Organic structure-directing agents

Soon afterwards, a second implication revolutionised the field as new zeolite structures were obtained. The synthesis by the Mobil group of zeolite Beta with interconnected large pores) and later 

By contrast, there were some examples in which the cation deserved the term template, because it was quite specific for a given zeolite, and because it showed a close correspondence between the size and shape of 

Finally, while most frequently an OSDA acts as a single molecule it is also possible to use a supramolecular assembly. Most interestingly, a n-n supramolecular assembly of two identical cations afforded the synthesis in fluoride medium at high concentration of the pure-silica analogue of zeolite LTA, which had defied synthesis for half a century. 

---

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 ... 

Zeolites having ZSM-48 topology also crystallize from hydrogels containing other linear organic structure directing agents, such as diamines (2) or various (poly)alkylamines ( ). 

Figure 3.1. Transport of organic structure directing agents from water to chloroform.

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... 

LTA framework could be increased up to about three. By using a supramolecular synthon as organic structure-directing agent, it has been possible to synthesize the Al-free as well as the pure-silica forms of zeolite ITQ-29 with the LTA structure.[58]... 

Table 5.13 Organic structure-directing agents and their functional groups...

In the last 10 yr, the field of chemistry of organized matter has opened the path to create organized or textured inorganic or hybrid networks, templated by organic structure directing agents (Fig. 1, Routes B and The success of this strategy is also... 

Materials Organic structure directing agent (OSDA) IZA Codes Channel systems (pore openings) Ref. 

---