MO calculations of some thymine radicals at the INDO level.

The results of MO INDO calculations of some thymine radicals are presented. These include as well as the hydrogen addition radicals the hydroxyl addition radicals to C5 and to C6 of the C5=C6 double bond of the thymine molecule. The radicals resulting from hydrogen abstraction from the methyl group and from the nitrogen N1 are also studied. Except for radicals where the main spin density is localized on nitrogen atoms, the agreement between experimental and theoretical couplings is satisfactory.