Synthesis, Characterization, and Optical Properties of Copolymers Containing Fluorine-Substituted Distyrylbenzene and Nonconjugated Spacers

Copolymers containing fluorinated distyrylbenzenes as conjugated segments have been synthesized using the Horner−Emmons reaction of dialdehydes and diphosphonates. The presence of well-defined conjugated fluorinated systems gives rise to strong blue emissions in solution. Quantum yields and emission maxima in solution depend on the substituents on the chromophore and the nature of the nonconjugated segments. Construction of conjugated segments containing a central perfluorophenyl ring and aromatic groups substituted with electron-donating groups at the terminae, as evidenced by strong solvatochromic behavior, allow an induced intramolecular charge transfer state. Face-to-face π stacking has been observed in thin films formed from each of the polymers and causes large red shifts in the emission as compared to those in solution. The low quantum yield of emission in thin films is a result of self-quenching due to stacking.