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MO: Fachverband Molekülphysik
MO 26: Spektroskopie in He-Tröpfchen
MO 26.1: Poster
Donnerstag, 13. März 2008, 16:30–19:00, Poster C1
Microsolvation of alkali metals in H2O, NH3 studied by photoionisation in helium nanodroplets — •Severin Müller1, Marcel Mudrich1, Frank Stienkemeier1, and Udo Buck2 — 1Universität Freiburg, Physikalisches Institut, D-79104 Freiburg, Germany — 2Max-Planck-Institut für Dynamik und Selbstorganisation, D-37073 Göttingen, Germany
Helium nanodroplets have proven to be a valuable tool for the study of tailor-made species assembled within the droplets. We apply helium nanodroplet isolation spectroscopy to study the microsolvation of alkali metal clusters in the polar solvents water and ammonia. The droplets are doped consecutively with solvent molecules and alkali atoms. Further downstream they are nonresonantly ionized by a Ti:Sa femtosecond oscillator or electron bombardment. The mass distribution of products is analyzed using a high-resolution quadrupole mass spectrometer. From the mass spectra numerous compounds of the alkali atom and different water-related particles like O, OH, H2O are identified and their relative intensities discussed. By comparing PI spectra of different products ion chemical reactions induced by the ionization can be separated from reactions occurring already in the cold (0.4K) superfluid helium matrix. Comparison with similar studies carried out in molecular beams [1] allows us to characterize the influence of the matrix on the solvation and ionization process.
[1] C. Steinbach, U. Buck: Reaction and solvation of sodium in hydrogen bonded solvent clusters. Phys. Chem. Chem . Phys. 2005, 7, 986