Molecular sieve. Computer graphic of a molecule of 2, 6-DIPN (2,6-diisopropylnaphthalene) passing through a channel in a molecule of mordenite. This graphic illustrates the use of mordenite as a insmolecular sieveins in the synthesis of the 2, 6 iso- mer of DIPN. 2, 6-DIPN is difficult to synthesize separately from the 2, 7 isomer. When mordenite is used as a catalyst, however, a higher proportion of the 2,6 isomer is made because the 2, 7 isomer passes less easily through mordenite's pores. Mordenite is one of many inszeolitesins used in indus- try for shape-sensitive catalysis. Its molecular framework is based on the formula (Si, Al)nO2n.