https://doi.org/10.1351/goldbook.E02087
A @[email protected] of @[email protected] produced at an @[email protected], and which occurs as an intermediate in a @[email protected] When the complex is formed from two molecular entities it is called an '@[email protected]'. A distinction between @[email protected] pairs and (larger) @[email protected] complexes may be relevant in some cases, e.g. for mechanisms involving @[email protected]