| Autor: |
D.R. Zook, W. B. Knighton, E.P. Grimsrud |
| Rok vydání: |
1991 |
| Předmět: |
|
| Zdroj: |
International Journal of Mass Spectrometry and Ion Processes. 104:63-80 |
| ISSN: |
0168-1176 |
| DOI: |
10.1016/0168-1176(91)85006-8 |
| Popis: |
The relative amounts of Br−2 and Br− formed from the attachment of thermal electrons to ten dibrominated hydrocarbons and fluorocarbon have been measured under a range of buffer gas conditions, including pressure variations from 1 Torr to 1 atm. Measurements by a pulsed e-beam high pressure mass spectrometer have been made at 1–4 Torr and 50°–150°C, using seven different buffer gases. Measurements by an atmospheric pressure ionization mass spectrometer have been made in nitrogen buffer gas at 100°–200°C. The relative abundances of Br−2 and Br− produced in these electron capture reactions are found to change significantly with variations in buffer gas pressure and, in the low-torr pressure range, with changes in the composition of the buffer gas. A model for the EC reactions of dibrominated compounds is proposed in which the branching ratio for the two pathways leading to Br−-2 and Br− depends on the extend of collisional quenching of vibrationally excited reaction intermediates by the buffer gas molecules. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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