Stimuli-responsive circularly polarized luminescence from an achiral perylenyl dyad

Stimuli-responsive circularly polarized luminescence (CPL) was successfully achieved through fine-tuning the conformation of a perylenyl dyad by using external stimuli. Monomer CPL was clearly detected from an inherent achiral monochromophore system in a simple perylene-carbazole dyad, and concentration-dependent CPL was observed from 'good solvent', giving an excimer-like CPL emission with a peak maximum at 643 nm. Moreover, the CPL bands depended on the aggregated state, which was identical to the emission changes in the THF-H2O system. It is noteworthy that the perylene-carbazole dyad emitted efficient CPL in thin films even without annealing processes. The specific perylenyl-carbazole structure plays a crucial role in CPL in response to the external environment. This novel molecular design strategy opens up a new perspective for the future development of smart CPL-active organic dyads.