Abstract
The complex formation molar ratio of methyl orange and cyclodextrin, position and freedom of motion after inclusion were examined by nuclear magnetic resonance (NMR). 1) Methyl orange forms 1 : 1 complexes with α- and β-cyclodextrin. 2) Methyl orange is included predominantly from the N, N-dimethylamino group side. α-Cyclodextrin includes firmly methyl orange at the N, N-dimethylaniline side and β-cyclodextrin includes methyl orange at the benzenesulfonate side with little perturbation. 3) The data of 1H NMR showed that α- and β-cyclodextrin include methyl orange in the whole of the cavity and the results of 13C NMR showed that deformation at the linkage positions of glucose is detectable.