Infrared spectroscopic studies of photoinduced reactions of methyl radical in solid parahydrogen

Photolysis of methyl iodide in solid parahydrogen crystal at about 5 K by a low-pressure mercury lamp produces methyl radical, methane and ethane as evidenced by their infrared absorption spectra. It is found that even after the complete depletion of methyl iodide the intensity of the ν3 and ν4 bands of methane continues to increase with the concomitant decrease of the intensity of the ν3 and ν4 bands of methyl radica as logn as the mercury lamp illumination is continued. Possible mechanisms of the spectral changes are proposed.