Four- and six-coordinate Zn(II), Cd(II) and Hg(II) complexes of terdentate benzoyl hydrazones

Abstract

The syntheses and characterisation of Zn(II), Cd(II) and Hg(II) complexes of benzoyl hydrazones derived from benzoyl hydrazine and orthohydroxy aldehydes and ketones are described. The complexes have been characterised on the basis of elemental analyses and infrared spectral data. The Zn(II) and Cd(II) complexes are dimeric having two tetrahedral units stacked together through phenoxide bridges as revealed by the presence of ▪ vibrations at 720–730 (Zn 2+) and 660–680 cm −1 (Cd 2+) and Hg(II) complexes are six-coordinate. The ligands act as terdentate chelating agents and ν(MO) (ketonic/enolic), ν(MN) and ν(MO) (phenolic) have been assigned and discussed.