Are adenine strands helical H-aggregates?
Hu L; Zhao Y; Wang F; Chen G; Ma C; Kwok WM; Phillips DL Department of Chemistry and Centre of Theoretical and Computational Physics, University of Hong Kong, Hong Kong, PR China. On the basis of our quantum mechanical calculation, we propose that homogeneous single-stranded adenine bases (Ade-DNA) form helical H aggregates, and the photoexcited states can be described as Frenkel excitons. The calculated excitonic coupling between adjacent transition dipoles is in good agreement with the measured absorption spectrum of 20-base homogeneous adenine stacks that exhibits a blue shift of 2.6 nm relative to that of the monomeric species.
