Calix[4]arene‐Based Chromogenic Chemosensor for the α‐Phenylglycine Anion: Synthesis and Chiral Recognition

Abstract

Abstract Calix[4]arene‐based two‐armed chiral anion receptors 3a and 3b have been synthesized and examined for their chiral anion‐binding abilities by UV/Vis absorption and 1 H NMR spectroscopy. The results of nonlinear curve fitting indicate that 3a and 3b form 1:1 stoichiometric complexes with the L ‐ or D ‐α‐phenylglycine anion by multiple hydrogen‐bonding interactions and exhibit good enantioselective recognition for the enantiomers of the α‐phenylglycine anions ( 3a : K ass(L) / K ass(D) = 4.76; 3b : K ass(D) / K ass(L) = 2.84). The marked colour changes observed for the complexation of 3a with the chiral anions and the good enantioselective recognition reveal that receptor 3a could be used as a good chiral chromogenic chemosensor for the enantiomers of the α‐phenylglycine anion. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)