The effects of micelles of sodium dodecyl sulphate (SDS) on aminolysis of ionized phenyl salicylate (PS-) and methyl salicylate (MS-) have been studied at 35 "C. An increase in the total concentration of SDS ([SDS],) from 0.0 to 0.2 rnol dm-3 results in a decrease in the observed nucleophilic second-order rate constants (k,) by a factor of ca. 3 for the reactions of PS-with propylamine and 1 -aminopropan-2-01. At high [SDS] plots of observed pseudo-first-order rate constants (kobs) versus total propylamine

The stability constants of iron, manganese, cobalt, and nickel complexes of glycine have been determined in aqueous solution by potentiometric titration with standard sodium hydroxide solution. The values of the stepwise stability constants were obtained by ORIGIN '50' program. The overall stability constants of the complexes were found to be similar.

The stepwise and the overall stability constants of the complexes formed by manganese (II) ion and twelve (12) amino acids have been determined. The dissociation constants, pKa, of the amino acids determined are; alanine (10.29), arginine (12.02), asparagine (9.39), glycine (9.87), histidine (7.01), lysine (9.28), methionine (9.68), phenyalanine (9.61), proline (10.54), threonine (10.31), tryptophan (9.77), and valine (9.99). The average number of amino acids coordinated to manganese (II) ion determined is 3. The Stepwise Stability Constants of manganese (II) amino acid complexes determined were found to decrease in the order K 1 > K 2 > K 3 for all the complexes. The values of the overall stability constants of the complexes obtained are relatively high indicating good stability for the complexes.

The dissociation constant (pKa) of non -polar amino acids including (alanine, glycine, valine phenylalanine and tryptophan) were determined by potentiometric titration technique. The pKa values obtained by extrapolation for alanine, glycine, and valine were 10.29, 9.87 and 9.91 respectively. The implications of the results are discussed and recommendations were made.

The dissociation constant,pKa of proline,threonine and asparagines were determined by potentiometric titration in aqueous solution.The pKa of proline,threonine and asparagines were found graphically by extrapolations to be 10.54, 10.31 and 9.39 respectively. The overall stability constant of the corresponding nickel (II) complexes were also determined by potentiometric titration in aqueous solution. The values of the constant were found using ORIGIN 50 program to be 28.75, 2743 and 25.64 for nickel (II) prolinate, nickel (II) threoninate, and nickel (II) asparaginate respectively. The number of coordinated amino acids to the nickel (II) ion in all the complexes was found to be three.