Hydrogen-Bond Network Transformation in Water-Cluster Anions Induced by the Complex Formation with Benzene.
We report spectroscopic evidence of isomer interconversion in water cluster anions, (H2O)n(-), which occurs through the interaction with a benzene molecule. An anion complex composed of (H2O)6(-) and benzene, Bz·(H2O)6(-), is formed via the reaction of (H2O)6(-)Arm with benzene. The reaction proceeds as an Ar-mediated association process such that a rapid energy dissipation by sequential Ar evaporation efficiently suppresses the thermionic emission of e(-), H2O, or both, giving rise to the formation of Bz·(H2O)6(-). Photoelectron spectroscopy is employed to probe the electronic properties of the anionic species, which reveals that "type I → type II" isomer interconversion proceeds in the (H2O)6(-) moiety during the formation of Bz·(H2O)6(-). With the aid of ab initio calculations, we conclude that the interconversion is driven by preferential stabilization of the H-bond network of type II arrangement through the formation of a nonconventional O-H···π hydrogen bond between (H2O)6(-) and Bz.
†Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan.
Ryuzo
R
Nakanishi
‡Photon Science Center, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Takeshi
T
Sato
§Fuel Cell Nanomaterials Center, University of Yamanashi, 6-43 Miyamae-cho, Kofu, Yamanashi 400-0021, Japan.
Kiyoshi
K
Yagi
†Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan.
Takashi
T
Nagata
anion photoelectron spectroscopy; benzene−water interactions; dipole-bound anions; hydrated electron clusters; nonconventional hydrogen bond