Abstract: The results of ¹H NMR investigation of α-cyclodextrin inclusions with p-and m-cresol in heavy water are reported in this paper. It was found that though there is difference in chemical shift of some protons in α-cyclodextrin cavity between after and before complexing with cresol, only singlet resonance peak had been detected by ¹H NMR, position of which was dependent upon the inclusive degree. The average geometrical structures of inclusion complexes and their equilibrium constants under different inclusive degrees had been calculated based on ¹H NMR data, and the situation of dynamic variation of entering depth of cresol into α-cyclodextrin cavity had been described. Meanwhile, the comparison of the above results of α-cyclodextrin with β-cyclodextrin are made in this paper.

Key words: cyclodextrin, Cresol, ¹H NMR, Inclusion, Binding equilibrium, Dynamic structure