Synthesis, characterization, cyclic voltammetry and biological studies of Zn (II), Cd (II), Hg (II) and UO₂²⁺ complexes of thiosemicarbazone salt

Abstract

Zn (II), Cd (II), Hg (II) and U (VI)O22+ complexes of water‐soluble thiosemicarbazone ligand (NaH3PyTSC) have been prepared and characterized using various techniques. Fourier transform‐infrared (FT‐IR) demonstrated that NaH3PyTSC ligand behaves as a binegative NOS tridentate in [Hg(H2PyTSC)(H2O)]2 and [UO2(H2PyTSC)(H2O)]2 complexes via the deprotonated SH, (C=N)az groups from one molecule and SO3− group from another molecule, while it behaves as a binegative NNSO tetradentate in [Cd(H2PyTSC)(H2O)2]2 complex through the deprotonated SH group, the SO3− group and the nitrogen of both the (C=N)az and (C=N)py. Finally, it behaves as a binegative OO bidentate in [Zn(H2PyTSC)(H2O)2]2·2H2O complex by the deprotonated OH group from one molecule and SO3− group from another ligand molecule. The spectral data suggest a tetrahedral coordination around Hg (II) and Zn (II) ions, and an octahedral coordination around Cd (II) and U (VI)O22+ ions. The NaH3PyTSC ligand exhibited maximum luminescent intensity at 501 nm, while Zn (II), Cd (II) and Hg (II) chelates show emission bands at 459, 458 and 358 nm, respectively. Two comparable methods were used to estimate various thermodynamic parameters. Cyclic voltammetry has been studied for Cd (II) complex in solution. Different biological applications of the isolated complexes have been estimated. It was found that [Cd(H2PyTSC)(H2O)2]2 showed the most effective antioxidant and anticancer activity.

Iron(III), copper(II), cadmium(II), and mercury(II) complexes of isatin carbohydrazone Schiff base ligand (H3L): Synthesis, characterization, X‐ray diffraction, cyclic voltammetry, fluorescence, density functional theory, biological activity, and molecular docking studies

“…Also, the data obtained from complexation between H 3 L and Cd(II) show that the Cd(II) system is also reversible entails two‐electron transfer (Cd(II)/Cd). The stability constant ( β MX ) for both complexes for each addition, formal peak potential, and Gibbs free energy (Δ G ) of the interaction of metal salt with H 3 L (Tables 2 and 3) were calculated using the equations [ 58,59 ] : where E ° M and E ° C are the formal peak potential of the metal in lack and presence of H 3 L, respectively; R is the universal gas constant; T is the absolute temperature, C x is the H 3 L concentration, and j is the coordination number of the complex.…”

Spectroscopic Characterization, Cyclic Voltammetry, Biological Investigations, MOE, and Gaussian Calculations of VO(II), Cu(II), and Cd(II) Heteroleptic Complexes

“…TGA coupled with DTA diagrams were used to estimate kinetic and thermodynamic parameters using Coats–Redfern and Horowitz–Metzger methods, − as shown in Figures 6S–11S. The calculated parameters ( E a , A , Δ H , Δ S , and Δ G ) for the thermal degradation steps (Tables 4S–6S) can be concluded as follows: (i) the high activation energy ( E a ) values for the thermal decomposition steps indicated the high stability of complexes; (ii) all decomposition steps were endothermic processes as a result of (+Δ H ) enthalpy values; (iii) the (+Δ S ) entropy values indicated the fast decomposition reactions while the (−Δ S ) entropy values revealed the slow degradation stages; (iv) the (+Δ G ) free energy values indicated that the free energy of the final residue is greater than that of the initial complex supporting the non-spontaneous processes. − …”

Fabrication of novel Fe (III), Co (II), Hg (II), and Pd (II) complexes based on water‐soluble ligand (NaH2PH): structural characterization, cyclic voltammetric, powder X‐ray diffraction, zeta potential, and biological studies

“…Biological activities of these complexes were evaluated as anticancer agents in (A549), (HTB177), (HCT116), (A375 (PC3), (MDA‐MB‐453), (HeLa), and (MRC‐5) cell lines. [ 11 ] In continuation of our previous work discussing the water‐soluble ligand derived from sodium 3‐formyl‐4‐hydoxy benzene sulfonate (NaH 3 PyTSC), [ 12,13 ] herein we isolated water‐soluble picolinate hydrazone ligand (NaH 2 PH) and its coordination behaviors toward Co (II), Fe (III), Hg (II), and Pd (II) metal ions were discussed. The modes of chelation were characterized utilizing analytical analysis, different spectroscopic (IR, UV–visible, PXRD, H NMR and MS) methods, magnetic measurements, and thermogravimetric analysis.…”