N4-hydroxyethyl-pyridinealdehyde thiosemicarbazone (HL, 1) as a tridentate Schiff base has been synthesized by 1:1 reaction of S-methyl-3-((pyridyl)methyl) dithiocarbazate and 2-aminoethanol. Complexes [Cd(HL)2](NO3)2 (2), [Cd(HL)I2] (3), [Cd(HL)Cl2] (4), [Cu(HL)2](NO3)2 (5) and [Cu(HL)Cl2] (6) have been obtained and characterized by elemental analyses, molar conductivities, and spectroscopic studies. The ligand molecule binds the metal ion using pyridyl nitrogen, azomethine nitrogen and the sulfur atoms. The crystal structure analysis of 3 has been determined and showed to be a distorted square pyramidal geometry complex. The inter- and intramolecular interactions give rise to a supramolecular network. Compounds 2, 3, 5 and 6 were assayed for their bioactivities against selected pathogens. Copper(II) complexes 5 and 6 showed antimicrobial activities against Gram-positive (Bacillus anthracis) and Gram-negative (Pseudomonas aeruginosa and Yersinia pseudotuberculosis) bacteria, complexes 2–4 showed antimicrobial activities against Bacillus atrophaeus, while the ligand itself showed antimicrobial activities against Escherichia coli and Y. pseudotuberculosis.

Keywords