Evidence of C−H···O Hydrogen Bonds in Liquid 4-Ethoxybenzaldehyde by NMR and Vibrational Spectroscopies
Autor(a) principal: | |
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Data de Publicação: | 2001 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10316/10422 https://doi.org/10.1021/jp0046041 |
Resumo: | Raman, FTIR, and NMR (both 13C and 17O) spectroscopies are used in a complementary way in order to study the occurrence of C−H···O intermolecular hydrogen bonds in liquid 4-ethoxybenzaldehyde (4EtOB). Additional information concerning the structure of the possible dimers is obtained through ab initio calculations, at the B3LYP/6-31G* level. The strongest evidences of the presence of C−H···O hydrogen bonds in the liquid phase arise from the temperature and solvent intensity dependence of the two bands observed in the νCO region of the vibrational spectra, as well as from the shift to low magnetic field detected for the carbonyl 17O NMR peak at higher dilutions. Further evidence is gathered from the changes observed in the νC-H vibrational modes, the 1JCH concentration dependence detected in the NMR spectra, and ab initio results. The experimental observations are consistent with the decrease of the C−H bond length upon hydrogen-bonding, as predicted for the nonstandard blue-shifting hydrogen bonds. Ab initio calculations predict several possible structures for the dimeric species, with nearly identical energies. The calculated dimerization energy is within the −5.1 to −6.5 kJ mol-1 range, considering both basis set superposition error and zero-point vibrational energy corrections, in agreement with the obtained experimental ΔH value of −5.7 ± 0.5 kJ mol-1. |
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Evidence of C−H···O Hydrogen Bonds in Liquid 4-Ethoxybenzaldehyde by NMR and Vibrational SpectroscopiesRaman, FTIR, and NMR (both 13C and 17O) spectroscopies are used in a complementary way in order to study the occurrence of C−H···O intermolecular hydrogen bonds in liquid 4-ethoxybenzaldehyde (4EtOB). Additional information concerning the structure of the possible dimers is obtained through ab initio calculations, at the B3LYP/6-31G* level. The strongest evidences of the presence of C−H···O hydrogen bonds in the liquid phase arise from the temperature and solvent intensity dependence of the two bands observed in the νCO region of the vibrational spectra, as well as from the shift to low magnetic field detected for the carbonyl 17O NMR peak at higher dilutions. Further evidence is gathered from the changes observed in the νC-H vibrational modes, the 1JCH concentration dependence detected in the NMR spectra, and ab initio results. The experimental observations are consistent with the decrease of the C−H bond length upon hydrogen-bonding, as predicted for the nonstandard blue-shifting hydrogen bonds. Ab initio calculations predict several possible structures for the dimeric species, with nearly identical energies. The calculated dimerization energy is within the −5.1 to −6.5 kJ mol-1 range, considering both basis set superposition error and zero-point vibrational energy corrections, in agreement with the obtained experimental ΔH value of −5.7 ± 0.5 kJ mol-1.American Chemical Society2001-05-31info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/10422http://hdl.handle.net/10316/10422https://doi.org/10.1021/jp0046041engThe Journal of Physical Chemistry A. 105:21 (2001) 5292-52971089-5639Marques, M. P. M.Costa, A. M. Amorim daRibeiro-Claro, Paulo J. A.info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2022-07-11T11:13:54Zoai:estudogeral.uc.pt:10316/10422Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:01:29.637225Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Evidence of C−H···O Hydrogen Bonds in Liquid 4-Ethoxybenzaldehyde by NMR and Vibrational Spectroscopies |
title |
Evidence of C−H···O Hydrogen Bonds in Liquid 4-Ethoxybenzaldehyde by NMR and Vibrational Spectroscopies |
spellingShingle |
Evidence of C−H···O Hydrogen Bonds in Liquid 4-Ethoxybenzaldehyde by NMR and Vibrational Spectroscopies Marques, M. P. M. |
title_short |
Evidence of C−H···O Hydrogen Bonds in Liquid 4-Ethoxybenzaldehyde by NMR and Vibrational Spectroscopies |
title_full |
Evidence of C−H···O Hydrogen Bonds in Liquid 4-Ethoxybenzaldehyde by NMR and Vibrational Spectroscopies |
title_fullStr |
Evidence of C−H···O Hydrogen Bonds in Liquid 4-Ethoxybenzaldehyde by NMR and Vibrational Spectroscopies |
title_full_unstemmed |
Evidence of C−H···O Hydrogen Bonds in Liquid 4-Ethoxybenzaldehyde by NMR and Vibrational Spectroscopies |
title_sort |
Evidence of C−H···O Hydrogen Bonds in Liquid 4-Ethoxybenzaldehyde by NMR and Vibrational Spectroscopies |
author |
Marques, M. P. M. |
author_facet |
Marques, M. P. M. Costa, A. M. Amorim da Ribeiro-Claro, Paulo J. A. |
author_role |
author |
author2 |
Costa, A. M. Amorim da Ribeiro-Claro, Paulo J. A. |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
Marques, M. P. M. Costa, A. M. Amorim da Ribeiro-Claro, Paulo J. A. |
description |
Raman, FTIR, and NMR (both 13C and 17O) spectroscopies are used in a complementary way in order to study the occurrence of C−H···O intermolecular hydrogen bonds in liquid 4-ethoxybenzaldehyde (4EtOB). Additional information concerning the structure of the possible dimers is obtained through ab initio calculations, at the B3LYP/6-31G* level. The strongest evidences of the presence of C−H···O hydrogen bonds in the liquid phase arise from the temperature and solvent intensity dependence of the two bands observed in the νCO region of the vibrational spectra, as well as from the shift to low magnetic field detected for the carbonyl 17O NMR peak at higher dilutions. Further evidence is gathered from the changes observed in the νC-H vibrational modes, the 1JCH concentration dependence detected in the NMR spectra, and ab initio results. The experimental observations are consistent with the decrease of the C−H bond length upon hydrogen-bonding, as predicted for the nonstandard blue-shifting hydrogen bonds. Ab initio calculations predict several possible structures for the dimeric species, with nearly identical energies. The calculated dimerization energy is within the −5.1 to −6.5 kJ mol-1 range, considering both basis set superposition error and zero-point vibrational energy corrections, in agreement with the obtained experimental ΔH value of −5.7 ± 0.5 kJ mol-1. |
publishDate |
2001 |
dc.date.none.fl_str_mv |
2001-05-31 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10316/10422 http://hdl.handle.net/10316/10422 https://doi.org/10.1021/jp0046041 |
url |
http://hdl.handle.net/10316/10422 https://doi.org/10.1021/jp0046041 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
The Journal of Physical Chemistry A. 105:21 (2001) 5292-5297 1089-5639 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
American Chemical Society |
publisher.none.fl_str_mv |
American Chemical Society |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
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1799133906352472064 |