Sequence-dependent thymine dimerization and lifetimes of the photoexcited state of oligonucleotides.

DNA-sequence-dependent thymine-thymine (TT) dimerization was investigated from the perspective of the UV-induced charge transfer state. Steady-state and transient absorption measurements suggest that the relatively small oxidation potential and long-lived charge transfer state at the neighboring nucleobases of the TT site may reduce DNA lesion accumulation.