Synthesis, characterization, thermodynamic and thermal studies of Zn(II) complexes with di-2-pyridyl ketone salicyloylhydrazone
Tipo
Artigo
Data de publicação
2004
Periódico
Polyhedron
Citações (Scopus)
11
Autores
Gaubeur I.
Guekezian M.
Terra L.H.S.A.
Moraes M.C.B.
Lago C.L.
Matos J.R.
Suarez-Iha M.E.V.
Guekezian M.
Terra L.H.S.A.
Moraes M.C.B.
Lago C.L.
Matos J.R.
Suarez-Iha M.E.V.
Orientador
Título da Revista
ISSN da Revista
Título de Volume
Membros da banca
Programa
Resumo
Zinc(II) in aqueous/ethanolic (50% V/V), pH 4.5, solution forms with di-2-pyridyl ketone salicyloylhydrazone (DPKSH) two complexes, [Zn(C 18H13N4O2)]+ and [Zn(C18H13N4O2)2], which were characterized by electron ionization and electrospray mass spectra, IR, thermogravimetry (TG) and differential scanning calorimetry (DSC). The overall formation constants and the molar absorptivies were obtained for both of the complexes. This paper shows the characteristics of a coordinated compound formed by zinc(II) and di-2-pyridyl ketone salicyloylhydrazone (DPKSH). The synthesized complex shows the formula: Zn(DPKSH)2. Elemental analysis, electron ionization and electrospray mass spectra indicated the 1:2 metal/ligand molar ratio. The IR spectra show that DPKSH is coordinated to zinc(II) through the oxygen from the enolic or the phenolic group as the vCO frequency was suppressed and the vCO (phenolic) band was shifted to higher frequency in the IR spectrum of the complex. Two other interactions can be attributed to the nitrogens from the azo and the pyridine groups. Thermal decomposition and differential scanning calorimetry (DSC) are different for the ligand and the complex. The overall formation constants were obtained in ethanolic solution 50% (V/V), at pH 4.5 and 25 °C, resulting in β1=1.07×105 and β2=1.05×1010. The molar absorptivies of the 1:1 (Îμ1) and 1:2 (Îμ2) complexes (Zn(II):DPKSH) were found to be 1.1Ã-104 and 4.5Ã-10 4 (M-1cm-1), respectively. © 2004 Elsevier Ltd.