School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, People's Republic of China.
Institut für Festkörpertheorie, Universität Münster, 48149 Münster, Germany.
Phys Rev Lett. 2014 Jun 6;112(22):228301. doi: 10.1103/PhysRevLett.112.228301. Epub 2014 Jun 3.
Charge-transfer (CT) excited states play an important role in the excited-state dynamics of DNA in aqueous solution. However, there is still much controversy on their energies. By ab initio many-body Green's function theory, together with classical molecular dynamics simulations, we confirm the existence of CT states at the lower energy side of the optical absorption maximum in aqueous DNA as observed in experiments. We find that the hydration shell can exert strong effects (∼1 eV) on both the electronic structure and CT states of DNA molecules through dipole electric fields. In this case, the solvent cannot be simply regarded as a macroscopic screening medium as usual. The influence of base stacking and base pairing on the CT states is also discussed.
电荷转移 (CT) 激发态在水溶液中 DNA 的激发态动力学中起着重要作用。然而，它们的能量仍然存在很大的争议。通过从头算多体格林函数理论，结合经典分子动力学模拟，我们在实验中观察到的水溶液 DNA 的光吸收最大值的较低能侧证实了 CT 态的存在。我们发现，水化壳可以通过偶极电场对 DNA 分子的电子结构和 CT 态产生强烈影响（约 1 eV）。在这种情况下，溶剂不能像通常那样简单地视为宏观屏蔽介质。还讨论了碱基堆积和碱基配对对 CT 态的影响。
