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

Abstract

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 MLX 2 (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-IR, 1 H and 13 C 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*, H*, S* and 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.

Some novel nanostructure Schiff base compounds: Antimicrobial and thermal behaviors

“…In the 1 H NMR spectrum of the ligand, the formation of the Schiff base ligand was confirmed by appearance of the azomethine proton signal (H d, H d′ ) as a doublet with a coupling constant of 9.0 Hz at 7.97 ppm. After complexation, this signal indicates downfield shift to new position in the range of 8.13 to 8.23 ppm with a coupling constants in the range of 6.0 to 8.4 Hz that well supports change in the electron density of azomethine hydrogens after linkage to zinc ion . The ligand spectrum shows the signals of aromatic ring protons (H g, H g′ and H h, H h′ ) as doublets at 7.34 and 6.66 ppm with coupling constants of 8.4 and 8.4 Hz, respectively.…”

“…In the 13 CNMR spectrum of the Schiff base ligand, azomethine carbon peak of (C 3,3´ ) appears at 164.11 ppm. This signal notably shifts to 167.23 to 168.60 ppm in its zinc complexes that is a mainspring to confirm the complex formation via azomethine nitrogen linkage to zinc ion . The peak at 151.22 ppm attributes to (C 9,9´ ) that undergoes a red shift to 152.00 to 154.81 ppm in the zinc complexes spectra.…”

“…Herein, in continuation of our previous reports, synthesis and characterization of some new zinc complexes of a new tridentate Schiff base ligand entitled as (E)‐N1‐((E)‐3‐phenylallylidene)‐N2‐(2‐((E)‐((E)‐3‐phenylallylidene) amino) ethyl) ethane‐1,2‐diamine are presented. Antibacterial/antifungal properties and thermal behaviors (TG/DTG/DTA) of all zinc complexes are described.…”

Synthesis, spectral, thermal behaviors, and antimicrobial studies of some nanostructure five coordinated Hg(II) complexes

“…An IR spectral comparison between the free ligand and its mercury complexes shows some changes in position of peaks. The spectrum of the free Schiff base ligand showed the peak of azomethine group (-CH=N) at 1635 cm -1 , which is shifted to lower wavenumbers at 1629-1633 cm -1 in the mercury complexes, that this shift confirms the involvement of ligand azomethine nitrogen in linkage to mercury ion [23][24][25][26][27][28]31]. The weak bands appearing at wavenumbers of 3056, 3025, 2925, and 2834 cm -1 in free ligand are assigned to stretching vibrations of aromatic, olefinic, aliphatic, and iminic C-H linkages, respectively, that shift to other wavenumbers after coordination to mercury center.…”

“…In this work, in continuation of our previous reports [23][24][25][26][27][28], the synthesis and characterization of some new mercury(II) complexes of a tridentate Schiff base ligand entitled as (3-phenyl-allylidene)-[2-(2-styryl-imidazolidin-1-yl)-ethyl]-amine is described. The prepared compounds have been characterized by UV-visible, FTIR, 1 H-NMR and 13 C-NMR spectra.…”