Click Reaction-Mediated Functionalization of Near-Infrared Pyrrolopyrrole Cyanine Dyes for Biological Imaging Applications.

A clickable pyrrolopyrrole cyanine (PPCy) dye was synthesized by incorporating an alkyne moiety, followed by click reaction with azide-functionalized molecules of different polarities. The clickable dyes are readily amenable to labelling diverse molecules and exhibit an exceptionally high photostability and an impressive fluorescence quantum yield.