Design, Synthesis, and Photophysical Studies of Functionalized Polyaromatic Isonitriles as Visible Light Photoredox Catalysts

The chemistry of imidoyl radicals derived from single-electron transfer to an isonitrile has been gaining increasing attention, thanks to their multifaceted reactivity. The latter involves the ability of aromatic isonitriles to harvest visible light, reach an electronically excited state, and trigger the formation of open-shell species from suitable radical precursors. We herein report the synthesis of structurally rich polyaromatic isonitriles, the characterization of their photophysical properties via UV–Vis absorption and fluorescence measurements, along with combined experimental and theoretical studies to evaluate both ground and excited-state redox properties. Finally, synthetic validation as photoredox catalysts enabled to highlight the best-performing isonitrile-based scaffolds, holding promise for further developments in the field.