Inclusion complexation and photoprototropic behaviour of 3-amino-5-nitrobenzisothiazole with beta-cyclodextrin.

The inclusion complexation and photoprototropic behaviour of 3-amino-5-nitrobenzisothiazole (ANBT) in aqueous beta-cyclodextrin (beta-CDx) solution have been investigated. Absorption and fluorescence intensities of the neutral form of ANBT are enhanced due to the formation of 1:1 complex with beta-CDx. The complex formation has been confirmed by IR spectral and SEM studies. In the presence of beta-CDx, no change was observed in the ground and excited state acidity constant values when compared with aqueous medium. Based on its inclusion complexation and photoprototropic characteristics of ANBT in beta-CDx, the structure of the 1:1 complex is proposed.