The v6 + v10 band of ethane

A Fourier transform interferometer was used to record the slit-jet cooled overtone absorption spectrum of ethane around 2.3 μm, at a spectral resolution of 0.01 cm−1. The rotational temperature was determined to be 35 K. A band observed around 4343 cm−1, of perpendicular type, was analysed. 139 lines were assigned to 7 different subbands. One of these subbands, K′ΔK = −2, shows torsional splittings. Effective rotational parameters were obtained for each subband. A strong perturbation obscures the K′ΔK = +1 subband, which thus could not be assigned. The vibrational band was assigned to the v6 + v10 combination band on the basis of the Coriolis ζ constant, which was found to be ζ6+10 = 0.26(3). The band origin was determined to be v6+100 = 4342.56(25) cm−1.