title: Synthesis and assembly of self-complementary calix[4]arenes.
abstract: A calix[4]arene was designed to reversibly dimerize and form an egg-shaped enclosure. Adhesive interactions in the assembly were provided by four self-associating ureas, which form a cyclic array containing 16 hydrogen bonds. The synthesis was completed in four steps from the previously described O,O',O",O"'-tetrabenzylcalix[4]arene. Evidence for dimerization of the calixarene tetraurea was provided by H NMR, mass spectrometry, and the observation of encapsulated molecules. The resulting cavity was of sufficient size to capture guests such as ethyl benzene and p-xylene.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, 02139, USA.
authors.forename: K D
authors.initials: KD
authors.lastname: Shimizu
authors.forename: J
authors.initials: J
authors.lastname: Rebek
mesh_terms: D001554:Benzene; D047250:Calixarenes; D002725:Chloroform; D007202:Indicators and Reagents; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013329:Structure-Activity Relationship
chemical_list: D007202:Indicators and Reagents; D046911:Macromolecular Substances; D047250:Calixarenes; D002725:Chloroform; D001554:Benzene