We report the synthesis of a novel, water-soluble aryl-extended calix[4]pyrrole receptor. The water-solubilising groups are placed at the lower rim of the receptor, leaving the binding pocket unperturbed and open for modification. Binding studies were performed with a series of pyridineN-oxides. These studies revealed the ability of the receptor to bind neutral and charged N-oxides in basified water with stability constants higher than 104 M−1.
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