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dc.contributor.author엄익환-
dc.date.accessioned2016-08-28T12:08:27Z-
dc.date.available2016-08-28T12:08:27Z-
dc.date.issued2010-
dc.identifier.issn0253-2964-
dc.identifier.otherOAK-7446-
dc.identifier.urihttps://dspace.ewha.ac.kr/handle/2015.oak/221513-
dc.description.abstractPseudo-first-order rate constants (kobsd) have been measured for nucleophilic substitution reactions of 2-pyridyl benzoate 5 with alkali metal ethoxides (EtOM, M = Li, Na, K) in anhydrous ethanol. The plots of k obsd vs. [EtOM]o are curved upwardly but linear in the excess presence of 18-crown-6-ether (18C6) with significant decreased k obsd values in the reaction with EtOK. The kobsd value for the reaction of 5 with a given EtONa concentration decreases steeply upon addition of 15-crown-5-ether (15C5) to the reaction medium up to ca. [15C5]/[EtONa]o = 1, and remains nearly constant thereafter, indicating that M+ ions catalyze the reaction in the absence of the complexing agents. Dissection kobsd into kEtO- and k EtOM, i.e., the second-order rate constants for the reaction with the dissociated EtO. and the ion-paired EtOM, respectively has revealed that ion-paired EtOM is 3.2-4.6 times more reactive than dissociated EtO. It has been concluded that M+ ions increase the electrophilicity of the reaction center through a 6-membered cyclic transition state. This idea has been examined from the corresponding reactions of 4-pyridyl benzoate 6, which cannot form such a 6-membered cyclic transition state.-
dc.languageEnglish-
dc.titleEffect of alkali metal ions on alkaline ethanolysis of 2-pyridyl and 4-pyridyl benzoates in anhydrous ethanol-
dc.typeArticle-
dc.relation.issue10-
dc.relation.volume31-
dc.relation.indexSCI-
dc.relation.indexSCIE-
dc.relation.indexSCOPUS-
dc.relation.indexKCI-
dc.relation.startpage2929-
dc.relation.lastpage2933-
dc.relation.journaltitleBulletin of the Korean Chemical Society-
dc.identifier.doi10.5012/bkcs.2010.31.10.2929-
dc.identifier.wosidWOS:000288766000030-
dc.identifier.scopusid2-s2.0-78049389348-
dc.author.googleLee J.-I.-
dc.author.googleKang J.-S.-
dc.author.googleKim S.-I.-
dc.author.googleUm I.-H.-
dc.contributor.scopusid엄익환(7006725706;6506759437)-
dc.date.modifydate20230411105538-
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자연과학대학 > 화학·나노과학전공 > Journal papers
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