Related Experiment Video
Updated: Dec 30, 2025

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
Heavy-Atom Tunneling in Organic Reactions
Claire Castro1, William L Karney1
1Department of Chemistry, University of San Francisco, 2130 Fulton St., San Francisco, CA, 94117, USA.
Abstract:
In the past few years, numerous investigations have been reported on the role of heavy-atom tunneling in the area of pericyclic reactions, π-bond-shifting, and other processes. These studies illustrate unique strategies for the experimental detection of heavy-atom tunneling and the increased use of calculations to predict it. This Minireview focuses primarily on carbon tunneling in ground-state processes but also highlights nitrogen tunneling and the first example of excited-state heavy-atom tunneling. Salient features of these reactions along with potential limitations are discussed, as well as challenges and directions for future investigation.
Related Concept Videos
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
E1 Reaction: Kinetics and Mechanism
Radical Reactivity: Intramolecular vs Intermolecular
E2 Reaction: Kinetics and Mechanism
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...
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...

