Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.author | 권동숙 | * |
dc.contributor.author | 엄익환 | * |
dc.date.accessioned | 2018-06-02T08:15:14Z | - |
dc.date.available | 2018-06-02T08:15:14Z | - |
dc.date.issued | 1996 | * |
dc.identifier.issn | 0253-2964 | * |
dc.identifier.other | OAK-16976 | * |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/244450 | - |
dc.description.abstract | Second-order rate constants have been measured spectrophotometrically for the reactions of aryl benzoates (X-C 6H 4CO 2 C 6H 4-Y) with EtO -, Z-C 6H 4O - and Z-C 6H 4C(Me)=NO - in absolute ethanol at 25.0 °C. All the reactions have been performed in the presence of excess 18-crown-6 ether in order to eliminate the catalytic effect shown by alkali metal ion. A good Hammett correlation has been obtained with a large ρ - value (-1.96) when σ - (Z) constant was used for the reaction of p-nitrophenyl benzoate (PNPB) with Z-C 6H 4O -. Surprisingly, the one for the reaction of PNPB with Z-C 6H 4C(Me)=NO - gives a small but definitely positive ρ value (+0.09). However, for reactions of C 6H 5CO 2C 6H 4-Y with EtO -, correlation of log k with σ - (Y) constant gives very poor Hammett correlation. A significantly improved linearity has been obtained when σ° (Y) constant was used, indicating that the leaving group departure is little advanced at the TS of the RDS. For reactions of X-C 6H 4CO 2C 6H 4-4-NO 2 with EtO -, C 6H 5O - and C 6H 5C(Me)=NO -, correlations of log k with σ (X) constants for all the three nucleophile systems give good linearity with large positive ρ values, e.g. 2.95, 2.81 and 3.06 for EtO -, C 6H 5O - and C 6H 5C(Me)=NO -, respectively. The large ρ values clearly suggest that the present reaction proceeds via a stepwise mechanism in which the formation of the addition intermediate is the RDS. | * |
dc.language | English | * |
dc.title | A mechanistic study on reactions of aryl benzoates with ethoxide, aryloxides and acetophenone oximates in absolute ethanol | * |
dc.type | Article | * |
dc.relation.issue | 9 | * |
dc.relation.volume | 17 | * |
dc.relation.index | SCI | * |
dc.relation.index | SCIE | * |
dc.relation.index | SCOPUS | * |
dc.relation.index | KCI | * |
dc.relation.startpage | 802 | * |
dc.relation.lastpage | 807 | * |
dc.relation.journaltitle | Bulletin of the Korean Chemical Society | * |
dc.identifier.scopusid | 2-s2.0-0030518002 | * |
dc.author.google | Um I.-H. | * |
dc.author.google | Oh S.-J. | * |
dc.author.google | Kwon D.-S. | * |
dc.contributor.scopusid | 권동숙(7103159894;16165739700) | * |
dc.contributor.scopusid | 엄익환(7006725706;6506759437) | * |
dc.date.modifydate | 20240423081003 | * |