Thermodynamics in [Mn(II)-antibiotics-bacitracin] mixed system: a polarographic approach

Polarographic technique was used to determine the kinetic parameters, thermodynamic parameters and stability constants (log(beta)) of Mn(II) complexes with neomycin, chlortetracycline, oxytetracycline, tetracycline, penicillin V and penicillin G as primary ligands and bacitracin as the secondary ligand, at pH 7.3+/-0.01 and an ionic strength mu=1.0 M (NaClO(4)) at 25 degrees C. The study was also carried out at 35 degrees C to determine the stability constants and thermodynamic parameters viz. enthalpy change (DeltaH), entropy change (DeltaS) and free energy change (DeltaG) of complexes.