The distance between donor and acceptor affects the proportion of C1' and C2' oxidation products of DNA in a BrU-containing excess electron transfer system.

We have investigated the products of (Br)U in excess electron transfer and have demonstrated that in DNA the proportion of products changes with the distance between the donor and acceptor. On the basis of a labeling experiment using H(2)(18)O, we have shown that hole migration from Py(•+) formed after charge separation is involved in the reaction.