Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.author | 엄익환 | - |
dc.date.accessioned | 2016-08-28T12:08:51Z | - |
dc.date.available | 2016-08-28T12:08:51Z | - |
dc.date.issued | 2010 | - |
dc.identifier.issn | 0253-2964 | - |
dc.identifier.other | OAK-7037 | - |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/221152 | - |
dc.description.abstract | Pseudo-first-order rate constants (kobsd) were measured spectrophotometrically for nucleophilic substitution reactions of 4-nitrophenyl picolinate (6) with alkali metal ethoxides (EtOM, M+ = K+, Na+ and Li+) in anhydrous ethanol at 25.0 ± 0.1 °C. The plot of kobsd vs. [EtOM] exhibits upward curvature regardless of the nature of M+ ions. However, the plot for the reaction of 6 with EtOK is linear with significantly decreased kobsd values when 18-crown-6-ether (18C6, a complexing agent for K+ ion) is added in the reaction medium. Dissection of kobsd into k EtO- and kEtOM (i.e., the second-order rate constant for the reaction with dissociated EtO- and ion-paired EtOM, respectively) has revealed that ion-paired EtOM is 3 ∼ 17 times more reactive than dissociated EtO-. The reaction has been proposed to proceed through a 5-membered cyclic transition state, in which M+ ion increases the electrophilicity of the reaction site. Interestingly, Na+ ion exhibits the largest catalytic effect. The presence of a nitrogen atom in the pyridine moiety of 6 has been suggested to be responsible for the high Na + ion selectivity. | - |
dc.language | English | - |
dc.title | Metal ion catalysis in nucleophilic substitution reaction of 4-nitrophenyl picolinate with alkali metal ethoxides in anhydrous ethanol | - |
dc.type | Article | - |
dc.relation.issue | 9 | - |
dc.relation.volume | 31 | - |
dc.relation.index | SCI | - |
dc.relation.index | SCIE | - |
dc.relation.index | SCOPUS | - |
dc.relation.index | KCI | - |
dc.relation.startpage | 2483 | - |
dc.relation.lastpage | 2487 | - |
dc.relation.journaltitle | Bulletin of the Korean Chemical Society | - |
dc.identifier.doi | 10.5012/bkcs.2010.31.9.2483 | - |
dc.identifier.wosid | WOS:000283953600009 | - |
dc.identifier.scopusid | 2-s2.0-77957046736 | - |
dc.author.google | Hong Y.-J. | - |
dc.author.google | Kim S.-I. | - |
dc.author.google | Um I.-H. | - |
dc.contributor.scopusid | 엄익환(7006725706;6506759437) | - |
dc.date.modifydate | 20230411105538 | - |