direct reaction

Also contains definition of: impulsive reaction
https://doi.org/10.1351/goldbook.D01773
A chemical process in which the @[email protected] has a @[email protected] that is shorter than its period of rotation. In a @[email protected] experiment the reaction products of a direct reaction are scattered, with reference to the centre of mass of the system, in preferred directions rather than at random. Some direct reactions are impulsive which means that there is an energy exchange that is very fast compared to the vibrational time scale. A direct reaction is to be contrasted with an @[email protected], also known as a @[email protected]
Source:
PAC, 1996, 68, 149. (A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)) on page 163 [Terms] [Paper]