Synthesis, Characterization, Thermal Behavior and Biological Properties of Zn (II) Schiff Base Complexes

Abstract

In this research, N, N`-bis ((E)-3-(4-dimethylamine) phenyl allylidene)-phenylen-1,2-diamine as a bidentate Schiff base ligand, was synthesized in ethanol and purified and then was identified by physical and spectral methods. Using this ligand, compounds with the general formula of ZnLX2 in which X is Clˉ, Brˉ, Iˉ, N3ˉ, SCNˉ and/or NO3ˉ. Different techniques such as FT-IR, UV-Vis, 1H-NMR, thermal analysis (TG, DTA, DTG), melting point and molar conductivity were used for characterization of the coordination compounds. The IR spectrum of the ligand shows the group (C=N) vibration frequency at 1604 cm-1 as main peak. However, the relevant frequency changed after complex formation which indicates coordination of the Schiff base ligand to the Zn metal ion. The data obtained from the UV-Vis spectra and the 1H-NMR of the ligand and its coordination compounds confirm their synthesis. Ultimately thermal behavior of the ligand and its metal compounds in the temperature range of 20-900˚C was studied and their decomposition steps were evaluated along with some thermo-kinetic parameters of thermal decomposition of the complexes in each decomposition step.