title: Spectroscopic and biological studies of new binuclear metal complexes of a tridentate ONS hydrazone ligand derived from 4-amino-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one and 4,6-diacetylresorcinol.
abstract: The binuclear hydrazone, H2L, ligand derived from 4-amino-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one and 4,6-diacetylresorcinol, in the molar ratio 2:1, and its copper(II), nickel(II), cobalt(II), zinc(II), cadmium(II), cerium(III), iron(III), oxovanadium(IV) and dioxouranium(VI) complexes have been synthesized. Structures of the ligand and its metal complexes were characterized by elemental analyses, spectral (infrared, electronic, mass, 1H NMR and ESR) data, magnetic susceptibility, molar conductivity measurements and thermal gravimetric analysis (TGA). The ligand acts as dibasic with two ONS tridentate sites. The bonding sites are the azomethine nitrogen, phenolate oxygen and sulfur atoms. The metal complexes exhibit different geometrical arrangements such as square planer, tetrahedral and octahedral. The Coats-Redfern equation was used to calculate the kinetic and thermodynamic parameters for the different thermal decomposition steps of some complexes. The ligand and its metal complexes showed antimicrobial activity towards Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Salmonella typhimurium and Escherichia coli), yeast (Candida albicans) and fungus (Aspergillus fumigatus). Structural parameters of the ligand and its metal complexes were theoretically computed on the basis of semiempirical PM3 level, and the results were correlated with their experimental data.
authors.affiliation: Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, Cairo 11711, Egypt. Electronic address: omima_adly@yahoo.com.
authors.forename: Omima M I
authors.initials: OM
authors.lastname: Adly
authors.affiliation: Department of Chemistry, University College in Makkah, Umm Al-Qura University, Makkah 21955, Saudi Arabia.
authors.forename: Adel A A
authors.initials: AA
authors.lastname: Emara
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D056831:Coordination Complexes / Q000494:pharmacology*; D004578:Electron Spin Resonance Spectroscopy; D004583:Electrons; D005658:Fungi / Q000187:drug effects; D006835:Hydrazones / Q000494:pharmacology*; D007700:Kinetics; D008024:Ligands; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D066244:Proton Magnetic Resonance Spectroscopy; D012118:Resorcinols / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013696:Temperature; D013818:Thermogravimetry; D014227:Triazines / Q000737:chemistry*
chemical_list: C526645:4,6-diacetylresorcinol; C000595697:4-amino-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one; D000890:Anti-Infective Agents; D000935:Antifungal Agents; D056831:Coordination Complexes; D006835:Hydrazones; D008024:Ligands; D012118:Resorcinols; D014227:Triazines
keywords: 4,6-Diacetyl-resorcinol; 4-Amino-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one; Antimicrobial activity; Binuclear complexes; Molecular modeling