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

IVAN ROMERO; BEATRIZ LANTAÑO; AL POSTIGO *; BONESI, SERGIO M.

JOURNAL OF ORGANIC CHEMISTRY

AMER CHEMICAL SOC

Lugar: Washington; Año: 2022 vol. 87 p. 13439 - 13454

0022-3263

10.1021/acs.joc.2c00756Direct irradiation of mono-, di- and tri-substituted triphenylaminederivatives in acetonitrileas solvent with light of 254 nm has been systematically investigated revealing thattheexo/endocarbazole derivatives were formed as the main photoproducts in modest to good yields for triphenylamines substituted with electron donor- and neutral- substituents. The kinetic profiles of the photoreaction 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.