From Highly Fluorescent Donors to Strongly Absorbing Acceptors: The Tunable Properties of Fluorubines

Dominique Mario Gampe, Stefan Schramm, Steffen Ziemann, Matthias Westerhausen, Helmar Görls, Pance Naumov, Rainer Beckert

Research output: Contribution to journalArticle


The synthesis and characterization of three novel fluorubine derivatives is reported via three to four simple reaction steps with isolatable intermediates. The functional dyes are characterized by their strong absorption peaks in the visible region and their high fluorescence quantum yields. A significant and useful feature is that the properties can be tuned over a wide range by changing the pH. Transformation of the dyes into protonated amidinium salts leads to narrower band gaps and to drastically lower LUMO energies. Further reduction of the pH results in the doubly protonated species with a high electron-deficiency and LUMO energies of -4.8 eV, bathochromic shifts, and a strong intensity increase of up to ϵ = 120 000 M-1 cm-1.

Original languageEnglish (US)
Pages (from-to)6153-6162
Number of pages10
JournalJournal of Organic Chemistry
Issue number12
StatePublished - Jun 16 2017


ASJC Scopus subject areas

  • Organic Chemistry

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