The nu[sub 9] band of propyne-d[sub 3]

A high-resolution Fourier transform spectrum of the [nu][sub 9] band of CD[sub 3]CCH has been recorded at an apodized resolution of 0.004 cm[sup [minus]1] and analyzed. More than 1,700 lines in the spectrum have been assigned and the parameters of the [nu][sub 9] state derived. The standard deviation of the fit was 0.00034 cm[sup [minus]1]. In order to achieve this fit it was necessary to include l-type doubling interaction and Fermi resonance between [nu][sub 9] and the E component of 2[nu][sub 10].