CYCLODEXTRIN COMPLEXES OF SUBSTITUTED PERBENZOIC AND BENZOIC-ACIDS AND THEIR CONJUGATE BASES - FREE-ENERGY RELATIONSHIPS SHOW THE INTERACTION OF POLAR AND STERIC FACTORS

The stability constants of the complexes of alpha-cyclodextrin and 4-m ethyl-, 4-nitro-, 4-sulfonato- and 3-chloro-substituted perbenzoic aci ds, perbenzoates and benzoates, but not benzoic acids, show linear fre e energy relationships. In contrast to alpha-cyclodextrin, the stabili ty constants of the beta-cyclodextrin complexes of perbenzoic acid and benzoic acids do show the same trend. The stability constants are dis cussed in terms of the orientation of the guest species in the cyclode xtrin cavity.