Full metadata record
DC Field | Value | Language |
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dc.contributor.author | 엄익환 | - |
dc.date.accessioned | 2016-08-28T11:08:27Z | - |
dc.date.available | 2016-08-28T11:08:27Z | - |
dc.date.issued | 2005 | - |
dc.identifier.issn | 0008-4042 | - |
dc.identifier.other | OAK-12827 | - |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/228895 | - |
dc.description.abstract | We report on a nucleophilic study of esters R-C(=X)-Y-Ar in which the electrophilic center has been modified by replacing O by S in the leaving group or carbonyl center: 4-nitrophenyl acetate (1), S-4-nitrophenyl thioacetate (2), 4-nitrophenyl benzoate (3), and O-4-nitrophenyl thionobenzoate (4). The studies include O - and S - nucleophiles as well as α nucleophiles in H 2O at 25.0 ± 0.1°C. The sulfur nucleophile (4-chlorothiophenoxide, 4-ClPhS -) exhibits significant enhanced reactivity for the reactions with thiol and thione esters 2 and 4 compared with their oxygen analogues 1 and 3. On the contrary, the common nucleophile OH - is much less reactive towards 2 and 4 compared with 1 and 3. The effect of changing both the electrophilic center and the nucleofugic center on the reactivity of the other oxygen nucleophiles is not so significant: 4-chlorophenoxide (4-ClPhO -) is four to six times more reactive in the reactions with thiol and thione esters 2 and 4 compared with their oxygen analogues 1 and 3. The α effects exhibited by butan-2,3-dione monoximate (Ox -) and HOO - are strongly dependent on the nature of the electrophilic center of the substrates, indicating that the difference in the ground-state solvation energy cannot be fully responsible for the α effect. Our results clearly emphasize the strong dependence of the α effect on the substrate structure, notably, the nature of the electrophilic center. The impact of change in the nucleofuge (1-→2) and the electrophilic center (3-→4) on reactivity indicates that ánucleophiles will need to be "purpose built" for decontamination and nucleophilic degradation of specific biocides. © 2005 NRC Canada. | - |
dc.language | English | - |
dc.title | Effect of modification of the electrophilic center on the α effect | - |
dc.type | Article | - |
dc.relation.issue | 9 | - |
dc.relation.volume | 83 | - |
dc.relation.index | SCI | - |
dc.relation.index | SCIE | - |
dc.relation.index | SCOPUS | - |
dc.relation.startpage | 1365 | - |
dc.relation.lastpage | 1371 | - |
dc.relation.journaltitle | Canadian Journal of Chemistry | - |
dc.identifier.doi | 10.1139/v05-157 | - |
dc.identifier.wosid | WOS:000234570000021 | - |
dc.identifier.scopusid | 2-s2.0-33644607765 | - |
dc.author.google | Um I.-H. | - |
dc.author.google | Lee J.-Y. | - |
dc.author.google | Bae S.-Y. | - |
dc.author.google | Buncel E. | - |
dc.contributor.scopusid | 엄익환(7006725706;6506759437) | - |
dc.date.modifydate | 20230411105538 | - |