Energy Dependence of the Cross Section for Methyl Iodide (+) Potassium yields Methyl Radical (+) Potassium Iodide Near Threshold.

摘要

The energy dependence of reaction cross sections of Methyl iodide + Potassium yields Methyl radical + Potassium iodide near threshold has been investigated by use of an idealized model of the hard-sphere collision of methyl iodide with potassium atom in which methyl iodide is assumed to undergo harmonic-vibrational motion. Near threshold only a small fraction of trajectories enters the reaction region, but they all pass on to reaction. As energy increases the cross section increases very sharply because more trajectories enter the reaction region. At still higher energies the cross section becomes small because a part of such trajectories reflects from the repulsive wall back to the reactant region. A maximum value of the cross section is found to be 35 angstrom-square at 3.2 kcal per mole. (Author)