engleski

Synthesis and alkali metal picrate extraction studies of lower rim functionalized p-tert-butylcalix[4]arene crown ethers

The syntheses of four new calix[4]arene receptors, i.e. 4-7, each of which contains an oxahexacyclic cage moiety, are reported. The structures of two of these receptors, i.e. 4 and 7, have been established via single crystal X-ray structural analysis. The complexation properties of 4-7 were determined via a series of alkali metal picrate extraction experiments. Two of the cage-functionalized calix[4]arene-crown-5 hosts, i.e. 4 and 5, display somewhat greater extraction avidity toward Na+ picrate vis-a-vis the remaining alkali metal picrates. By way of contrast, host systems 6 and 7 function effectively as a moderately selective K+ extractants and display significantly increased extraction avidity toward K+ picrate vis-a-vis 4 and 5.

p-tert-butylcalix[4]arene; crown ethers

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