Research Abstract |
In order to investigate the inclusion abilities of the multi- functionalized azacalixarenes, in which the cation sites and the anion sites exist in one molecule, so-called betaine-type host molecules, we started to synthesize the calixarenes, in which several nitrogen atoms are at the side chains in the macro rings. At first, couplingreactions between the para-substituted 2,6-bis(hydroxymethyl)phenols and benzylamine were carried out and the targeted molecule, [3.3.3]- azacalixarene, were obtained. The quartenarization of the nitrogen atoms at the side chains gave the unexpected step-shaped molecule, according to the steric interactions between the aromatic rings and the bulky benzyl groups at the side chains. In case of diaza[3.1.3.1]calixarene derivative, the quarternarization of the two nitrogen atoms at the side-chains, followed by the deprotection at the phenolic hydroxyl groups, gave the expected target molecule, the betaine-type macrocyclic host molecule. The investigations of the inclusion phenomena between the obtained betaine-type azacalixarene as the host molecule and the betaine-type guest molecule, such as the amino adds, are now under way.
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