Doubly-charged ethane ions: Solution to the dilemma of stability predicted by theory and instability observed in experiment
✍ Scribed by G. C. Shields; T. F. Moran
- Publisher
- John Wiley and Sons
- Year
- 1986
- Tongue
- English
- Weight
- 604 KB
- Volume
- 21
- Category
- Article
- ISSN
- 1076-5174
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✦ Synopsis
Potential energy curves have been computed for [CZ&]" ions and the results used to interpret the conspicuous absence of these ions in 2E mass spectra and in charge-stripping experiments. The energies and structures of geometry-optimized ground-state singlet and excited-state triplet [CzH$+ ions have been determined along with energies for different decomposition barriers and dissociation asymptotes. Although singlet and triplet [CzHJZ' ions can exist as stable entities, they possess low energy barriers to decomposition. Vertical Franck-Condon transitions, involving electron impact ionization of ethane as well as charge-stripping collisions of [Cz&]+ ions, produce [ C , & ] 2 ' ions which promptly dissociate since they are formed with energies in excess of various decomposition barriers. Appearance energies computed for doubly-charged ethane fragment ions are in accordance with experimental values.