Kinetics and Mechanism of Nanoparticles-Catalyzed Piperidinolysis of Anionic Phenyl Salicylate

Abstract

The values of the relative counterion (X) binding constant RXBr (=KX/KBr, where KX and KBr represent cetyltrimethylammonium bromide, CTABr, micellar binding constants of Xv- (in non-spherical micelles), v=1,2, and Br− (in spherical micelles)) are 58, 68, 127, and 125 for Xv−=1−, 12−, 2−, and 22-, respectively. The values of 15 mM CTABr/[NavX] 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 NavX = Na1, Na21, Na2, and Na22, respectively. Almost entire catalytic effect of nanoparticles catalyst is due to the ability of nonreactive counterions, Xv-, to expel reactive counterions, 3−, from nanoparticles to the bulk water phase.