Highly contorted superhelicene hits near-infrared circularly polarized luminescence. Issue 35 (17th August 2022)

• Record Type: Journal Article
• Authors: Míguez-Lago, Sandra; Mariz, Inês F. A.; Medel, Miguel A.; Cuerva, Juan M.; Maçôas, Ermelinda; Cruz, Carlos M.; Campaña, Araceli G.
• Is Part Of: Chemical science. Volume 13:Issue 35(2022)
• Page Start: 10267
• Page End: 10272
• Publication Date: 2022-08-17
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d2sc03452b
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : This twisted superhelicene employed its twists and loops to shine chiral emission into the NIR region. The proof of its promising applicability in optoelectronic devices is the analogous chiroptical properties obtained in solution and thin films. Abstract : Herein we describe a novel superhelicene structure consisting of three hexa- peri -hexabenzocoronene (HBC) units arranged in a helical geometry and creating two carbo[5]helicenes and a carbo[7]helicene. The central HBC bears a tropone moiety, which induces a saddle-helix hybrid geometry into the 3D structure of the prepared nanographene. The introduction of multiple helicenes and the position of the tropone unit trigger near-infrared circularly polarized luminescence (NIR-CPL, up to 850 nm, | g lum | = 3.0 × 10 −3 ) combined with good photoluminescence quantum yields ( ϕ F = 0.43) and upconverted emission based on two-photon absorption (TPA). Compared to previously reported superhelicenes of similar size, higher quantum yields, CPL brightness, and red-shifted absorption and emission spectra are achieved. Besides, chiroptical properties of enantiopure thin films were evaluated. These findings place this novel superhelicene as the first NIR-CPL superhelicene ever reported and make it a promising candidate for use as a chiral luminescent material in optoelectronic devices.