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Thiosemicarbazide copper (II) complexes; [Cu2(HL1)2(H2O)2Cl2].H2O (1) and [Cu2(HL2)2(H2O)2Cl2].2H2O (2) (where H2L1 = 2‐picolinoyl‐N‐(pyridin‐2‐yl)hydrazine‐1‐carbothioamide and H2L2 = 2‐(2‐(2‐aminothiazol‐4‐yl)acetyl)‐N‐(pyridin‐2‐yl)hydrazine‐1‐carbothioamide) have been synthesized and characterized. Analytical and spectroscopic data revealed that ligands behaves as monobasic tetradentate with octahedral geometry. In addition, the optimized geometry of the ligands and their complexes was approved with the Jaguar 9.1 program in the Schrödinger set using DFT (density functional theory) to predict chemical processes and to estimate the properties of the material made by the hybrid functional density system B3LYP. Furthermore, the thermal degradation curves of complexes were discussed in order to determine the kinetic and thermodynamic parameters by various approaches. Additionally, the antioxidant (using the DPPH and SOD methods) and the antibacterial potency of the compounds were examined. Also, docking study of ligands and their complexes was carried out against Staphylococcus aureus gram +ve, gram ‐ve bacterial strains of Escherichia coli and Candida albicans using the XP glide protocol of Schrödinger suite.

A series of some transition metal, Fe(III), Cu(II), Cd(II), and Hg(II), complexes with N′,2‐bis((Z)‐2‐oxoindolin‐3‐ylidene)hydrazine‐1 carbohydrazide (H3L) ligand have been synthesized, and their structures were elucidated based on their spectral analyses (Fourier transform infrared [FT‐IR], 1H nuclear magnetic resonance (NMR) and 13C NMR, UV‐visible (UV‐Vis), electron spin resonance (ESR), powder X‐ray diffraction [XRD], and mass spectroscopy), elemental analyses, conductance, and magnetic susceptibility measurements. The structures of the H3L ligand and its metal complexes were optimized using the DMol3 tool in the material studio package. The ligand behaves as binegative N2O3 pentadentate in [Fe(HL)(Cl)]·2H2O complex, mononegative N2O3 pentadentate in [Cu(H2L)(OAc)]·2H2O complex, mononegative N2O tridentate in [Cd(H2L)2]·H2O complex, and finally, neutral N2 bidentate in [Hg(H3L)(Cl)2]·2H2O complex. Coats–Redfern and Horowitz–Metzger methods were used to estimate the various thermodynamic and kinetic parameters. Cyclic voltammetry of the ligand in the absence and presence of Cd(II) and Hg(II) ions was studied. Fluorescence studies were performed in DMSO and showed that Cu(II) ions quench the fluorescence spectrum of the free ligand, whereas Cd(II) ions enhance it. The in vitro antimicrobial activities of the free ligand and its complexes against different bacterial strains and fungi Candida albicans were screened using agar‐disc diffusion techniques. The antioxidant potentials of the isolated compounds were also screened by employing SOD and ABTS free radical scavenging methods. Molecular docking studies were performed using Auto‐Dock tools to predict the best binding mode and predominant binding interactions.

A novel chemosensor, namely 3-(4-chlorophenyl)-1-(pyridin-2-yl)prop-2-en-1one, CPPEO, and its metal complexes have been synthesized and characterized by using sets of chemical and spectroscopic techniques, such as elemental analysis, mass, Fourier transform-infrared and UV-Vis spectral analysis. The thermal properties of the metal complexes have been investigated by thermogravimetric techniques. The decomposition mechanism of the titled complexes was suggested. The results showed that the Co 2+ and Mn 2+ complexes have an octahedral geometry, while Zn 2+ and Cd 2+ complexes have tetrahedral geometry. The kinetic and thermodynamic parameters of the thermal decomposition stages have been evaluated using the Coats-Redfern method. The optical sensing response of the investigated chemosensor to the different metal ions was investigated. It responds well to the tested metal ions as reflected from the significant change in both absorption and emission spectra upon adding different concentrations of the metal salts, confirming the intramolecular charge transfer of the chemosensor upon effective coordination with the used metal ions.This leads to enhancing ICT interaction, causing a significant shift in the presence of strongly complexing metal ions. This was fully reversible, where the solution of dye-metal ion complex was decomplexed by adding an EDTA solution to revert the original spectrum of the dye. The stability constants, K, for the complexes of the investigated chemosensor with the mentioned metal ions were calculated, indicating that Co 2+ is the most effectively detected, and the potential of the novel dye was highly efficient switchers for Co 2+ ions. Additionally, the molecular modeling was carried out for the chemosensor and its metal complexes. Finally, the solid complexes have been tested for their in vitro antimicrobial activities against some bacterial strains (Gram +ve and Gram −ve bacteria), as well as antifungal strains.

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