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Eight novel mixed-ligand copper(II) complexes of the type [Cu(L)(phen)](ClO4) (1–8) synthesized from S-methyldithiocarbazate Schiff bases [H(L1)–H(L8)] and 1,10-phenanthroline (phen) ligands have been characterized using various physicochemical, spectroscopic and electrochemical methods. The structures of seven out of the eight Cu(II) complexes have been determined by single crystal X-ray diffraction. The coordination geometry around the Cu(II) ion is distorted square pyramidal (τ, 0.24–0.49). The heterocyclic and azomethine nitrogens along with thiolato sulphur of the deprotonated tridentate ligand (NNS) and one of the imine nitrogens of phen form the equatorial CuN3S square plane, while the other imine nitrogen atom of phen occupies the axial position. The geometry of the Cu(II) center in the solid state is preserved in DMF solution, stabilizing to distorted square pyramidal, as suggested by the low-temperature EPR data g‖ > g⊥ > 2.0. Cyclic voltammetry showed that the Cu(II) complexes display quasi-reversible electrochemistry. The efficiency of the complexes in killing the human lung epithelial adenocarcinoma cells (A549) has also been studied along with the cell viability assay against the noncancerous human lung epithelial cells (L132) under in vitro conditions. They were found to exhibit excellent cytotoxicity against A549 cancer cells without affecting the normal L132 cells. The activity of all the complexes was significantly superior to that of cisplatin. The 2′,7′-dichlorodihydrofluorescein diacetate (DCHF-DA) experiment indicated that cancer cells produce more reactive oxygen species (ROS) than normal cells. Further, they cause cell death mainly through apoptotic mode, as revealed by the observation of a higher percentage of apoptotic cells in acridine orange (AO) or ethidium bromide (EB) or 4′,6′-diamidino-2-phenylindole (DAPI) stained cancer cells. Thus, ROS generation in tumor cells is implicated in cytotoxicity, demonstrating the versatile nature of presently accessible mixed-ligand copper(II) complexes for cancer therapy by means of ROS-induced apoptotic cell death. [ABSTRACT FROM AUTHOR]

In this research, a joint theoretical and experimental investigation was performed on the structural and spectral data (FT‐IR, Laser‐Raman, NMR, and UV–vis) of N,N‐dimethyl‐2‐[(1E)‐({[(methylsulfanyl)methanethioyl]amino}imino)methyl]aniline molecule. The theoretical electronic structure analyses were fulfilled by the density functional theory at the B3LYP level with the 6‐311++G(d,p) basis set in the gas phase of the isolated compound at the ground state. The vibrational works were analyzed in terms of potential energy distribution analysis to make the assignments of fundamental vibrational frequencies and the assigned modes of the title compound were compared with the reported experimental vibrational data. Later, Hirshfeld surface analysis over crystalline structure of the title compound was made to define the possible inter‐molecular interactions. In addition, the HOMO (highest occupied molecular orbital), LUMO (lowest unoccupied molecular orbital), UV–vis, and molecular electrostatic potential analyses were done. The molecular docking investigation was done in order to analyze the presence of interactions between the title ligand compound and the receptor protein 2VN0. [ABSTRACT FROM AUTHOR]

The title compound bis[2-hydroxybenzylidenehydrazono)(methylthio)methyl]disulfide (1), an S-methyldithiocarbazate derivative with a disulfide bond has been synthesized by the condensation of 2-hydroxybenzaldehyde with S-methyldithiocarbazate. It has been characterized by elemental analyses, 1H, 13C NMR and FT-IR spectroscopy and mass spectrometry. The single crystal X-ray structure shows that the compound exists in a tautomeric thione form with the dithiocarbazate fragment adopting an EE configuration with respect to the C=N bond of the benzylidene moiety. The thermal behaviour of the compound has been studied using thermogravimetric analysis (TGA). The molecular geometry of the compound in the ground state has been optimized using density functional theory (DFT/B3LYP) method with the 6-311++G(d,p) basis sets. Molecular docking of the compound with human carbonic anhydrase II has been performed to probe the nature of interaction. [ABSTRACT FROM AUTHOR]