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Bowl Shaped Cavitands Dimerize and Complex Certain Organic Guests in Organic Solvents which Themselves are Poor Guests

Christoph von dem Bussche-Hünnefeld ; Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
Roger C. Helgeson ; Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
Dirk Bühring ; Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
Carolyn B. Knobler ; Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
Donald J. Cram ; Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA


Puni tekst: engleski pdf 27.883 Kb

str. 447-458

preuzimanja: 231

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Sažetak

The syntheses and binding properties of rigidly bowl-shaped polycyclic cavitands (1—4) are reported. Attached to the four aryl rim positions of the bowls are four benzenes substituted in their para positions with four CC^Me, Br, OH or NO2 groups, which deepen the bowls. Attached to the base of the bowls are four pentyl feet, which increase the solubilities of these hosts in organic solvents. Of the four hosts, only the one containing the CO2Me groups dimerized both in the crystalline state and in solution in ten deute- rated solvents which themselves are poor guests. In three other deuterated solvents, no dimerization was observed. A crystal structure of the dimer showed that one p-MeC^CCs^ group of each monomer occupied the cavity of its complexing partner in a reciprocating double host-guest arrangement. Such a structure is compatible with the ^H-NMR spectra of the dimer in solution. The dimer was also detected in its FAB-MS. The tetrabromocavitand at low concentrations in CD2CI2 complexed MeCC^C^Me, MeCC^Me, PhCC^Me and MeCOC^CC^Me. Tetranitrocavitand 4 also complexed MeC02CH2Me in CD2CI2 as solvent.

Ključne riječi

Hrčak ID:

136666

URI

https://hrcak.srce.hr/136666

Posjeta: 804 *