2,6-Anthracenyl(anthraquinonyl)-substituted difluoroboron dipyrromethenes: Synthesis, spectroscopy, electrochemistry and quantum chemical calculations

Abstract A series of anthracenyl(anthraquinonyl)-substituted difluoroboron dipyrromethene dyes were synthesized through a Suzuki cross-coupling reaction. The crystal structure combined with geometric optimization reveals a moderate dihedral angle between the anthracenyl(anthraquinonyl) plane and the connected pyrrolyl plane. Photophysical characterization shows that the introduction of anthracenyl(anthraquinonyl) moiety to the BODIPY core effectively tunes the emission properties of BODIPY while retaining the separate absorption properties of BODIPY and anthracene(anthraquinone). High fluorescent quantum yields of up to 0.70 and a large Stokes shift (ca. 1707 cm −1 ) were noted. Electrochemical characterization suggests that the anthracenyl(anthraquinonyl) linkage and BODIPY unit lead to rich and tunable potentials. TD-DFT calculation proved a moderate intramolecular charge-transfer process between the BODIPY core and anthracenyl(anthraquinonyl) moiety.