Thymine Oxetanes as Charge Traps for Chemical Monitoring of Nucleic Acid Mediated Transfer of Excess Electrons

摘要

Nucleic acid mediated electron transfer in DNA is highly relevant for the understanding of DNA damage and repair.[1] The investigation of the distance and sequence dependence of electron transfer in DNA is necessary to estimate its application as a molecular wire in nanobiotechnology.[2] While principles of hole transfer in DNA were basically elucidated by a combination of modern time-resolved spectroscopy[3] and chemical monitoring,[4] the detailed investigation of the long-range transfer of excess electrons is still problematic owing to the lack of a suitable acceptor system for chemical monitoring. The extensively used cyclobutane pyrimidine dimer (CPD) proved to be unsuitable for chemical monitoring of excess-electron transfer: its redox potential[5] is unfavorable compared to that of thymine (G+0.1 eV), and the cycloreversion rate[6] of the detecting reaction is slow (10~6 s~(-1)).