Spectroscopic investigation of cyclodextrin monomers, derivatives, polymers and azo dyes (1)

Abstract

Circular dichroism (CD) and visible spectra of inclusion compounds between Methyl Orange (MO) analogues and α-, β-, γ-cyclodextrin (cdx), 2,6-dimethyl-and 2,3,6-trimethyl-β-cdx, water soluble α-, β-, γ-cdx polymer products were investigated. In the CD-spectroscopic investigation, the complex with α-cdx epichlorohydrin condensate showed a large amplitude and splitting of the induced π → π^* band. Fractions of glyceryl ether of less than 2000 and polymer of more than 10000 dalton molecular mass were separated. Complexes of above two fractions and MO showed the same splitting spectral pattern. Job's plots from visible spectra showed the formation of the 1∶1 complex and CD-data suggested the co-existence of the 2∶1 MO-cdx complex. This splitting pattern showed the reversal of the signs when α-cdx-ethyleneglycol-bis(epoxypropyl) ether was used and disappeared when larger host molecules and azo dyes were used. The splitting was explained by exciton interaction.