A Doubly Alkynylpyrene‐Threaded [4]Rotaxane That Exhibits Strong Circularly Polarized Luminescence from the Spatially Restricted Excimer1. (27th October 2014)

• Record Type: Journal Article
• Authors: Inouye, Masahiko; Hayashi, Koichiro; Yonenaga, Yuki; Itou, Tatsuya; Fujimoto, Kazuhisa; Uchida, Taka‐aki; Iwamura, Munetaka; Nozaki, Koichi
• Is Part Of: Angewandte Chemie. Volume 126:Number 52(2014)
• Page Start: 14620
• Page End: 14624
• Publication Date: 2014-10-27
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201408193
• Languages: English
• ISSNs: 0044-8249

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The Sonogashira coupling of γ‐CD‐encapsulated alkynylpyrenes with terphenyl‐type stopper molecules gave a doubly alkynylpyrene‐threaded [4]rotaxane. The rotaxane showed only excimer emission, with a high fluorescence quantum yield of <italic>Φ</italic>_f=0.37, arising from the spatially restricted excimer within the cavity of the γ‐CD. The excimer emission suffered little from self‐quenching up to a concentration of 1.5×10⁻⁵ <sc>M</sc> and was circularly polarized with a high <italic>g</italic>_lum value of −1.5×10⁻². The strong circularly polarized luminescence may result from the two stacked pyrenes existing in the rotaxane in an asymmetrically twisted manner.</p> </abstract>