Heterocyclic [9]Helicenes Exhibiting Bright Circularly Polarized Luminescence

作者：Stefan S. Warthegau, Andreas Erbs Hillers‐Bendtsen, Stephan K. Pedersen, Cecilie Rindom, Christoffer Bræstrup, Jeppe S. Jensen, Ole Hammerich, Maria Storm Thomsen, Fadhil S. Kamounah, Patrick Norman, Kurt Valentin Mikkelsen, Theis Brock‐Nannestad, Michael Pittelkow · 发表于：Chemistry - A European Journal · 年份：2023 · DOI：10.1002/chem.202301815 · 被引用次数：14 · 研究领域：Synthesis and Properties of Aromatic Compounds、DNA and Nucleic Acid Chemistry、Fullerene Chemistry and Applications

Abstract We describe a concise synthetic strategy for the preparation of heterocyclic [9]helicenes and a simple preparative‐scale protocol for the optical resolution of the resulting M‐ and P‐enantiomers. The helicenes were characterized by single‐crystal X‐ray diffraction along with a range of spectroscopic and computational techniques. A fluorescence quantum yield of up to 65 % was observed, and the chiroptical properties of both M‐ and P‐helicenes revealed large dissymmetry factors. The circularly polarized luminescence brightness reaches up to 17 M −1 cm −1 , as measured experimentally and verified computationally, which makes this the highest circularly polarized luminescence brightness among heterocyclic helicenes. We describe how chiroptical properties (both circular dichroism and circularly polarized luminescence) can be described and predicted using quantum chemical calculations. The synthetic approach also reveals by‐products that originate from internal oxidation reactions, presumably mediated by the close proximity of the π‐surfaces in the helicene structure.