One-step rapid synthesis of π-conjugated large oligomers via C–H activation coupling

A variety of diketopyrrolopyrrole (DPP)-based linear or branched π-conjugated oligomers, with a core of phenyl, phenyl-DPP, tetraphenylethene, pyrene and spirobifluorene, containing sequentially bis-, tris-, and tetra-DPP with various geometries and molecular weights of several thousands has been effectively accessed by one-step C–H activated coupling followed by a single column chromatographic separation. A further optical property study of all eight synthesized oligomers reveals the correlation between light absorption and the variation of geometries and π-conjugation lengths. This atom- and step-economical, and versatile synthetic strategy will be a powerful tool for accessing π-functional large oligomers, which enriches the library of π-materials and thus facilitates the fundamental structure–property study.