HIGH RESOLUTION FEIR AND DIODE LASER SPECTRA OF PROPYNE-D IN THE 9-11 pm REGION

$^{1.}$ J. I. Duncan, I. J. Wright, and D. Ellis, J. Mol. Spectrosc. 37, 394 (1971). $^{2.}$ T. Al Adlounl, F. Meyer, G. Meyer .J.G. Layabe. and A. Fayt, Int .J. Infrared and Millimeter Waves 7, 405 (1986). $^{3.}$ R. K. Thomas and H. W. Thompson, Spectrochim. Acta. 24A. 1353 (1968).Author Institution: Molecular Physics Division, National Institute of Standards and Technology; Spectroscopy Division, Bhabha Atomic Research CentreMethyl acetylene (propyne) is of interest because of its presence in planetary atmospheres, application in optically pumped lasers, and possible sotope enrichment. Almost all the energy levels of the isotopic propynes interact strongly giving a variety of perturbation effects, which make their vibration-rotation spectra very complex. An understanding of the spectra is possible only by a detailed study of the various transitions in the different isotopomers. In this paper we present the results of our high resolution Fourier transform and diode laser spectral studies on $CH_{3}CCD$ in the $9-11 \mu m$ region. The $2\nu_{g}$ and $\nu_{g}$ bands fall in this region. It has been conjectured by earlier workers (1,2) from indirect evidence that the K-nubering of Thomas and Thompson (3) for the $\nu_{3}$ band of $CH_{3}CCH$ requires a revision by 3 units. Our studies give direct evidence for such a renumbering in $CH_{3}CCD$ also. This and other interesting features of the $2\nu_{2}$ and $\nu_{2}$ bands, together with detailed assignments and analysis of the lines in the 9-11 pm region will be presented and discussed