title: Intermolecular proton transfer in anionic complexes of uracil with alcohols.
abstract: A series of 18 alcohols (ROH) has been designed with an enthalpy of deprotonation in the gas phase (H(DP)) in the range 13.8-16.3 eV. The effects of excess electron attachment to the binary alcohol-uracil (ROH...U) complexes have been studied at the density functional level with a B3LYP exchange-correlation functional and at the second-order Møller-Plesset perturbation theory level. The photoelectron spectra of anionic complexes of uracil with 3 alcohols (ethanol, 2,2,3,3,3-pentafluoropropanol, and 1,1,1,3,3,3-hexafluoro-2-propanol) have been measured with 2.54 eV photons. For ROHs with deprotonation enthalpies larger than 14.8 eV, only the ROH...U- minimum exists on the potential energy surface of the anionic complex. For alcohols with deprotonation enthalpies in the range 14.3-14.8 eV, two minima might exist on the anionic potential energy surface, which correspond to the RO-...HU* and ROH...U- structures. For ROHs with deprotonation enthalpies smaller than 14.3 eV, the excess electron attachment to the ROH...U complex always induces a barrier-free proton transfer from the hydroxyl group of ROH to the O8 atom of U, with the product being RO-...HU*.
authors.affiliation: Department of Chemistry, University of Gdańsk, Sobieskiego 18, 80-952 Gdańsk, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Harańczyk
authors.forename: Janusz
authors.initials: J
authors.lastname: Rak
authors.forename: Maciej
authors.initials: M
authors.lastname: Gutowski
authors.forename: Dunja
authors.initials: D
authors.lastname: Radisic
authors.forename: Sarah T
authors.initials: ST
authors.lastname: Stokes
authors.forename: Kit H
authors.initials: KH
authors.lastname: Bowen