Organic zeolite data types

Specific structure-directing effects of some organic bases or cations When in the procedure BT Pr N is replaced by other organics, various pentasil-type zeolitic precursors are formed. It appears that specific zeolites are formed only when quaternary ammonium salts are used, their nature (structure) being essentially dependent on the length of the alkyl chains pure ZSM-8, ZSM-5 and ZSM-11 are obtained respectively with Et N+, Pr N+ and Bu N cations. TG data indicate that the latter fill nearly completely the zeolitic channel system (Table VIII). 

The three-letter framework-type codes, recognized by the IUPAC Commission on Zeolite Nomenclature, have been used to organize the entries in this publication. The powder diffraction data and simulated patterns for the reference structures are listed alphabetically according to the respective framework type code. An index of material names, and associated three-letter codes, is included in the companion volume, the Atlas of Zeolite Framework Types (Baerlocher, McCusker and Olson (2007)). 

One-step hydroxylation of aromatic nucleus with nitrous oxide (N2O) is among recently discovered organic reactions. A high eflSciency of FeZSM-5 zeolites in this reaction relates to a pronounced biomimetic-type activity of iron complexes stabilized in ZSM-5 matrix. N2O decomposition on these complexes produces particular atomic oj gen form (a-oxygen), whose chemistry is similar to that performed by the active oxygen of enzyme monooxygenases. Room temperature oxidation reactions of a-oxygen as well as the data on the kinetic isotope effect and Moessbauer spectroscopy show FeZSM-5 zeolite to be a successfiil biomimetic model. 

Numerous organic species are known to lead to the crystallization of the MFI-type structure (7). but the tetrapropylammonium cations can be considered to be the most specific. To our knowledge no thermodynamic data such as standard formation enthalpies (AfH°) and stabilization energies attributed to the organic species have been published to corroborate this experimental observation. The published thermodynamic data (AfG°, AfH°, AfS°. Cp) are for natural zeolites (8-11) or for organic-free synthetic zeolites. However. some data have been obtained by calculations using lattice energy minimization and extended Hiickel theory (1 2) or by semi-empirical methods based on addition of the thermodynamic functions of the oxide compo-... 

For example, two comprehensive databases, ICSD and CSD, contain crystallographic data and structural information about inorganic, and organic and metal organic compounds, respectively, while NIST database encompasses all types of compounds but provides only crystal data with references. Other databases are dedicated to specific classes of materials, such as metals and alloys, proteins and macromolecules, minerals or zeolites. Search-match utilities are usually provided with databases or they may be obtained separately. 

Fig. 14. Zeolite-modified Pd-doped Sn02 sensor design (left DVM digital voltmeter). The plots on the right display the sensor resistance as a function of the type and concentration of the organic vapour (methane or ethanol). The measurements were done at 350 °C with 0% relative humidity in the feed. The data for the unmodified (reference) sensor and the sensors modified with layers of silicalite-1 and zeolite A are shown. [121]...

Inorganic structures are said to be structures which do not contain any C-H bonds or C-C bonds in any residue and contain at least one nonmetal. In addition ICSD contains metal carbides and inoiganic frameworks including organic residues (e.g., zeolites including ethanol). The database tries to be complete for all papers from the beginning of X-ray diffraction in 1915 up to the present. The release 1997/II contains 45 914 entries. Each entry contains the primary data for a complete description of a crystal structure and some additional information. This is typical for this type of database but may differ in detail from database to database. 

---