Chiral fluorescent sensors based on cellulose derivatives bearing terthienyl pendants

Abstract

Chiral fluorescent sensors were designed and synthesized from naturally occurring optically active cellulose, in which a terthienyl moiety was used as a fluorescent signaling unit, and their chiral recognition abilities were investigated on the basis of an enantioselective fluorescence response to aromatic nitro compounds as quenchers. A cellulose phenylcarbamate derivative (Ce-1b) exhibited an apparent enantioselectivity for various types of aromatic nitro compounds containing either central or axial chirality. Considering the fact that a corresponding monosaccharide derivative showed almost no enantioselectivity, the chiral recognition ability of the cellulose-based fluorescence sensor is attributed to its regular higher-order structures, probably a one-handed helical conformation. The resolution ability of Ce-1b as a chiral stationary phase for high-performance liquid chromatography was basically higher than that of the previously reported cellulose tris(phenylcarbamate), revealing that the terthienyl-based pendant provides attractive chiral recognition sites along the helical backbone as well as the fluorescent functionality.