Infrared spectroscopic studies on photolysis of ethyl iodide in solid parahydrogen

The photolysis of ethyl iodide in solid parahydrogen leads to the formation of ethyl radical, ethylene, and ethane upon near-UV illumination at about 5 K which are characterized by vibrational spectroscopy. The mechanism of the formation of the products is elucidated consistently. Two kinds of ethylene are discriminated spectroscopically which show distinctly different temporal behaviors during illumination and standing under dark. One of them is attributed to a complex between ethylene and iodine atom. The present work demonstrates that the cage effect is insignificant in the solid parahydrogen matrix, and a variety of elementary reactions of in situ photolysis can be studied in detail in contrast to conventional rare gas matrices.