Pure Polymorph C of Zeolite Beta Synthesized by Using Framework Isomorphous Substitution as a Structure-Directing Mechanism

Subsitution of germanium for silicon in the preparation of the zeolite Beta allows the synthesis and characterization of a third, heretofore predicted, polymorph "C"; a [001] view is shown in the picture. Germanium preferentially occupies positions in double four-membered ring cages, the secondary building units of polymorph C, and favors the formation of polymorph C regardless of which of the eight organic structure-directing agents were used. Supporting information for this article is available on the WWW under http://www.angewandte.com or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.