Abstract
Electron impact ionization of helium nano-droplets containing several 104 He atoms and doped with CCl4 or SF6 molecules is studied with high-mass resolution. The mass spectra show significant clustering of CCl4 molecules, less so for SF6 under our experimental conditions. Positive ion efficiency curves as a function of electron energy indicate complete immersion of the molecules inside the helium droplets in both cases. For CCl4 we observe the molecular parent cation CCl4+ that preferentially is formed via Penning ionization upon collisions with He*. In contrast, no parent cation SF6+ is seen for He droplets doped with SF6. The fragmentation patterns for both molecules embedded in He are compared with gas phase studies. Ionization via electron transfer to He+ forms highly excited ions that cannot be stabilized by the surrounding He droplet. Besides the atomic fragments F+ and Cl+ several molecular fragment cations are observed with He atoms attached.
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- Category:
- Articles
- Type:
- artykuł w czasopiśmie wyróżnionym w JCR
- Published in:
-
INTERNATIONAL JOURNAL OF MASS SPECTROMETRY
no. 280,
pages 26 - 31,
ISSN: 1387-3806 - Language:
- English
- Publication year:
- 2009
- Bibliographic description:
- Schobel H., Dampc M., Ferreira D., Mauracher A., Zappa F., Denifl S., Tilmann M., Scheier P.: Electron impact iozization of CCl4 and SF6 embedded in superfluid helium droplets// INTERNATIONAL JOURNAL OF MASS SPECTROMETRY. -Vol. 280, nr. Iss. 1-3, February (2009), s.26-31
- Verified by:
- Gdańsk University of Technology
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