C3D, v = 0, v4 = 1, 2Σμ
Propynylidyne, deuterated isotopomer, X 2Πr; v = 0 and v4 = 1, 2Σμ
Species tag 038503
Date of EntryMar. 2009
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 27.2 cm–1 above the lowest rotational state (N = 1, J = 0.5, F = 0 of the 2Π1/2 ladder). The energy difference is only 9.812 cm–1 for C3D ! 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.
With respect to the Aug. 2004 entry, low-N transitions in the 2Π1/2 spin-component have been reported by
(2) E. Kim and S. Yamamoto, 2005, J. Mol. Spectrosc. 233, 93.
The D hyperfine structure may be resolvable for transitions with low values of N. Therefore, a separate hyperfine calculation is provided up to N = 5. These predictions should be viewed with some caution for the higher lying 2Π3/2 spin component as well as for the excited 2Σμ. Note: The partition function given below includes the D hyperfine splitting !
Some caution is advised for transitions with predicted uncertainties larger than 1 MHz.
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 e037501.cat.
A substantial transition dipole moment between v = 0 and v4 = 1 can be expected – a value of 0.5 D was assumed in (1). Since no rovibrational transitions have been observed thus far for C3D, predictions of this type of transitions should be viewed with caution.

Lines Listed1770
Frequency / GHz< 2104
Max. J86
log STR0-7.0
log STR1-6.0
Isotope Corr.-3.953
Egy / (cm-1)0.0, 9.812
 µa / D3.55, 3.55
 µb / D0.5
 µc / D 
 A / MHz 
 B / MHz10097.38, 10125.53
 C / MHz 
detected in ISM/CSMno

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