Synthesis, characterization, optical and electrochemical properties of spirobifluorene based polymers containing electron deficient moieties

2,7-linked or 2,2′-linked 9,9′-spirobifluorene based polymers containing electron deficient moieties such as naphthalene bisimide and/or benzothiadiazole were synthesized through Suzuki cross-coupling reaction. Alternating polymers containing spirobifluorene and naphthalene bisimide moieties showed a relative low band gap compared to that of the spirobifluorene and benzothiadiazole containing polymers and their random copolymers due to the strong charge transfer interaction between spirobifluorene and naphthalene bisimide units.205