title: Dehydration of Methanediol in Aqueous Solution: An ONIOM(QM/MM) Study.
abstract: We used ONIOM(QM/MM) method to examine the dehydration of a methanediol in aqueous solution. A methanediol and a small number of water molecules in the proximity of the methanediol are calculated with quantum mechanics (QM), while a number of water molecules far from the methanediol are calculated with molecular mechanics (MM). A molecular dynamical simulation shows that 12 water molecules are located within the hydration shell of a methanediol. The energy barrier for the dehydration of a methanediol decreases when we increase the number of water molecules in the QM region and converges toward a finite value when 12 water molecules are included in the QM region. This indicates a significant effect of water molecules within the hydration shell on the dehydration process of a methanediol in aqueous solution. The dehydration rate calculated with the ONIOM(QM/MM) method agrees well with that obtained from a laboratory experiment.
authors.affiliation: School of International Liberal Studies, Waseda University , 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Inaba
authors.affiliation: Department of Chemistry, Faculty of Science, Hokkaido University , North-10 West-8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
authors.forename: W M C
authors.initials: WM
authors.lastname: Sameera