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Journal of the Korean Chemical Society (JKCS)

ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 38, Number 6
JKCSEZ 38(6)
December 20, 1994 

 
Title
Kinetics and Mechanism of Nucleophilic Addition of Sodium Thiophenoxide to α-(n-Butyl)-N-Phenylnitrone Derivatives

α-(n-Butyl)-N-Phenylnitrone 유도체에 대한 Sodium Thiophenoxide의 친핵성 첨가반응 메카니즘과 그의 반응 속도론적 연구
Author
Kwang-Il Lee, Suck-Woo Lee, Chun-Geun Kwak, Young-Ju Kim, Seung-Il Rho, Ki-Chang Lee

이광일, 이석우, 곽천근, 김영주, 노승일, 이기창
Keywords
Abstract
α-(n-Butyl)-N-Phenylnitrone 유도체의 첨가 반응속도상수를 25℃의 수용액에서 자외선 분광광도법으로 측정하여 넓은 pH범위에서 잘 맞는 반응속도식을 유도하였다. 첨가반응생성물은 α-phenylthiobutylidene-aniline이었으며, 첨가반응속도상수 측정과 반응속도식의 유도, 일반기염 효과, 치환기 효과 및 최종생성물의 결과로부터 반응 메카니즘을 제안하였다. 즉, pH 3.0 이하에서는 티오페놀의 첨가로 반응이 시작되며, pH 3.0∼10.0에서는 티오페놀과 티오페녹시드 음이온이 경쟁적으로 첨가되어 진행되며, pH10.0이상에서는 티오페녹시드 음이온의 첨가에 의해서 반응이 진행된다.

The rate constants of the nucleophilic reaction of α-(n-butyl)-N-phenylnitrone and its derivatives have been determined by ultraviolet spectrophotometry at 25℃ and a rate equation which can be applied over a wide pH range was obtained. Final product of the addition reaction was α-phenylthiobutylidene-aniline. Base on the rate equation, genernal base effect, substituent effect and final product, plausible mechanism of addition reaction have been proposed. Below pH 3.0 the reaction was inititated by the addition of thiophenol, and in the range of pH 3.0∼10.0, proceeded by the competitive addition of thiophenol and thiophenoxide anion. Above the pH 10.0, the reaction proceeded through the addition of a thiophenoxide anion.

Page
442 - 448
Full Text
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