Abstract
Although the use of zeolites as catalysts has been fairly well established [1], their utility as molecular reaction vessels has not attracted wide attention [2]. It is this less explored aspect of zeolites that is of interest to us and forms part of this presentation [3]. Zeolites may be regarded as open structures of silica in which aluminum has been substituted in a fraction (X/X+Y) of the tetrahedral sites [4]. The framework thus obtained contains pores, channels and cages. As the trivalent aluminum ions replace tetravalent silicon ions at lattice positions, the network bears a net negative charge which must be compensated by other counter ions. The latter are mobile and may occupy various exchange sites depending upon their radius, charge and degree of hydration. They can be replaced, to varying degrees, by exchange with other cations. If zeolite water is removed, many other organic and inorganic molecular entities can be accommodated in the intracrystalline cavities.