One-Pot Access to Ethylene-Bridged BODIPY Dimers and Trimers through Single-Electron Transfer Chemistry.

A Cu(I)-promoted oxidative dimerization of BODIPY dyes was developed to give a series of α,α- ethylene-bridged BODIPY dimers and trimers for the first time. This methodology does not need harsh conditions but relies on the singlet-electron-transfer process between alkylated BODIPYs and Cu(I) salt to generate BODIPY-based radical species, which undergo a selective radical homocoupling reaction. Moreover, these resultant dimers and trimers showed high attenuation coefficients, small line widths of the absorption and emission, and intense fluorescence.