Complex Formation of Cefazolin with Ca2+ and Mg2+: Synthesis, DFT, Spectral and Antibacterial Determination

Abstract Mg(II) and Ca(II) complexes with cefazolin were synthesized and investigated using elemental and atomic‐emission analysis, TGA, X‐ray diffraction, FT‐IR spectroscopy, 1 H and 13 CNMR, DFT calculations, and QTAIM analysis. The thermal behavior of these complexes was also studied. In the magnesium complex, two cefazolin ions are coordinated to the metal ion through the oxygen atoms of the lactam and carboxylate groups as a bidentate ligand. However, cefazolin chelated to the calcium ion through both oxygen atoms of the carboxylate groups and the lactam groups′ oxygen atoms as tridentate ligand. Sodium cefazolin and metal complexes were also screened for antibacterial activity against Staphylococcus aureus and Escherichia coli . The calcium complex exhibited higher antibacterial effects than the magnesium complex (5.2–7.7 % higher against S. aureus – and 15.4–27.3 % against E. coli ), which is related to weaker binding of Ca, compared to Mg, with the oxygen atom of lactam group and, as a result, more free releasing of the lactam group in the solving process.