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dc.creatorNikolić, Katarina
dc.date.accessioned2019-09-02T11:02:59Z
dc.date.available2019-09-02T11:02:59Z
dc.date.issued2006
dc.identifier.issn0166-1280
dc.identifier.urihttp://farfar.pharmacy.bg.ac.rs/handle/123456789/669
dc.description.abstractA dominant transfer mechanism [hydrogen atom transfer (HAT) or proton-coupled electron transfer (PCET)] in the reaction of phenols with certain types of oxygen-centered radicals was selected by examining the conformations, singly occupied molecular orbitals (SOMOs), charge separation and spin density in optimized transition structures (TSs) such as (CH3)(3)-C-O-3-O-2-(HO1)-H-...-O-...-Ar and (CH3)(3)-C-O-2 (...) H (...) O-1-Ar. The change in charge on the hydrogen (Delta H) and the SOMO conformations in the TS (CH3)(3)-C-O-3-O-2 (....) H (...) O-1-Ar or (CH3)(3)-C-O-2(....) H-.... O-1-Ar were used as criteria for determining the dominant H-atoin transfer mechanism. Increased electron density on the O-2 and O-3 oxygens in the PCET-TS selectively stabilizes the TS by providing greater binding energy for H+ transfer. Thus, the (O-2+O-3-O-1) charges, Delta(O-2+O-3-O-1) charges, and (O-2+O-3) spin densities in the PCET-TS were well correlated with the experimental antioxidative activity (k(1)). The spin densities on the radical oxygens (O-2+O-3) in the HAT-TS were highly negatively correlated with k(1), while the spin densities on the ring in the HAT-TS showed good positive correlation with k(1) values. In the TS of phenols containing O-7(para) in the structure, the spin densities on O-7(para) and on the ring were correlated well with ki. Since the reactivity of phenols with an alkylperoxy radical does not strongly depend on the radical structure, the procedure presented here can be used to estimate phenol reactivity with any alkylperoxy radical (R-O-O-').en
dc.publisherElsevier Science BV, Amsterdam
dc.rightsrestrictedAccess
dc.sourceJournal of Molecular Structure - THEOCHEM
dc.subjectantioxidant activityen
dc.subjectphenolsen
dc.subjectbond dissociation enthalpyen
dc.subjectmolecular orbitalesen
dc.subjecttransition statesen
dc.titleTheoretical study of phenolic antioxidants properties in reaction with oxygen-centered radicalsen
dc.typearticle
dc.rights.licenseARR
dcterms.abstractНиколић, Катарина;
dc.citation.volume774
dc.citation.issue1-3
dc.citation.spage95
dc.citation.epage105
dc.citation.other774(1-3): 95-105
dc.citation.rankM23
dc.identifier.wos000242206600017
dc.identifier.doi10.1016/j.theochem.2006.07.017
dc.identifier.scopus2-s2.0-33748464701
dc.identifier.rcubconv_1802
dc.type.versionpublishedVersion


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