Line strengths, spin-splittings, and forbidden transitions in the (101) band of 14N 16O 2

Abstract

Measurements of line strengths in the (101) and (111)-(010) bands of 14N 16O 2 have been made at a resolution of 0.02 cm −1 in the region 2863 to 2934 cm −1. The strength data in the (101) band were analyzed to determine a vibrational band strength and coefficients of the F factor. Each subband for K −1 ≤ 9 was analyzed separately and all the F-factor coefficients in terms of the rotational quantum number, N, were found to be too small to be of significance. However, F was found to be dependent on K −1 and the experimentally determined subband strengths were least-squares fitted to the expression S v 0· F, where S v 0 = 68.3 cm −2 atm −1 at 296 K and F = 1 + (2.899 × 10 −3) K −1 + (4.08 × 10 −3) K −1 2 − (2.34 × 10 −4) K −1 3. The integrated strengths for the (101) and (111)-(010) bands were found to be 70.9 ± 2.3 and 2.7 ± 0.3 cm −2 atm −1 at 296 K, respectively. Also included in this study are measurements of line center positions in the two bands and spin-splittings in the (101) band. Recent frequency measurements of lines with K −1 ≤ 8 in the (101) band have been made at a resolution of 0.0033 cm −1 by V. Dana and J. P. Maillard ( J. Mol. Spectrosc. 71, 1–4) (1978)) for the region above 2889 cm −1 and our values are in excellent agreement with theirs. Separations of the split lines measured in this work ( K −1 ≤ 10) agree well with calculated values using expressions which include the η aaaa K −1 4 term with η′ aaaa = −1.70 ± 0.15 × 10 −4 cm −1 as derived for the (101) state. Three forbidden (Δ N ≠ Δ J, Δ K −1 = 0) transitions in the (101) band were observed with their identifications based on the agreement between measured and calculated line positions and strengths.