The far-infrared spectrum of 12C2HD

The infrared spectrum of 12C2HD has been studied using synchrotron radiation at the far-infrared beam line, Canadian Light Source, Saskatoon, Canada. The spectra were recorded at a resolution of 0.00096 cm-1 in the 60 to 360 cm-1 range using a Bruker IFS 125 Fourier transform spectrometer. In total, 821 vibration rotation lines were observed and assigned to the P(J), Q(J) and R(J) transitions of the 5 4 difference band and associated hot bands with J'' up to 35 and (4 + 5) up to 3. These new transitions were analysed together with 4518 transitions involving bending states with (4 + 5) up to 3 available in the literature. The spectroscopic parameters obtained from the fit reproduce 4909 transitions with a standard deviation of 0.00028 cm-1. The 5 4 bands of 13CH12CD and 12CH13CD were also detected and analysed.