Solvent-free synthesis, characterization and antimicrobial studies of calcium and potassium complexes with some cephalosporin antibiotics

摘要

The solid complexes of potassium and calcium were synthesized with some cephalosporin antibiotics which include: cefixime (CFI), cefuroxime (CFU) and cefradine (CFA). The complexes were synthesized by solvent-free technique and characterized by solubility, molar conductivity, melting point, UV-Vis, IR and elemental analysis. The analytical data of these complexes showed that the antibiotics coordinated to the metals through oxygen atom of the carboxylate anion, oxygen atom of nitrate ion and oxygen atom of carbonyl in both complexes due to similarity in structures of the antibiotics to give a coordination number of five with proposed molecular formula as [M(CFI)NO3], [M(CFU)NO3] and [M(CFA)NO3] where M represents potassium or calcium. The molar conductance values of the complexes suggest that they are non-electrolytes, while the result of antimicrobial activity showed that the complexes have more activity than the antibiotics. The melting point, color and electronic spectra of the complexes were different from those of the antibiotics, which suggest the formation of coordination compounds.