Two Chirality Transfer Channels Assist Handedness Inversion and Amplification of Circularly Polarized Luminescence in Chiral Helical Polyacetylene Thin Films

Precisely and conveniently controlling the handedness and magnitude of circularly polarized luminescence (CPL) is a key issue in developing CPL-active materials. In this work, a series of chiral helical polyacetylenes bearing pendant pyrene groups were synthesized. CPL inversion occurred when the polymer solutions fabricated into thin solid films. More interestingly, amplification of CPL was also observed during this process; that is, the polymer solution showed a luminescence dissymmetry factor (<i>g</i>_lum) of 1 × 10^–3, while over 100-fold magnitude amplification of <i>g</i>_lum values is obtained in the polymer films. Significantly, the <i>g</i>_lum values of the films can be regulated from 10^–1 to 10^–3 by simply changing the film-forming solvents. The cause of the above phenomena is due to the presence of two different chirality transfer channels: intermolecular interactions in the solutions and the “matching rule” in the films. This study provides a new strategy to construct CPL materials with tunable handedness and a large dissymmetry factor.