A complex of ceftriaxone with Pb(II): synthesis, characterization, and antibacterial activity study

A Pb(II) complex with ceftriaxone (H2Ceftria) antibiotic was synthesized by reaction of ceftriaxone disodium salt (hemi) heptahydrate with lead nitrate in water-ethanol medium. The complex was characterized on the basis of complexometric titration, spectrophotometric and thermogravimetric analyses, capillary electrophoresis, IR, Raman and UV-vis spectroscopies, and density functional theory calculations. Pb(II) is five-coordinate with distorted square pyramidal geometry. The coordination of Ceftria(2-) to Pb(II) occurs through N and O of the triazine, lactam carbonyl, carboxylate, and amine groups. The antibacterial activity study showed that Klebsiella pneumoniae is resistant to [Pb(Ceftria)]center dot 3H(2)O. The antibacterial activity of [Pb(Ceftria)]center dot 3H(2)O against Staphylococcus aureus is reduced compared with ceftriaxone. In contrast, the antibacterial activity of [Pb(Ceftria)]center dot 3H(2)O against Escherichia coli is 28% higher than that of ceftriaxone antibiotic.