Voltammetric study and electrode kinetics of [Mn-sulfonamide-cephazolin] system at dropping mercury electrode

Electrochemical Laboratory, Department of Chemistry, Dr. H. S. Gour University, Sagar 470 003, Madhya Pradesh, India E-mail : faridkhan58@yahoo.com; farid.fk@rediffmail.com Manuscript received 12 July 2007, revised 23 April 2008, accepted 6 May 2008 Stability constants (log β) of ternary complex of MnII with sulfadiazine, sulfisoxazole, sulfamethaxyzole, sulfamethazine, sulfathiazole, sulfacetamide and sulfanilamide as primary ligands and cephazolin as secondary ligands were reported at pH = 7.30 ± 0.01 at µ = 1.0 M NaCIO4 at 25 ºC by polarographic technique. The kinetic parameters like transfer coefficient (α), degree of irreversibility (λ), diffusion coefficient (D) and rate constant (k), were determined. The rate constants (k) that varied from 3.61 cm s-1 to 9.93 cm s-1 confirmed the quasi-reversible nature of electrode processes. The study was carried out at 25 ºC and 35 ºC. Thermodynamic parameters such as entropy change (ΔS), enthalpy change (ΔH) and free energy change (ΔG) were determined. The values of stability constants (log β) that varied from 1.75 to 9.13 showed these drugs or their complexes might be effective against Mn toxicity