Synthesis of helically π-stacked poly(quinolylene-2,3-methylene)s with anthracene derivatives at the chain end: intramolecular energy transfer based on the π-stacked architecture

Polymers with layered pi-stacked structures have attracted the greatest attention as novel materials with characteristic optoelectrical properties. However, the difficulty in constructing pi-stacked polymers has made it challenging to incorporate sophisticated designs to express functionality. Previously, poly(quinolylene-2,3-methylene)s (PQMs) synthesized by living cyclocopolymerization were reported to form pi-stacked helical structures. Herein, we report the design and synthesis of pi-stacked PQMs with anthracene derivatives as energy acceptors at the alpha-chain-end using the end-functionalization method. The resulting polymers exhibited emission derived from the terminal anthracenyl group at the excitation wavelength of the quinoline rings in the main chain. A comparison of the UV and emission spectra of the obtained polymers revealed that the resulting polymers exhibited energy transfer from the quinoline rings of the main chain to the terminal anthracene group as an emission trap. Furthermore, it was found that a stable pi-stacked structure was essential for efficient energy transfer.