Complexes of Mn(II), Co(II), Ni(II), Cu(II) & Zn(II) with dibasic tridentate benzoylacet-ortho-substituted anilides

Abstract

Complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with dibasic tridentate ligands, benzoylacet<em>-ortho</em>-substituted anilides, (the substituents being OH, SH or COOH) have been prepared and characterized by elemental and thermogravimetric analysis.IR and ¹H NMR spectral data indicate that bonding occurs through deprotonated COOH, SH or OH; enolate oxygen; and anilide nitrogen. Electronic and EPR spectra reveal that Mn(II), Co(II) and Ni(II) complexes are octahedral, Cu(II) complexes are square-planar, and Zn(II) complexes are tetrahedral. Potentiometric titrations indicate the formation of 1:1 complexes in solution; their conditional stability constants have also been calculated.