1. Neither the isomorphous substitution of Si by pentavalent elements like P, As...thus leading to the well known large family of microporous (silico)aluminophpsphates (arsenates...), nor the new microporous Ge and Sn sulfides based on tetrahedral sulfide frameworks, nor a series of newly reported miscellaneous frameworks brielly mentioned in ref. [9], are discussed here.
2. As a quite complete and recent review on the use of heteroatom molecular sieves as shape selective catalysts, see S.M. Csicsery, Stud. Surf. Sci. Catal., 94, 1 (1995), and references therein.
3. R.M. Barrer, Hydrotharmal Chemistry of Zeolites, Academic Press, London 1982, 543 pp.
4. M. Tielen, M. Geelen, and P.A. Jacobs, Acta Phys. Chem. 31, 1 (1985).
5. K.G. Ione and L.A. Vostrikova, Russ. J. Chem. Rev. 56, 231 (1987).