Synthesis and evaluation of extraction ability of calix[4]-crown-6 cone conformer and its oligomeric analogue

摘要

The synthesis of the cone conformers of 5,1 1,17,23-tetra-tert-butyl-25,27-bis[(4-nitrobenzyloxy)-26,28-dihydroxy]-calix[4]-arene (2), 5,11, 17,23-tetra-tert-butyl-25,27-bis[(4-nitrobenzyloxy)]calix[4]arene-crown-6 (3) and 5, 11, 17, 23-tetra-tert-butyl-25,27-bis[(4-aminobenzyloxy)]calix[4]arene-crown-6 (4) containing polymerizable side arms, along with their oligomeric analogue 5, is reported. Extraction studies with monomers 3 and 4 and the oligomer 5 show no difference in their extraction behavior and selectivity, whereas, ionophore 2 is a poor extractant for alkali metal cations. These observations suggest that, substitution of side arms on the lower rim of calix moiety can enhance the calix[4]-crown-6 cone conformers function to extract alkali metal cations in two phase extraction systems.