"Fluorubine" - Dihydro-5,6,7,12,13,14-hexaazapentacene- was described first by Hinsberg and Schwantes in 1903.[1] Nowadays, N-substituted fluorubines are well known as stable and highly emissive dyes which exhibit quantum yields up to 100%.[2] In addition, due to their electronic properties, they might of interest for applications in semiconducting devices.[3] Miao et. al. used TIPS ethinyl substituted fluorubine systems in order to construct highly electron-deficient hexaazapentacenes and examined the fluorubine-hexaazapentacene redox system.[4] Recently, we developed a simple two-step synthesis for a functional dye possessing the fluorubine substructure. The new chromophore/fluorophore is featured by high extinction coefficients and quantum yields. In addition, this derivative of dihydroazaacenes reveals redox activity and solvatochromism/acidochromism. Furthermore, the structure offers the possibility for subsequent reactions, like N-alkylations or Buchwald-Hartwig cross coupling reactions.
[1]O. Hinsberg, E. Schwantes, Chem. Ber. 1903, 36, 4039 – 4050. [2]a) C.E. Foster, GB2.430.936, 2007; b) G. J. Richards, J. P. Hill, N. K. Subbaiyan, F. D’Souza, P. A. Karr, M. R. J. Elsegood, S. J. Teat, T. Mori, K. Ariga, J. Org. Chem. 2009, 74, 8914 – 8923; c) J. Fleischhauer, S. Zahn, R. Beckert, U.-W. Grummt, E. Birckner, H. Görls, Chem. Eur. J. 2012, 18, 4549 – 4557. [3]J. Fleischhauer, R. Beckert, Y. Jüttke, D. Hornig, W. Günther, E. Birckner, U.-W. Grummt, H. Görls, Chem. Eur. J. 2009, 15, 12799 – 12806. [4]Z. He, D. Liu, R. Mao, Q. Tang, Q. Miao, Org. Lett. 2012, 14, 1050 – 1053