Identification and analysis of the perturbed cΠ3(v=1)–XΣ+1 and kΠ3(v=5)–XΣ+1 absorption bands of carbon monoxide

Jacob Baker, Françoise Launay
2005 Journal of Chemical Physics  
Two new red-degraded bands in the room-temperature vacuum-ultraviolet absorption spectrum of carbon monoxide have been identified in the 94 000-94 500 cm −1 energy region and analyzed. One of the bands at Ϸ94 225 cm −1 ͑106.1 nm͒ has three observable bandheads and is partially overlapped with the strong C 1 ⌺ + -X 1 ⌺ + ͑1-0͒ transition at lower energy. It is assigned to the c 3 ⌸ -X 1 ⌺ + ͑1-0͒ transition. The other band at Ϸ94 437 cm −1 ͑105.9 nm͒ with one clear bandhead is assigned to the k
more » ... assigned to the k 3 ⌸ -X 1 ⌺ + ͑5-0͒ transition. A strong homogeneous perturbation was found to exist between the two upper states that strongly influences the line positions and shapes of these bands. A rotational deperturbation analysis was performed and molecular rotational constants for both upper states were determined. These deperturbed molecular constants are entirely consistent with the expected values for the k 3 ⌸ valence and c 3 ⌸ Rydberg states. The Hamiltonian interaction term between these two states is found to be separable into vibrational and electronic factors and the electronic factor is determined to be H e = 323± 40 cm −1 . A discrepancy in the literature regarding the location of the c 3 ⌸ ͑v =1͒ state is identified and discussed.
doi:10.1063/1.2136869 pmid:16392915 fatcat:hey2dxgx2bcgjg7bxcnksv2zou