The metal(II) ion complexes of a tetradentate ligand (L), namely bis[O,O-2,4-O,O-6,7-(thiocyanatecarboxylic methylidene)]-L-ascorbic acid are synthesized and characterized by 1H,13C-NMR, elemental analysis (CHN), mass spectroscopy, UV-visible and Fourier Transform infrared (FTIR) methods. This ligand is prepared from the reaction of the L-ascorbic acid and two moles of trichloroacetic acid in basic medium (compound I) with two moles of potassium thiocyanate. The reaction of (L) in ethanol with MCl2.xH2O gave complexes with the general formula [M(L)Cl2] (where M= Ni(II), Cu(II) and Zn(II), respectively) characterized by FTIR, UV-Visible, molar conductance, atomic absorption, magnetic susceptibility. The analysis of IR, spectral data of all complexes indicated that (L) is bonded to metal(II) ions through the two nitrogen atoms of thiocyanate groups and two oxygen atoms of hydroxyl moieties. The synthesized complexes were proposed to be octahedral in geometry. Among these complexes, the Zn(II) complex demonstrated good antibacterial activity.
Key words: Synthesis, tetradentate, thiocyanate, metal complexes, analysis.
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