Successive inclusion of water, [H3NCH2CH2NH3](2+) and [H3NCH2CH2NH2](+) inthe aromatic cavity of (p-sulfonato)calix[4]arene

Titration of the sulfonic protons of (p-sulfonato) calix [4] arene (H8L) wi th two equivalents of ethylenediamine affords [H3NCH2CH2NH3](2)[H4L(H2O)(3) ].H2O, a molecular complex in which water is included inside the macrocycle . Deprotonation of one of the phenolic groups expels the water molecules fr om the aromatic cavity, leading to the formation of [H3NCH2CH2NH3](1.5)[(H3 L) (H3NCH2CH2NH3)].(H2O)(5.5), which represents an unprecedented example of the inclusion of a dication in a calixarene. Further addition of ethylened iamine affords the mixed salt [H3NCH2CH2NH3](2)-[(H3L) (H3NCH2CH2NH2)].(H2O )(4.5) in which the monocation [H3NCH2CH2NH2](+) is preferentially bound to the cavity through a non-classical hydrogen bond involving an N-H...pi fac ial aromatic contact. Inclusion phenomena are indicated both by NMR and X-r ay structure determinations. In the same way as their inorganic-organic cou nterparts, these clay-like materials are organised into parallel organic-or ganic layers.