Novel metal chelates with thiourea and nicotinic acid: Synthesis, structural characterization, and biological properties

The interaction of nicotinic acid and thiourea with the chloride salts of Ca(II), Mg(II), Co(II), Ni(II), Cu(II), and Fe(III) ions led to the synthesis of a unique series of metal chelates. All formed metal complexes were clarified using a variety of analytical and spectral techniques, besides magnetic moment and thermal tests. The electronic and magnetic measurements indicated that the paramagnetic chelates (3) and (4), as well as the diamagnetic complexes (1) and (2), were responsible for the tetrahedral geometrical structure. The outcomes also led to the production of square-planar, and high-spin octahedral structures for chelates (5) and (6). Thermodynamic studies using activation energy values revealed that complex (1) is more thermally stable than complex (2) and complex (3) is more stable than complex (4). Fe(III) complex exhibits higher antibacterial and antifungal activities than other metal complexes. Chelate (6) exhibits the highest rate of germination in wheat

Spectral, thermal, and biological activity studies of some nano divalent (E,Z)-methyl N {[(methylamino)carbonyl]oxy}ethanimidothioate metal chelates

A novel set of biologically active Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) chelates was prepared from (E,Z)-methyl N-{[(methylamino)carbonyl]oxy}ethanimidothioate. The chemical structural of the reported chelates was identified by means of some physicochemical and spectral approaches. All chelates were found to be non-electrolytic except Cd(II) possessed electrolytic character. The elemental analysis declared that the designated complexes were formed with (1:1), (2:1) and (1:3) (M:L) stoichiometry. The infrared spectral data revealed the neutral ONS tridentate and NS bidentate behavior of ligand towards metal ions. The octahedral structure of the produced chelates was proposed from the electronic absorption spectral data alongside the magnetic susceptibility measurements. TG/DTG demonstrated the superior complexes' thermal stability in comparison to that of free ligand. Ligand and its synthesized chelates were screened in vitro towards E. vermiculata for their anti-molluscicidal characteristic. The findings showed that each tested compound had varying degrees of sensitivity to the tested land snail species, with significant anti-molluscicidal action. In addition, ligand and its chelates were examined for their antibacterial screening towards both gram-positive (B. subtilis, S. aureus and M. sp. RCMB 028 (1)) and gram-negative bacteria (E. coli, P. aeruginosa and P. vulgaris) as well as their antifungal activity against C. albicans and A. fumigatus. The results indicated that the coordinated constructions have extraordinary activity compared to the ligand, in which Ni(II) and Cd(II) chelates were more active than the reference itself. X-ray diffraction data reflected that Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) crystallized at nano-scale. Some theoretical studies were validated, and the experimental results were interpreted