Poly(quinoxaline-2,3-diyl) as a Multifunctional Chiral Scaffold for Circularly Polarized Luminescent Materials: Color Tuning, Energy Transfer, and Switching of the CPL Handedness

Random poly(quinoxaline-2,3-diyl) copolymers, containing achiral 5,8-diarylquinoxaline units and chiral units bearing (S)-2-butoxymethyl groups, exhibited circularly polarized luminescence (CPL). The emission color was fully tunable by changing the aryl substituents on the 5,8-diarylquinoxaline units. An energy transfer from the quinoxaline main chain to the 5,8-diarylquinoxaline units was observed. The handedness of the CPL was dependent on the helical chirality of the polymer main chain, which could be switched by changing the solvent from CHCl₃ to 1,1,2-trichloroethane or n-octane to cyclooctane, depending on the chiral side chain.