title: Synthesis, spectroscopic characterization, electrochemical behaviour and thermal decomposition studies of some transition metal complexes with an azo derivative.
abstract: Complexes of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) with a novel heterocyclic azo derivative, formed by coupling diazotized 2-amino-3-carbethoxy-4,5-dimethylthiophene with acetylacetone were synthesized and characterized on the basis of elemental analyses, molar conductance, magnetic susceptibility measurements, UV-vis, IR, (1)H NMR and EPR spectral data. Spectral studies revealed that the ligand existed in an internally hydrogen bonded azo-enol form rather than the keto-hydrazone form and coordinated to the metal ion in a tridentate fashion. Analytical data revealed that all the complexes exhibited 1:1 metal-ligand ratio. On the basis of electronic spectral data and magnetic susceptibility measurements, suitable geometry was proposed for each complex. The nickel(II) complex has undergone facile transesterification reaction when refluxed in methanol for a long period. The ligand and the copper(II) complex were subjected to X-ray diffraction study. The electrochemical behaviour of copper(II) complex was investigated by cyclic voltammetry. The thermal behaviour of the same complex was also examined by thermogravimetry.
authors.affiliation: Department of Chemistry, University of Kerala, Kariavattom Campus, Trivandrum, Kerala, India.
authors.forename: M S
authors.initials: MS
authors.lastname: Sujamol
authors.forename: C J
authors.initials: CJ
authors.lastname: Athira
authors.forename: Y
authors.initials: Y
authors.lastname: Sindhu
authors.forename: K
authors.initials: K
authors.lastname: Mohanan
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D004563:Electrochemistry; D004578:Electron Spin Resonance Spectroscopy; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008345:Manganese / Q000737:chemistry; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry; D013696:Temperature; D013818:Thermogravimetry; D028561:Transition Elements / Q000737:chemistry*; D014961:X-Ray Diffraction; D015032:Zinc / Q000737:chemistry
chemical_list: D001391:Azo Compounds; D008024:Ligands; D028561:Transition Elements; D003035:Cobalt; D008345:Manganese; D003300:Copper; D009532:Nickel; D015032:Zinc