Stoichiometric Solvation Effects. Solvolysis of Methanesulfonyl Chloride

구인선,양기열,안선경,이종광,이익춘,Gu, In Seon,Yang, Gi Yeol,An, Seon Gyeong,Lee, Jong Gwang,Lee, Ik Chun Korean Chemical Society 2000 Bulletin of the Korean Chemical Society Vol.21 No.10

Solvolyses of methanesulfonyl chloride in water, $D^2O$, $CH^3OD$, and in aqueous binary mixtures of acetone, eth-anol and methanol are investigated at 25, 35 and $45^{\circ}C.$ The Grunwald-Winstein plot of first-order rate con-stants for the solvolytic react ion of methanesulfonyl chloride with YCl (based on 2-adamantyl chloride) shows marked dispersions into three separate lines for three aqueous mixtures with a small m value (m < 0.30), and shows a rate maximum for aqueous alcoholic solvents. Stoichiometric third-order rate constants, kww and kaa were calculated from the observed first-order rate constants and (kaw + kwa) was calculated from the kww and kaa values. The kinetic solvent isotope effects determined in water and methanol are consistent with the proposed mechanism of the general base catalyzed and/or SAN/SN2 reaction mechanism for methanesulfonyl chloride solvolyses based on mass law and stoichiometric solvation effect studies.

메탄올-아세톤 혼합용매계에서 염화벤질술포닐과 파라치환 아닐린과의 친핵성 치환반응에 대한 속도론적 연구

구인선,고철주,강대호 慶尙大學校 기초과학연구소 1985 基礎科學硏究所報 Vol.1 No.-

The second order rate constants have been determined for the nucleophilic substitution reaction of benzylsulfonyl chloride with anilines in MeOH-(Me)_2CO mixtures at 25℃ and 35℃. Results were shown that (ⅰ)the rate constant of the reaction is the largest in 100-90% MeOH solvent and increase with the electron donating substituent anilines, (ⅰ) the magnitudes of ρ and β associated with a change of substituent in the nucleophile are large and indicate a relatively advanced bond-formation in the transition state, (ⅲ) the reaction procceds via S_n2 mechanism with product-like transition state from solvent effect and quantum mechanical approach.

3-Chloro-1,2-benzisothiazole-1,1-dioxide (pseudosaccharin chloride)의 가용매 분해반응

구인선,김정자,윤용진,이익춘,In-Sun Koo,Jeong-Ja Kim,Yong-Jin Yoon,Ikchoon Lee 대한화학회 1986 대한화학회지 Vol.30 No.3

MeOH-$H_2O$, EtOH-$H_2O$, MeOH-MeCN and MeOH-$(Me)_2$CO 혼합용매계에서 pseudo-saccharinechloride의 가용매분해반응에 대한 유사일차 반응속도상수를 여러 온도에서 구하였다. Kivinen식의 n값과 Grunwald-Winstein식의 m값을 구하고 분광용매화 관계식의 파라메타들을 결정하였다. 이들 용매효과 파라메타와 활성화 파라메타들을 종합하여 볼때 Pseudo saccharinechloride의 가용매 분해반응은 $S_N2$ 반응으로 진행됨을 알았다. The pseudo-first order rate constants have been obtained for the solvolysis of pseudo-saccharinechloride in MeOH-$H_2O$, EtOH-$H_2O$, MeOH-MeCN and MeOH-$(Me)_2$CO solvents mixtures at various temperatures. Values of n and m in the Kivinen and Grunwald-Winstein plots, respectively, have been determined and the Taft's solvatochromic parameters were obtained; based on these solvent effect parameters as well as on the activation parameters it was concluded that reaction proceeds via an $S_N2$ mechanism.

제7차의 탐구요소들에 의한 중학교 과학 3교과서의 탐구 영역 분석 - 화학 분야에 대하여 -

구인선,이종원,강대호,Koo, In-Sun,Lee, Jong-Won,Kang, Dae-Ho 대한화학회 2004 대한화학회지 Vol.48 No.4

이 연구는 9학년 과학교과서의 화학분야 탐구영역(탐구과정, 탐구활동)을 제7차 과학교육과정에서 제시한 탐구요소들에 근거하여, 교과서별, 단원별로 분석하였다. 연구의 목적은 제7차 과학교육과정에 제시된 탐구요소들이 중학교 최고학년인 9학년 과학교과서의 탐구영역에 반영된 정도를 알아보고, 다양한 탐구학습을 위한 교육적 시사점을 찾고자 하는데 있다. 9학년 과학교과서의 탐구영역에 대한 전체적인 탐구요소들의 분석에서, 기초탐구요소들은 분류를 제외하고는 제7차 중학교 과학교과서들에 비교적 잘 반영되어 있으나, 통합탐구요소들은 자료해석이 거의 절반을 차지하였다. 이와 같은 현상은 탐구과정과 탐구활동의 분석에서 유사하게 나타났다. 특히, 제7차 과학교육과정의 탐구활동유형으로 신설된 과제연구와 견학은 거의 반영되어 있지 않았다. 제7차 과학교육과정은 과학과의 교수방법 해설에서, 9학년을 탐구의 수준에서 고학년 과정으로 구분하고 있으나, 통합탐구요소들과 탐구활동의 유형들은 다양하게 반영되어 있지 못하다. 그러므로 9학년의 탐구학습은 본 연구의 자료를 바탕으로 탐구영역을 재구성하여 다양하게 운영하는 것이 바람직하다. 앞으로 통합탐구요소들과 탐구활동유형들이 9학년의 탐구영역에 활용되는 정도와 비율에 관한 연구가 계속되어야겠다. This study analysed inquiry process and activities of the inquiry area in the chemistry field of middle school science textbooks by the inquiry elements based on the 7th science curriculum. The purpose of this study is to grasp a degree of reflecting the 7th science curriculum in the 9th grade science textbooks, and to find out educational implications for the various inquiry learning. Overall, for the analysis of inquiry elements, basic inquiry elements except classification were well reflected on the middle school science textbooks in 9th grade. However, for the integrated inquiry elements, interpreting data occupies almost half of them. This phenomenon is shown in the analysis of inquiry process and inquiry activities, as well. Especially, project and field trip introduced in the 7th science curriculum are hardly found in the textbooks. 9th grade is classified as an upper grade in the 7th science curriculum in terms of inquiry level. Integrated inquiry elements and inquiry activity types, however, are not thoroughly reflected in the 9th grade science textbooks. It is desirable that a variety of inquiry learning of 9th grade be implemented by reconstructing inquiry area based on the results of this study. Hence the degree and ratio of utilizing the integrated inquiry elements and inquiry activity types to the inquiry area of science textbook in 9th grade should be studied.

Limitation of the Transition State Variation Model (Ⅰ) Dual Reaction Channels for Sovolyses of Mesitylenesulphonyl Chloride

구인선,이익춘,Gu, In Seon,T. William Bentlry,Lee, Ik Choon Korean Chemical Society 1990 대한화학회지 Vol.34 No.3

알코올-물 혼합 용매계에서 치환된 염화신남오일의 가용매분해반응에 관한 속도론적 연구

구인선,김정순,안선경,양기열,이익춘,Koo, In Sun,Kim, Jung Soon,An, Sun Kyoung,Yang, Kyu Il,Lee, Ic Hoon 대한화학회 1999 대한화학회지 Vol.43 No.5

아세톤, 에탄올, 메탄올 이성분 혼합수용액에서 파라치환된 cinnamoyl chloride의 가용매분해반응을 25$^{\circ}C$에서 수행하였다. 이들 속도자료로부터 Grunwald-Winstein관계식, Hammett 식, PES 모형과 QM모형을 이용하여 해석 하였다. 파라 치환된 cinnamoyl chloride의 일차반응속도상수를 이용하여 Grunwald-Winstein 도시를 한 결과 세 개의 분리된 곡선으로 분산 현상을 보였으며 알코올 수용액에서 큰 m 값을 나타내었다. PES 모형과 QM 모형에 의한 전이상태 변화에 대한 예측으로부터 본 연구에서의 반응은 결합 이탈이 많이 진전된 $S_N1$형 $S_N2$ 반응으로 진행되고 있음을 알 수 있었다. Solvolyses of para-substituted cinnamoyl chlorides in aqueous binary mixtures of acetone, ethanol, methanol were investigated at 25.0$^{\circ}C$. These data were interpreted using the Grunwald-Winstein relationship, Hammett equation, and quantum mechanical model. Grunwald-Winstein plots of the first-order rate constants for para-substituted cinnamoyl chlorides with $Y_{CI}$ showed marked dispersions into three separate curves for the three aqueous mixtures with a large m vaIue for aqueous alcohol solvents. This study has shown that the potential energy surface and quanturm mechanical model predict transition state variation correctly for $S_N1$ like $S_N2$ reaction mechanism of para-substituted cinnamoyl chlorides.

Stoichiometric Solvation Effects. Solvolysis of Isopropylsulfonyl Chloride

구인선,양기열,Hyeon Bae Shin,Sun Kyoung An,이종팔,이익춘 대한화학회 2004 Bulletin of the Korean Chemical Society Vol.25 No.5

Limitations of the Transition State Variation Model. Part 8. Dual Reaction Channels for Solvolyses of 3,4-Dimethoxybenzenesulfonyl Chloride

구인선,Eunju Kwon,Hojune Choi,양기열,박종근,Jong Pal Lee,Ikchoon Lee,T. William Bentley* 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.12

Solvolyses of 3,4-dimethoxybenzenesulfonyl chloride (DSC) in water, D2O, CH3OD, and in aqueous binary mixtures of acetone, acetonitrile, 1,4-dioxane, ethanol, methanol, and 2,2,2-trifluoroethanol (TFE) have been investigated at 25.0 oC. Kinetic solvent isotope effects (KSIE) in water and in methanol and product selectivities in alcohol-water mixtures are also reported. The Grunwald-Winstein plot of first-order rate constants for the solvolyic reaction of DSC with YCl shows marked dispersions into separated lines for various aqueous mixtures. With use of the extended Grunwald-Winstein equation, the l and m values obtained are 1.12 and 0.58 respectively for the solvolyses of DSC. The relatively large magnitude of l is consistent with substantial nucleophilic solvent assistance. From Grunwald-Winstein plots the rate data are dissected approximately into contributions from two competing reaction channels. This interpretation is supported for alcohol-water mixtures by the trends of product selectivities, which show a maximum for ethanol-water mixtures. From the KSIE of 1.45 in methanol, it is proposed that the reaction channel favored in methanol-water mixtures and in all less polar media is general-base catalysed and/or is possibly (but less likely) an addition-elimination pathway. Also, the KISE value of 1.35 for DSC in water is expected for SN2-SN1 processes, with minimal general base catalysis, and this mechanism is proposed for solvolyses in the most polar media.

메탄올-아세토니트릴 혼합용매계에서 할로겐화 펜아실과 피리딘유도체와의 친핵성 치환반응에 대한 속도론적 연구

구인선,양기열,박종근,이익춘 대한화학회 1997 대한화학회지 Vol.41 No.1

25℃와 35℃에서 메탄올-아세토니트릴 혼합용매계에 대한 할로겐화 펜아실과 피리딘 치환체와의 친핵성치환반응을 속도론적으로 연구하였다. 전이상태 파라미터인 ΔH≠와 ΔS≠ 및 Brosted β값으로 보아 $S_N2$반응 메카니즘을 예상할 수 있었고, 이탈기 변화에 따른 QM모형의 적용으로 이들 반응의 전이상태 역시 생성물 닮은 구조임을 알 수 있었다. Kinetic studies on nucleophilic substitution reaction of phenacyl bromide and phenacyl chloride with pyridines were conducted at 25℃ and 35℃ in methanol-acetonitrile solvents mixtures. It was shown that the reaction proceeds via an SN2 reaction mechanism based on the transition state parameters, ΔH≠ and ΔS≠ and Bro nsted β values. Quantum mechanical model predicted a product-like transition state, where bond-formation is much more progressed than bond breaking, upon changing the leaving group to that with a better leaving ability.

Solvolyses of N-Methyl-N-phenylcarbamoyl Chlorides with Electron Acceptor Substituents in A Queous Binary Mixtures

구인선,안선경,양깅열,고한중,최문호,이익춘,Gu, In Seon,An, Seon Gyeong,Yang, Yeol,Go, Han Jung,Choe, Mun Ho,Lee, Ik Chun Korean Chemical Society 2001 Bulletin of the Korean Chemical Society Vol.22 No.8

Solvolyses of N-methyl-N-phenylcarbamoyl chlorides in aqueous binary mixtures of acetone, ethanol, methanol and in water, D2O, and 50% D2O-CH3OD are investigated at 25.0 $^{\circ}C.$ The Grunwald-Winstein plots of first-ord er rate constants for N-methyl-N-phenylcarbamoyl chlorides with YCl (based on 2-adamantyl chloride) show a dispersion phenomenon. The ring parameter (I) has been shown to give considerable improvement when it is added as an hI term to the original Grunwald-Winstein and extended Grunwald-Winstein correlations for the solvolyses of N-methyl-N-phenylcarbamoyl chlorides. This study has shown that the magnitude of l, m and h values associated with a change of solvent composition is able to predict the dissociative SN2 transition state. The kinetic solvent isotope effects determined in deuterated water are consistent with the proposed mechanism of the general base catalyzed and/or a dissociative SN2 mechanism channel for N-methyl-N-phenylcarbamoyl chlorides solvolyses.