Preparation, characterization and photochemistry of 4,4′-diacetamidostilbene and its β-cyclodextrin inclusion complex

Abstract

The inclusion complex of trans-4,4′-diacetamidostilbene ( 1, DAST) with β-cyclodextrin ( 2, DAST—CD) was prepared. The formation of the complex and its photochemical behaviour were investigated using a range of physical methods ( 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, fluorescence and absorption spectroscopy). The results indicate that a stable 1 : 1 inclusion complex is produced in the solid state and in methanol and dimethylsulphoxide. The guest molecule is completely encapsulated in the β-cyclodextrin cavity. No difference in stability was observed between DAST and DAST—CD when the samples were irradiated by UV light in methanol. The photolysis products in dimethylsulphoxide were studied using 1H NMR spectroscopy; the results indicate that the photolysis products are cis-DAST and 4,4′-diacetamidophenanthrene for DAST—CD, but cis-DAST only for DAST.