Cyclic and Linear Chiral Polymers Bearing 1,2,3‐Triazole Units: Chirality Enhancement by Cyclic Structure and Circularly Polarized Luminescence Sign Reversal by Protonation

Copper(I)‐catalyzed azide–alkyne cycloaddition between (1 R , 2R )‐ or (1 S , 2S )−1,2‐diazidocyclohexane and 1,3‐diethynylbenzene resulted in cyclic polymer and linear–cyclic mixture polymer bearing 1,2,3‐triazole units in the main chain, respectively, at a lower and higher monomer concentrations in feed. The polymers showed circularly dichroism (CD) spectra in solution and in film reflecting their conformational chirality where sign and intensity were modulated by protonation of 1,2,3‐triazole units with CH 3 SO 3 H. Films composed of the polymers and pyrene exhibited efficient CD signals as well as circularly polarized luminescence (CPLm) arising from pyrene through chirality transfer from the polymers to pyrene where anisotropy factor (g lum ) was as high as of 10 −2 order. The cyclic polymer showed more efficient transfer. The sign of CPLm was unexpectedly reversed by protonation of 1,2,3‐triazole units both for cyclic and linear–cyclic mixture polymers. Chirality transfer was confirmed for cyclic polymer even in solution by CD and CPLm but not for linear–cyclic mixture polymer. Thus, the chain topology, cyclic or linear, and the charge state were demonstrated to remarkably affect the chirality functions.