Journal of the American Chemical Society 2002-03-20

Distance-dependent activation energies for hole injection from protonated 9-amino-6-chloro-2-methoxyacridine into duplex DNA.

William B Davis, Stephan Hess, Izabela Naydenova, Reinhard Haselsberger, Alexander Ogrodnik, Marshall D Newton, Maria-E Michel-Beyerle

Index: J. Am. Chem. Soc. 124(11) , 2422-3, (2002)

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Abstract

The recent investigation of the apparently anomalous attenuation factor (beta > 1.5 A(-1)) for photoinduced hole injection into DNA duplexes modified by protonated 9-amino-6-chloro-2-methoxyacridine (X+) led to the conclusion that in addition to the electronic couplings, the activation energy must also be distance-dependent. In this communication we report the verification of this postulate by direct measurements of the activation energies for a series of (X+)-modified DNA duplexes which sample an appreciable range of donor-acceptor distances (approximately 4-11 A). The resulting changes in thermal activation energy can be explained within the framework of a distance-dependent reorganization energy.