Synthesis and Optical Properties of Monodisperse Phenothiazinevinylene‐Based Conjugated Oligomers.

A series of novel monodisperse, structurally well defined vinylene‐linked phenothiazine oligomers containing up to 7 phenothiazine units have been designed and synthesized by Heck reaction and McMurry reaction with a convergent approach. These conjugated oligomers showed a progressive bathochromic shift of the absorption maxima and high fluorescence quantum yields in solutions. Notably, the oligomers without strong donor and acceptor units exhibit two‐photon absorption properties, and the two‐photon absorption cross sections (δ) increase with the number of covalently linked phenothiazine units, and δ reaches up to 2071 GM for the one with 7 phenothiazine units at 800 nm. The oligomers might be used as models to study structure–property relationship for their corresponding polymers or applied in organic electronic materials. [ABSTRACT FROM AUTHOR]