Benzo-Extended [<i>n</i>]Phenacenes: e-Flow Synthesis and Length-Dependent Properties

This study presents an efficient method for synthesizing twisted benzo-extended [<i>n</i>]-phenacenes ([<i>n</i>]-BPs) featuring an electrochemical flow (e-flow) Scholl reaction of the corresponding [<i>n</i>]-BP precursors from a one-pot three-component Suzuki-Miyaura coupling reaction. The e-flow Scholl reaction offers advantages such as reduced oxidant usage and overoxidation byproducts, and easy scale-up through extended electrolysis time toward these intricate polycyclic aromatic hydrocarbons. In addition, the increase in molecular length decreases the optical bandgap of [<i>n</i>]-BPs and thus tunes their photophysical properties. This work provides a green and sustainable synthetic strategy for diverse [<i>n</i>]-BPs and enables facile bandgap modulation through π-conjugation extension, offering potential for organic semiconductor applications in optoelectronic devices.