Postfunctionalization is a useful strategy to tune the properties of conjugated polymers, while polymer reactions in the main chain of a conjugated backbone are still underexplored. Here we report the postfunctionalization of the main chain of a conjugated polymer via nucleophilic aromatic substitution reaction. Poly­(9,9-dioctylfluorene-alt-tetrafluoro-p-phenylene) is used as a precursor to react with thiophenol derivatives in the presence of a base to enable multiple introduction of arylthio groups into the polymer main chain in high yield with preserving the backbone and the dispersity of the precursor polymer. The main chain structure and optoelectronic properties of the resulting polymers were significantly changed, evidenced by spectroscopic analysis of both model compounds and polymers as well as a computational simulation.

A postpolymerization nucleophilic aromatic substitution reaction is used as a strategy to efficiently diversify conjugated polymers. Conjugated polymers and small molecular models bearing tetrafluorophenyl and octafluorobiphenyl units are reacted with thiophenol derivatives, phenol derivatives, and carbazole in the presence of bases. Model reactions provide insights into the reactivity, numbers and patterns of substitution, structural features, and spectroscopic data. Thiophenol derivatives and carbazole achieve complete substitution of fluorine atoms in both the polymer and the model reactions, whereas phenol derivatives result in di-substitution in each arene ring with para-selectivity. The highly twisted and structurally rigid main chain structures are confirmed for a fully substituted arene motif in both the polymers and the models, resulting in the formation of syn- and anti-atropisomer or axial chirality and in the twisted intramolecular charge transfer character. The obtained polymers and models show unique optical and electrochemical properties, including phosphorescence at low temperatures in the case of the sulfur-containing materials.