A prototype of benzobis(imidazolium)-embedded conjugated polyelectrolyte: Synthesis by direct C–H arylation and fluorescent responses to anions

We report the convenient synthesis of a benzobis(imidazolium)-embedded conjugated polyelectrolyte pBBI by a Cu-catalyzed direct C–H arylation of a cationic benzobis(imidazolium)monomer with a di-iodide comonomer.pBBI shows weak fluorescence in solution due to rotation of the repeat units in the conjugated backbone,and enhanced fluorescence when electrostatically interacting with a variety of an-ions to form aggregates.Specially,pBBI responds to the bisulfite anion with intensified unique deep-blue fluorescence easily discriminated by naked eye.