| pubmed-article:19006164 | pubmed:abstractText | The absorption spectrum of A-T DNA is computed for the first time in aqueous solution by means of quantum mechanical calculations performed on realistic models, thereby accounting for both stacking and base pairing interactions and including solvent effects through the polarizable continuum model. The computed and experimental spectra are in close agreement. Our analysis allows the identification of all the electronic transitions hidden in the broad absorption spectrum of A-T DNA, thus determining their most relevant properties and providing an explanation for the most significant experimental features, such as the small blue shift of the band maximum and the appearance of a shoulder on the red wing of the absorption band. The lowest-energy dark excited state corresponds to a charge-transfer state between two stacked adenine bases. | lld:pubmed |
