Selective functionalization of the external surface of zeolite L

Methods for the functionalization of the external surface of zeolites are discussed with emphasis on zeolite L. Concepts are presented which allow for assigning functionalities to the whole external surface or selectively to the regions of the external surface where the channel entrances are located. This latter principle implies the development of so-called stopcocks. Stopcock molecules are designed to provide the possibility to reversibly or irreversibly plug the entrances of zeolite channels and assign functionalities to those parts of the external surface where the pore openings are located. Examples are presented in which the functionalization of the external zeolite surface is applied to define and optimize the interface between guest molecules in the channels of the zeolite and external species. © 2005 Academie des sciences. Published by Elsevier SAS. All rights reserved.