Article

4. Undecabenzo[7]superhelicene: A Helical Nanographene Ribbon as a Circularly Polarized Luminescence Emitter

Carlos M. Cruz, Silvia Castro-Fernández, Ermelinda Maçôas, Juan M. Cuerva and Araceli G. Campaña*

Angew. Chem. Int. Ed. 2018, 57, 14782–14786 - DOI: 10.1002/anie.201808178 - URI: hdl.handle.net/10481/52640

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ABSTRACT - The synthesis and characterization of an enantiopure superhelicene nanographene is reported in which two saddle-shaped and one planar hexabenzocoronene (HBC) units are arranged in a helicoidal shape to form an undecabenzo[7]carbohelicene. The described compound is the first fully π-extended [7]helicene. Racemic resolution of the helical nanographene permitted analysis of the chiroptical properties and revealed dissymmetry factors in the range of 2×10−3 both in the absorption and in the emission measurements. Remarkably, non-linear photophysical analysis demonstrated a two-photon absorption cross-section of 870 GM at 800 nm and a perfect overlap between linear, non-linear, and chiral emissions