11,11,12,12-Tetracyano-4,5-pyrenoquinodimethanes: air-stable push-pull o-quinodimethanes with S2 fluorescence.
The synthesis and properties of 11,11,12,12-tetracyano-4,5-pyrenoquinodimethanes (4,5-TCNPs), a new family of isolable and air-stable o-quinodimethanes, are reported. The ortho disposition of the dicyanomethane substituents strongly polarizes the pyrene framework to promote broad and intense intramolecular charge-transfer transitions. In addition, spectroscopic studies reveal that 4,5-TCNPs violate Kasha's rule and emit from the S2 level.
†POLYMAT, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, E-20018 Donostia-San Sebastian, Spain.
Raúl
R
García
†POLYMAT, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, E-20018 Donostia-San Sebastian, Spain.
Sandeep
S
More
‡Centro de Cîencias e Tecnologias de Computação, CCTC Universidade do Minho, 4710-057 Braga, Portugal.
Manuel
M
Melle-Franco
†POLYMAT, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, E-20018 Donostia-San Sebastian, Spain.|§Ikerbasque, Basque Foundation for Science, Bilbao, Spain.
Aurelio
A
Mateo-Alonso