Unusual solvent effects in the reactions of 1-halo-2,4-dinitrobenzenes andaniline in aprotic and dipolar-aprotic solvents. Effects of aggregates

The kinetics of reactions between 1-halogeno-2,4-dinitrobenzene (halogen = F, Cl) and aniline were studied in toluene, acetone, dimethylsulfoxide and in toluene-acetone mixtures. Unexpectedly, when chlorine is the nucleofugue, the second rate coefficients, kA, in toluene shows a parabolic dependence...

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Autores principales:	Alvaro, C.E.S., Nudelman, N.S.
Formato:	JOUR
Materias:	Aprotic solvents Aromatic nucleophilic substitutions Dimer nucleophile mechanism Mixed aggregates 1 chloro 2,4 dinitrobenzene 1 fluoro 2,4 dinitrobenzene acetone amine aniline chlorine dimer dimethyl sulfoxide fluorine toluene addition reaction article chemical reaction concentration (parameters) dimerization kinetics solvent effect substitution reaction
Acceso en línea:	http://hdl.handle.net/20.500.12110/paper_14246376_v2003_n10_p95_Alvaro
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	todo:paper_14246376_v2003_n10_p95_Alvaro
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spelling	todo:paper_14246376_v2003_n10_p95_Alvaro2023-10-03T16:13:39Z Unusual solvent effects in the reactions of 1-halo-2,4-dinitrobenzenes andaniline in aprotic and dipolar-aprotic solvents. Effects of aggregates Alvaro, C.E.S. Nudelman, N.S. Aprotic solvents Aromatic nucleophilic substitutions Dimer nucleophile mechanism Mixed aggregates 1 chloro 2,4 dinitrobenzene 1 fluoro 2,4 dinitrobenzene acetone amine aniline chlorine dimer dimethyl sulfoxide fluorine toluene addition reaction article chemical reaction concentration (parameters) dimerization kinetics solvent effect substitution reaction The kinetics of reactions between 1-halogeno-2,4-dinitrobenzene (halogen = F, Cl) and aniline were studied in toluene, acetone, dimethylsulfoxide and in toluene-acetone mixtures. Unexpectedly, when chlorine is the nucleofugue, the second rate coefficients, kA, in toluene shows a parabolic dependence on the amine concentration which indicates a third order in amine kinetic law, while in the dipolar aprotic solvent the dependence is linear. Small additions of acetone to the solvent produce an important increase in rate, much greater then the increase in the permittivity, which is surprising on the basis of the classical effect of a dipolar medium on a dipolar transition state. The reactions with fluorine as the nucleofugue show similar behaviours. All these results are well explained in the frame of the "dimer nucleophile" mechanism. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_14246376_v2003_n10_p95_Alvaro
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Aprotic solvents Aromatic nucleophilic substitutions Dimer nucleophile mechanism Mixed aggregates 1 chloro 2,4 dinitrobenzene 1 fluoro 2,4 dinitrobenzene acetone amine aniline chlorine dimer dimethyl sulfoxide fluorine toluene addition reaction article chemical reaction concentration (parameters) dimerization kinetics solvent effect substitution reaction
spellingShingle	Aprotic solvents Aromatic nucleophilic substitutions Dimer nucleophile mechanism Mixed aggregates 1 chloro 2,4 dinitrobenzene 1 fluoro 2,4 dinitrobenzene acetone amine aniline chlorine dimer dimethyl sulfoxide fluorine toluene addition reaction article chemical reaction concentration (parameters) dimerization kinetics solvent effect substitution reaction Alvaro, C.E.S. Nudelman, N.S. Unusual solvent effects in the reactions of 1-halo-2,4-dinitrobenzenes andaniline in aprotic and dipolar-aprotic solvents. Effects of aggregates
topic_facet	Aprotic solvents Aromatic nucleophilic substitutions Dimer nucleophile mechanism Mixed aggregates 1 chloro 2,4 dinitrobenzene 1 fluoro 2,4 dinitrobenzene acetone amine aniline chlorine dimer dimethyl sulfoxide fluorine toluene addition reaction article chemical reaction concentration (parameters) dimerization kinetics solvent effect substitution reaction
description	The kinetics of reactions between 1-halogeno-2,4-dinitrobenzene (halogen = F, Cl) and aniline were studied in toluene, acetone, dimethylsulfoxide and in toluene-acetone mixtures. Unexpectedly, when chlorine is the nucleofugue, the second rate coefficients, kA, in toluene shows a parabolic dependence on the amine concentration which indicates a third order in amine kinetic law, while in the dipolar aprotic solvent the dependence is linear. Small additions of acetone to the solvent produce an important increase in rate, much greater then the increase in the permittivity, which is surprising on the basis of the classical effect of a dipolar medium on a dipolar transition state. The reactions with fluorine as the nucleofugue show similar behaviours. All these results are well explained in the frame of the "dimer nucleophile" mechanism.
format	JOUR
author	Alvaro, C.E.S. Nudelman, N.S.
author_facet	Alvaro, C.E.S. Nudelman, N.S.
author_sort	Alvaro, C.E.S.
title	Unusual solvent effects in the reactions of 1-halo-2,4-dinitrobenzenes andaniline in aprotic and dipolar-aprotic solvents. Effects of aggregates
title_short	Unusual solvent effects in the reactions of 1-halo-2,4-dinitrobenzenes andaniline in aprotic and dipolar-aprotic solvents. Effects of aggregates
title_full	Unusual solvent effects in the reactions of 1-halo-2,4-dinitrobenzenes andaniline in aprotic and dipolar-aprotic solvents. Effects of aggregates
title_fullStr	Unusual solvent effects in the reactions of 1-halo-2,4-dinitrobenzenes andaniline in aprotic and dipolar-aprotic solvents. Effects of aggregates
title_full_unstemmed	Unusual solvent effects in the reactions of 1-halo-2,4-dinitrobenzenes andaniline in aprotic and dipolar-aprotic solvents. Effects of aggregates
title_sort	unusual solvent effects in the reactions of 1-halo-2,4-dinitrobenzenes andaniline in aprotic and dipolar-aprotic solvents. effects of aggregates
url	http://hdl.handle.net/20.500.12110/paper_14246376_v2003_n10_p95_Alvaro
work_keys_str_mv	AT alvaroces unusualsolventeffectsinthereactionsof1halo24dinitrobenzenesandanilineinaproticanddipolaraproticsolventseffectsofaggregates AT nudelmanns unusualsolventeffectsinthereactionsof1halo24dinitrobenzenesandanilineinaproticanddipolaraproticsolventseffectsofaggregates
_version_	1807321178780467200

Unusual solvent effects in the reactions of 1-halo-2,4-dinitrobenzenes andaniline in aprotic and dipolar-aprotic solvents. Effects of aggregates

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