Related Experiment Video
Updated: Apr 18, 2026

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
Published on: May 29, 2018
Fast photoinduced reactions in the condensed phase are nonexponential
Ron Simkovitch1, Rinat Gepshtein, Dan Huppert
1Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University , Tel Aviv 69978, Israel.
Abstract:
Time-resolved measurements of photoinduced reactions reveal that many ultrafast reactions in the femto- to picosecond time scale are nonexponential. In this article we provide several examples of reactions that exhibit a nonexponential rate. We explain the wide range of the nonexponential reaction by the lack of time separation between τ(s), the characteristic fast equilibration time of the population in the reactant potential well, and the longer time τ(e), the characteristic time to cross the energy barrier between the reactant and the product.
More Related Videos
Related Concept Videos
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Cycloaddition Reactions: MO Requirements for Photochemical Activation
Thermal and Photochemical Electrocyclic Reactions: Overview
Deactivation Processes: Jablonski Diagram
The Photochemical Reaction Center
Reaction Mechanisms
For instance, the decomposition of ozone appears to follow a mechanism with two steps:

