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Study of infrared emission spectroscopy for the B¹Δg-A¹Πu and B'¹Σg+-A¹Πu systems of C2.
- Source :
-
Journal of Chemical Physics . 2016, Vol. 144 Issue 6, p1-11. 11p. 1 Diagram, 11 Charts, 5 Graphs. - Publication Year :
- 2016
-
Abstract
- Thirteen bands for the B¹Δg-A¹Πu system and eleven bands for the B'¹Σg+-A¹Πu system of C2 were identified in the Fourier transform infrared emission spectra of hydrocarbon discharges. The B'¹Σg+ v = 4 and the B¹Δg v = 6, 7, and 8 vibrational levels involved in nine bands were studied for the first time. A direct global analysis with Dunham parameters was carried out satisfactorily for the B¹Δg-A¹Πu system except for a small perturbation in the B¹Δg v = 6 level. The calculated rovibrational term energies up to B¹Δg v = 12 showed that the level crossing between the B¹Δg and d³Πg states is responsible for many of the prominent perturbations in the Swan system observed previously. Nineteen forbidden transitions of the B¹Δg-a3?u transition were identified and the off-diagonal spin-orbit interaction constant AdB between d³Πg and B¹Δg was derived as 8.3(1) cm-1. For the B'¹Σg+-A¹Πu system, only individual band analyses for each vibrational level in the B'¹Σg+ state could be done satisfactorily and Dunham parameters obtained from these effective parameters showed that the anharmonic vibrational constant wexe is anomalously small (nearly zero). Inspection of the RKR (Rydberg-Klein-Rees) potential curves for the B'¹Σg+ and X¹Σg+ states revealed that an avoided crossing or nearly avoided crossing may occur around 30 000 cm-1, which is responsible for the anomalous molecular constants in these two states. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00219606
- Volume :
- 144
- Issue :
- 6
- Database :
- Academic Search Index
- Journal :
- Journal of Chemical Physics
- Publication Type :
- Academic Journal
- Accession number :
- 113170101
- Full Text :
- https://doi.org/10.1063/1.4940907