Fotoquímica de ß-Carbolinas en soluciones orgánicas diluidas

In this work the photochemical behavior of full aromatic b-carbolines (nor-harmane, harmane, harmine and harmol) and two 3,4-dihydro b-carbolines (harmaline and harmalol) was studied. For the first time the UV absorption, emission and excitation spectra in organic solutions were described as well as...

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Detalles Bibliográficos
Autor principal: Biondic, Miriana Carla
Otros Autores: Erra Balsells, Rosa
Formato: Tesis doctoral publishedVersion
Lenguaje:Español
Publicado: Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales 1996
Materias:
SS-CARBOLINAS
FOTOQUIMICA DE SS-CARBOLINAS
SS-CARBOLINAS-TETRACLORURO DE CARBONO
EQUILIBRIO ACIDO-BASE DE SS-CARBOLINAS
ESPECTROS ELECTRONICOS DE SS-CARBOLINAS
SS-CARBOLINES
SS-CARBOLINES-PHOTOCHEMISTRY
SS-CARBOLINES-CARBON-TETRACHLORIDE
SS-CARBOLINES-ACID-BASE EQUILIBRIUM
SS-CARBOLINES-ELECTRONIC SPECTRA
Acceso en línea:https://hdl.handle.net/20.500.12110/tesis_n2831_Biondic
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id tesis:tesis_n2831_Biondic
record_format dspace
spelling tesis:tesis_n2831_Biondic2025-03-31T21:11:30Z Fotoquímica de ß-Carbolinas en soluciones orgánicas diluidas Photochemistry of ß-carbolines in diluted organic solutions Biondic, Miriana Carla Erra Balsells, Rosa SS-CARBOLINAS FOTOQUIMICA DE SS-CARBOLINAS SS-CARBOLINAS-TETRACLORURO DE CARBONO EQUILIBRIO ACIDO-BASE DE SS-CARBOLINAS ESPECTROS ELECTRONICOS DE SS-CARBOLINAS SS-CARBOLINES SS-CARBOLINES-PHOTOCHEMISTRY SS-CARBOLINES-CARBON-TETRACHLORIDE SS-CARBOLINES-ACID-BASE EQUILIBRIUM SS-CARBOLINES-ELECTRONIC SPECTRA In this work the photochemical behavior of full aromatic b-carbolines (nor-harmane, harmane, harmine and harmol) and two 3,4-dihydro b-carbolines (harmaline and harmalol) was studied. For the first time the UV absorption, emission and excitation spectra in organic solutions were described as well as on solid supports (silica gel, paper) and on powdered sample. The K of the complexation equilibrium between the full aromatic b-carbolines with alcohols forming a 1:2 adducts were measured and the pKa and pKa* in acetonitrile were determined by means of electronic absorption and fluorescence spectroscopy. Considering that these compounds are markedly fluorescent their behavior in the presence of CCl4 and other halomethanes (CH2Cl2, CHCl3, CH2BrCH2Br, CHBr3 and CBr4) which act as quenchers using either EtOH, iso-PrOH or MeCN as solvents was studied. We concluded that this quenching is dynamic and may take place through the formation of an exciplex followed by an electron transfer from the excited b-carboline to the halogenated compound starting the photochemical reaction. When a solution of either of these alkaloids (10-3 M) was irradiated in the presence of CCl4 in a protic organic solvent, the main product obtained, with more than 98% yield, was the hydrochloride. Besides, the gc-MS analysis showed traces of carboalcoxy and chloro-derivatives.%The feasibility of an exciton or a photon single electron transfer mechanism is discussed and parameters such as DGote, Ksv, kq, DG‡, DG‡(0), l, and E0ox were calculated using the Rehm-Weller, Marcus and Stern-Volmer models.%The quantum yield of photobleaching in different solvents was determined relative to the disappearance of harmane in EtOH-CCl4, which in turn was determined using potassium ferrioxalate as actinometer. Fil: Biondic, Miriana Carla. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales 1996 info:eu-repo/semantics/doctoralThesis info:ar-repo/semantics/tesis doctoral info:eu-repo/semantics/publishedVersion application/pdf spa info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-sa/2.5/ar https://hdl.handle.net/20.500.12110/tesis_n2831_Biondic
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
language Español
orig_language_str_mv spa
topic SS-CARBOLINAS
FOTOQUIMICA DE SS-CARBOLINAS
SS-CARBOLINAS-TETRACLORURO DE CARBONO
EQUILIBRIO ACIDO-BASE DE SS-CARBOLINAS
ESPECTROS ELECTRONICOS DE SS-CARBOLINAS
SS-CARBOLINES
SS-CARBOLINES-PHOTOCHEMISTRY
SS-CARBOLINES-CARBON-TETRACHLORIDE
SS-CARBOLINES-ACID-BASE EQUILIBRIUM
SS-CARBOLINES-ELECTRONIC SPECTRA
spellingShingle SS-CARBOLINAS
FOTOQUIMICA DE SS-CARBOLINAS
SS-CARBOLINAS-TETRACLORURO DE CARBONO
EQUILIBRIO ACIDO-BASE DE SS-CARBOLINAS
ESPECTROS ELECTRONICOS DE SS-CARBOLINAS
SS-CARBOLINES
SS-CARBOLINES-PHOTOCHEMISTRY
SS-CARBOLINES-CARBON-TETRACHLORIDE
SS-CARBOLINES-ACID-BASE EQUILIBRIUM
SS-CARBOLINES-ELECTRONIC SPECTRA
Biondic, Miriana Carla
Fotoquímica de ß-Carbolinas en soluciones orgánicas diluidas
topic_facet SS-CARBOLINAS
FOTOQUIMICA DE SS-CARBOLINAS
SS-CARBOLINAS-TETRACLORURO DE CARBONO
EQUILIBRIO ACIDO-BASE DE SS-CARBOLINAS
ESPECTROS ELECTRONICOS DE SS-CARBOLINAS
SS-CARBOLINES
SS-CARBOLINES-PHOTOCHEMISTRY
SS-CARBOLINES-CARBON-TETRACHLORIDE
SS-CARBOLINES-ACID-BASE EQUILIBRIUM
SS-CARBOLINES-ELECTRONIC SPECTRA
description In this work the photochemical behavior of full aromatic b-carbolines (nor-harmane, harmane, harmine and harmol) and two 3,4-dihydro b-carbolines (harmaline and harmalol) was studied. For the first time the UV absorption, emission and excitation spectra in organic solutions were described as well as on solid supports (silica gel, paper) and on powdered sample. The K of the complexation equilibrium between the full aromatic b-carbolines with alcohols forming a 1:2 adducts were measured and the pKa and pKa* in acetonitrile were determined by means of electronic absorption and fluorescence spectroscopy. Considering that these compounds are markedly fluorescent their behavior in the presence of CCl4 and other halomethanes (CH2Cl2, CHCl3, CH2BrCH2Br, CHBr3 and CBr4) which act as quenchers using either EtOH, iso-PrOH or MeCN as solvents was studied. We concluded that this quenching is dynamic and may take place through the formation of an exciplex followed by an electron transfer from the excited b-carboline to the halogenated compound starting the photochemical reaction. When a solution of either of these alkaloids (10-3 M) was irradiated in the presence of CCl4 in a protic organic solvent, the main product obtained, with more than 98% yield, was the hydrochloride. Besides, the gc-MS analysis showed traces of carboalcoxy and chloro-derivatives.%The feasibility of an exciton or a photon single electron transfer mechanism is discussed and parameters such as DGote, Ksv, kq, DG‡, DG‡(0), l, and E0ox were calculated using the Rehm-Weller, Marcus and Stern-Volmer models.%The quantum yield of photobleaching in different solvents was determined relative to the disappearance of harmane in EtOH-CCl4, which in turn was determined using potassium ferrioxalate as actinometer.
author2 Erra Balsells, Rosa
author_facet Erra Balsells, Rosa
Biondic, Miriana Carla
format Tesis doctoral
Tesis doctoral
publishedVersion
author Biondic, Miriana Carla
author_sort Biondic, Miriana Carla
title Fotoquímica de ß-Carbolinas en soluciones orgánicas diluidas
title_short Fotoquímica de ß-Carbolinas en soluciones orgánicas diluidas
title_full Fotoquímica de ß-Carbolinas en soluciones orgánicas diluidas
title_fullStr Fotoquímica de ß-Carbolinas en soluciones orgánicas diluidas
title_full_unstemmed Fotoquímica de ß-Carbolinas en soluciones orgánicas diluidas
title_sort fotoquímica de ß-carbolinas en soluciones orgánicas diluidas
publisher Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales
publishDate 1996
url https://hdl.handle.net/20.500.12110/tesis_n2831_Biondic
work_keys_str_mv AT biondicmirianacarla fotoquimicadeßcarbolinasensolucionesorganicasdiluidas
AT biondicmirianacarla photochemistryofßcarbolinesindilutedorganicsolutions
_version_ 1831982179731636224

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