Dicyclopenta[cd,jk]pyrene based acceptors in conjugated polymers†
A series of reduced band gap donor–acceptor copolymers that contain electron accepting 1,2,6,7-tetra(4-dodecylphenyl)dicyclopenta[cd,jk]pyrene were prepared. The hydrocarbon acceptor relies on its cyclopenta-fused polycyclic aromatic hydrocarbon (CP-PAH) character to access a relatively reduced lowest unoccupied molecular orbital. The donor unit was varied between thiophene, bithiophene, and 1,4-diethynyl-2,5-bis(octyloxy)-benzene producing polymers with band gaps between 1.69–1.74 eV. The synthetic methodology as well as the optoelectronic properties of the donor–acceptor copolymers, including thin-film absorption and cyclic voltammetry, are presented.