Zeolite synthesis organic structure-directing

Al-containing ITQ-21 zeolite ((Si+Ge)/Al=25, Si/Ge=20) was synthesized using N(16)-methyl-sparteinium cation (MSPT+) as the organic structure-directing agent in combination with fluoride anions and germanium as described in [1], The composition of the final synthesis gel was ... 

Microporous materials are typified by natural and synthetic zeolites that are crystalline 3D aluminosilicates with open channels or cages. Synthetic and structural concepts of zeolites have to a large extent shaped the development of microporous materials during the past 50 years. For example, the use of organic structure-directing agents in the synthesis of high-silica zeolites and their all-silica polymorphs contributed to... 

Itabashi K, Kamimura Y, lyoki K, Shimojima A, Okubo T. A working hypothesis for broadening framework types of zeolites in seed-assisted synthesis without organic structure-directing agent J Am Chem Soc 2012 134 11542-9. 

At this point in time a completely designed synthesis of a zeolite has not occurred. However, the evidence presented here paints a bright picture for the future. The design of organic structure-directing agents and molecular building blocks is now a... 

Since then, organic amines, quaternary-ammonium bases, metal complexes, and other compounds have been extensively used in zeolite synthesis, acting as space fillers with low specificity, structure-directing agent, or true templates ... 

Burton, A., and Zones, S. (2007) Organic molecules in zeolite synthesis their preparation and structure-directing effects, in Introduction to Zeolite Science and Practice, 3rd Revised edn (eds ). Cejka, H. Van Bekkum, A. Cornia, and... 

The synthesis of pentasil zeolites is supported by organic cations. Argauer et al. (1) first described syntheses with tetraalkylammonium and tetraalkylphosphonium compounds. The organic cations may not only initiate and sustain a certain crystallization process but also may lead to products of a new structure. This "templating" behaviour is explained by the structure-directing effect of the organic cations in the process of crystallization (2,3). 

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