Paddle-Wheel BODIPY–Hexaoxatriphenylene Conjugates: Participation of Redox-Active Hexaoxatriphenylene in Excited-State Charge Separation to Yield High-Energy Charge-Separated States

Hexaoxatriphenylene, a scaffold linker often utilized in building covalent organic frameworks, is shown to be electroactive and a useful entity to build light energy-harvesting donor–acceptor systems. To demonstrate this, new donor–acceptor conjugates have been synthesized by employing BODIPY as a sensitizer. Excited-state electron transfer leading to high-energy charge-separated states, useful to drive energy-demanding photocatalytic reactions, from the electron-rich hexaoxatriphenylene to 1BODIPY*, in the synthesized tri-BODIPY–hexaoxatriphenylene “paddle-wheel” conjugates, has been successfully demonstrated using femtosecond transient absorption spectroscopy. The measured rate of charge separation was in the range of ∼3–10 × 1011 s–1, revealing ultrafast charge separation.