The kinetics of the title reaction has been investigated both in the aqueous and aqueous cationic micelles of tetradecyltrimethylammonium bromide (TTABr) solutions using UV–vis spectrophotometry at 343 K and pH 5.0. Ninhydrin reacts with [Cu(II)–Gly-l-Ala]+ complex in the stoichiometric ratio of 1:1 in both media. To explain the dependence of the reaction rate on [TTABr], pseudo-phase model proposed by Berezin et al. [27] and developed by Bunton [28] and Vera and Rodenas [29] was used. The reaction follows first- and fractional-order kinetics with respect to [Cu(II)–Gly-l-Ala]T+ and [ninhydrin]T, respectively, in aqueous and TTABr micelles. The values of km, kw, KA, KNin, Ea, ΔH#, ΔS#, and ΔG# have been calculated. The effect of inorganic (NaNO3, Na2SO4, Na3PO4)/organic (NaBenz, NaSal) salts and organic solvents on the reaction rate has also been seen. A mechanism consistent with observed kinetic data has been proposed.
د. عادل أحمد محمد سعيد | Dr. Adel Ahmed Mohammed Seaad | 13665