Portal de Periódicos da CAPES

Dynamics of superexchange photoinduced electron transfer in duplex DNA

2001; Elsevier BV; Volume: 2; Issue: 1 Linguagem: Inglês

10.1016/s1389-5567(01)00008-9

1873-2739

Frederick D. Lewis, Yansheng Wu,

Porphyrin and Phthalocyanine Chemistry

Photoinduced electron transfer (PET) in DNA can occur via one of two mechanisms, single-step superexchange and multi-step hole hopping. The dynamics of superexchange charge separation and charge recombination has recently been investigated in several structurally well-defined systems. In each of these systems, an electron acceptor is separated from a guanine or deazaguanine nucleobase donor by a variable number of A:T base pairs. The results of experimental studies on these and related systems are presented and analyzed within the framework of semi-classical electron transfer theory. Comparison of the results with those for other bridge-mediated electron transfer systems indicates that the π-stacked bases of DNA provide a better medium for electron transfer than the sigma bonded pathways of proteins and saturated hydrocarbons but do not function as a molecular wire.