Electronic excitation in potentially reactive atom–molecule collisions

Abstract

Inelastic differential scattering cross sections for the system potassium + alkyl halide have been measured in the small angle region for Eχ between 20–1000 eV°. Electronic excitation of both collision partners is seen together with vibrational excitation of the alkyl halide.

Evidence is adduced suggesting that excitation occurs by either of two paths corresponding to the preliminary transfer of an electron in the entrance channel or as the colliding pair recedes. A harpooning model incorporating bond stretching in the negative molecular ion is developed that agrees well with most of the observations.