Artículos de revistas
Bichromophoric behavior of nitrophenyl-triazene anions: a resonance Raman spectroscopy investigation
Fecha
2008Registro en:
JOURNAL OF RAMAN SPECTROSCOPY, v.39, n.5, p.607-610, 2008
0377-0486
10.1002/jrs.1891
Autor
ANDO, Romulo A.
SANTOS, Ana P. V. dos
HOERNER, Manfredo
SANTOS, Paulo S.
Institución
Resumen
Highly delocalized molecular frameworks with intense charge transfer transitions, known as push-pull systems, are of central interest in many areas of chemistry, as is the case of nitrophenyl-triazene derivatives. The 1,3-bis(2-nitrophenyl)triazene and 1,3-bis(4-nitrophenyl)triazene were investigated by electronic (UV-Vis) and resonance Raman (RR) spectroscopies. The bichromophoric behavior of 1,3-bis(4-nitrophenyl)triazene anion opens the possibility of tuning with visible radiation, two distinct electronic states. The RR profiles of nitrophenyl-triazene derivatives clearly show that the first allowed electronic state can be assigned to a charge transfer from the ring pi system to the NO2 moiety (ca 520 nm), while the second, as a charge transfer from N-3(-) to the aromatic ring (ca 390 nm). In the para-substituted derivative, a more efficient electron transfer and a greater energy separation between the two excited states are observed. Copyright (C) 2008 John Wiley & Sons, Ltd.