Tunable properties based on regioselectivity of 1,2,3-triazole units in axially chiral 2,2?-linked 1,1?-binaphthyl-based copolymers for ions and acid responsiveness

Abstract

The synthesis and optical studies of a new chiral binaphthyl-based polymeric sensor are described herein. The polymers were prepared using the copper-catalyzed azide?alkyne cycloaddition reaction between fluorene and binaphthyl monomeric units. Resulted polymers differ in the orientation of the 1,2,3-triazole unit as a linker in polymeric backbone based on monomeric character. The responses of these polymers to both exposure to metal ions and the acidic medium were investigated by UV?vis absorbance, circular dichroism and fluorescence analysis. The changes in the absorption, chiroptical and fluorescence properties of the polymers indicate a change of the dihedral angle between the two naphthalene units on the binaphthyl moiety and tunability in conjugation. Moreover, an influence of regioselectivity of 1,2,3-triazole unit in polymer backbone in regards to complexation was discussed. The modulation in signal was detected in real time and makes this system a suitable candidate for further applications as an ion sensor or acid-responsive material