The Fourth Positive (A1Π-X1Σ+) System of 12C18O and 13C18O: Perturbations in the A1Π State

✍ Scribed by C. Haridass; S.P. Reddy; A.C. Lefloch

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 684 KB
• Volume: 167
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1994.1240

✦ Synopsis

The fourth positive (\left(A^{\prime} \Pi-X^{1} \Sigma^{+}\right.)) system of the carbon monoxideisotopomers ({ }^{12} \mathrm{C}^{18} \mathrm{O}) and ({ }^{13} \mathrm{C}^{18} \mathrm{O}) excited in the anode column of a hollow-cathode discharge tube was recorded in the spectral region (1710-1935 \AA) on a (10.6-\mathrm{m}) vacuum grating spectrograph. Of the eight bands of ({ }^{12} \mathrm{C}^{18} \mathrm{O}) observed with (v^{\prime}=0) to 2 and (v^{\prime \prime}=2) to 6 , and three bands of ({ }^{13} \mathrm{C}^{18} \mathrm{O}) with (v^{\prime}=0) and 1 and (v^{\prime \prime}=4) and 5 , the rotational structure of five bands of the former and two bands of the latter was analyzed. Several perturbations were observed in the (A^{\prime} \Pi) I state of both isotopomers. These include, for ({ }^{12} \mathrm{C}^{18} \mathrm{O}), strong perturbations on the order of (2 \mathrm{~cm}^{-1}) in (A, v=1) caused by (a^{33} \Sigma^{+}, v) (=10) and weak perturbations in (A, v=1) by (D^{1} \Delta, v=1) and (d^{3} \Delta, v=5), and in (A, v=2) by (I^{1} \Sigma^{-}, v=3, e^{3} \Sigma^{-}, v=4), and (d^{3} \Delta, v=7), and for ({ }^{13} \mathrm{C}^{18} \mathrm{O}). weak perturbations in (A, v=1) by (a^{3} \Sigma^{+}, v=10) and (d^{3} \Delta, v=5). The observed perturbations are in good agreement with those estimated by theoretical calculation. The deperturbed molecular constants were obtained for the (A^{\prime} \Pi I) state of both isotopomers. Perturbation parameters and mixing coefficients which characterize each perturbation were also derived. 1994 Academic Press. Inc.