Comparative study of cw CO2 laser induced and SF6 sensitized decomposition of methyl iodides CH3I and CD3I

The decomposition of methyl iodide-d3 initiated by the irradiation of a cw CO2 laser in the presence of SF6 proceeds under comparable conditions faster, particularly in the shorter wavelength region of the CO2 laser spectrum, than the decomposition of methyl iodide. The differences can be explained by the different distribution of energy levels of both reactants. Observable differences are also in the composition of the reaction products. All these facts indicate the participation of at least two reaction mechanisms, a radical one and and a molecular one, which can probably proceed via the collision of two vibrationally excited molecules of CX3I.