Transition metal complexes of acetamidomalondihydroxamate: Synthesis, spectral, thermal and electrochemical studies

YILMAZ F., Yilmaz V. T., Topcu S.

JOURNAL OF COORDINATION CHEMISTRY, cilt.57, sa.6, ss.525-534, 2004 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 57 Sayı: 6
  • Basım Tarihi: 2004
  • Doi Numarası: 10.1080/00958970410001696843
  • Dergi Adı: JOURNAL OF COORDINATION CHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.525-534
  • Anahtar Kelimeler: acetamidomalondihydroxamate, metal complexes, square wave voltammetry, cyclic voltammetry, ACIDS, SIDEROPHORES, CONSTANTS, SERIES, LIGAND
  • Karadeniz Teknik Üniversitesi Adresli: Hayır

Özet

Acetamidomalondihydroxamate (K(2)AcAMDH) and its manganese(II), iron(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes were synthesized and characterized by elemental analysis, UV-VIS, IR and magnetic susceptibility. The pK(a1) and pK(a2) values of the dihydroxamic acid in aqueous solution were found to be 8.0 +/- 0.1 and 9.7 +/- 0.1. The dihydroxamate anion AcAMDH behaves as a tetradentate bridging ligand through both hydroxamate groups, forming complexes with a metal to ligand ratio of 1:1 in the solid state. The FTIR spectra and thermal decompositions of the ligand and its metal complexes were recorded. The redox behavior of the complexes was investigated in aqueous solution by square wave voltammetry and cyclic voltammetry at neutral pH. In contrast to the solid state, in solution the copper(II) and zinc(II) ions form stable complex species with a metal to ligand ratio of 1 : 2. The iron(II) and nickel(II) complexes show a two-electron irreversible reduction behavior, while the copper(II) and zinc(II) complexes undergo reversible electrode reactions. The stability constants of the complexes were determined by square wave voltammetry.