Spectrophotometric study on micelle-mediated shift in kinetic and equilibrium of complex formation between Ni and 2-amino-cyclopentene-1-dithiocarboxylic acid

The significant shift in kinetic and equilibrium behavior of complex formation between Ni2 and 2-amino-cycloŽ . Ž . pentene-1-dithiocarboxylic acid ACDA in a solution of ionic surfactant cetyltrimethylammonium bromide CTAB was studied spectrophotometrically in 0.1 M NaBr medium at 30 C. A model based on distributions of ligand Ž . Ž . ACDA and complex Ni ACDA between aqueous and micellar pseudo-phase was applied to account for the shift 2 in the apparent formation constant and observed pseudo-first order rate constant. Partition constants were evaluated by using a technique based on the principal component analysis method. The proposed model, states that the reaction occurs only in the aqueous phase. Apparent formation constants and the observed rate constants decreased with increasing the micelle concentration. Good agreement between experimental and calculated values indicates that, the applied model provides a good description of the micellar effects on complex formation between Ni2 and ACDA. 2001 Elsevier Science B.V. All rights reserved.