Outer-sphere electron transfer from carbazoles to halomethanes. Reduction potentials of halomethanes measured by fluorescence quenching experiments.

Kinetic studies on the photoinduced electron transfer reduction of a variety of halomethanes in acetonitrile and ethanol at 298 K are reported in terms of the quenching rate constants (kq) with a series of reductants (carbazoles and anthracenes) whose one-electron oxidation potentials (Eox) have bee...

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Autores principales: Bonesi, S.M., Erra-Balsells, R.
Formato: JOUR
Materias:
Charge transfer
Dissociation
Electron transport properties
Enthalpy
Fluorescence
Gibbs free energy
Irradiation
Mathematical models
Molecular dynamics
Quenching
Rate constants
Reduction
Carbazoles
Electron transfer
Halomethanes
Solvent reorganization energy
Organic compounds
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_03009580_v_n7_p1583_Bonesi
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_03009580_v_n7_p1583_Bonesi2023-10-03T15:18:07Z Outer-sphere electron transfer from carbazoles to halomethanes. Reduction potentials of halomethanes measured by fluorescence quenching experiments. Bonesi, S.M. Erra-Balsells, R. Charge transfer Dissociation Electron transport properties Enthalpy Fluorescence Gibbs free energy Irradiation Mathematical models Molecular dynamics Quenching Rate constants Reduction Carbazoles Electron transfer Halomethanes Solvent reorganization energy Organic compounds Kinetic studies on the photoinduced electron transfer reduction of a variety of halomethanes in acetonitrile and ethanol at 298 K are reported in terms of the quenching rate constants (kq) with a series of reductants (carbazoles and anthracenes) whose one-electron oxidation potentials (Eox) have been measured again in the present work vs. SCE and independently vs. ferrocene. The Rehm-Weller Gibbs energy relationship is applied to determine the fundamental parameters for the one-electron reduction, i.e., the one-electron reduction potentials (ERX/RẊ) of the halomethanes and the intrinsic barrier for the electron transfer reduction (ΔG‡o). The ERX/RX-̇ values obtained were related to the concerted electron transfer-bond breaking reduction potentials (ERX/R·+x-) and the standard free enthalpies of dissociation of RX-̇ (ΔGo,dissRX-̇) were estimated in each solvent. Additionally, the one-electron reduction potential (ERX/RX-̇) values estimated in acetonitrile were also related to different thermodynamic parameters such as electron affinity (EA), LUMO-HOMO energy differences (ΔE) and the bond dissociation energy (DRX). Optimized geometry, EA and ΔE for halomethanes were calculated by an ab initio method at the B3LYP level using 3-21G, 6-31 + G(d,p) and G-311 + G(3df,2pd) basis sets. In all these cases good linear correlations were obtained. The ΔG‡o values obtained are compared with those calculated using the equation ΔG‡o = λ/4 with λ = λi + λo where the solvent reorganization energy (λo) and the inner-sphere reorganization energies (λi) associated with the structural change upon the electron-transfer process were calculated, the former by using the Marcus-Hush model and the latter by using semiempirical and ab initio molecular modeling and QSAR properties. Results obtained from the preparative irradiation of carbazoles in the presence of halomethanes, which are consistent with a photoinduced electron transfer mechanism are also discussed. Fil:Bonesi, S.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Erra-Balsells, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_03009580_v_n7_p1583_Bonesi
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Charge transfer
Dissociation
Electron transport properties
Enthalpy
Fluorescence
Gibbs free energy
Irradiation
Mathematical models
Molecular dynamics
Quenching
Rate constants
Reduction
Carbazoles
Electron transfer
Halomethanes
Solvent reorganization energy
Organic compounds
spellingShingle Charge transfer
Dissociation
Electron transport properties
Enthalpy
Fluorescence
Gibbs free energy
Irradiation
Mathematical models
Molecular dynamics
Quenching
Rate constants
Reduction
Carbazoles
Electron transfer
Halomethanes
Solvent reorganization energy
Organic compounds
Bonesi, S.M.
Erra-Balsells, R.
Outer-sphere electron transfer from carbazoles to halomethanes. Reduction potentials of halomethanes measured by fluorescence quenching experiments.
topic_facet Charge transfer
Dissociation
Electron transport properties
Enthalpy
Fluorescence
Gibbs free energy
Irradiation
Mathematical models
Molecular dynamics
Quenching
Rate constants
Reduction
Carbazoles
Electron transfer
Halomethanes
Solvent reorganization energy
Organic compounds
description Kinetic studies on the photoinduced electron transfer reduction of a variety of halomethanes in acetonitrile and ethanol at 298 K are reported in terms of the quenching rate constants (kq) with a series of reductants (carbazoles and anthracenes) whose one-electron oxidation potentials (Eox) have been measured again in the present work vs. SCE and independently vs. ferrocene. The Rehm-Weller Gibbs energy relationship is applied to determine the fundamental parameters for the one-electron reduction, i.e., the one-electron reduction potentials (ERX/RẊ) of the halomethanes and the intrinsic barrier for the electron transfer reduction (ΔG‡o). The ERX/RX-̇ values obtained were related to the concerted electron transfer-bond breaking reduction potentials (ERX/R·+x-) and the standard free enthalpies of dissociation of RX-̇ (ΔGo,dissRX-̇) were estimated in each solvent. Additionally, the one-electron reduction potential (ERX/RX-̇) values estimated in acetonitrile were also related to different thermodynamic parameters such as electron affinity (EA), LUMO-HOMO energy differences (ΔE) and the bond dissociation energy (DRX). Optimized geometry, EA and ΔE for halomethanes were calculated by an ab initio method at the B3LYP level using 3-21G, 6-31 + G(d,p) and G-311 + G(3df,2pd) basis sets. In all these cases good linear correlations were obtained. The ΔG‡o values obtained are compared with those calculated using the equation ΔG‡o = λ/4 with λ = λi + λo where the solvent reorganization energy (λo) and the inner-sphere reorganization energies (λi) associated with the structural change upon the electron-transfer process were calculated, the former by using the Marcus-Hush model and the latter by using semiempirical and ab initio molecular modeling and QSAR properties. Results obtained from the preparative irradiation of carbazoles in the presence of halomethanes, which are consistent with a photoinduced electron transfer mechanism are also discussed.
format JOUR
author Bonesi, S.M.
Erra-Balsells, R.
author_facet Bonesi, S.M.
Erra-Balsells, R.
author_sort Bonesi, S.M.
title Outer-sphere electron transfer from carbazoles to halomethanes. Reduction potentials of halomethanes measured by fluorescence quenching experiments.
title_short Outer-sphere electron transfer from carbazoles to halomethanes. Reduction potentials of halomethanes measured by fluorescence quenching experiments.
title_full Outer-sphere electron transfer from carbazoles to halomethanes. Reduction potentials of halomethanes measured by fluorescence quenching experiments.
title_fullStr Outer-sphere electron transfer from carbazoles to halomethanes. Reduction potentials of halomethanes measured by fluorescence quenching experiments.
title_full_unstemmed Outer-sphere electron transfer from carbazoles to halomethanes. Reduction potentials of halomethanes measured by fluorescence quenching experiments.
title_sort outer-sphere electron transfer from carbazoles to halomethanes. reduction potentials of halomethanes measured by fluorescence quenching experiments.
url http://hdl.handle.net/20.500.12110/paper_03009580_v_n7_p1583_Bonesi
work_keys_str_mv AT bonesism outersphereelectrontransferfromcarbazolestohalomethanesreductionpotentialsofhalomethanesmeasuredbyfluorescencequenchingexperiments
AT errabalsellsr outersphereelectrontransferfromcarbazolestohalomethanesreductionpotentialsofhalomethanesmeasuredbyfluorescencequenchingexperiments
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