Amphiprotism-Coupled Near-Infrared Emission in Extended Pyrazinacenes Containing Seven Linearly Fused Pyrazine Units

Gary J Richards (1, 2) , Aël Cador (3) , Shinji Yamada (1) , Anna Middleton (4) , Whitney A Webre (4) , Jan Labuta (2) , Paul A Karr (5) , Katsuhiko Ariga (6, 2) , Francis d'Souza (4) , Samia Kahlal (3) , Jean-François Halet (3) , Jonathan P Hill (2)

1 Ochanomizu University
2 WPI-MANA - International Center for Materials Nanoarchitectonics
3 ISCR - Institut des Sciences Chimiques de Rennes
4 UNT - University of North Texas
5 Wayne State College
6 UTokyo - The University of Tokyo

Peripherally substituted tetradecaazaheptacene (NHp) compounds, exhibiting amphiprotism-coupled emission, have been synthesized. X-ray crystallography reveals a planar acene-like chromophore, and electronic absorption and emission occur in the near-infrared biological transparency window (650-900 nm). The compounds exhibit long-wavelength emission with photoluminescence quantum yields Φ up to ∼0.61 at 686 nm, with the monodeprotonated state Φ ≈ 0.58 at 712 nm. This unprecedented highly nitrogenous chromophore illustrates the stability and utility of the pyrazinacenes for different applications based on their photophysical properties and chemical structures.

Domains: Chemical Sciences

Gary J Richards, Aël Cador, Shinji Yamada, Anna Middleton, Whitney A Webre, et al.. Amphiprotism-Coupled Near-Infrared Emission in Extended Pyrazinacenes Containing Seven Linearly Fused Pyrazine Units. Journal of the American Chemical Society, 2019, 141 (50), pp.19570-19574. ⟨10.1021/jacs.9b10952⟩. ⟨hal-02397311⟩