Infrared vibration-rotation spectra of ethane. The parallel band, v₉ + v₁₀, of C₂D₆

Abstract

The weak combination band of C₂D₆ near 2816 cm^-1 has been studied at a resolution of 0.012 cm^-1. No K-structure is observed indicating that (A'- B')-(A'- B') is very small (less than c.10^-4 cm^-1). The band has been measured from R(38) to P(36), and lines of two hot bands, probably arising from excited levels of the torsion, and distinguishable only after the resolution had been increased by deconvolution, have also been measured and analysed. The constants determined from the mainband are: v_o = 2816.2327 ± 0.0012 cm^-1, B' = 0.459675 ± 0.000036 cm^-1, B' = 0.458652 ± 0.000061 cm^-1, D'_j = (4.18 ± 0.36) × 10^-7 cm^-1 and D'_j =(3.81 ± 0.65 )10^-7 cm^-1.