Study of inclusion complex of β-cyclodextrin and nitrobenzene

β-cyclodextrin can react with nitrobenzene to form an inclusion complex which is characterized by 1H NMR and powder X-ray diffractometry. The ratio of β-CD to NB in inclusion complex is determined as 1:1. At 25 °C, the dissociated constant, KD, of the inclusion complex is measured as 6.5 × 10−3 M in neutral solution (pH = 7.0), but in alkali (pH = 13.5), KD is 3.2 × 10−2 M which is much larger than that measured in neutral.