Synthesis and spectral properties of poly(fluorene) copolymers containing low band gap substituents: suppression of excimer formation

Poly(fluorene) copolymers containing either perylene or α-cyanostilbene units within the polymer main chain are synthesized and characterized. It is demonstrated that the formation of excimer in these copolymers upon thermal annealing can be suppressed by the incorporation of lower band gap chromophoric segments which serve as efficient excitonic energy traps upon excitation of the poly(fluorene) segments. This provides indirect evidence of the possible role of the anthracene subunits in DHF/ANT copolymers in suppressing excimer formation.