Converged electronic polarization of acetone in liquid water and the role in the n–π∗ transition

The electronic polarization of acetone in liquid water is obtained using an iterative procedure in the sequential Monte Carlo/quantum mechanics methodology. MP2/aug-cc-pVDZ calculations of the dipole moment of acetone in water are performed on statistically uncorrelated structures extracted from isothermic–isobaric MC simulations. After electrostatic equilibrium the calculated dipole moment of acetone is obtained as 4.80 ± 0.03 D, with an increase of 60% compared to the gas phase value. This solute polarization is used to obtain the shift of 1650 ± 42 cm−1 for the n–π∗ transition of acetone in water, in agreement with the experimental result of 1500–1700 cm−1.