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Journal of the Korean Chemical Society (JKCS)

ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 40, Number 5
JKCSEZ 40(5)
October 20, 1996 

 
Title
The Effect of Pressure on the Rate of Solvolysis(Ⅱ). Reactions of Methyl-, Phenyl Chloroformate and 1-Adamantyl Derivatives

가용매분해반응에 대한 압력의 영향(II), Methyl-, Phenyl Chloroformate와 1-Adamantyl 유도체에 대한 반응
Author
Oh Cheun Kwun, Jeong Rim Kim, Jin Burm Kyong, Young Hoon Lee, Jong Chul Kim

권오천,김정림,경진범,이영훈,김종철
Keywords
Abstract
이성분혼합용매내에서 methyl-, phenyl chloroformate와 1-adamantyl 유도체들의 가용매분해 반응속도를 여러 온도와 압력하에서 전도도 방법에 의하여 측정하였다. 이들 속도상수로부터 활성화 부피(ΔVo≠), 활성화 엔탈피(ΔH≠), 활성화 엔트로피(ΔS≠) 값을 구하였다. 이 때 모든 혼합물내에서 ΔVo≠와 ΔS≠는 음의 값을 나타내었으며, ΔH≠는 양의 값을 얻었다. 이 현상을 용매구조변화에 대하여 논의하였다. 또한 활성화 부피와 활성화 엔트로피 값들을 플로트하여 본 반응에 대한 반응 경향성을 조사하였다. 이들 결과로부터 methyl-, phenyl chloroformate와 1-adamantyl fluoroformate(알코올 수용액)는 이분자반응이, 1-adamantyl fluoroformate(TFE 수용액)와 1-adamantyl tosylate는 일분자반응이 일어나는 것으로 추정할 수 있었다.

The rates of solvolylsis of methyl chloroformate, phenyl chloroformate and 1-adamantyl derivatives in binary solvent mixtures have been measured by conductometric method at various temperatures and pressures. The activation parameters were estimated from the rate constants. The activation volume (ΔVo≠) and the activation entropy (ΔS≠) are both negative, but the activation enthalpy (ΔH≠) is positive. This behavior is discussed in terms of electrostriction of solvation. The reactivities of these reactions were also estimated from the correlation of the activation volumes with the activation entropies. From these results, it could be estimated that the solvolyses of 1-adamantyl fluoroformate (in aqueous TFE) and 1-adamantyl tosylate have pathway involving unimolecular reaction, while the reaction of methyl chloroformate, phenyl chloroformate and 1-adamantyl fluoroformate (in aqueous alcohol) proceed through a bimolecular reaction.

Page
327 - 332
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