| Autor: |
Campbell JS; School of Chemistry, University of New South Wales, Sydney, NSW, Australia., Nauta K; School of Chemistry, University of New South Wales, Sydney, NSW, Australia., Kable SH; School of Chemistry, University of New South Wales, Sydney, NSW, Australia., Hansen CS; School of Chemistry, University of New South Wales, Sydney, NSW, Australia. |
| Jazyk: |
angličtina |
| Zdroj: |
The Journal of chemical physics [J Chem Phys] 2021 Nov 28; Vol. 155 (20), pp. 204303. |
| DOI: |
10.1063/5.0073974 |
| Abstrakt: |
The photodissociation dynamics of jet-cooled trifluoroacetaldehyde (CF 3 CHO) into radical products, CF 3 + HCO, was explored using velocity mapped ion imaging over the wavelength range 297.5 nm ≤λ≤ 342.8 nm (33 613-29 172 cm -1 ) covering the entire section of the absorption spectrum accessible with solar actinic wavelengths at the ground level. After initial excitation to the first excited singlet state, S 1 , the radical dissociation proceeds largely via the first excited triplet state, T 1 , at excitation energies above the T 1 barrier. By combining velocity-mapped ion imaging with high-level theory, we place this barrier at 368.3 ± 2.4 kJ mol -1 (30 780 ± 200 cm -1 ). After exciting to S 1 at energies below this barrier, the dissociation proceeds exclusively via the ground electronic state, S 0 . The dissociation threshold is determined to be 335.7 ± 1.8 kJ mol -1 (28 060 ± 150 cm -1 ). Using laser-induced fluorescence spectroscopy, the origin of the S 1 ← S 0 transition is assigned at 28 903 cm -1 . The S 0 dissociation channel is active at the S 1 origin, but the yield significantly increases above 29 100 cm -1 due to enhanced intersystem crossing or internal conversion. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
|
