Water microjet photoemission experiments and scattering calculations reveal genuine properties of the hydrated electron.

No abstract

Angle-resolved photoelectron spectroscopy of the unpaired electron in sodium-doped water, methanol, ammonia, and dimethyl ether clusters is presented. The experimental observations and the complementary calculations are consistent with surface electrons for the cluster size range studied. Evidence against internally solvated electrons is provided by the photoelectron angular distribution. The trends in the ionization energies seem to be mainly determined by the degree of hydrogen bonding in the solvent and the solvation of the ion core. The onset ionization energies of water and methanol clusters do not level off at small cluster sizes but decrease slightly with increasing cluster size.

It is investigated how far the vibrational exciton approximation is suitable to describe the characteristic band shapes in the infrared spectra of CO2 and N2O nanoparticles. The particles typically contain between 50 and 104 molecules and have spatial dimensions between 1 and 10 nm. The accuracy of the exciton approach is estimated by comparison with experimental data and quantum chemical calculations for small clusters. The spectral changes due to different particle shapes and particle sizes are investigated with respect to the estimated accuracy. This includes the determination of a typical effective range for the dipole–dipole coupling.

The determination of accurate size distributions and chemical composition of volatile and semivolatile ultrafine aerosol particles with sizes in the subnanometer to several tens of nanometers range is a problem that plagues many studies in aerosol research. We propose to employ sodium-doping of the aerosol particles with subsequent photoionization in the ultraviolet combined with mass spectrometric detection to solve this problem. Comparison with “soft” EUV ionization demonstrates that this technique can determine size distributions and to some extent the chemical composition of weakly bound ultrafine aerosol particles largely destruction-free. We also discuss how sodium-doping can be turned into a viable quantitative technique for the sizing of ultrafine aerosol particles.