Thermal Reactions of Hydrogen Atoms with Organic Compounds in Sulfuric Acid Glasses at Low Temperature

The formation (G values) and the thermal disappearance of hydrogen atoms in sulfuric acid glasses were measured as a function of time and concentration of organic additives (isopropanol, ethanol, thymidine, and 5-bromodeoxyuridine). Thermal hydrogen atoms react with isopropanol and ethanol at 77°K by abstraction and with thymidine by addition. With 5-bromodeoxyuridine as additive, the production of at least two different radical species was found at low temperature. One radical is due to the reaction with thermal hydrogen atoms, whereas the other radical could result from the reaction with the (<tex-math>${\rm SO}{}_{4}{}^{-}$</tex-math>) radical. A "stepwise" disappearance of the hydrogen atoms at different isopropanol concentration was observed.