NMR Spectroscopy on the Complexation of 3,6-Anhydro-β-cyclodextrin with 2,6-Naphthalenedicarboxylate Ion

Abstract The 2,6-naphthalenedicarboxylate ion (2,6-NDC) was included into the interior cavity of 3A,6A-anhydro-β-cyclodextrin (1) in D2O containing 0.1 mol dm−3 Na2CO3 and caused a shift in the 1H NMR signals due to the C3- and C5-H’s of 1 to different directions, depending on the positions of glucose units (anisotropic ring-current effect). The decrease in entropy accompanied by the complexation was much larger than that for the complexation of native β-cyclodextrin with 2,6-NDC. These results indicate that the molecular rotation of 2,6-NDC is retarded within the deformed cavity of 1.