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

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(−), 1(2−), 2(−), and 2(2−), respectively. The values of 15 mM CTABr/[Na(v) 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 Na(v) X = Na1, Na(2) 1, Na2, and Na(2) 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.