Journal ArticleDOI
Gas-phase SN2 and E2 reactions of alkyl halides
TLDR
In this paper, rate coefficients have been measured for the gas phase reactions of methyl, ethyl, n-propyl, isopropyl, tert-butyl, and neopentyl chlorides and bromides with the following set of nucleophiles, listed in order of decreasing basicity.Abstract:
Rate coefficients have been measured for the gas-phase reactions of methyl, ethyl, n-propyl, isopropyl, tert-butyl, and neopentyl chlorides and bromides with the following set of nucleophiles, listed in order of decreasing basicity: HO − , CH 3 O − , F − , HO − (H 2 O), CF 3 CH 2 O − , H 2 NS − , C 2 F 5 CH 2 O − , HS − , and Cl − . For methyl chloride the reaction efficiency first falls significantly below unity with HO − (H 2 O) as the nucleophile and for methyl bromide with HS − as the nucleophile; in both cases the overall reaction exothermicity is about 30 kcal mol −1 . Earlier conclusions that these halides react slowly with stronger bases are shown to be in error. In the region where the rates are slow oxygen anions react with the alkyl chlorides and bromides by elimination while sulfur anions of the same basicity react by substitution. This difference is due to a slowing down of elimination with the sulfur bases; sulfur anions show no increased nucleophilicity as compared to oxy anions of the same basicityread more
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Chemistry with ADF
G. te Velde,F.M. Bickelhaupt,Evert Jan Baerends,C. Fonseca Guerra,S. J. A. van Gisbergen,J.G. Snijders,T. Ziegler +6 more
TL;DR: The “Activation‐strain TS interaction” (ATS) model of chemical reactivity is reviewed as a conceptual framework for understanding how activation barriers of various types of reaction mechanisms arise and how they may be controlled, for example, in organic chemistry or homogeneous catalysis.
Journal ArticleDOI
Understanding reactivity with Kohn–Sham molecular orbital theory: E2–SN2 mechanistic spectrum and other concepts
TL;DR: In this article, a detailed understanding of the electronic structure of a reaction system can help recognize certain characteristics of the process, yielding valuable mechanistic concepts, such as the E2−SN2 spectrum.
Journal ArticleDOI
A SN2 Reaction That Avoids Its Deep Potential Energy Minimum
TL;DR: The finding that the majority of trajectories avoided this potential energy minimum and instead dissociated directly to products and may be applicable to other reactive systems where there is a hierarchy of time scales for intramolecular motions and thus inefficient IVR.
Journal ArticleDOI
Imaging nucleophilic substitution dynamics.
Jochen Mikosch,Jochen Mikosch,Sebastian Trippel,Sebastian Trippel,C. Eichhorn,C. Eichhorn,R. Otto,R. Otto,Upakarasamy Lourderaj,Upakarasamy Lourderaj,Jiaxu Zhang,Jiaxu Zhang,William L. Hase,William L. Hase,Matthias Weidemüller,Matthias Weidemüller,Roland Wester,Roland Wester +17 more
TL;DR: The dynamics of the SN2 reaction of Cl– + CH3I were uncovered in detail by using crossed molecular beam imaging and reveal an indirect roundabout reaction mechanism involving CH3 rotation.
Journal ArticleDOI
Simulations of Gas-Phase Chemical Reactions: Applications to SN2 Nucleophilic Substitution.
TL;DR: The dynamical model of SN2 reactions that emerges from the computer studies, and its relation to statistical theories, is discussed here.