Host-guest inclusion complexes chiral crown ether hosts

HOST-GUEST INCLUSION COMPLEXES Chiral crown ether hosts... [Pg.213]

Host-guest inclusion complexes, 262—263 antibiotic hosts, 231—233 cahxarene hosts, 228—231 chiral crown ether hosts, 213—218 cyclic oligosaccharide hosts, 218—222 cyclodextrin host selectivities, 223/ host molecular size, 221 hnear ohgosaccharide hosts, 222—228 ir- TT stacking interactions, 217 proteic hosts, 231 Human 15-hpoxygenase, 52/... [Pg.340]

Inclusion complexing partners are classified as hosts and guests [46]. There are two types of hosts that were successfully employed in the chromatographic separation of enantiomers hosts that have a hydrophobic interior and hosts with a hydrophilic interior. The hydrophilic interior means that the cavity contains heteroatoms such as oxygen, where lone-pair electrons are able to participate in bonding to electron acceptors such as an organic cation (e.g., chiral crown ethers). In contrast, a host with a hydrophobic interior cavity is able to include hydrocarbon-rich parts of a molecule [47]. This type of host is found in the cyclodextrins. [Pg.1002]

Tricyclic derivatives, such as (96), of diaza-12-crown-4 form inclusion complexes with suitable guest ammoniimi salts. Some structural selectivity is shown for example diamine salts H3N(CH2) NH3 with n = 5 or 6 give the strongest complexes with (96), presumably by host recognition of a best fit in its cavity. In a study of complexes of chiral diaza-crown ethers such as (97) with chiral... [Pg.169]

A broad range of macrocyclic compounds can be used as chiral selectors for enantioselective HPLC. Besides synthetic crown ethers, derivatized cyclodextrins and cyclic antibiotics are also used as chiral stationary phases. Enantiomer separation employing these compounds is often based on host-guest interactions [15], whereby the cyclic molecules form an inclusion compound or an association complex with the analyte. [Pg.446]