Synthesis of Co(II) and Cr(III) salicylidenic Schiff base complexes derived from thiourea as precursors for nano-sized Co3O4 and Cr2O3 and their catalytic, antibacterial properties

Abstract

This study focuses on the synthesis of Co(II) and Cr(III) Schiff base complexes obtained from thiourea. The complexes were synthesized by template method and characterized by elemental analysis (CHNS), FT-IR, UVvis spectroscopy, conductivity measurement and magnetic moment. The spectroscopic studies suggested the octahedral and square-pyramidal structures for Co(II) and Cr(III) complexes, respectively. Then the complexes were used as precursors for preparation of Co 3 O 4 and Cr 2 O 3 nanoparticles via solid-state thermal decomposition without using a catalyst, toxic solvent, template or surfactant and complicated equipment, which makes it efficient, one-step, simple and environment-friendly. The chemical structure of the metal oxides is studied by FT-IR, XRD and SEM. To investigate the applications of the synthesized complexes, in the next step, the complexes were screened for antibacterial activity against clinically important bacteria such as Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The Cr(III) and Co(II) complexes showed good biological activity against all the tested bacteria. Also, the catalytic activities of the complexes were studied in toluene using non-toxic hydrogen peroxide as the oxidant. The results showed that Co(II) complex has catalytic activity for oxidation of toluene, but Cr(III) complex did not show any catalytic activity.

Synthesis, DFT Calculations, DNA Interaction, and Antimicrobial Studies of Some Mixed Ligand Complexes of Oxalic Acid and Schiff Base Trimethoprim with Various Metal Ions

“…The electronic spectrum of the Cr(III) complex showed two bands at 509 and 604 nm. The spectral band is consistent with that of five coordinated Cr(III) complexes (Cr(III), d 3 , Term symbol of 4 F), so a "regular" square-pyramidal geometry may be assigned for this complex [34][35]41]. However, distorted geometry is observed in this instance.…”

Synthesis of Some Novel Nanosized Chelates of Anchoring Bisazo Dye 5-[5-(4,6-Dioxo-2-thioxo-hexahydro-pyrimidin-5-ylazo)-naphthalen-1-ylazo]-2-mercapto-1H-pyrimidine-4,6-dione and Their Applications as Antioxidant and Antitumor Agents

“…The size of Fe 2 O 3 nanoparticles was approximately 20 nm. The XRD and TEM particle sizes were different because the XRD particle is the crystallized size or primary particle, which is a single crystal particle, but that of TEM is a particle consisting of one or two or even more primary particles …”

Tin(IV) Schiff base complexes: Synthesis, thermodynamic and anti bacterial investigation, experimental and theoretical studies

“…Schiff base ligands containing hetero atoms such as N, O, and S show a broad biological activity and are of special interest because of their variety of ways in which they are interacted to metal ions. Schiff base in neutral and deprotonated forms react with organotin(IV) halides and the complexes extensively studied because they have some characteristics properties like manifestations of novel structures, thermal stability, high synthesis flexibility, medicinal utility, industrial applications and relevant biological properties [9][10][11][12]. In addition to their special antimicrobial activities, organotin(IV) compound with Schiff bases present an interesting variety of structural possibilities, so that a remarkable diversity in structure may be observed even when only a small change in the chemistry occurs [13].…”