| Abstract
| - The 1H NMR chemical shifts, coupling constants, temperature coefficients, and exchange rateshave been measured for the hydroxy protons of aqueous solutions of α-, β-, and γ-cyclodextrins,maltose, and maltoheptaose. In cyclodextrins (CDs), the high chemical shift of the O(3)H signaland its small 3JOH,CH value suggest that O(3)H is involved in a hydrogen bond. The small temperaturecoefficients and rate of exchange values of O(2)H and O(3)H confirm the involvement of O(3)H inhydrogen bonding and indicate that O(2)H is the hydrogen bond partner. In maltose, two distinctNMR signals with two different vicinal coupling constants are found for O(2‘)H. A cross-peak inthe ROESY spectrum indicates chemical exchange between the O(2‘)H and O(3)H protons. Theexistence of two distinct NMR signals with different J values for O(2‘)H shows the influence ofanomeric configuration on the O(2‘)H−O(3)H interaction. The effect of complexation with methylbenzoate, adamantane-1-carboxylic acid, adamantane-1-ol, and l- and d-tryptophane on the NMRspectra of the hydroxy protons of α-, β-, and γ-cyclodextrins and of maltose has been investigated.No significant spectral changes were observed upon addition of methyl benzoate and adamantane-1-carboxylic acid. The addition of adamantane-1-ol resulted in an upfield shift and a strongbroadening of the O(2)H signal from α-CD, and a small temperature coefficient was measured uponcomplexation. The O(2)H and O(3)H signals in β-CD were broadened and shifted downfield uponaddition of l- and d-tryptophane.
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