Preparation and spectral characterization of new macrocyclic Ni(II) and Co(II) complexes derived from 1,4- bis (2-carboxyaldehydephenoxy)butane and various diamines

Abstract

Six new macrocyclic complexes were synthesized by the template effect from reaction of 1,4-bis(2-carboxyaldehydephenoxy)butane, Ni(NO3)2 · 6H2O or Co(NO3)2 · 6H2O and various diamines. The metal-to-ligand ratios of Ni(II) or Co(II) metal complexes were found to be 1 : 1. Coordination of the Schiff base to Ni(II) and Co(II) through the two nitrogen and two oxygen atom (ONNO) are expected to reduce the electron density in the azomethine link and hydroxyl group. The Ni(II) and Co(II) complexes are proposed to be tetrahedral and are 1 : 2 electrolytes as shown by their molar conductivities (ΛM) in DMF (dimethyl formamide) at 10−3 M. The structures are proposed from elemental analysis, FT-IR, UV-VIS, magnetic susceptibility measurements, molar conductivity measurements, and mass spectra.