Indeno[1,2,3,4-pqra]Perylene: A Medium-Sized Aromatic Hydrocarbon Exhibiting Full-Range Visible-Light Absorption

Chemistry. 2022 Jan 10;28(2):e202103647. doi: 10.1002/chem.202103647. Epub 2021 Dec 7.

Abstract

We report the synthesis and properties of indeno[1,2,3,4-pqra]perylene, which was prepared by the fusion of one anthracene unit with one naphthalene unit via three carbon-carbon bonds. The synthetic route through two-fold C-H arylation enabled not only the synthesis of unsubstituted indenoperylene, but also rapid access to its arylated derivatives on the gram scale. Indenoperylene is a medium-sized aromatic hydrocarbon with the composition C24 H12 that is isomeric to coronene. Nevertheless, its absorption covers the entire visible region owing to its small HOMO-LUMO gap. Furthermore, indenoperylene exhibits high stability despite the absence of peripheral substituents. We propose that the unique electronic structure of indenoperylene originates from the coexistence of an electron-withdrawing subunit (benzoaceanthrylene) and an electron-donating subunit (perylene). The electronic properties of indenoperylene were modulated via post-functionalization through regioselective bromination. The current research demonstrates that indenoperylene is a promising candidate as a main skeleton for near-infrared-responsive and redox-active materials.

Keywords: CH arylation; indenoperylene; narrow HOMO-LUMO gap; polycyclic aromatic hydrocarbons; visible-light absorption.