title: Synthesis, spectroscopic characterization and thermal behavior of metal complexes formed with N'-(1-(4-hydroxyphenyl) ethylidene)-2-oxo-2-(phenylamino) acetohydrazide (H3OPAH).
abstract: Complexes of Co(II), Ni(II), Cu(II), Mn(II), Cd(II), Zn(II), Hg(II) and U(IV)O(2)(2+) with N'-(1-(4-hydroxyphenyl) ethylidene)-2-oxo-2-(phenylamino) acetohydrazide (H(3)OPAH) are reported and have been characterized by various spectroscopic techniques like IR, UV-visible, (1)H NMR and ESR as well as magnetic and thermal (TG and DTA) measurements. It is found that the ligand behaves as a neutral bidentate, monoanionic tridentate or tetradentate and dianionic tetradentate. An octahedral geometry for [Mn(H(3)OPAH)(2)Cl(2)], [Co(2)(H(2)OPAH)(2)Cl(2)(H(2)O)(4)] and [(UO(2))(2)(HOPAH)(OAc)(2)(H(2)O)(2)] complexes, a square planar geometry for [Cu(2)(H(2)OPAH)Cl(3)(H(2)O)]H(2)O complex, a tetrahedral structure for [Cd(H(3)OPAH)Cl(2)], [Zn(H(3)OPAH)(OAc)(2)] and [Hg(H(3)OPAH)Cl(2)]H(2)O complexes. The binuclear [Ni(2)(HOPAH)Cl(2)(H(2)O)(2)]H(2)O complex contains a mixed geometry of both tetrahedral and square planar structures. The protonation constants of ligand and stepwise stability constants of its complexes at 298, 308 and 318 K as well as the thermodynamic parameters are being calculated. The bond lengths, bond angles, HOMO, LUMO and dipole moments have been calculated to confirm the geometry of the ligand and the investigated complexes. Also, thermal properties and decomposition kinetics of all compounds are investigated. The interpretation, mathematical analysis and evaluation of kinetic parameters (E(a), A, ΔH, ΔS and ΔG) of all thermal decomposition stages have been evaluated using Coats-Redfern and Horowitz-Metzger methods.
authors.affiliation: Department of Chemistry, Faculty of Science, Mansoura University, Mansoura, Egypt.
authors.forename: Sara F
authors.initials: SF
authors.lastname: Ahmed
authors.forename: Ola A
authors.initials: OA
authors.lastname: El-Gammal
authors.forename: Gaber
authors.initials: G
authors.lastname: Abu El-Reash
mesh_terms: D000814:Aniline Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D006834:Hydrazines / Q000138:chemical synthesis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D013055:Spectrophotometry, Infrared; D013816:Thermodynamics
chemical_list: D000814:Aniline Compounds; D056831:Coordination Complexes; D006834:Hydrazines; C569801:N'-(1-(4-hydroxyphenyl)ethylidene)-2-oxo-2-(phenylamino)acetohydrazide