Complexation of Cu(II) with cefotaxime in NaCl solution

Abstract

Complexation of Cu²⁺ cations with anions of cefotaxime antibiotic (Cxm^–) was studied by pH-metric titration at 37°C in 0.15 mol/L NaCl background electrolyte. The formation of complex of composition CuCxm was revealed, the value of logβ(CuCxm) = 2.3 ± 0.2 was calculated. A computer model of the complex was calculated by DFT using B3LYP hybrid functional and LACV3P**++ basis set. According to calculation results, Cu(II) in the complex has CN = 4, close to square planar structure of coordination sphere, and coordinates Cxm^– through the oxygen atoms of the carboxylate, β-lactame, and amide groups, as well as through the nitrogen atom of the thiazole ring.