UV-induced protonation of molecules adsorbed on ice surfaces at low temperature.
UV irradiation of ice films adsorbed with methylamine molecules induces protonation of the adsorbate molecules at low temperature (50-130 K). The observation indicates that long-lived protonic defects are created in the ice film by UV light, and they transfer protons to the adsorbate molecules via tunneling mechanism at low temperature. The methylammonium ion formed by proton transfer remains to be stable at the ice surface. It is suggested that this solid-phase protonation might play a significant role in the production of molecular ions in interstellar clouds.
Moon
Eui-Seong
ES
Department of Chemistry, Seoul National University, Gwanak-gu, Seoul 151-747, Republic of Korea.
Lee
Chang-Woo
CW
Kim
Joon-Ki
JK
Park
Seong-Chan
SC
Kang
Heon
H