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dc.contributor.author엄익환-
dc.date.accessioned2016-08-28T12:08:51Z-
dc.date.available2016-08-28T12:08:51Z-
dc.date.issued2010-
dc.identifier.issn0253-2964-
dc.identifier.otherOAK-7037-
dc.identifier.urihttp://dspace.ewha.ac.kr/handle/2015.oak/221152-
dc.description.abstractPseudo-first-order rate constants (kobsd) were measured spectrophotometrically for nucleophilic substitution reactions of 4-nitrophenyl picolinate (6) with alkali metal ethoxides (EtOM, M+ = K+, Na+ and Li+) in anhydrous ethanol at 25.0 ± 0.1 °C. The plot of kobsd vs. [EtOM] exhibits upward curvature regardless of the nature of M+ ions. However, the plot for the reaction of 6 with EtOK is linear with significantly decreased kobsd values when 18-crown-6-ether (18C6, a complexing agent for K+ ion) is added in the reaction medium. Dissection of kobsd into k EtO- and kEtOM (i.e., the second-order rate constant for the reaction with dissociated EtO- and ion-paired EtOM, respectively) has revealed that ion-paired EtOM is 3 ∼ 17 times more reactive than dissociated EtO-. The reaction has been proposed to proceed through a 5-membered cyclic transition state, in which M+ ion increases the electrophilicity of the reaction site. Interestingly, Na+ ion exhibits the largest catalytic effect. The presence of a nitrogen atom in the pyridine moiety of 6 has been suggested to be responsible for the high Na + ion selectivity.-
dc.languageEnglish-
dc.titleMetal ion catalysis in nucleophilic substitution reaction of 4-nitrophenyl picolinate with alkali metal ethoxides in anhydrous ethanol-
dc.typeArticle-
dc.relation.issue9-
dc.relation.volume31-
dc.relation.indexSCIE-
dc.relation.indexSCOPUS-
dc.relation.indexKCI-
dc.relation.startpage2483-
dc.relation.lastpage2487-
dc.relation.journaltitleBulletin of the Korean Chemical Society-
dc.identifier.doi10.5012/bkcs.2010.31.9.2483-
dc.identifier.wosidWOS:000283953600009-
dc.identifier.scopusid2-s2.0-77957046736-
dc.author.googleHong Y.-J.-
dc.author.googleKim S.-I.-
dc.author.googleUm I.-H.-
dc.contributor.scopusid엄익환(7006725706;6506759437)-
dc.date.modifydate20170601135413-
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자연과학대학 > 화학·나노과학전공 > Journal papers
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