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Inclusion chemistry calixarenes

It should be stressed that there is not alwaysjustice in reseach evaluation. The selective formation of inclusion complexes by cyclodextrins (such as 11) was established by Cramer [6] at least 15 years earlier than that by crown ethers. However, cyclodextrin studies forming an independent branch of host-guest chemistry seem underestimated in spite of their considerably greater practical importance at present than that of other host macrocycles (crown ethers 17, calixarenes 18, etc.). Sometimes they are even totally neglected by discussing inclusion phenomena [7]. [Pg.44]

T. Kappe, The early history of calixarene chemistry ,. /. Inclusion Phenom. Mol. Recognit. Chem., 1994,19, 3-15 (reprinted in Calixarenes, ed. Z. Asfari, J. Vicens and J. McB. Harrowfield, Kluwer Academic, Dordrecht, 1995). [Pg.78]

The synergistic effect was only found in mixed stationary phases that have a special selectivity. Those stationary phases were CD, crown ether, liquid crystal-hne, resorcarene, calixarene, AgNOs, and others. Crown ether, CD, cahxarene, and resorcarene possess cyclic moieties with cavity-like structures that are able to form inclusion complexes with metal ions and organic molecules. Liquid crystalhne stationary phases have temperature-dependent ordered structures and the retention is governed by the solute s length-to-breadth ratio. AgNOs retards olefins by the formation of loose adducts. Together with the above special selectivity stationary phases, they have already been the focal point of sup-ramolecular chemistry. [Pg.1563]

Only few investigations have been published on the gas-phase ion chemistry of host-guest complexes of calixarenes. With the advent of ESI mass spectrometry, especially when combined with ion-trap and FT-ICR mass spectrometry, this field has started to be developed. Binding selectivities of alkali metal ions to cahxarene-based crown ethers and open-chain ethers have been studied , the inclusion of neutral guests into the protonated resorcarene-based cavitand hosts by gas-phase ion-molecule reactions with amines have been studied and the formation of capsules from various calixarene tetraether derivatives and alkylammonium ions as ionic guests (notably enabling their detection by mass spectrometry) have been described recently . ... [Pg.322]

Study of the inclusion behaviors of the cavity of many commonly known macrocyclic receptors like calixarenes, cyclodextrins and cyclic oligopeptides draws considerable interest in supramolecular chemistry. However, the construction of inclusion compounds using self-assembly of... [Pg.43]

Hofmann-type clathrates Werner clathrates clathrate hydrates inclusion compounds of urea, thiourea, and selenourea cyclodextrins calixarenes gossypol hexa-hosts hydroquinone phenol and Dianin s compounds graphite intercalates natural and pillared clays and others. Such studies contributed to the birth of supramolecular chemistry, with relevance to a new understanding of the world of materials that was emphasized with a Nobel Prize. [Pg.1302]

Amphiphilic macrocyclic host molecules have been investigated for many years. Among others, it is known that amphiphilic crown ethers, " cryptands, calixarenes, cyclodextrins, and curcubitnrils can form bilayer vesicles in aqueous solution. However, the host-guest chemistry of such host vesicles remained largely unexplored for many years. Darcy and Ravoo prepared bilayer vesicles composed entirely of amphiphilic cyclodextrin host molecules. These vesicles have a membrane that displays a high density of embedded host molecules that bind hydrophobic guest molecules such as f-butylbenzyl and adamantane derivatives. The characteristic size-selective inclusion behavior of the cyclodextrins is maintained, even when the host molecules are embedded in a hydrophobic... [Pg.511]

Cahxarenes are one of the most interesting scaffolds for molecular recognition in host guest chemistry. The versatihty of calixarene macrocycles includes modification of their upper and lower rims, different conformation behavior, and hydrophobic cavity for the inclusion of guest molecules. The conformational preference of calixarene derivatives depends on the substitution at the upper and lower rim. Numerous attractive receptors have been developed for the detection of various guest molecules. The molecular recognition can be characterized by various... [Pg.757]


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Calixarene

Calixarenes

Inclusion chemistry

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