Confinement of (S)-serine in tetra-p-sulfonatocalix[4]arene bilayers

Supramolecular complexes of tetra-p-sulfonatocalix[4]arene and (S)-serine have been isolated in the solid state and their molecular structures elucidated by X-ray diffraction studies. Chiral pairs of (S)-serine molecules are confined in ‘capsules’ of tetra-p-sulfonatocalix[4]arene in an overall bilayer arrangement. Complexes containing differing amounts of sodium and caesium cations are reported.