Benzene-fused BODIPYs: synthesis and the impact of fusion mode

摘要

BODIPY derivatives with one or two benzene units fused at different positions are prepared using novel synthetic methods. The resulting dye 1 shows deep red fluorescence with a large Stokes shift Dyes 2 and 3 are reported for the first time and 3 exhibits near infrared absorption. The impact of benzannulation at different positions of BODIPY is discussed, and the geometry and electronic structure are studied by DFT calculations. 4,4-Difluoro4-bora-3a,4a-dia2a-s-indacene, abbreviated as BODIPY, represents a family of extremely versatile fluorophores which are currently attracting increasing interest among various research areas including bio-labeling/bio-imaging and photovoltaic devices, owing to their remarkable photophysical features, such as excellent thermal and photochemical stability, intense absorption, sharp fluorescence with high quantum yield, and outstanding inertness to the polarity and pH of the environment.