Design of New Tetrazine-Triphenylamine Bichromophores - Fluorescent Switching by Chemical Oxidation

• Published in: European Journal of Organic Chemistry 2012-03, Vol.2012 (7), p.1394-1403
• Main Authors: Quinton, Cassandre, Alain-Rizzo, Valérie, Dumas-Verdes, Cécile, Clavier, Gilles, Miomandre, Fabien, Audebert, Pierre
• Format: Article
• Language: English
• Subjects: Chemistry; Donor-acceptor systems; Exact sciences and technology; Fluo­rescence; Heterocyclic compounds; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Molecular modeling; Organic chemistry; Preparations and properties; Redox chemistry; Synthesis design
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.201101584

Original new fluorescent and electroactive compounds have been prepared, which feature two different fluorescent groups linked through an oxygen atom spacer. We describe here the synthesis, photophysical and electrochemical properties and their interplay, and our theoretical calculations. These molecules are composed of two fluorophores, an electron‐rich triphenylamine unit and an electron‐poor tetrazine unit. Although the bichromophores are not fluorescent in the neutral state due to a photoinduced electron transfer from the triphenylamine unit to the tetrazine unit, one can restore the fluorescence by oxydation of the triphenylamine moiety. Thus, a redox‐fluorescent switch has been realized. Tetrazine–triphenylamine bichromophores linked by an oxygen atom were designed and synthesized. Their photophysical and electrochemical properties were investigated. These dyads are nonfluorescent compounds in their neutral state because of phoinduced electron transfer. However, tetrazine fluorescence was restored by chemical oxidation (cation radical formation).