Some new IIB group complexes of an imidazolidine ligand: Synthesis, spectral characterization, electrochemical, thermal and antimicrobial properties

An imidazolidine Schiff base ligand, (E)-N-(4-nitrobenzylidene)-2-(2-(4-nitrophenyl) imidazolidine-1-yl) ethaneamine (L) has been synthesized by a condensation reaction between N'-(2-aminoethyl)-ethane-1,2-diamine and 4-nitrobenzaldehyde in 1:2 ratio and then characterized by physical and spectral data. Some new complexes with general formula of MLX2(wherein M is Zn(II),Cd(II) and Hg(II) and X is chloride, bromide and/or iodide) have been prepared and characterized by physical and spectroscopic studies such as elemental analysis, molar conductance measurements, FT-ER, H-1 and C-13 NMR and UV Visible electronic spectra. The spectral data indicate that the ligand is coordinated to zinc(II) as a bidentate ligand in imidazolidine form but it binds to other metal salts as bis-imine tridentate ligand. Furthermore, cyclic voltammetry technique was applied for recording the electrochemical behaviour of the ligand and its complexes. Cyclic voltamogram of the ligand showed that it is reduced at four cathodic potentials and then oxidized only in two anodic potentials in reverse direction. The electrochemical behaviour of ligand is affected by coordination. Thermal analysis of ligand and its complexes revealed that they are decomposed via 3-4 thermal steps. Moreover, some activation thermodynamic parameters such as A, E*, Delta H*, Delta S* and Delta G* were calculated based on TG/DTA plots using Coats-Redfern relation. The Schiff base ligand and its complexes have also been tested in vitro to evaluate their antimicrobial activities.