Electronic spectroscopy of the b-carboline derivatives: nitronorharmanes, nitroharmanes, nitroharmines and chloroharmines in homogeneous media and solid matrix” . (número dedicado a la Prof. Dra. R. M. de Lederkremer)

I. TARZI, OLGA; A. PONCE, MARIA; M. CABRERIZO, FRANCO; M. BONESI, SERGIO; ERRA BALSELLS, ROSA

Arkivoc

ARKAT-USA, Inc.

Lugar: TAMPA, FLORIDA; Año: 2006 vol. XII p. 295 - 310

1424-6376

Abstract Electronic spectra (absorption, fluorescence and phosphorescence emission spectra) of nitro-b-carboline derivatives (nitronorharmanes, nitroharmanes and nitroharmines) in acetonitrile and in methanol solution at 298 K and in solid matrix at 77 K have been recorded and compared with those of the corresponding b-carbolines and chloroharmine derivatives. The electronic absorption spectra of triplet transients of these b-carbolines, the triplet lifetime, tT, and the intersystem crossing quantum yield, fisc, were measured by Laser Flash Photolysis at 298 K. The dynamic properties of the lowest excited singlet and triplet states (tf, tp, ff and fp) have been measured in the same experimental conditions. From these data, the radiative and radiationless rate constants (kof , kisc and kic) were derived. The intramolecular spin – orbital coupling effect on the spectroscopic data and photophysical rate constant were also analyzed.   Keywords: b-Carbolines; Nitro-b-carbolines; Spectroscopic and photophysics.