Tetraazacoronenes and Their Dimers, Trimers and Tetramers

Chiral Bay-Alkynylated Tetraazaperylenes: Photophysics and Chiroptical Properties

Fully bay-alkynylated octaazaperopyrene dioxide (OAPPDO) derivatives were accessible through Stille cross coupling reaction of the corresponding bay-chlorinated derivatives. This steric congestion of the bay area led to helically chiral fluorophores, and chiral resolution of two derivatives allowed the investigation of their chiroptical properties as well as their kinetics of enantiomerization and the related thermodynamic parameters depending on the size of the terminal alkynyl substituent. An increase of the latter resulted in stable OAPPDO atropisomers at room temperature. The dynamics of the photoexcited states of two of the OAPPDO derivatives were investigated by transient absorption (TA) and time-resolved photoluminescence (tr-PL) spectroscopy.

Zipping up tetraazaperylene: synthesis of tetraazacoronenes via double coupling in the bay positions

Substituted tetraazacoronene fluorophores have been obtained selectively by double Suzuki-Miyaura cross coupling of symmetrically substituted 1,2-bis(pinacolatoboryl)alkenes with a bay-substituted octaazaperopyrenedioxide (OAPPDO). Subsequent Scholl reaction of the dimethoxyphenylated derivative allowed further π-extension of the azaperylene core, yielding a highly redox-active bis(phenanthro)tetraazacoronene.