Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.author | 엄익환 | - |
dc.date.accessioned | 2016-08-28T12:08:03Z | - |
dc.date.available | 2016-08-28T12:08:03Z | - |
dc.date.issued | 2008 | - |
dc.identifier.issn | 0253-2964 | - |
dc.identifier.other | OAK-5056 | - |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/220062 | - |
dc.description.abstract | Second-order rate constants (kN) have been measured spectrophotometrically for reactions of 3,4-dinitrophenyl 2-thiophenecarboxylate (2) with a series of alicyclic secondary amines in 80 mol % H2O/20 mol % dimethyl sulfoxide at 25.0 °C. The Brønsted-type plot exhibits a downward curvature for the aminolysis of 2. The curved Brønsted-type plot is similar to that reported for the corresponding reactions of 2,4-dinitrophenyl 2-thiophenecarboxylate (1). The reactions of 1 and 2 have been suggested to proceed through the same mechanism, i.e., through a zwitterionic tetrahedral intermediate (T±) with a change in the rate-determining step. Substrate 2 is less reactive than 1 toward weakly basic amines (e.g., pKa < 10.4) but becomes more reactive as the basicity of amines increases further. Dissection of kN into the microscopic rate constants has revealed that the reaction of 2 results in a smaller k2/k-1 ratio but larger k1 than the corresponding reaction of 1. Steric hindrance exerted by the ortho-nitro group has been suggested to be responsible for the smaller k1 value found for the reactions of 1. | - |
dc.language | English | - |
dc.title | Aminolysis of 2,4-dinitrophenyl and 3,4-dinitrophenyl 2- thiophenecarboxylates: Effect of ortho-nitro group on reactivity and mechanism | - |
dc.type | Article | - |
dc.relation.issue | 8 | - |
dc.relation.volume | 29 | - |
dc.relation.index | SCI | - |
dc.relation.index | SCIE | - |
dc.relation.index | SCOPUS | - |
dc.relation.index | KCI | - |
dc.relation.startpage | 1459 | - |
dc.relation.lastpage | 1463 | - |
dc.relation.journaltitle | Bulletin of the Korean Chemical Society | - |
dc.identifier.wosid | WOS:000259292000007 | - |
dc.identifier.scopusid | 2-s2.0-50449110073 | - |
dc.author.google | Seo J.-A. | - |
dc.author.google | Chun S.-M. | - |
dc.author.google | Um I.-H. | - |
dc.contributor.scopusid | 엄익환(7006725706;6506759437) | - |
dc.date.modifydate | 20230411105538 | - |