A THERMODYNAMIC STUDY OF COMPLEXATION REACTION OF YTTRIUM(III), LANTHANUM(III) AND CERIUM(III) WITH TYROSINE

The thermodynamic stability constants and thermodynamic parameters for complexation reaction of Y3+, La3+, and Ce3+ with tyrosine have been determined pH metrically. The study reveals the formation of 1∶1 complexes for La3+ and Ce3+ whereas Y3+ yields both 1∶1 and 1∶2 complexes. The values of enthalpy changes (ΔHo) indicate that unionised hydroxy group also participates in complexation.