High-pressure photoionization mass spectrometry. Effect of internal energy and density on the ion–molecule reactions occurring in methyl, dimethyl, and trimethylamine
✍ Scribed by L. Hellner; L. W. Sieck
- Publisher
- John Wiley and Sons
- Year
- 1973
- Tongue
- English
- Weight
- 439 KB
- Volume
- 5
- Category
- Article
- ISSN
- 0538-8066
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✦ Synopsis
The ion-molecule reactions of CHaNH2+, (CH3),NH+, and (CH3)3Nf with the respective amines have been investigated at thermal kinetic energies in a high-pressure photoionization mass spectrometer at several wavelengths (energies) in the vacuum ultraviolet.
The absolute rate coefficient for proton transfer from (CH3)3N+ to (CH&N decreases from 8.2 x cm3/molecule.sec at 147.0 nm (8.4 eV) to 4.9 X 10-lo cm3/molecule.sec at 106.7-104.8 n m (1 1.7 eV). I n dimethylamine, the rate coefficient decreases from 11.6 X 10-10 cm3/molecular 'set at 8 4 eV to 10.2 X 10-10 cm3/molecule .set at 11.7 eV, while no significant effect of energy was detected in methylamine. The reactions of several fragment ions are also reported. Experiments were also carried out at pressures u p to 0.5 torr in order to investigate the further solvation of CHSNH2+, (CH3)2NH2+, and (CH,)DH+. It was found that the maximum proton solvation numbers in methyl-, dimethyl-, and trimethylamine are 4, 3, and 2, respectively, under these conditions.