On the effect of dielectric constant on formation and stability constants of vanadium(V) with leucine in mixed solvent of methanol plus water at 298.15 K

Equilibria in aqueous solutions in the system leucine + VO2+ has been studi ed by a combination of potentiometric and spectrophotometric methods, in th e pH range 3-4.4 with high ligand-to-metal ratios. An equilibrium model, MY , is assumed, where M and Y represent the metal ion and fully dissociated a mino acid anion, respectively. The results showed that formation and stabil ity constants of complex system increased with decrease of dielectric const ants. Linear relationships were observed when log K-P was plotted vs. 1/D, where K-P and D represent stability and dielectric constants of the system, respectively.