title: Reversible encapsulation of disc-shaped guests by a synthetic, self-assembled host.
abstract: Here, the synthesis of a bowl-shaped molecule is described and evidence of its reversible dimerization by means of hydrogen bonds is presented. The dimer features a flattened spherical cavity of peculiar symmetry and acts as a host for the encapsulation of guest molecules of complementary shape. Encapsulation of aromatic guests in chloroform solution and of cyclohexane in p-xylene solution was demonstrated by nuclear magnetic resonance experiments. The passage of guests into and out of the cavity is slow and occurs on a time scale of hours. The system was used to explore the effects of size, shape, and solvation on molecular recognition coupled with assembly.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge 02139, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Grotzfeld
authors.forename: N
authors.initials: N
authors.lastname: Branda
authors.forename: J
authors.initials: J
authors.lastname: Rebek
mesh_terms: D002725:Chloroform / Q000737:chemistry; D003510:Cyclohexanes / Q000737:chemistry; D006860:Hydrogen Bonding; D007093:Imidazoles / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D014992:Xylenes / Q000737:chemistry
chemical_list: D003510:Cyclohexanes; C097752:D(3d) symmetrical dimer 5-5; D007093:Imidazoles; D011108:Polymers; D014992:Xylenes; C031286:4-xylene; D002725:Chloroform