Complexos de vanádio contendo bases de Schiff como catalisadores na oxidação do cicloexano
Autor(a) principal: | |
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Data de Publicação: | 2014 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFSCAR |
Texto Completo: | https://repositorio.ufscar.br/handle/ufscar/6311 |
Resumo: | The vanadium complexes of the type [VO(acac)2], [VO(acac)(apftsc)], [VO(acac)(apmtsc)], [VO(acac)(aptsc)], [VO(acac)(apf)], vanadium (IV) and [VO2(apftsc)], [VO2(apmtsc)], [VO2(aptsc)] e [VO2(apf)], vanadium (V), were used as catalysts for cyclohexane oxidation using 30% hydrogen peroxide (H2O2) as oxidizing agent in acetonitrile at 40ºC. The cyclohexanol (OL) and cyclohexanone (ONA) were quantified by means of gas chromatography by the internal padronization method. Variation in the molar ratio of oxidizing, substrate and nitric acid with catalyst, as well as the effect of the addition of triphenylphosphine in catalytic properties were studied for all complexes. For the complex [VO(acac)(apftsc)], yielded the kinetic parameters with rate constant (k = 3,87 x 10-1 L.mol-1.min-1), reaction order relative to catalysts (nCat = 0,8) and to substrate (nS = 0,6); the thermodynamic parameters of activation Eap = 11 kcal.mol-1, ΔG# = + 0.6 kcal.mol-1, ΔH# = + 10.2 kcal.mol-1, ΔS# = + 30.8 cal.mol-1.K-1. The EPR spectrum data using 5,5-dimethyl-1-pyrroline Noxide (DMPO) as spin trap confirm that the mechanism the formation of radicals. The radicals ( acac) and hydroxyl ( OH) from the acetylacetonate e and hydrogen peroxide, respectively, was identified by forming the respective adduct, DMPO-Acac and DMPO-OH. From the mass spectrometry data it was possible to suggest a synthetic route for the formation of the oxo(peroxo)vanadate complex, an important intermediate in the catalytic cycle. It has been proposed also a mechanism for cyclohexane oxidation. |
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Cantanhede, Leonardo BaltazarMarques, Clélia Mara de Paulahttp://genos.cnpq.br:12010/dwlattes/owa/prc_imp_cv_int?f_cod=K4796205D7http://lattes.cnpq.br/0740032606397506bb80aff3-f142-47b5-8fdf-04fd996aaeb62016-06-02T20:34:54Z2014-09-182016-06-02T20:34:54Z2014-03-27CANTANHEDE, Leonardo Baltazar. Vanadium complexes as catalysts for the oxidation of cyclohexane. 2014. 160 f. Tese (Doutorado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2014.https://repositorio.ufscar.br/handle/ufscar/6311The vanadium complexes of the type [VO(acac)2], [VO(acac)(apftsc)], [VO(acac)(apmtsc)], [VO(acac)(aptsc)], [VO(acac)(apf)], vanadium (IV) and [VO2(apftsc)], [VO2(apmtsc)], [VO2(aptsc)] e [VO2(apf)], vanadium (V), were used as catalysts for cyclohexane oxidation using 30% hydrogen peroxide (H2O2) as oxidizing agent in acetonitrile at 40ºC. The cyclohexanol (OL) and cyclohexanone (ONA) were quantified by means of gas chromatography by the internal padronization method. Variation in the molar ratio of oxidizing, substrate and nitric acid with catalyst, as well as the effect of the addition of triphenylphosphine in catalytic properties were studied for all complexes. For the complex [VO(acac)(apftsc)], yielded the kinetic parameters with rate constant (k = 3,87 x 10-1 L.mol-1.min-1), reaction order relative to catalysts (nCat = 0,8) and to substrate (nS = 0,6); the thermodynamic parameters of activation Eap = 11 kcal.mol-1, ΔG# = + 0.6 kcal.mol-1, ΔH# = + 10.2 kcal.mol-1, ΔS# = + 30.8 cal.mol-1.K-1. The EPR spectrum data using 5,5-dimethyl-1-pyrroline Noxide (DMPO) as spin trap confirm that the mechanism the formation of radicals. The radicals ( acac) and hydroxyl ( OH) from the acetylacetonate e and hydrogen peroxide, respectively, was identified by forming the respective adduct, DMPO-Acac and DMPO-OH. From the mass spectrometry data it was possible to suggest a synthetic route for the formation of the oxo(peroxo)vanadate complex, an important intermediate in the catalytic cycle. It has been proposed also a mechanism for cyclohexane oxidation.Os complexos de vanádio do tipo [VO(acac)2], [VO(acac)(apftsc)], [VO(acac)(apmtsc)], [VO(acac)(aptsc)], [VO(acac)(apf)] de vanádio (IV) e [VO2(apftsc)], [VO2(apmtsc)], [VO2(aptsc)] e [VO2(apf)] de vanádio (V), foram utilizados como catalisadores para a oxidação do cicloexano, utilizando o peróxido de hidrogênio (H2O2) a 30% como oxidante, em acetonitrila a 40ºC. O cicloexanol (OL) e a cicloexanona (ONA), foram quantificados por Cromatografia a Gás, por padronização interna. Variações nas razões molares entre oxidante, substrato e ácido nítrico com o catalisador, bem como o efeito da adição de trifenilfosfina nas propriedades catalíticas foram estudadas para todos os complexos. Para o complexo [VO(acac)(apftsc)], obteve-se os parâmetros cinéticos de constante de velocidade (k = 3,87 x 10-1 L.mol-1.min-1), ordem de reação em relação ao catalisador (nCat = 0,8 ) e ao substrato (nS = 0,6 ); os parâmetros termodinâmicos de ativação de Eap = 11 kcal.mol-1, ΔG# = + 0,6 kcal.mol-1, ΔH# = + 10,2 kcal.mol-1. ΔS# = + 30,8 cal.mol-1.K-1. Os espectros de EPR, utilizando 5,5 dimetil-1-pirrolina-N-óxido (DMPO) como spin trap confirmam um mecanismo radicalar. Os radicais ( acac) e ( OH) provenientes do acetilacetonato e H2O2, respectivamente, foram identificados através da formação dos respectivos adutos DMPO-Acac e DMPO-OH. A partir dos resultados de espectrometria de massas em modo positivo (ESI+) foi sugerida uma rota de síntese para o complexo oxo(peroxo)vanadato, intermediário importante no ciclo catalítico. Foi proposto também um mecanismo para a oxidação do cicloexano.Fundação de Amparo a Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhãoapplication/pdfporUniversidade Federal de São CarlosPrograma de Pós-Graduação em Química - PPGQUFSCarBRCatáliseComplexos de vanádioHidrocarbonetos - oxidaçãoCicloexanoCIENCIAS EXATAS E DA TERRA::QUIMICAComplexos de vanádio contendo bases de Schiff como catalisadores na oxidação do cicloexanoVanadium complexes as catalysts for the oxidation of cyclohexaneinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesis-1-1a20981f8-5050-4af2-b325-04e85155cc87info:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINAL6158.pdfapplication/pdf2068212https://repositorio.ufscar.br/bitstream/ufscar/6311/1/6158.pdf5fb6c77702dc109cacb7fd2b8114e1abMD51TEXT6158.pdf.txt6158.pdf.txtExtracted texttext/plain0https://repositorio.ufscar.br/bitstream/ufscar/6311/4/6158.pdf.txtd41d8cd98f00b204e9800998ecf8427eMD54THUMBNAIL6158.pdf.jpg6158.pdf.jpgIM Thumbnailimage/jpeg6224https://repositorio.ufscar.br/bitstream/ufscar/6311/5/6158.pdf.jpg814e5d3fdc9c0d6ff52bc1c372836742MD55ufscar/63112023-09-18 18:30:36.956oai:repositorio.ufscar.br:ufscar/6311Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-09-18T18:30:36Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false |
dc.title.por.fl_str_mv |
Complexos de vanádio contendo bases de Schiff como catalisadores na oxidação do cicloexano |
dc.title.alternative.eng.fl_str_mv |
Vanadium complexes as catalysts for the oxidation of cyclohexane |
title |
Complexos de vanádio contendo bases de Schiff como catalisadores na oxidação do cicloexano |
spellingShingle |
Complexos de vanádio contendo bases de Schiff como catalisadores na oxidação do cicloexano Cantanhede, Leonardo Baltazar Catálise Complexos de vanádio Hidrocarbonetos - oxidação Cicloexano CIENCIAS EXATAS E DA TERRA::QUIMICA |
title_short |
Complexos de vanádio contendo bases de Schiff como catalisadores na oxidação do cicloexano |
title_full |
Complexos de vanádio contendo bases de Schiff como catalisadores na oxidação do cicloexano |
title_fullStr |
Complexos de vanádio contendo bases de Schiff como catalisadores na oxidação do cicloexano |
title_full_unstemmed |
Complexos de vanádio contendo bases de Schiff como catalisadores na oxidação do cicloexano |
title_sort |
Complexos de vanádio contendo bases de Schiff como catalisadores na oxidação do cicloexano |
author |
Cantanhede, Leonardo Baltazar |
author_facet |
Cantanhede, Leonardo Baltazar |
author_role |
author |
dc.contributor.authorlattes.por.fl_str_mv |
http://lattes.cnpq.br/0740032606397506 |
dc.contributor.author.fl_str_mv |
Cantanhede, Leonardo Baltazar |
dc.contributor.advisor1.fl_str_mv |
Marques, Clélia Mara de Paula |
dc.contributor.advisor1Lattes.fl_str_mv |
http://genos.cnpq.br:12010/dwlattes/owa/prc_imp_cv_int?f_cod=K4796205D7 |
dc.contributor.authorID.fl_str_mv |
bb80aff3-f142-47b5-8fdf-04fd996aaeb6 |
contributor_str_mv |
Marques, Clélia Mara de Paula |
dc.subject.por.fl_str_mv |
Catálise Complexos de vanádio Hidrocarbonetos - oxidação Cicloexano |
topic |
Catálise Complexos de vanádio Hidrocarbonetos - oxidação Cicloexano CIENCIAS EXATAS E DA TERRA::QUIMICA |
dc.subject.cnpq.fl_str_mv |
CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
The vanadium complexes of the type [VO(acac)2], [VO(acac)(apftsc)], [VO(acac)(apmtsc)], [VO(acac)(aptsc)], [VO(acac)(apf)], vanadium (IV) and [VO2(apftsc)], [VO2(apmtsc)], [VO2(aptsc)] e [VO2(apf)], vanadium (V), were used as catalysts for cyclohexane oxidation using 30% hydrogen peroxide (H2O2) as oxidizing agent in acetonitrile at 40ºC. The cyclohexanol (OL) and cyclohexanone (ONA) were quantified by means of gas chromatography by the internal padronization method. Variation in the molar ratio of oxidizing, substrate and nitric acid with catalyst, as well as the effect of the addition of triphenylphosphine in catalytic properties were studied for all complexes. For the complex [VO(acac)(apftsc)], yielded the kinetic parameters with rate constant (k = 3,87 x 10-1 L.mol-1.min-1), reaction order relative to catalysts (nCat = 0,8) and to substrate (nS = 0,6); the thermodynamic parameters of activation Eap = 11 kcal.mol-1, ΔG# = + 0.6 kcal.mol-1, ΔH# = + 10.2 kcal.mol-1, ΔS# = + 30.8 cal.mol-1.K-1. The EPR spectrum data using 5,5-dimethyl-1-pyrroline Noxide (DMPO) as spin trap confirm that the mechanism the formation of radicals. The radicals ( acac) and hydroxyl ( OH) from the acetylacetonate e and hydrogen peroxide, respectively, was identified by forming the respective adduct, DMPO-Acac and DMPO-OH. From the mass spectrometry data it was possible to suggest a synthetic route for the formation of the oxo(peroxo)vanadate complex, an important intermediate in the catalytic cycle. It has been proposed also a mechanism for cyclohexane oxidation. |
publishDate |
2014 |
dc.date.available.fl_str_mv |
2014-09-18 2016-06-02T20:34:54Z |
dc.date.issued.fl_str_mv |
2014-03-27 |
dc.date.accessioned.fl_str_mv |
2016-06-02T20:34:54Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
CANTANHEDE, Leonardo Baltazar. Vanadium complexes as catalysts for the oxidation of cyclohexane. 2014. 160 f. Tese (Doutorado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2014. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufscar.br/handle/ufscar/6311 |
identifier_str_mv |
CANTANHEDE, Leonardo Baltazar. Vanadium complexes as catalysts for the oxidation of cyclohexane. 2014. 160 f. Tese (Doutorado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2014. |
url |
https://repositorio.ufscar.br/handle/ufscar/6311 |
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por |
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a20981f8-5050-4af2-b325-04e85155cc87 |
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openAccess |
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Universidade Federal de São Carlos |
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Programa de Pós-Graduação em Química - PPGQ |
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UFSCar |
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BR |
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Universidade Federal de São Carlos |
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