A unique small molecule class of fluorophores with large Stokes shift based on the electron deficient 9-methoxypyrroloisoquinolinetrione core. (July 2022)

• Record Type: Journal Article
• Authors: Khitrov, Michael D.; Platonov, Dmitry N.; Belyy, Alexander Yu; Trainov, Konstantin P.; Velmiskina, Julia A.; Medvedev, Michael G.; Salikov, Rinat F.; Tomilov, Yury V.
• Is Part Of: Dyes and pigments. Volume 203(2022)
• Publication Date: 2022-07
• Subjects: Fluorescence -- 5-hydroxyisoquinolones -- 9-methoxypyrroloisoquinolinetrione -- Large Stokes shift -- Solvatochromism -- PBE0 calculations; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2022.110344
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: A novel fluorescent core based on electron-deficient 9-methoxypyrroloisoquinolinetrione moiety with a condensed imide cycle is developed. The new class of dyes show large Stokes shift up to 6519 cm-1 (Δλ up to 130 nm), however, unlike parent 5-hydroxyisoquinolones, 9-methoxypyrroloisoquinolinetrione are not superphotoacidic which could be responsible for the large Stokes shifts. At the same time methylation of 5-hydroxyisoquinolones reduces Stokes shift from 5086 to 4689 cm-1. The increase in Stokes shift upon the formation of an imide cycle was shown to be due to unusual bond-lengths relaxation involving the imide ring. Graphical abstract: Image 1 Highlights: Fluorescent electron-deficient 9-methoxypyrroloisoquinolinetriones are developed. The new class of dyes show large Stokes shift up to 6519 cm-1 (Δλ up to 130 nm). The large Stokes shift is due to unusual bond-lengths relaxation.