title: DFT study of the gas phase proton transfer in guanine assisted by water, methanol, and hydrogen peroxide.
abstract: A computational study of hydrogen-bonded complexes between the oxo-/hydroxo-amino N7/9H tautomers of guanine and water, methanol, and hydrogen peroxide has been performed at the B3LYP/6-31 + G(d) level of theory. The mechanisms of the water-, methanol-, and hydrogen peroxide-assisted proton transfers in guanine were studied and compared with the intramolecular proton transfer in guanine in the gas phase. It was found that the assisted proton transfers pass through about three times lower energy barriers than those found for isolated guanine tautomers.
authors.affiliation: Department of Physical Chemistry, University of Plovdiv, Plovdiv, Bulgaria. vdelchev@hotmail.com
authors.forename: Vassil B
authors.initials: VB
authors.lastname: Delchev
authors.forename: Hans
authors.initials: H
authors.lastname: Mikosch
mesh_terms: D005740:Gases; D006147:Guanine / Q000737:chemistry*; D006860:Hydrogen Bonding; D006861:Hydrogen Peroxide / Q000737:chemistry; D000432:Methanol / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D011522:Protons; D014867:Water / Q000737:chemistry
chemical_list: D005740:Gases; D011522:Protons; D014867:Water; D006147:Guanine; D006861:Hydrogen Peroxide; D000432:Methanol