Propyne, methylacetylene; isotopomer with D on C1
Species tag 041501
Date of EntryApr. 2002
ContributorH. S. P. Müller

The observed lines are from
(1) R. Trambarulo and W. Gordy, 1950, J. Chem. Phys. 18, 1613;
(2) L. F. Thomas, E. I. Sherrard, and J. Sheridan, 1955, Trans.Faraday Soc. 51, 619;
(3) C. D. Cogley, L. M. Tack, and S. G. Kukolich, 1982, J. Chem. Phys. 76, 5669
; and from
(4) M. Le Guennec, J. Demaison, G. Wlodarczak, and C. J. Marsden, 1993, J. Mol. Spectrosc. 160, 471.
The purely K-dependent parameters (A and DK), needed to obtain reasonable intensities, as well as the dipole moment were taken from the main isotopomer, see At low temperatures, it may be necessary to discern between A-CH3CCD and E-CH3CCD. The A state levels are described by K = 3n, those of E state by K = 3n ± 1. The nuclear spin-weight ratio is 2 : 1 for A-CH3CCH with K > 0 and all other states, respectively. The JK = 11 level is the lowest E state level. It is approximately 5.54 cm–1 above ground.
The dipole moment was assumed to be the same as for the main isotopomer, see

Lines Listed965
Frequency / GHz< 995
Max. J64
log STR0-7.0
log STR1-7.0
Isotope Corr.-3.9537
Egy / (cm-1)0.0
 µa / D0.784
 µb / D 
 µc / D 
 C = B
detected in ISM/CSMyes

Database maintained by Holger S. P. Müller and Sven Thorwirth, programming by D. Roth and F. Schloeder