SSZ-35 and SSZ-44: Two Related Zeolites Containing Pores Circumscribed by Ten- and Eighteen-Membered Rings

Abstract

Unusual one-dimensional pores circumscribed by 10- and 18-membered rings are a feature of the structures of two high-silica molecular sieves, SSZ-44 and SSZ-35. Structure solution and Rietveld refinement from synchrotron powder X-ray data reveal that the two materials are the pure end-member polymorphs of a new fault series and contain similar layerlike units (see picture). The SSZ-44 structure is formed by an AB stacking of the layers, whereas the SSZ-35 structure is formed through an ABC stacking of the layer units.