Molecular recognition study on a supramolecular system (ⅩⅤ)──Molecular recognition of aliphatic alcohols by some phenyl-selenium modified β-cyclodextrins

The spectrophotometric titrations have been performed at 298.15 K in buffered aqueous solution （pH 7.20） to give the stability constants （logK-s） for the supramolecular system formed by mono-[6-（phenylseleno）-6-deoxy]-β-cyclodextrin （2）, mono-[6-（p-tolylseleno）-6-deoxy]-β-cyclodextrin （3）, mono-[6-（o-tolylseleno）-6-deoxy]-β-cyclodextrin （4）, mono-[6-（m-tolylseleno）-6-deoxy]-β-cyclodextrin （5） with a series of aliphatic alcohols. The results were compared with the data reported for the parent β-cyclodextrin. The molecular binding ability and selectivity for aliphatic alcohols of modified β-cyclodextrins （25） were discussed from the viewpoints of the induced-fit and geometrical complement. The results obtained indicate that the phenylseleno moiety of β-cyclodextrin derivatives （25） as a probe for spectrometry can enhance not only the molecular binding ability but also the molecular recognition ability.