Hydrated electron: Nonempirical cluster approach

Abstract

ABSTRACT:Interface water anions composed of several chainlike or cyclic fragments were simulated with a 6-31ϩϩG** basis set at the unrestricted Hartree-Fock level with the second-order Moeller-Plesset perturbation theory corrections taken into account. The estimated vertical electron detachment energies (VDEs) of (H 2 O) n Ϫ anions were approximated by a VDE-n Ϫ1/3 dependence close to the experimental one. A hypothesis about the predominant formation of interface structures under conditions of molecular flows is put forward. The atomic population analysis, character of the highest occupied molecular orbital, and changes in the geometry of interface anions with an increase in their molecular size reveal the compact localization of the excess electron density in water clusters and allow evaluating the effective excess-electron radius of condensed water as 2.5 Å, in good agreement with a similar empirical estimate. The scope of the data obtained shows the relatively low probability of the formation of octahedral hydration shells compared to the tetrahedral coordination of solvating water molecules.

Reactivity of Hydrated Hydroxide Anion Clusters with H and Rb: An ab Initio Study

“…This is particularly the case for water clusters. Numerous theoretical and experimental studies have been dedicated to the understanding of the structure and dynamics of neutral water clusters, hydrated ions, hydrated electrons − and protons, and anionic water clusters …”

Anionic water clusters with large vertical electron binding energies and their electronic spectra: (H2O)11– and (H2O)14–

“…16,22,27 As an alternative building principle, so-called interface anions, where an electron binds water cluster fragments, have been discussed. 21,23,28 Relatively few calculations have been reported so far on larger anionic water clusters, in particular those with n > 11. In a pioneering quantum path-integral molecular-dynamics simulation employing empirical electron-water and waterwater interaction potentials, Landman and collaborators have addressed the problem of interior versus surface bound states of the excess electron in medium-size and large water clusters.…”

“…31 The calculated VDE of this structure was obtained in good agreement with the experimental value of ref. 28 As summarized by Ayotte and Johnson 12 and reemphasized by Coe, 14 '' the deceptively simple (H 2 O) n À system has not yet yielded to a self-consistent explanation of the experimental observations ''. Both Coe et al 11 and Ayotte and Johnson 12 have grounded their analysis on the paradigm of the cavity model of the hydrated electron, i.e., on the concept of an isolated excess electron in a cavity of liquid water.…”