Studies on the s-cis-trans isomerism for some furan derivatives through IR and NMR spectroscopies and theoretical calculations

dc.creatorRittner, R
dc.creatorDucati, LC
dc.creatorTormena, CF
dc.creatorCormanich, RA
dc.creatorFiorin, BC
dc.creatorBraga, CB
dc.creatorAbraham, RJ
dc.date2013
dc.dateFEB 15
dc.date2014-07-31T14:18:40Z
dc.date2015-11-26T17:48:14Z
dc.date2014-07-31T14:18:40Z
dc.date2015-11-26T17:48:14Z
dc.date.accessioned2018-03-29T00:31:03Z
dc.date.available2018-03-29T00:31:03Z
dc.identifierSpectrochimica Acta Part A-molecular And Biomolecular Spectroscopy. Pergamon-elsevier Science Ltd, v. 103, n. 84, n. 89, 2013.
dc.identifier1386-1425
dc.identifierWOS:000315011600012
dc.identifier10.1016/j.saa.2012.11.013
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/75239
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/75239
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1289031
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionThe s-cis-trans isomerism of two furan derivatives [2-acetyl- (AF) and 2-acetyl-5-methylfuran, (AMF)] was analyzed, using data from the deconvolution of their carbonyl absorption band in two solvents (CH2-Cl2 and CH3CN). These infrared data showed that the O,O-trans conformers predominate in the less polar solvent (CH2Cl2), but these equilibria change in a more polar solvent (CH3CN) leading to a slight predominance of the O,O-cis conformers, in agreement with the theoretical calculations. The later results were obtained using B3LYP-IEFPCM/6-31++g(3df,3p) level of theory, which taking into account the solvent effects at IEFPCM (Integral Equation Formalism Polarizable Continuum Model). Low temperature C-13 NMR spectra in CD2Cl2 (ca. -75 degrees C) showed pairs of signals for each carbon, due to the known high energy barrier for the cis-trans interconversion leading to a large predominance of the trans isomers, which decreases in acetone-d(6). This was confirmed by their H-1 NMR spectra at the same temperatures. Moreover, despite the larger hyperconjugative interactions for the O,O-cis isomers, obtained from NBO data, these isomers are destabilized by the their Lewis energy. (C) 2012 Elsevier B.V. All rights reserved.
dc.description103
dc.description84
dc.description89
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionFundacao Araucaria
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.languageen
dc.publisherPergamon-elsevier Science Ltd
dc.publisherOxford
dc.publisherInglaterra
dc.relationSpectrochimica Acta Part A-molecular And Biomolecular Spectroscopy
dc.relationSpectroc. Acta Pt. A-Molec. Biomolec. Spectr.
dc.rightsfechado
dc.rightshttp://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy
dc.sourceWeb of Science
dc.subjectConformational analysis
dc.subjectS-cis-trans isomerism
dc.subjectInfrared spectroscopy
dc.subjectNMR spectroscopy
dc.subjectTheoretical calculations
dc.subjectFuran derivatives
dc.subjectNuclear-magnetic-resonance
dc.subjectConformations
dc.subjectThiophene
dc.subject2-acetylfuran
dc.subjectAcetyl
dc.titleStudies on the s-cis-trans isomerism for some furan derivatives through IR and NMR spectroscopies and theoretical calculations
dc.typeArtículos de revistas


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