Three molecular baskets were synthesized. Binding studies in CDCl₃, DMSO-d₆, and toluene-d₈ were performed with thirty-one guests. The best guests were those that were most complementary to the cavity. Guests possessing halogen atoms were the stronger binders. Analysis indicated that the reason for this selectivity was the formation of polydentate C-H   X-R hydrogen bonds between host and guest.

            NMR was used to monitored guest orientation within the cavity of each host. These results indicated that both the functional group on the guest and the solvent played a role in determining the orientation of the guest within the cavity. We will also discuss VanŐt Hoff analyses that reveal the enthalpic and entropic contributions to complexation.

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2. Gibb, C. L. D.; Stevens, E. D.; Gibb, B. C.; J. Am. Chem Soc., 2001, 123, 5849.

3. Laughrey, Z. R., Gibb; C. L. D.; Senechal, T.; Gibb, B.C.; Chem. Eur. Journal., in press.