Thermodynamic Parameters of Some Transition Metal ion Complexes of Some Substituted Hydrazones and Their Antibacterial Activity

Potentiometric studies have been carried out on transition metal complexes of Mn⁺², Co⁺², Ni⁺², Cu⁺², Zn⁺² with hydrazones synthesized from 4-amino benzoic acid hydrazide and 2-hydroxy acetophenone/2-hydroxy-4methyl acetophenone. The dissociation constants of ligand and formation constants of its metal complexes have been determined by Calvin-Bjerrum pH titration technique, as adopted by Irving and Rossotti at 27±0.1°C and at an ionic strength of 0.1M in 60:40 (v/v) dioxane water medium. The order of the stability of complexes is Cu⁺² > Ni⁺² > Co⁺² > Mn⁺² > Zn⁺² for ligand AHEH and Co⁺² > Cu⁺² > Ni⁺² > Mn⁺² > Zn⁺² for AMEH respectively. All the metal complexes screened for their antibacterial activity. The result indicates that the growth of the tested organism was inhibited by most of the compounds.