From byproducts to efficient fluorophores: a route to the synthesis of fluorubines.
The reaction of bis(imidoyl) chlorides of oxalic acid with monoalkyl hydrazines leads to substituted Delta(2)-1,2-diazetines, which are versatile building blocks for ring-transformation reactions. One remarkable product originating from side reactions featured by a strong orange/red fluorescence was confirmed as a novel fluorubine derivative. In continuing our studies to substituted oligoazaacenes, we developed several synthetic entries to build up novel fluorubine derivatives, in which particularly aminobridged bis(quinoxaline)s are the key products for cationic hexaazapentacenes. We would like to discuss the possible formation pathways of these fluorubine derivatives, which exhibit interesting photophysical and chemical properties. The structures of all new derivatives were confirmed by common analytical methods (NMR spectroscopy, CV, UV/Vis, mass spectrometry, elemental analysis, and X-ray structural analysis) and will be discussed on selected examples in more detail.
FB 18, Nature science, Chemistry of Mesoscopic Systems, Heinrich-Plett-Str. 40, 34132 Kassel, Germany.
Jan
J
Fleischhauer
Rainer
R
Beckert
Yvonne
Y
Jüttke
David
D
Hornig
Wolfgang
W
Günther
Eckhard
E
Birckner
Ulrich-W
UW
Grummt
Helmar
H
Görls