pre-association

https://doi.org/10.1351/goldbook.P04794
A step on the @[email protected] of some @[email protected] in which the @[email protected] C is already present in an @[email protected] or @[email protected] with A during the formation of B from A, e.g.
P04794.png
In this mechanism the @[email protected] C may but does not necessarily assist the formation of B from A, which may itself be a @[email protected] reaction with some other @[email protected] [email protected]@ is important when B is too short-lived to permit B and C to come together by @[email protected]
See also:
microscopic diffusion control
,
spectator mechanism
Source:
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1152 [Terms] [Paper]