Formation of Hydroxyl Radicals in Thymine Solution by Excited Hydrogen or Argon from a Gas Discharge

Summary

The effects of hydrogen gas excited in a radiofrequency discharge on oxygen-free solutions of thymine have been followed chemically. Two main reaction products have been identified: 5,6-dihydrothymine and 5,6-thymine glycol. The latter product was found to be the only significant species if discharge-excited argon was pumped through the solutions instead of hydrogen. Although dihydrothymine clearly is the reaction product of atomic hydrogen generated in the hydrogen discharge, the glycol requires the formation of OH radicals in the solution. A mechanism is proposed by which this species is produced through (super) excitation and decay of water molecules by energy transfer from the excited gas.