Complexation of some hydrazones bearing the quinoline ring: potentiometric studies

Abstract

Three hydrazones (oximic: MHQ; ketonic: BHQ and phenolic: AHQ) bearing the quinoline moiety were prepared and characterized. Their dissociation constants as well as their stability constants with some transition, lanthanide and actinide metal ions have been investigated potentiometrically in 75% (v/v) dioxane-water at 303K. Also, stability constants of cobaloximes in 75% (v/v) solvent-water (solvent = dioxane, isopropanol, ethanol and methanol) as well as in 75, 70, 65, 60 and 55% (v/v) ethanol-water at 303K were evaluated. A linear regression analysis was used to evaluate the stability constants in the aqueous medium. Irving-Williams order for stability is not strictly obeyed.