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dc.contributor.author엄익환-
dc.date.accessioned2016-08-28T12:08:06Z-
dc.date.available2016-08-28T12:08:06Z-
dc.date.issued2008-
dc.identifier.issn0253-2964-
dc.identifier.otherOAK-5199-
dc.identifier.urihttp://dspace.ewha.ac.kr/handle/2015.oak/220093-
dc.description.abstractSecond-order rate constants (kN) have been measured spectrophotometrically for reactions of 3,4-dinitrophenyl benzoates (5b) with a series of alicyclic secondary amines in 80 mol % H2O/20 mol % DMSO at 25.0 ± 0.1°C. The kinetic data have been compared with the data reported previously for the corresponding reactions of 2,4-dinitrophenyl benzoates (5a) to investigate the effect of changing the nucleofuge from 2,4-dinitrophenoxide to 3,4-dinitrophenoxide on reactivity and mechanism. The kinetic results show that aminolyses of 5a and 5b proceed through the same mechanism, i.e., a zwitterionic tetrahedral intermediate (T±) with a change in the rate-determining step (RDS). Substrate 5a is more reactive than 5b when breakdown of T± is the RDS but less reactive when formation of T± is the RDS. Dissection of kN values into the microscopic rate constants (e.g., k1 and k 2/k-1 ratio) has revealed that 5a results in larger k 2/k-1 ratios but smaller k1 values than 5b for all the amines studied. Since 2,4-dinitrophenoxide is less basic and a better nucleofuge than 3,4-dinitrophenoxide, the larger k2/k-1 ratios determined for the reactions of 5a than for those of 5b are as expected. The steric hindrance exerted by the ortho-nitro group on 5a contributes to the smaller k1 values found for the reactions of 5a than for those of 5b.-
dc.languageEnglish-
dc.titleAminolysis of 2,4-dinitrophenyl and 3,4-dinitrophenyl benzoates: Effect of ortho-nitro group on reactivity and mechanism-
dc.typeArticle-
dc.relation.issue10-
dc.relation.volume29-
dc.relation.indexSCIE-
dc.relation.indexSCOPUS-
dc.relation.indexKCI-
dc.relation.startpage1915-
dc.relation.lastpage1919-
dc.relation.journaltitleBulletin of the Korean Chemical Society-
dc.identifier.wosidWOS:000260810500010-
dc.identifier.scopusid2-s2.0-55249106912-
dc.author.googleSeo J.-A.-
dc.author.googleLee H.-M.-
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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