Structural relaxation accompanied by photo-induced chromatic phase transition of polydiacetylenes with butylene-N-difluorophenyl carbamate side chains

► We have synthesized polydiacetylene (PDA) with difluorophenyl carbamate side chain. ► PDAs show distinct phase transition (PT) depending on the side-chain structure. ► PDA with 3,4-difluorophenyl carbamate shows PT by thermal stimulation. ► However, PDA with 2,4-difluorophenyl carbamate shows PT only under photo-excitation.