ISSN:
1434-193X
Keywords:
Calixarenes
;
Inclusion compounds
;
Hydrogen bonds
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Titration of the sulfonic protons of (p-sulfonato)calix[4]arene (H8L) with 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 from the aromatic cavity, leading to the formation of [H3NCH2CH2NH3]1.5[(H3L)(H3NCH2CH2NH3)]·(H2O)5.5, which represents an unprecedented example of the inclusion of a dication in a calixarene. Further addition of ethylenediamine 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···π facial aromatic contact. Inclusion phenomena are indicated both by NMR and X-ray structure determinations. In the same way as their inorganic-organic counterparts, these clay-like materials are organised into parallel organic-organic layers.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
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