Concentration and solvent effects on the conformational equilibrium of cis-3-ethoxycyclohexanol by H-1 NMR and IR spectroscopy

dc.creatorde Oliveira, PR
dc.creatorOrtiz, DS
dc.creatorRittner, R
dc.date2006
dc.dateMAY 8
dc.date2014-11-17T10:53:57Z
dc.date2015-11-26T17:28:33Z
dc.date2014-11-17T10:53:57Z
dc.date2015-11-26T17:28:33Z
dc.date.accessioned2018-03-29T00:15:41Z
dc.date.available2018-03-29T00:15:41Z
dc.identifierJournal Of Molecular Structure. Elsevier Science Bv, v. 788, n. 41699, n. 16, n. 21, 2006.
dc.identifier0022-2860
dc.identifierWOS:000239135100003
dc.identifier10.1016/j.molstruc.2005.11.009
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/56445
dc.identifierhttp://www.repositorio.unicamp.br/handle/REPOSIP/56445
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/56445
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1285084
dc.descriptionNMR data, in CCl4, show that an increase in the concentration of cis-3-ethoxycyclohexanol (cis-3-ECH) shifts the conformational equilibrium from the ax-ax conformer (Xax-ax = 51 % at 0.01 mol L-1), stabilized by an intramolecular hydrogen bond (IAHB), to the eq-eq conformer (Xeq-eq = 67% at 0.40 mol L-1), which forms intermolecular hydrogen bonds (IEHB), as confirmed by IR data. The Delta v values, obtained by IR spectra, indicated that cis-3-ECH presents a stronger IAHB than the cis-3-methoxycyclohexanol, due to the increase in substituent steric and group electronegativity effects. The percentage of eq-eq conformer also increases with the solvent basicity, from 5 1 % (Delta G(eqeq-axax) = - 0.03 kcal mol(-1) in CCl4 to 97% (Delta G(eqeq)-(axax) = -2.05 kcal mol(-1)) in DMSO. Values of 4.58 and 5.39 kcal mol for the IAHB strength in cis-3-ECH, were obtained from the theoretical data at CBS-4M and B3LYP/6-311 + G** levels, respectively. (c) 2005 Elsevier B.V. All rights reserved.
dc.description788
dc.description41699
dc.description16
dc.description21
dc.languageen
dc.publisherElsevier Science Bv
dc.publisherAmsterdam
dc.publisherHolanda
dc.relationJournal Of Molecular Structure
dc.relationJ. Mol. Struct.
dc.rightsfechado
dc.rightshttp://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy
dc.sourceWeb of Science
dc.subjectconformational analysis
dc.subjectintramolecular hydrogen bond
dc.subjectNMR spectroscopy
dc.subjectIR spectroscopy
dc.subjecttheoretical calculations
dc.subjectSet Model Chemistry
dc.subjectHydrogen-bonds
dc.subjectDensity
dc.subjectElectronegativities
dc.subjectEnergies
dc.subjectExchange
dc.subjectNmr
dc.titleConcentration and solvent effects on the conformational equilibrium of cis-3-ethoxycyclohexanol by H-1 NMR and IR spectroscopy
dc.typeArtículos de revistas


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