Novel metal complexes of the type [M(L)X] (where M= Cu(II), Ni(II) and Fe(III), L = N2,N6-bis(5-mercapto-1,3,4-thiadiazol-2-yl)pyridine-2,6-dicarboxamide, X= Cl−, CH3COO−) were synthesized by the reaction of pyridine-2,6-dicarboxylic acid and 2-amino-5-mercepto-1,3,4-thiadiazole. The synthesized ligand was reacted in THF with metal salts (Cu, Ni and Fe) to form complexes. Deprotonated ligand shows tridentate nature and coordinate to metal ion to form pincer cavity. In all, complexes metals were surrounded by three nitrogen atom and other site coordinated by other groups (chloride, acetate). All the synthesized complexes were characterized by spectroscopic techniques like UV-visible, 13C NMR and 1HNMR, IR spectroscopy, DSC, elemental analysis and molar conductance measurements. The ligand and its metal complexes were tested for antimicrobial activity against bacterial and fungal strains by determining inhibition zone, minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The complexes showed moderate antimicrobial activity and antifungal activity when tested against bacteria and fungi

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This article reports an amide based Chemosensor used for selective detection of divalent Cu+2 and Ni+2 ions via Fluorescence turn off. The selective sensing ability of Chemosensor was investigated in presence of different metal ions Mg2+, Ag+, Fe2+, K+, Cu2+, Ni2+, Hg2+, Pb2+, Mn2+, Pd2+, Cd2+ and Mn3+ as competitive ions. The receptor i. e. Chemosensor formed complexes with metal ions in 1:1 stoichiometric ratio. The detection limit and binding constant calculated as 1.92×10–4 and 1.4×10–4 M and 2.16×103 M−1 and 3.09×103 M−1 for Cu2+ and Ni2+ions respectively. The complexes were characterized by UV/visible, FT-IR, 13C NMR and 1H NMR spectroscopy. Further the structure and Crystallinity were calculated by P-XRD spectral analysis. The crystallinity found to be 65.27 and 67.87% respectively

A series of transition metal complexes of the type [MLX2], where M = Mn(II), Fe(II), Co(II), Ni(II), X = Cl–/CH3COO– and L = Schiff base derived from 4-nitrobenzene-1,2-diamine and 5-chloroisatin have been synthesized and characterized by elemental analysis, molar conductance, IR, UV-visible, magnetic moments measurement, 1H & 13C NMR and mass spectral studies. On the basis of physico-chemical studies and spectral evaluation, an octahedral geometry have been proposed for all metal(II) complexes. The antimicrobial activity of ligand and its metal complexes have been additionally screened against bacteria and fungi. Metal(II) complexes show good activity as compared to ligand towards studied microorganisms and also metal complexes checked for their catalytic properties for benzoylation of phenol.

A new Schiff base ligand (L) [2,2′-((1Z,1′Z)-((4-methyl-1,2- phenylene)bis(azanylidene))bis(methanylylidene))diphenol], derived from condensation of salicyaldehyde and 3,4-diamino toluene. The synthesized ligand was used for complexation with different metal ions Cr(III), Co(II), Zn(II) and Cd(II) using a molar ratio of metal:ligand (1:1). The synthesized ligand and its metal complexes were characterized by TLC, NMR (1H & 13C), UV-visible, mass, FT-IR spectroscopies, elemental analysis, magnetic moment and conductivity measurement. On the basis of above studies the proposed structure of synthesized mononuclear metal complexes have been found to possess tetrahedral geometry while Cr(III) and Co(II) ions possess octahedral geometry. The spectral studies revealed that the synthesized ligand was acting as tetradentate chelating agent and coordinated to metal centre via deprotonated phenolate oxygen and azomethine-N atom. The biological activity of ligand and its metal complexes were screened in vitro against Gram-negative bacteria (Salmonella typhimurium and E. coli), Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and fungus (Aspergillus fumigatus) to ascertain their antibacterial and antifungal properties.