Photoinduced [6π]-electrocyclic reaction of mono-, di-, and tri-substituted triphenylamines in acetonitrile. A steady-state investigation

IVAN ROMERO CORDERO; BEATRIZ LANTAÑO; AL POSTIGO; BONESI SERGIO M

JOURNAL OF ORGANIC CHEMISTRY

AMER CHEMICAL SOC

Lugar: Washington; Año: 2022

0022-3263

Direct irradiation of mono-, di- and tri-substituted triphenylamine derivatives in acetonitrileas solvent with light of 254 nm has been systematically investigated revealing that the exo/endocarbazole derivatives were formed as the main photoproducts from modest to good yields fortriphenylamines substituted with electron donor- and neutral- substituents. The kinetic profiles of thephotoreaction were also recorded and the consumption rate constants (k) were measured. These kinetic parameters show dependance on the nature of the substituents and linear Hammett correlations were carried out to showcase the substituent effect. On the other hand, the spectroscopic behavior of the electron-rich substituted triphenylamines has been analyzed suggesting that the fluorescence emission spectra display a mirror image of the lower energy absorption bands while for those amines bearing electron-acceptor groups the formation of charge-transfer complexes and their fluorescence emissions constitute the main deactivation pathway of the photoreaction.