Hydrogen bonding probes of phenol -OH groups

dc.contributor.authorKontogianni, V. G.en
dc.contributor.authorCharisiadis, P.en
dc.contributor.authorPrimikyri, A.en
dc.contributor.authorPappas, C. G.en
dc.contributor.authorExarchou, V.en
dc.contributor.authorTzakos, A. G.en
dc.contributor.authorGerothanassis, I. P.en
dc.date.accessioned2015-11-24T16:39:13Z
dc.date.available2015-11-24T16:39:13Z
dc.identifier.issn1477-0520-
dc.identifier.urihttps://olympias.lib.uoi.gr/jspui/handle/123456789/8131
dc.rightsDefault Licence-
dc.subjectmagnetic-resonance-spectroscopyen
dc.subjecth-1-nmr chemical-shiftsen
dc.subjectaqueous-solutionen
dc.subjectconformational-analysisen
dc.subjecttemperature-dependenceen
dc.subjectmolecular-structuresen
dc.subjectcrystal-structureen
dc.subjectnmr-spectroscopyen
dc.subjecthydroxyl protonsen
dc.subjectab-initioen
dc.titleHydrogen bonding probes of phenol -OH groupsen
heal.abstractCorrelations between hydrogen bonds and solvent effects on phenol -OH proton shieldings, temperature coefficients (Delta delta/Delta T) and effects on OH diffusion coefficients for numerous phenolic acids, flavonols, flavones, and oleuropein derivatives of biological interest were investigated in several organic solvents and were shown to serve as reliable indicators of hydrogen bonding and solvation state of -OH groups. The temperature coefficients span a range of -0.5 to -12.3 ppb K-1. Shielding differences of 2.0 to 2.9 ppm at 298 K were observed for solvent exposed OH groups between DMSO-d(6) and CD3CN which should be compared with a shielding range of similar to 7 ppm. This demonstrates that the solvation state of hydroxyl protons is a key factor in determining the value of the chemical shift. For -OH protons showing temperature gradients more positive than -2.5 ppb K-1, shielding changes between DMSO-d(6) and CD3CN below 0.6 ppm, and diffusion coefficients significantly different from those of traces of H2O, there is an intramolecular hydrogen bond predictivity value of 100%. The C-3 OH protons of flavonols show very significant negative temperature coefficients and shielding changes between DMSO-d(6) and CD3CN of similar to 2.3 ppm, which indicate the absence of persistent intramolecular hydrogen bonds, contrary to numerous X-ray structures.en
heal.accesscampus-
heal.fullTextAvailabilityTRUE-
heal.identifier.primaryDoi 10.1039/C2ob27117f-
heal.identifier.secondary<Go to ISI>://000313664100018-
heal.identifier.secondaryhttp://pubs.rsc.org/en/Content/ArticleLanding/2013/OB/c2ob27117f-
heal.journalNameOrganic and Biomolecular Chemistryen
heal.journalTypepeer reviewed-
heal.languageen-
heal.publicationDate2013-
heal.publisherRoyal Society of Chemistryen
heal.recordProviderΠανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείαςel
heal.typejournalArticle-
heal.type.elΆρθρο Περιοδικούel
heal.type.enJournal articleen

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