Related Experiment Video
Updated: Jul 12, 2026

Spin Saturation Transfer Difference NMR (SSTD NMR): A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes
Published on: November 12, 2016
Simulations of Gas-Phase Chemical Reactions: Applications to SN2 Nucleophilic Substitution
Abstract:
Computer simulations and animations of the motion of atoms as a chemical reaction proceeds give a detailed picture of how the reaction occurs at a microscopic level. This information is particularly useful for testing the accuracy of statistical models, which are used to calculate various attributes of chemical reactions. Such simulations and animations, in concert with experimental and ab initio studies, have begun to provide a microscopic picture of the intimate details of a particular class of gas-phase ion-molecule bimolecular reactions known as S(N)2 nucleophilic substitution. In these reactions, a nucleophile is displaced from a molecule by another nucleophile. The dynamical model of S(N)2 reactions that emerges from the computer studies, and its relation to statistical theories, is discussed here.
Related Concept Videos
Predicting Products: SN1 vs. SN2
With increased substitution on the alkyl halide,...
SN2 Reaction: Kinetics
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a reaction.
SN2 Reaction: Transition State
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...
Nucleophilic Aromatic Substitution: Addition–Elimination (SNAr)
The reaction begins with an attack of the nucleophile on the carbon that holds the leaving group. This results in the delocalization of the π electrons over the ring carbons. The resonance interaction between the...
SN2 Reaction: Mechanism
The presence of the more electronegative halogen in the substrate creates a polarized carbon-halide bond. The halide pulls the electron cloud generating an electrophilic center at the carbon atom. Thus, the carbon atom carries a partial positive charge while the halide has a...
Nucleophilic Substitution Reactions
In 1896, the German chemist Paul Walden discovered that he could interconvert pure enantiomeric (+) and (-) malic acids through a series of reactions. This conversion suggested the involvement of optical inversion during the substitution reaction. Further, in 1930, Sir Christopher Ingold described for the first time two different forms of nucleophilic substitution reactions, which are known as SN1 (nucleophilic substitution unimolecular) and SN2 (nucleophilic substitution...
![The Synthesis of [Sn10(Si(SiMe3)3)4]2- Using a Metastable Sn(I) Halide Solution Synthesized via a Co-condensation Technique](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F54498.jpg&w=3840&q=50)