Synthesis, characterization and biological evaluation of coordination polymers synthesized from 2,5-bis(p-tolylcarbamoyl)terephthalic acid

A novel ligand 2,5-bis(p-tolylcarbamoyl)terephthalic acid (3) was synthesized by using pyromellitic dianhydride (1) with p-toluidine (2). Novel coordination polymers 4(a-f) of this ligand were prepared by using various metal salts viz. Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II). The coordination polymers and ligand were characterized by physicochemical, thermogravimetric and spectroscopic techniques. Electronic spectral analysis and magnetic measurement studies were taken into account for the geometry of coordination polymers. Polymeric properties like, Number average molecular weight (\( \overline{\mathrm{Mn}} \)) and Degree of polymerization (DP) has also been carried out. Antimicrobial activity was carried out against various strains of bacteria and spores of fungi. Compounds (3 and 4a–f) were evaluated for their antibacterial activity against Gram-positive bacterial strains (Bacillus subtilis [BS] and Staphylococcus aureus [SA]) and Gram-negative bacterial strains (Salmonella typhimurium [ST] and Escherichia coli [EC]) utilizing the agar diffusion assay. Growth inhibition was compared with the standard drug ciprofloxacin. Compounds (3 and 4a–f) were also examined for antifungal activity against different fungal strains, i.e. Penicillium expansum [PE], Botryodiplodia theobromae [BT], Nigrospora sp. [NS], Trichothesium sp. [TS]. The antifungal drug, ketoconazole was used as a positive control.