Term: cage effect
https://doi.org/10.1351/goldbook.C00771

Definition:
When in a condensed phase, or in a dense gas, reactant molecules come together, or species are formed in proximity to one another, and are caged in by surrounding molecules, they may undergo a set of collisions known as an encounter; the term 'cage effect' is then applied.The cage effect is also known as the Franck–Rabinowitch effect.

Related Terms:
1) cage (http://doi.org/10.1351/goldbook.C00769).
2) reactant (http://doi.org/10.1351/goldbook.R05163).
3) encounter (http://doi.org/10.1351/goldbook.E02086).

Source: PAC, 1996, 68, 149. 'A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)' on page 155 (https://doi.org/10.1351/pac199668010149)

Citation: 'cage effect' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.C00771

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