Phenyleneethynylene trimer-based rigid-flexible [2+2] macrocycles for nucleic acid labelling in live cells

Fluorescent macromolecules were developed for intracellular labeling in live cells. Coupling rigid rod phenyleneethynylene trimers with flexible amphiphilic diamines via the imine-bond formation chemistry yielded rigid-flexible [2+2] macromolecules showing nucleic acids selectivity and nontoxicity in live cells.