Stability constants of α-cyclodextrin complexes of para-substituted aromatic ketones in aqueous solution

Stability constants for α-cyclodextrin complexes of 21 para-substituted acetophenones and related aryl ketones have been determined spectrophotometrically or potentiometrically. It has been found that the presence of ketone-containing substituents generally results in destabilisation of complex formation. It is postulated that steric hindrance at the narrow end of the cyclodextrin cavity causes the benzene ring to be displaced from its optimal position or orientation.