COMPLEX-FORMATION OF SELECTED TRIVALENT METAL-IONS WITH (4R)-THIAZOLIDINE-4-CARBOXYLIC ACID AND SOME OF ITS DERIVATIVES

The complex formation of Al(III), Ga(III), In(III), Fe(III), La(III), and Ce(III) with (4R)-thiazolidine-4-carboxylic acid (TCA) and some of its 2-alkyl/aryl-substituted derivatives in aqueous solutions at ioni c strength I = 0.1 mol dm(-3) (NaCl) and temperature theta = 25 degree s C was studied using the potentiometric titration method. The satisfy ing results were attained only for Al(III), Ga(III), and In(III) in re action with TCA and its 2-alkyl-substituted derivatives. Other M(III) tested did not allow to evaluate their complex stability constants bec ause of the precipitate creation or poor interaction. Further it was f ound that 2-aryl- or 2,2-dimethyl-substituted TCA derivatives are rapi dly changed in aqueous solutions resulting in impossibility to determi ne their correct dissociation constants and hence to quantify the comp lex formation constants.