Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.author | 엄익환 | - |
dc.date.accessioned | 2016-08-28T10:08:59Z | - |
dc.date.available | 2016-08-28T10:08:59Z | - |
dc.date.issued | 2012 | - |
dc.identifier.issn | 0253-2964 | - |
dc.identifier.other | OAK-9376 | - |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/223142 | - |
dc.description.abstract | Second-order rate constants for the reactions of phenyl Y-substituted-phenyl carbonates 5a-g with Zsubstituted- phenoxides (kZ-PhO-) have been measured spectrophotometrically in 80 mol % H 2O/20 mol % DMSO at 25.0 ± 0.1 oC. 4-Nitrophenyl phenyl carbonate (5e) is up to 235 times more reactive than 4- nitrophenyl benzoate (4e). The Brønsted-type plot for the reactions of 5e with Z-substituted-phenoxides is linear with β nuc = 0.54, which is typical for reactions reported previously to proceed through a concerted mechanism. Hammett plots correlated with σ° and σ - constants for the reactions of 5a-f with 4-chlorophenoxide exhibit highly scattered points. In contrast, the Yukawa-Tsuno plot results in an excellent linear correlation with ρY = 1.51 and r = 0.52, indicating that the leaving-group departure occurs at the rate-determining step (RDS). A stepwise mechanism, in which leaving-group departure occurs at RDS, has been excluded since the incoming 4-ClPhO - is more basic and a poorer nucleofuge than the leaving Y-substituted-phenoxides. Thus, the reaction has been concluded to proceed through a concerted mechanism. Our study has shown that the modification of the nonleaving group from benzoyl to phenyloxycarbonyl causes a change in the reaction mechanism (i.e., from a stepwise mechanism to a concerted pathway) as well as an increase in the reactivity. © 2005 KCSNET. | - |
dc.language | English | - |
dc.title | A kinetic study on nucleophilic substitution reactions of phenyl y-substituted-phenyl carbonates with z-substituted-phenoxides: Effect of modification of nonleaving group from benzoyl to phenyloxycarbonyl on reactivity and reaction mechanism | - |
dc.type | Article | - |
dc.relation.issue | 10 | - |
dc.relation.volume | 33 | - |
dc.relation.index | SCI | - |
dc.relation.index | SCIE | - |
dc.relation.index | SCOPUS | - |
dc.relation.index | KCI | - |
dc.relation.startpage | 3253 | - |
dc.relation.lastpage | 3257 | - |
dc.relation.journaltitle | Bulletin of the Korean Chemical Society | - |
dc.identifier.doi | 10.5012/bkcs.2012.33.10.3253 | - |
dc.identifier.wosid | WOS:000310659900017 | - |
dc.identifier.scopusid | 2-s2.0-84867887427 | - |
dc.author.google | Min S.-W. | - |
dc.author.google | Kim M.-Y. | - |
dc.author.google | Um I.-H. | - |
dc.contributor.scopusid | 엄익환(7006725706;6506759437) | - |
dc.date.modifydate | 20230411105538 | - |