Aggregation-Induced Emission of Contorted Polycondensed Aromatic Hydrocarbons Made by Edge Extension Using a Palladium-Catalyzed Cyclopentannulation Reaction.

Contorted polycyclic aromatic hydrocarbons (PAHs), and , bearing peripheral five-membered rings were synthesized employing a palladium-catalyzed cyclopentannulation reaction using specially designed diaryl acetylene synthons and with commercially available dibromo- anthracene and bianthracene derivatives. The resulting target compounds and were isolated in excellent yield and found to be highly soluble in common organic solvents, which allowed for their structural characterization and investigation of the photophysical properties, disclosing their aggregation-induced emission (AIE) properties in THF at selective concentration ranges of water fractions in the solvent mixture. Examination of the contorted PAH structures by means of density functional theory (DFT) revealed higher electronic conjugation in the more rigid and planar anthracene-containing derivatives when compared to the twisted bianthracene-bearing moieties with HOMO-LUMO bandgaps (Δ) of ∼2.32 eV for the former PAHs and ∼2.78 eV for the latter ones.