Synthesis and Reactivity of Triazaphenanthrenes.
Pyridonaphthyridines (triazaphenanthrenes) were prepared in 4 steps and in 13-52% overall yield using Negishi cross-couplings between iodopicolines and 2-chloro-pyridylzinc derivatives. After chlorination, Gabriel amination and spontaneous ring-closure, the final aromatization leading to the triazaphenanthrenes was achieved with chloranil. This heterocyclic scaffold underwent a nucleophilic addition at position 6 leading to further functionalized pyridonaphthyridines. The influence of these chemical modifications on the optical properties was studied by steady-state and time-resolved optical spectroscopy. While the thiophene-substituted heterocycles exhibited the most extended absorption, the phenyl- and furan-substituted compounds showed a stronger photoluminescence, reaching above 20% quantum yield and lifetimes of several nanoseconds.
Department of Chemistry, Ludwig-Maximilians-Universität , Butenandtstr. 5-13, 81377 Munich, Germany.
Sarah
S
Fernandez
Department of Chemistry, Ludwig-Maximilians-Universität , Butenandtstr. 5-13, 81377 Munich, Germany.
Maximilian A
MA
Ganiek
Department of Chemistry, Ludwig-Maximilians-Universität , Butenandtstr. 5-13, 81377 Munich, Germany.
Mariia
M
Karpacheva
Department of Chemistry, Ludwig-Maximilians-Universität , Butenandtstr. 5-13, 81377 Munich, Germany.|Center for NanoScience (CeNS), University of Munich , 81377 Munich, Germany.
Fabian C
FC
Hanusch
Department of Chemistry, Ludwig-Maximilians-Universität , Butenandtstr. 5-13, 81377 Munich, Germany.|Center for NanoScience (CeNS), University of Munich , 81377 Munich, Germany.
Stephan
S
Reuter
Department of Chemistry, Ludwig-Maximilians-Universität , Butenandtstr. 5-13, 81377 Munich, Germany.|Center for NanoScience (CeNS), University of Munich , 81377 Munich, Germany.
Thomas
T
Bein
Department of Chemistry, Ludwig-Maximilians-Universität , Butenandtstr. 5-13, 81377 Munich, Germany.|Center for NanoScience (CeNS), University of Munich , 81377 Munich, Germany.
Florian
F
Auras
Department of Chemistry, Ludwig-Maximilians-Universität , Butenandtstr. 5-13, 81377 Munich, Germany.
Paul
P
Knochel