Palladium/norbornene-catalyzed C–H bond activation and annulation to construct polycyclic aromatic hydrocarbon-based fluorescent materials

Reported herein is the first example of NBE-CO₂Me-mediated palladium-catalyzed C-H bond activation and annulation of bromo(hetero)aromatics to construct structurally diverse polycyclic aromatic hydrocarbon (PAH)-based fluorescent materials. The approach shows a broad substrate scope and provides straightforward access to screening high-performance fluorescent materials. A novel organic single-molecule white-light material with anti-Kasha dual-emission characteristics has been developed herein. Furthermore, the anti-Kasha dual-emission material was fabricated as water-dispersed nanoparticles (NPs) to target the mitochondria of living cells. The corresponding NPs could be further applied in two-channel emission intensity ratio imaging to observe the cellular local imaging information and the intercellular structure.