| Abstract |
Kinetic data for the silver (I) activated homogeneous and heterogeneous quaternization of tributylamine by alkyl iodides in toluene is presented. Silver iodide was used as a solid catalyst. Solution and surface parameters were obtained applying the multistep kinetic model, previously proposed by Santos and Barbosa. A scrutiny of the derived quantities evidences competing structural and electronic effects. The solution reaction is dominated by structural factors while electronic effects govern the surface process. An overall analysis considering data from triethylamine systems, earlier investigated, allowed the establishment of a parallelism between the homogeneous and heterogeneous processes. A molecular level study involving size, shape and orientation of the chemical species on the surface, lead to estimates of interfacial layer thicknesses. A combination of surface parameters superficial reacting monolayer thicknesses and, the parallelism between homogeneous and heterogeneous catalysis consented the evaluation of volumetric surface rate constants which are directly comparable with their solution counterparts. (C) 2012 Elsevier BM. All rights reserved. |
