CC13CH, v = 0, v4 = 1, 2Σμ
Propynylidyne, 13C on C3, X 2Πr; v = 0 and v4 = 1, 2Σμ
Species tag 038506
Date of EntryAug. 2004
ContributorH. S. P. Müller

The Renner-Teller effect splits the two Σ components of the CCH bending mode ν4 (≈ 600 cm–1) of C3H such that the lower component 2Σμ is only 27.20 cm–1 above the lowest rotational state (N = 1, J = 0.5, F = 0 of the 2Π1/2 ladder). This leads to considerable Coriolis interaction, as shown by
(1) S. Yamamoto, S. Saito, H. Suzuki, S. Deguchi, N. Kaifu, S.-I. Ishikawa, and M. Ohishi, 1990, Astrophys. J. 348, 363. In the case of CC13CH, this enegy difference is 26.56 cm–1.
In the present fit, all five isotopomers studied by laboratory spectroscopy were fit together in order to constrain some higher order constants and the 1H hyperfine splitting. This is reflected in the code for the quantum number format.
C3H and C3D experimental lines were taken from (1).
Additional C3H millimeter transitions come from
(2) C. A. Gottlieb, J. M. Vrtilek, E. W. Gottlieb, P. Thaddeus, and Å. Hjalmarson, 1985, Astrophys. J. 294, L55.
Further C3H low frequency transitions were taken from astronomical observations by
(3) N. Kaifu, M. Ohishi, K. Kawaguchi, S. Saito, S. Yamamoto, T. Miyaji, K. Miyazawa, S.-I. Ishikawa, C. Noumara, S. Harasawa, M. Okuda, and H. Suzuki, 2004, Publ. Astron. Soc. Japan 56, 69.
Data for the three 13C species were taken from
(4) M. Kanada, S. Yamamoto, S. Saito, and Y. Osamura, 1996, J. Chem. Phys. 104, 2192.
Predictions for low N transitions should be viewed with some caution mainly because of the uncertainties in the 13C hyperfine parameters. Increasing caution is advised for extrapolations beyond the experimentally accessed ~330 GHz.
The state numbers 0 and 1 refer to the ground vibrational state and the excited v4 = 1, 2Σμ state, respectively.
The dipole moment was assumed to be the same as for the main isotopomer, see
A substantial transition dipole moment between v = 0 and v4 = 1 can be expected – a value of 0.5 D was assumed in (1). However, because of the large uncertainty of the band origin, rovibrational transitions were omitted from the prediction.

Lines Listed1475
Frequency / GHz< 998
Max. J46
log STR0-7.0
log STR1-5.0
Isotope Corr.-1.980
Egy / (cm-1)0.0, 26.56
 µa / D3.55
 µb / D 
 µc / D 
 A / MHz 
 B / MHz10842.5, 10863.3
 C / MHz 
detected in ISM/CSMno

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