SF Negative Ion Formation in Charge Transfer Experiments.

In the present work, we report an update and extension of the previous ion-pair formation study of Hubers, M.M.; Los, J.

Peptide Bonds in the Interstellar Medium: Facile Catalytic Formation from Nitriles on Water-Ice Grains.

A recent suggestion that acetamide, CHC(O)NH, could be readily formed on water-ice grains by the acid induced addition of water across the C≡N bond has now been shown to be credible. Computational modeling of the reaction between R-CN (R = H, CH) and a cluster of 32 molecules of water and one HO proceeds catalytically to form first a hydroxy imine R-C(OH)═NH and second an amide R-C(O)NH. Quantum mechanical tunneling, computed from small-curvature estimates, plays a key role in the rates of these reactions.

Isotope Effect in DO Negative Ion Formation in Electron Transfer Experiments: DO-D Bond Dissociation Energy.

HO/DO negative ion time-of-flight mass spectra from electron transfer processes at different collision energies with neutral potassium yield OH/OD, O, and H/D. The branching ratios show a relevant energy dependence with an important isotope effect in DO. Electronic state spectroscopy of water has been further investigated by recording potassium cation energy loss spectra in the forward scattering direction at an impact energy of 205 eV (lab frame), with quantum chemical calculations for the lowest-lying unoccupied molecular orbitals in the presence of a potassium atom supporting most of the experimental findings.