New anti‐bacterial polychelates: synthesis, characterization, and anti‐bacterial activities of thiosemicarbazide–formaldehyde resin and its polymer–metal complexes

Abstract

New polymeric ligand (resin) was prepared by the condensation of thiosemicarbazides with formaldehyde in the presence of acidic medium. Thisemicarbazide-formaldehyde polymer-metal complexes were prepared with Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) in 1 : 2 metal : ligand molar ratio. The polymeric ligand and its polymer-metal complexes were characterized by elemental analysis, thermogravimetric analysis (TGA), FTIR, 13 C NMR and 1 H NMR. The geometry of central metal ions was conformed by electronic (UV-vis) and EPR spectra. The antibacterial activities of all the synthesized polymers were investigated against Bacillus subtilis and Staphylococcus aureus (Gram-positive) and Escherichia coli and Salmonella typhi (Gram-negative). These compounds showed excellent activities against these bacteria using the shaking flask method.

Bifunctional Electrocatalysts (Co9S8@NSC) Derived from a Polymer‐metal Complex for the Oxygen Reduction and Oxygen Evolution Reactions

“…The synthesis strategy of Co 9 S 8 @NSC nanocomposites are schematically depicted in Scheme . The phenylthiourea‐formaldehyde polymer cobalt complexes [PTF−Co(II)] were prepared using the polymeric ligand and the cobalt chloride (see the details for synthesis and characterization in the Supporting Information) . To prepare Co 9 S 8 @NSC nanocomposite, PTF−Co(II) is used as the source of nitrogen, sulfur, carbon and metal ion as cobalt.…”

Studies of new oligomer–metal complexes and their antibacterial activities

“…Compared to the ligand, the metal complexes show higher activity because of the presence of metal ions complexed with the donor atoms of the ligand and also due to the π‐electron delocalization over the chelate ring . This effect increases the lipophilic character of the metal ion, which favours permeation through the lipoid layers of the bacterial membranes , . It is perceived that factors such as solubility, conductivity, dipole moment and cell permeability may also contribute to the increased activity of the complexes.…”

Kinetic and mechanistic studies on the reaction of thiosemicarbazide with [(H2O)(tap)2RuORu(tap)2(H2O)]2+ {tap = 2-(m-tolylazo)pyridine}

“…In the present article, we present mechanistic aspects of the interaction of thiosemicarbazide with the title complex in aqueous medium, where ruthenium(II) is stable even at biological pH 7.4 due to the presence of the strong p-acceptor ligand tap {2-(m-tolylazo)pyridine} [18]. Studies on the bioactivity of thiosemicarbazide have continued [19]. New platinum(II) complexes of thiosemicarbazide have been prepared, and these results indicate that the design and synthesis of metallated-thiosemicarbazone compounds may lead to the discovery of novel antitumour agents that are able to circumvent resistance to existing drugs, in particular tumour cell lines [20][21][22][23][24].…”