Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.author | 엄익환 | - |
dc.date.accessioned | 2016-08-28T12:08:42Z | - |
dc.date.available | 2016-08-28T12:08:42Z | - |
dc.date.issued | 2011 | - |
dc.identifier.issn | 0253-2964 | - |
dc.identifier.other | OAK-7602 | - |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/221643 | - |
dc.description.abstract | Second-order rate constants (kN) have been measured spectrophotometrically for nucleophilic substitution reactions of 2,4-dinitrophenyl phenyl thionocarbonate 4 with a series of Z-substituted pyridines in 80 mol % H 2O/20 mol % DMSO at 25.0 ± 0.1 oC. The Brønsted-type plot for the reactions of 4 exhibits downward curvature (i.e., β1 = 0.21 and β2 = 1.04), indicating that the reactions proceed through a stepwise mechanism with a change in rate-determining step. It has been found that 4 is less reactive than its oxygen analogue, 2,4- dinitrophenyl phenyl carbonate 3, although the thionocarbonate is expected to be more electrophilic than its oxygen analogue. The pKa° at the center of the Brønsted curvature, defined as pKa o, has been analyzed to be 6.6 for the reactions of 4 and 8.5 for those of 3. Dissection of k N into the microscopic rate constants k1 and k 2/k-1 ratio has revealed that the reactions of 4 result in smaller k1 values but larger k2/k-1 ratios than the corresponding reactions of 3. The larger k2/k-1 ratios have been concluded to be responsible for the smaller pKa° found for the reactions of 4. | - |
dc.language | English | - |
dc.title | Pyridinolysis of 2,4-dinitrophenyl phenyl thionocarbonate: Effect of changing electrophilic center from c=o to c=s on reactivity and mechanism | - |
dc.type | Article | - |
dc.relation.issue | 4 | - |
dc.relation.volume | 32 | - |
dc.relation.index | SCI | - |
dc.relation.index | SCIE | - |
dc.relation.index | SCOPUS | - |
dc.relation.index | KCI | - |
dc.relation.startpage | 1165 | - |
dc.relation.lastpage | 1169 | - |
dc.relation.journaltitle | Bulletin of the Korean Chemical Society | - |
dc.identifier.doi | 10.5012/bkcs.2011.32.4.1165 | - |
dc.identifier.wosid | WOS:000290366200012 | - |
dc.identifier.scopusid | 2-s2.0-79954595984 | - |
dc.author.google | Son M.J. | - |
dc.author.google | Kim S.-I. | - |
dc.author.google | Um I.-H. | - |
dc.contributor.scopusid | 엄익환(7006725706;6506759437) | - |
dc.date.modifydate | 20230411105538 | - |