Thermal stability of copper(II) and nickel(II) Schiff base complexes

Abstract

From the reaction of 1,2-di(o-aminophenylthio)ethane (dapte) and 5-bromosalicylaldehyde, Schiff base ligand N,N′-bis(5-bromosalicylaldehyde)-1,2-di(o-iminophenylthio)ethane ((Brsal)2dapte) was synthesized and characterized by elemental analyses (CHN), FT-IR, 13C and 1HNMR spectroscopy, as well as thermal analysis. Then, starting from (Brsal)2dapte, new complexes with copper(II) and nickel(II) were synthesized and characterized by elemental analyses (CHN) and FT-IR spectroscopy, as well as thermal analysis. FT-IR spectra of complexes indicate the deprotonated Schiff base ligand that coordinates with metal ions through azomethine nitrogen and phenolic oxygen. The thermal behavior of ligand and complexes provides useful information about the decomposition of all compounds in the subsequent steps. Nanoparticles of CuO and NiO were successfully prepared by solid-state thermal decomposition of the Schiff base complexes as novel precursor at 600 °C for 3 h without employing toxic solvent or surfactant and complicated equipment. The crystalline structures and morphology of final products were studied by X-ray powder diffraction and transmission electron microscopy.