Production and stability of singly and doubly charged O2 clusters

✍ Scribed by P. Scheier; A. Stamatovic; T.D. Märk

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 525 KB
• Volume: 144
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(88)87101-x

✦ Synopsis

Clusters of (Or), molecules produced by supersonic nozzle expansion have been investigated using electron impact ionization mass spectrometry. Mass-resolved spectra (with n up to 110) show three homologous series consisting of (Oz):, ((Or), .O)+ and (( OZ ). .O) *+ ions. The critical appearance size found for doubly charged, stoichiometric and fragment, Or cluster ions is n, I 92. This confirms a recent prediction about nt in van der Waals clusters. The appearance energy AE of ((O*);O) *+ is shifted well below the appearance energy of 0 '+ from OZ. This is in accordance with a recently suggested sequential ionization mechanism for the production of stable doubly charged cluster ions, Moreover, the shape of the ionization cross section curve of singly charged cluster ions indicates that above the appearance energy of doubly charged ions an appreciable number of singly charged ions are produced via Coulomb explosion of unstable doubly charged ions.