encounter complex

https://doi.org/10.1351/goldbook.E02087
A @C01203@ of @M03986@ produced at an @E02089@, and which occurs as an intermediate in a @M03804@. When the complex is formed from two molecular entities it is called an '@E02090@'. A distinction between @E02086@ pairs and (larger) @E02086@ complexes may be relevant in some cases, e.g. for mechanisms involving @P04794@.
Source:
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1112 [Terms] [Paper]