期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1981
卷号：78
期号：12
页码：7250-7253
DOI：10.1073/pnas.78.12.7250
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Gaseous molecular ions containing argon and perchlorethylene, Arn(C2Cl4)m+ in which n [≥] 1-29 and m [≥] 1-4, are produced by electron bombardment of van der Waals clusters formed by expanding an Ar/C2Cl4 mixture through a supersonic nozzle. Previous attempts to observe such ions in a high-pressure mass spectrometer were not successful, as with many other ("bastard") ions that similarly lack a stable chemically bound neutral parent molecule. This is probably due to dissociation induced by the large exoergicity from charge transfer between species that differ greatly in ionization potential. Use of van der Waals clusters as parent species avoids entirely the exoergicity problem and thus offers a general method to generate bastard ions. The Ar(C2Cl4)m+ ions have been suspected of interfering with collection of 37Ar+ ions produced by the 37Cl(v,e-)37Ar+ reaction in the solar neutrino observatory. Although, as shown by our results, these ions are stable, they are unlikely to inhibit collection on the long time scale of the solar neutrino experiment.
关键词：molecular beam ; supersonic expansion ; mass spectroscopy
