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.
Source:
PAC, 1996, 68, 149
(A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996))
on page 155
