Studies on the binary and ternary complexes of mercury (ii)‎ with gallic acid and adrenaline

Abstract EN

The Interaction of mercury (II) ions with garlic acid (3, 4, 5-trihydroxybenzolc acid) (GAL) and adrenaline (epinephrine) (l-( 3, 4-dihydroxyphenyi)-2- methyiaminoethanol) (ADR) were Investigated by potentiometric and optical means.

The stoichiometry's and stability constants of the binary and ternary complexes have been determined ph-metrically in aqueous solution at 25°C and in ionic strength 0.1 M (NaNOs).

The complex formation equilibria Involving adrenaline were characterized.

The equilibrium Hg (GAL) ^2 + Hg (ADR) ^2 = 2Hg(GAL)(ADR), the corresponding constant is logJM.22.

e constant due to Aiog^ = log^^ / 4ai)-log^^K) is 0.75.

The results indicate that the overall ratio of the ternary complex Hg(GAL)(ADR) Is 1 : 1 : 1 and the mixed-ligand complex Is more stable than one expected from purely statistical reasons.

UV-Vis spectroscopy gave additional support to the results.

There is a strong evidence from FT-IR spectrum that adrenaline chelates by the phenolic groups.