STUDIES ON THE BINARY AND TERNARY COMPLEXES OF ALUMINIUM(III) WITH GALLIC ACID AND ADRENALINE

The reaction of aluminium(III) ions with gallic acid (3,4,5–trihydroxybenzoic acid) (GAL) and adrenaline (epinephrine) (1-(3,4–dihydroxyphenyl)-2–methylaminoethanol) (ADR) was investigated by potentiometric and optical means. Stability constants of the binary and ternary complexes at 25°C and in 0.1 M NaNO3 ionic strength in aqueous solution have been determined. The complex formation equilibria involving adrenaline were characterized
The constant due to is 0.75. The results indicate that the overall ratio of the ternary complex Al(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.