Experimental and theoretical study of iron(III) salts with penicillin and cephalosporin anions

Iron(III) salts with benzylpenicillin, Oxacillin, Cephazolin, Cefotaxime, and Ceftriaxone anions were isolated in solid state from aqueous solution, characterized by elemental analysis, and studied by spectral and thermal methods. Structure modeling of the obtained compounds by NDDO semiempirical quantum chemical method was performed with the use of PM6 modern parametric model with MOPAC 2009 software. On the basis of experimental data and the results of computer modeling, a conclusion was drawn on the intra-complex structure of the Cephazolin, Cefotaxime, and Ceftriaxone salts. The structure of Fe(III) coordination sphere and donor atoms of the antibiotic anions were determined.