Effect of ionic strength on the stabilities of ciprofloxacin – Metal complexes

Proton–ligand dissociation constant of 1-cyclopropyl-1,4-dihydro-4-oxo-7-(1-piperazinyl) quinolone-3-carboxylic acid is ciprofloxacin and metal–ligand stability constants of its complexes with some metal ions have been determined potentiometrically in the presence of (0.01, 0.02 and 0.03 mol/dm3) NaClO4. The order of the stability constants of the formed complexes increases in the sequence Cu2+, Fe3+, Ni2+ and Zn2+ and decreases with increase in the concentration of ionic strength.