Cryptophane

Fig. 16. (a) Inclusion complex of a cryptophane and (b) a carceplex (carcerand inclusion complex). 

The cryptophane is typical of the chiral resolution of methane derivatives (eg, CHFClBr) (146) and the basket-shaped host of Figure 23d exhibits extremely high enantioselectivity for various peptides (144). 

Other molecules include cryptophanes (e.g., 23), ° hemispherands (an example is 24 ° ), andpodands The lastnamed are host compounds in which two or more arms come out of a central structure. Examples are 2S °° and 26. ° Compound 26,... 

Collet, A., Dutasta, J.-P., Lozach, B., and Canceill, J. Cyclotriveratrylenes and Cryptophanes Their Synthesis and Applications to Host-Guest Chemistry and to the Design of New Materials. 165, 103-129 (1993). 

The same strategy can be used with polyfunctional building blocks, and a variety of peptoid-based cryptands, cages, and cryptophanes was synthesized (Scheme 26) [100]. 

CONTENTS Preface. George W. Gokel. Cryptophanes Receptors for Tetrahedral Molecules, Andre Collett, Jean-Pierre Dutasta and Benedict Lozach. Inclusion Polymerization in Steroidal Canal Complexes, Kiichi Takemoto, Mikiji Miyata. Functionalized Tetraazamacrocycles Ligands with Many Aspects, Thomas A. Kaden. Calixarenes as the Third Supramolecular Host, Seiji Shinkai, Kyushu University, Japan. Fluorescent Chemosensors for Metal and Non-Metal Ions in Aqueous Solutions Based on the Chief Paradigm, Anthony W. Czamik. Index. 

Cyclotriveratrylenes and Cryptophanes Their Synthesis and Applications to Host-Guest Chemistry and to the Design of New Materials... 

The spherically shaped cryptophanes are of much interest in particular for their ability to bind derivatives of methane, achieving for instance chiral discrimination of CHFClBr they allow the study of recognition between neutral receptors and substrates, namely the effect of molecular shape and volume complementarity on selectivity [4.39]. The efficient protection of included molecules by the carcerands [4.40] makes possible the generation of highly reactive species such as cyclobutadiene [4.41a] or orthoquinones [4.41b] inside the cavity. Numerous container molecules [A.38] capable of including a variety of guests have been described. A few representative examples of these various types of compounds are shown in structures 59 (cyclophane) 60 (cubic azacyclophane [4.34]), 61a, 61b ([4]- and [6]-calixa-renes), 62 (cavitand), 63 (cryptophane), 64 (carcerand). 

Figure 4.27 Crystal structure of [(Cp Ru)6(( )-cryptophane-E)]6+ 4.68, showing inclusion of a triflate anion within the cage structure.52...

---