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Journal of the Korean Chemical Society (JKCS)

ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 33, Number 6
JKCSEZ 33(6)
December 20, 1989 

 
Title
Phase Transfer Catalytic Effects for Thiocyanate Displacement on Benzyl Chloride

티오시안산 염에 의한 염화벤질의 치환반응에 미치는 상이동 촉매효과
Author
Seung Hyun Chang, Mu Hong Yoon, Chang Su Kim, Kwang Bo Chung, Jae Hu Shim

장승현, 윤무공, 김창수, 정광보, 심재후
Keywords
Abstract
액-액 불균일계에서 염화벤질의 KSCN에 의한 친핵치환반응에 미치는 상이동 촉매 효능을 검토하였다. 반응은 염화벤질의 농도에 의존하는 유사일차 반응이었고, 반응속도 상수(kobsd)는 촉매농도에 비례하였으며, 반응온도 및 용매 등에 영향을 받았다. 본 치환반응에 대한 상이동 촉매능의 순위는 NH4Cl < BTMAC < 18-crown-6 < BTEAC < PEG < TBAC < CTMAB 이었다. 반응의 활성화 엔탈피 및 엔트로피는 각각 15∼20 Kcal·mol-1, -12∼-29 eu.이었으며, 반응은 미세한 유탁액으로 이루어지는 중간상인 interphase에서 일어남을 알 수 있었다.

The catalytic effects of several phase-transfer catalysts (PTC) on the liquid-liquid heterogeneous nucleophilic displacement reaction of thiocyanate on benzyl chloride have been determined. Reactions followed a pseudo-first order dependency on the benzyl chloride concentration and the observed rate constant (kobsd) were linearly related to the concentration of catalyst and varied with variables such as reaction temperature and solvent. The sequences of catalytic activity of the displacement were NH4Cl < BTMAC < 18-crown-6 < BTEAC < PEG < TBAC < CTMAB. Enthalpies and entropies of activation associated with the displacement were 15∼20 Kcalmol-1, -12∼-29 eu. respectively and the reaction occurs in the interphase comprising of microemulsion.

Page
651 - 656
Full Text
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