Mp. Gaigeot et al., Analysis of uracil hydration by means of vibrational spectroscopy and density functional calculations, J MOL STRUC, 565, 2001, pp. 469-473
Interaction of water molecules (up to seven) with uracil (RNA base) through
the first hydration shell has been analysed by means of density functional
theory (DFT) calculations at the B3LYP/6-31G(*) level. Water molecules in
uracil + 2H(2)O and uracil + 4H(2)O complexes interact with adjacent N-H an
d C double bondO chemical groups of the base. In addition to these groups,
water molecules are also H-bonded to the uracil C-H groups in the uracil 7H(2)O complex. It has been shown that the formation of water dimer and wat
er trimer around uracil is necessary to complete its first hydration shell.
Harmonic vibrational calculations have been performed after full geometry
optimisation of each compound. A discussion has then been undertaken on the
vibrational analysis of uracil in going from gas phase to solution state o
n the basis of available observed vibrational spectra and those calculated
for isolated uracil and uracil + nH(2)O complexes. (C) 2001 Elsevier Scienc
e B.V. All rights reserved.