Synthesis of (2-hydroxo-5-chlorophenylaminoisonitrosoacetyl)phenyl ligands and their complexes: Spectral, thermal and solvent-extraction studies

Abstract

Four different types of new ligands Ar(COC(NOH)R)n (Ar=biphenyl, n = 1 H2L 1 ; Ar=biphenyl, n = 2 H4L 2 ; Ar=diphenylmethane, n = 1 H2L 3 ; Ar=diphenylmethane, n = 2 H4L 4 ; R=2�amino�4�chlo� rophenol in all ligands) have been obtained from 1 equivalent of chloroketooximes Ar(COC(NOH)Cl) n (HL 1 -H2L 4 ) and 1 equivalent of 2�amino�4�chlorophenol (for H2L 1 and H2L 3 ) or 2 equivalent of 2�amino� 4�chlorophenol (for H4L 2 and H4L 4 ). (Mononuclear or binuclear cobalt(II), nickel(II), copper(II) and zinc(II) complexes were synthesized with these ligands.) These compounds have been characterized by ele� mental analyses, AAS, infrared spectra and magnetic susceptibility measurements. The ligands have been further characterized by 1 H NMR. The results suggest that the dinuclear complexes of H 2 L 1 and H 2 L 3 have a metal:ligand ratio of 1:2; the mononuclear complexes of H4L 2 and H4L 4 have a metal:ligand ratio of 1:1 and dinuclear complexes H4L 2 and H4L 4 have a metal:ligand ratio of 2:1. The binding properties of the ligands towards selected transition metal ions (Mn II , Co II , Ni II , Cu II , Zn II , Pb II , Cd II , Hg II ) have been established by extraction experiments. The ligands show strong binding ability towards mercury(II) ion. In addition, the thermal decomposition of some complexes is studied in nitrogen atmosphere.