Distance and sequence dependence of DNA electron transfer

ORGN 769

Pierre Daublain, p-daublain@northwestern.edu, Huihe Zhu, Boiko Cohen, Mike R. Wasielewski, wasielew@chem.nwu.edu, and Frederick. D. Lewis, lewis@chem.nwu.edu. Department of Chemistry, Northwestern University, 2145 N. Sheridan Road, Evanston, IL 60208
The mechanism and dynamics of photoinduced charge separation and charge recombination in synthetic DNA hairpins possessing hole donor and hole acceptor stilbenes have been investigated by transient absorption spectroscopy. A crossover from a superexchange to a hopping mechanism for charge separation was observed as the distance between the chromophores increased; and the effect of shallow G:C hole traps on the overall charge migration kinetics was quantified. Transient absorption studies as well as time-dependent dehalogenation experiments on DNA hairpins containing pyrene donors and aromatic diimide or halouracil acceptors provided a mechanistic insight into excess electron transfer processes in DNA.

 

Physical Organic Chemistry: Calculations, Mechanisms, Photochemistry, and High Energy Species
8:00 AM-12:00 PM, Thursday, March 29, 2007 McCormick Place Lakeside -- Room E451A/B, Level 4, Oral

Division of Organic Chemistry

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007