Articles you may be interested inPhotoelectron spectroscopy of aqueous solutions: Streaming potentials of NaX (X = Cl, Br, and I) solutions and electron binding energies of liquid water and X− Photoelectron spectroscopy of iodine anion solvated in water clusters J. Chem. Phys. 95, 9416 (1991);

We have measured the photoelectron spectra of clusters of I- solvated in water up to fifteen water molecules. The vertical binding energy of the electron increases with cluster size and levels off in clusters containing more than six water molecules. These results strongly indicate that the first solvation layer around the ion consists of six water molecules. This picture is quantitatively consistent with the photoelectron spectroscopy result of I- solvated in bulk water.

Binding of excess electrons to nanosize water droplets, with a focus on the hitherto largely unexplored properties of doubly-charged clusters, were investigated experimentally using mass spectrometry and theoretically with large-scale first-principles simulations based on spin-density-functional theory, with all the valence electrons (that is, 8e per water molecule) and excess electrons treated quantum mechanically. Singly-charged clusters (H(2)O)(n)(-1) were detected for n = 6-250, and our calculated vertical detachment energies agree with previously measured values in the entire range 15 ≤ n ≤ 105, giving a consistent interpretation in terms of internal, surface and diffuse states of the excess electron. Doubly-charged clusters were measured in the range of 83 ≤ n ≤ 123, with (H(2)O)(n)(-2) clusters found for 83 ≤ n < 105, and mass-shifted peaks corresponding to (H(2)O)(n-2)(OH(-))(2) detected for n ≥ 105. The simulations revealed surface and internal dielectron, e(-)(2), localization modes and elucidated the mechanism of the reaction (H(2)O)(n)(-2) → (H(2)O)(n-2) (OH(-))(2) + H(2) (for n ≥ 105), which was found to occur via concerted approach of a pair of protons belonging to two water molecules located in the first shell of the dielectron internal hydration cavity, culminating in formation of a hydrogen molecule 2H(+) + e(-)(2) → H(2). Instability of the dielectron internal localization impedes the reaction for smaller (n < 105) doubly-charged clusters.

The photophysical properties of bimanes (l,5-diazabicyclo[3.3.0]octa-3,6-diene-2,8-diones) exhibit two types of behavior in solution. The maximal absorption energies, the maximal emission energies, the quantum yields of fluorescence, and the radiative rate constants all decrease (a) moderately fast with solvent polarities up to the intermediate range and (b) slowly from the intermediate polarity range up to water. The bimanes examined include syn-(hydro,hydro)bimane (1), -sy«-(methyl, fluoro)bimane ( 2), sy«-(methyl,hydro) bimane (3), ^(0)-jy«-(methylene,methyl)bimane ( 4), 5y«-(methyl,chloro)bimane ( 5), and jy«-(methyl,methyl)bimane ( 6). The effects are interpreted in terms of two conformational isomers, "bent" and "quasi-planar", for both the ground and excited states. The magnitude of the solvent sensitivities of the photophysical properties, the nature of the conjugation, and the shapes observed in crystal structures suggest that solvent polarity affects the conformation of the bent conformers. The equilibrium between bent and quasi-planar forms may not vary much with solvent polarity, but the appearance of the emission spectrum changes drastically due to substantial differences in the radiative rates for the two conformers.

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