(C H3)2 N H2) (Ga Ge3 O8).pdf

J. Am. Chem. Soc. 1998, 120, 1338913397 13389 Hydrothermal Synthesis and Structural Characterization of Zeolite-like Structures Based on Gallium and Aluminum Germanates Xianhui Bu, Pingyun Feng, Thurman E. Gier, Dongyuan Zhao, and Galen D. Stucky* Contribution from the Department of Chemistry, Uniersity of California, Santa Barbara, California 93106 Recei ed August 24, 1998 Abstract: While extensive commercial success has been achieved through the use of organic molecules in the synthesis of aluminosilicate zeolites, the synthesis of the germanium-based zeolite structures using organic structure-directing agents is a largely unexplored area. Here we report a novel class of germanate zeolite structures prepared with inorganic cations or organic amines as structure-directing agents. These new materials possess five 4-connected 3-dimensional topologies with large (12-ring), medium (10-ring), small (8-ring), or ultrasmall (6-ring) pores. They have a variety of chemical compositions such as various Ge to Ga (or Al) ratios and exhibit interesting structural features such as helical chains and odd-membered rings. UCSB-15GaGe and UCSB-15AlGe are the first germanate-based structures with 5-rings. UCSB-7 refers to a collection of isostructural, large-pore zeolite-like structures constructed by the cross-linking of helical ribbons. UCSB- 3GaGe is the only known T3/T4 (T refers to tetrahedral atoms) based zeolite structure with the net 38 topology. This structure is unusual because of its very high framework charge density unsurpassed by other amine- directed zeo