Thymine dimer scission

In late 1996, a new family of DNA-mediated ET experiments began to be reported. In these the ET donor is comprised of one or more DNA nucleotides (either G, GG, GGG, or a covalent thymine dimer) while the other is a covalently attached, photoactivated electron acceptor (either anthraquinone, pyrene, or an tris-polypyridyl M(III) complex, where M = Ru or Rh) [74-80]. These experiments have much in common with the kind of experiments outlined immediately above and with the new hairpin studies recently reported. They will be discussed toward the end of this chapter. They differ from the pre-1997 ET kinetics experiments that will be discussed immediately below in that none of them has reported ET rate measurements. Rather, yields of net photochemistry (either DNA strand cleavage or thymine dimer scission) are presented as evidence that photoinduced ET events occurred. For comparison of experimental results with ET theory it is clear that at a minimum ET rates must be measured and at a maximum several rates should be measured for a given D/A pair at a variety of separation distances. 

C. Long-Range Photooxidatlve Thymine Dimer Scission... 

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