Fourier transform emission spectroscopy of the g 4Δ- a 4Δ system of FeCl
Abstract
The emission spectrum of FeCl has been investigated at high resolution in the near infrared. The molecule was excited in a microwave discharge lamp using a mixture of FeCl 3 vapor and 4.9 Torr of He, and the spectra were recorded in the 3000-12 200 cm -1 region using a Fourier transform spectrometer. New bands with R heads near 7725, 8149, 8577, 8949, 9319, 9686, and 10 050 cm -1 have been assigned as the 0-2, 0-1, 0-0, 1-0, 2-0, 3-0, and 4-0 bands (respectively) of a new 4Δ- 4Δ system of FeCl. The strong bands of this system consist of four sub-bands assigned as 4Δ 1/2- 4Δ 1/2, 4Δ 3/2- 4Δ 3/2, 4Δ 5/2- 4Δ 5/2, and 4Δ 7/2- 4Δ 7/2. This transition is analogous to the 1 μm transitions of FeH and FeF. A rotational analysis of a number of bands in each sub-band has been obtained and spectroscopic constants extracted. The lower a 4Δ state is affected by perturbations from a nearby electronic state, while the excited g4Δ state is free from perturbation. This work represents the first observation of a transition involving quartet states of FeCl.
- Publication:
-
Journal of Molecular Spectroscopy
- Pub Date:
- October 2003
- DOI:
- 10.1016/S0022-2852(03)00225-X
- Bibcode:
- 2003JMoSp.221..261R