A reaction or process generating free @[email protected] (or some other @[email protected] @[email protected]) which then induce a @[email protected] For example, in the chlorination of @[email protected] by a radical mechanism the initiation step is the @[email protected] of molecular chlorine.
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1125 [Terms] [Paper]
PAC, 1996, 68, 149. (A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)) on page 169 [Terms] [Paper]