/dichloroacetic acid cocrystal against human breast cancer: Design, synthesis, characterization, DFT studies and cytotoxicity assays

Binuclear copper(ii) cocrystal "[Cu₂(valdien)₂⋯2Cl₂CHCOOH]," 1 was synthesized from H₂valdien scaffold and anticancer drug pharmacophore "dichloroacetic acid" embedded with two Cu(ii) connected via a hydrogen bonded network. [Cu₂(valdien)₂⋯2Cl₂CHCOOH] 1 was thoroughly characterized by single-crystal XRD and by other spectroscopic techniques. The non-covalent interaction (NCI) index and Hirshfeld surface analysis were used to study the various kinds of interactions (O⋯H, N⋯H, H⋯Cl, Cu⋯H, C⋯O, N⋯O, C⋯Cl, and O⋯Cl, etc.) responsible for the stabilization of crystal lattice. [Cu₂(valdien)₂⋯2Cl₂CHCOOH] 1 was validated as potential antitumor drug entity by studying its DNA binding profile, cleavage mechanism with pBR322 by gel electrophoretic assay and in vitro cytotoxicity on MCF-7 cancer cell lines. The mechanistic pathways were also deduced via dual staining AO/EB of cancer cells which confirmed the potential of the cocrystal [Cu₂(valdien)₂⋯2Cl₂CHCOOH] 1 to act as effective anticancer agent towards breast cancers.