Surface impact induced fragmentation and charging of neat and mixed clusters of SO2 and H2O

Autor: Christoph Gebhardt, Vladimir V. Gridin, Israel Schechter, Anna Tomsic, Hartmut Schröder, Karl-Ludwig Kompa
Rok vydání: 2004
Předmět:
Zdroj: International Journal of Mass Spectrometry. 232:1-7
ISSN: 1387-3806
DOI: 10.1016/j.ijms.2003.10.003
Popis: Cluster impact induced charge separation was studied with neat and mixed clusters of SO2 and H2O impinging at hyperthermal velocities on a SiOx target held at different temperatures. At 750 K, impact of SO2 clusters produces positively and negatively charged cluster fragments of the form [(SO2)n − K, Na] + and [(SO2)m − SO2] − which is explained in terms of the known cluster-impact induced pickup of alkali surface adsorbates. The high sensitivity of this channel promises applications for the analysis of alkali surface contaminations. The dominant fragments observed during the impact of binary SO2/H2O clusters at the same target temperature were [(H2O)n − H] + and [(SO2)p (H2O)q − HSO3] − , which indicates an intracluster proton transfer reaction. Similar fragments were also detected as minor spectral progressions during the surface impact of neat SO2 clusters at a target temperature of 380 K. This is interpreted in terms of an impact-induced pickup of water surface adsorbates into the neat sulfur dioxide cluster during the surface collision. Upon impact of neat water clusters, fragment ions of the form [(H2O)n − H] + and [(H2O)q − OH] − are observed, which can be explained in terms of the autoprotolysis reaction in bulk water.
Databáze: OpenAIRE
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