Kinetics and mechanism of nanoparticles-catalyzed piperidinolysis of anionic phenyl salicylate.

Abstract

The values of the relative counterion (X) binding constant R X Br (=K X/K Br, where K X and K Br represent cetyltrimethylammonium bromide, CTABr, micellar binding constants of X v− (in non-spherical micelles), v = 1,2, and Br− (in spherical micelles)) are 58, 68, 127, and 125 for X v− = 1−, 12−, 2−, and 22−, respectively. The values of 15 mM CTABr/[Nav X] nanoparticles-catalyzed apparent second-order rate constants for piperidinolysis of ionized phenyl salicylate at 35°C are 0.417, 0.488, 0.926, and 0.891 M−1 s−1 for Nav X = Na1, Na2 1, Na2, and Na2 2, respectively. Almost entire catalytic effect of nanoparticles catalyst is due to the ability of nonreactive counterions, X v−, to expel reactive counterions, 3 −, from nanoparticles to the bulk water phase.