INVESTIGADORES
BONESI Sergio Mauricio
artículos
Título:
Synthesis and Electronic Spectroscopy of Bromo Carbazoles. Direct Bromination of N- and C-Substituted Carbazoles by N-Bromosuccinimide and N-Bromosuccinimide Silica Gel System
Autor/es:
PONCE MARÍA B., CABRERIZO FRANCO M., BONESI SERGIO M. ERRA BALSELLS ROSA.
Revista:
HELVETICA CHIMICA ACTA
Editorial:
Verlag Helvetica Chimica Acta
Referencias:
Lugar: Zurich; Año: 2006 vol. 89 p. 1123 - 1139
ISSN:
0018-019X
Resumen:
The preparation, isolation and characterization by elemental analysis and 1H-NMR, 13C-NMR, and
MS data of the bromo derivatives of N-substituted carbazoles, i.e., of 9-methyl-9H-carbazole (1), 9-phenyl-
9H-carbazole (2), 9-benzyl-9H-carbazole (3), 2-methoxy-9-methyl-9H-carbazole (4), and of C-substituted
carbazoles, i.e., of 2-(acetyloxy)-9H-carbazole (5) and 3-nitro-9H-carbazole (6), are reported, in
part for the first time. As brominating reagents, N-bromosuccinimide (NBS) or NBS/silica gel in
CH2Cl2, NBS in AcOH, KBrO3/KBr in EtOH doped with a catalytic amount of H2SO4, or KBrO3/KBr
in AcOH were employed, and their uses were compared. Semi-empirical PM3 calculations were performed
to predict the reactivity of the N-substituted and C-substituted carbazoles and of their bromo
derivatives and found to verify the experimental results. The UV-absorption and fluorescence and phosphorescence
emission spectra of the bromocarbazole derivatives in MeCN solution at 298 K and in a solid
matrix at 77 K were compared with those of the corresponding carbazoles 16. The dynamic properties
of the lowest excited singlet and triplet states (tf, tp, ff, and fp) were measured under the same experimental
conditions. The intramolecular spinorbital-coupling effect of the Br-atom and NO2 group on the
spectroscopic data, photophysical parameters, and on the photo reactivity were also briefly analyzed.1H-NMR, 13C-NMR, and
MS data of the bromo derivatives of N-substituted carbazoles, i.e., of 9-methyl-9H-carbazole (1), 9-phenyl-
9H-carbazole (2), 9-benzyl-9H-carbazole (3), 2-methoxy-9-methyl-9H-carbazole (4), and of C-substituted
carbazoles, i.e., of 2-(acetyloxy)-9H-carbazole (5) and 3-nitro-9H-carbazole (6), are reported, in
part for the first time. As brominating reagents, N-bromosuccinimide (NBS) or NBS/silica gel in
CH2Cl2, NBS in AcOH, KBrO3/KBr in EtOH doped with a catalytic amount of H2SO4, or KBrO3/KBr
in AcOH were employed, and their uses were compared. Semi-empirical PM3 calculations were performed
to predict the reactivity of the N-substituted and C-substituted carbazoles and of their bromo
derivatives and found to verify the experimental results. The UV-absorption and fluorescence and phosphorescence
emission spectra of the bromocarbazole derivatives in MeCN solution at 298 K and in a solid
matrix at 77 K were compared with those of the corresponding carbazoles 16. The dynamic properties
of the lowest excited singlet and triplet states (tf, tp, ff, and fp) were measured under the same experimental
conditions. The intramolecular spinorbital-coupling effect of the Br-atom and NO2 group on the
spectroscopic data, photophysical parameters, and on the photo reactivity were also briefly analyzed.N-substituted carbazoles, i.e., of 9-methyl-9H-carbazole (1), 9-phenyl-
9H-carbazole (2), 9-benzyl-9H-carbazole (3), 2-methoxy-9-methyl-9H-carbazole (4), and of C-substituted
carbazoles, i.e., of 2-(acetyloxy)-9H-carbazole (5) and 3-nitro-9H-carbazole (6), are reported, in
part for the first time. As brominating reagents, N-bromosuccinimide (NBS) or NBS/silica gel in
CH2Cl2, NBS in AcOH, KBrO3/KBr in EtOH doped with a catalytic amount of H2SO4, or KBrO3/KBr
in AcOH were employed, and their uses were compared. Semi-empirical PM3 calculations were performed
to predict the reactivity of the N-substituted and C-substituted carbazoles and of their bromo
derivatives and found to verify the experimental results. The UV-absorption and fluorescence and phosphorescence
emission spectra of the bromocarbazole derivatives in MeCN solution at 298 K and in a solid
matrix at 77 K were compared with those of the corresponding carbazoles 16. The dynamic properties
of the lowest excited singlet and triplet states (tf, tp, ff, and fp) were measured under the same experimental
conditions. The intramolecular spinorbital-coupling effect of the Br-atom and NO2 group on the
spectroscopic data, photophysical parameters, and on the photo reactivity were also briefly analyzed.H-carbazole (2), 9-benzyl-9H-carbazole (3), 2-methoxy-9-methyl-9H-carbazole (4), and of C-substituted
carbazoles, i.e., of 2-(acetyloxy)-9H-carbazole (5) and 3-nitro-9H-carbazole (6), are reported, in
part for the first time. As brominating reagents, N-bromosuccinimide (NBS) or NBS/silica gel in
CH2Cl2, NBS in AcOH, KBrO3/KBr in EtOH doped with a catalytic amount of H2SO4, or KBrO3/KBr
in AcOH were employed, and their uses were compared. Semi-empirical PM3 calculations were performed
to predict the reactivity of the N-substituted and C-substituted carbazoles and of their bromo
derivatives and found to verify the experimental results. The UV-absorption and fluorescence and phosphorescence
emission spectra of the bromocarbazole derivatives in MeCN solution at 298 K and in a solid
matrix at 77 K were compared with those of the corresponding carbazoles 16. The dynamic properties
of the lowest excited singlet and triplet states (tf, tp, ff, and fp) were measured under the same experimental
conditions. The intramolecular spinorbital-coupling effect of the Br-atom and NO2 group on the
spectroscopic data, photophysical parameters, and on the photo reactivity were also briefly analyzed.i.e., of 2-(acetyloxy)-9H-carbazole (5) and 3-nitro-9H-carbazole (6), are reported, in
part for the first time. As brominating reagents, N-bromosuccinimide (NBS) or NBS/silica gel in
CH2Cl2, NBS in AcOH, KBrO3/KBr in EtOH doped with a catalytic amount of H2SO4, or KBrO3/KBr
in AcOH were employed, and their uses were compared. Semi-empirical PM3 calculations were performed
to predict the reactivity of the N-substituted and C-substituted carbazoles and of their bromo
derivatives and found to verify the experimental results. The UV-absorption and fluorescence and phosphorescence
emission spectra of the bromocarbazole derivatives in MeCN solution at 298 K and in a solid
matrix at 77 K were compared with those of the corresponding carbazoles 16. The dynamic properties
of the lowest excited singlet and triplet states (tf, tp, ff, and fp) were measured under the same experimental
conditions. The intramolecular spinorbital-coupling effect of the Br-atom and NO2 group on the
spectroscopic data, photophysical parameters, and on the photo reactivity were also briefly analyzed.N-bromosuccinimide (NBS) or NBS/silica gel in
CH2Cl2, NBS in AcOH, KBrO3/KBr in EtOH doped with a catalytic amount of H2SO4, or KBrO3/KBr
in AcOH were employed, and their uses were compared. Semi-empirical PM3 calculations were performed
to predict the reactivity of the N-substituted and C-substituted carbazoles and of their bromo
derivatives and found to verify the experimental results. The UV-absorption and fluorescence and phosphorescence
emission spectra of the bromocarbazole derivatives in MeCN solution at 298 K and in a solid
matrix at 77 K were compared with those of the corresponding carbazoles 16. The dynamic properties
of the lowest excited singlet and triplet states (tf, tp, ff, and fp) were measured under the same experimental
conditions. The intramolecular spinorbital-coupling effect of the Br-atom and NO2 group on the
spectroscopic data, photophysical parameters, and on the photo reactivity were also briefly analyzed.2Cl2, NBS in AcOH, KBrO3/KBr in EtOH doped with a catalytic amount of H2SO4, or KBrO3/KBr
in AcOH were employed, and their uses were compared. Semi-empirical PM3 calculations were performed
to predict the reactivity of the N-substituted and C-substituted carbazoles and of their bromo
derivatives and found to verify the experimental results. The UV-absorption and fluorescence and phosphorescence
emission spectra of the bromocarbazole derivatives in MeCN solution at 298 K and in a solid
matrix at 77 K were compared with those of the corresponding carbazoles 16. The dynamic properties
of the lowest excited singlet and triplet states (tf, tp, ff, and fp) were measured under the same experimental
conditions. The intramolecular spinorbital-coupling effect of the Br-atom and NO2 group on the
spectroscopic data, photophysical parameters, and on the photo reactivity were also briefly analyzed.N-substituted and C-substituted carbazoles and of their bromo
derivatives and found to verify the experimental results. The UV-absorption and fluorescence and phosphorescence
emission spectra of the bromocarbazole derivatives in MeCN solution at 298 K and in a solid
matrix at 77 K were compared with those of the corresponding carbazoles 16. The dynamic properties
of the lowest excited singlet and triplet states (tf, tp, ff, and fp) were measured under the same experimental
conditions. The intramolecular spinorbital-coupling effect of the Br-atom and NO2 group on the
spectroscopic data, photophysical parameters, and on the photo reactivity were also briefly analyzed.16. The dynamic properties
of the lowest excited singlet and triplet states (tf, tp, ff, and fp) were measured under the same experimental
conditions. The intramolecular spinorbital-coupling effect of the Br-atom and NO2 group on the
spectroscopic data, photophysical parameters, and on the photo reactivity were also briefly analyzed.tf, tp, ff, and fp) were measured under the same experimental
conditions. The intramolecular spinorbital-coupling effect of the Br-atom and NO2 group on the
spectroscopic data, photophysical parameters, and on the photo reactivity were also briefly analyzed.2 group on the
spectroscopic data, photophysical parameters, and on the photo reactivity were also briefly analyzed.