Abstract
Formation of an inclusion complex between 7-iodo-8-hyroxyquinoline-5-sulfonic acid (IHQS) and beta-cyclodextrin is studied by spectrophotometry and H-1 NMR techniques. Spectral changes in the emission spectra upon the addition of beta-cyclodextrin to IHQS in aqueous media were too small to allow for the determination of the binding constant. On the other hand; absorption spectra show a pronounced changes upon the addition of beta-cyclodextrin that allowed for the determination of the binding constant. Absorption measurements show 1:1 inclusion of IHQS in the beta-cyclodextrin cavity with an association constant of 135 +/- A 25 M-1. H-1-NMR studies are used to confirm the inclusion and to provide information about the geometry of IHQS inclusion in the cavity of beta-cyclodextrin.