Sunghwan Kim - Effects of microsolvation on uracil and its radical anion: Uracil·(H2O)n (n=1-5)

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      Publication Details (including relevant citation   information):

      S. Kim and H.F.   Schaefer;

      Journal of Chemical Physics, 2006,   125, 144305.



      Microsolvation effects on the stabilities of uracil and its anion   have been investigated by explicitly considering the structures   of complexes of uracil with up to five water molecules at the   B3LYPDZP++ level of theory. For all five systems, the global   minimum of the neutral cluster has a different equilibrium   geometry from that of the radical anion. Both the vertical   detachment energy (VDE) and adiabatic electron affinity (AEA) of   uracil are predicted to increase gradually with the number of   hydrating molecules, qualitatively consistent with experimental   results from a photodetachment-photoelectron spectroscopy study   [J. Schiedt, Chem. Phys. 239, 511 (1998)]. The trend in the AEAs   implies that while the conventional valence radical anion of   uracil is only marginally bound in the gas phase, it will form a   stable anion in aqueous solution. The gas-phase AEA of uracil   (0.24 eV) was higher than that of thymine by 0.04 eV and this gap   was not significantly affected by microsolvation. The largest AEA   is that predicted for uracil (H2 O)5, namely, 0.96 eV. The VDEs   range from 0.76 to 1.78 eV.


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