CH3CCH, v10 = 1
Propyne, methylacetylene, v10 = 1
Species tag 040504
Version1
Date of EntryJan. 2003
ContributorH. S. P. Müller

The v10 = 1 state of propyne is the lowest excited, doubly degenerate bending state of this molecule. It corresponds to v8 = 1 of CH3CN, which has been detected in the ISM. The rotational lines were taken from
(1) A. Bauer and J. Burie, 1969, C. R. Acad. Sci. Paris, Ser. B 268, 800;
(2) J. M. Ware and J. A. Roberts, 1984, J. Chem. Phys. 81, 1215;
(3) G. Wlodarczak, R. Bocquet, A. Bauer, and J. Demaison, 1988, J. Mol. Spectrosc. 129, 371
; and
(4) H. S. P. Müller, P. Pracna, and V.-M. Horneman, 2002, J. Mol. Spectrosc. 216, 397.
Transitions with the state number 1 and 2 are those with K·l10 ≤ 0 and > 0, respectively.
The data have been subjected to a combined fit with the ν10 band data from (4), the v = 0 data from (4) and references therein (see also e040502.cat). The interactions of v10 = 1 with v9 = 1 and v10 = 2, as described in (4), have been taken into account. In particular because of these interactions, predictions with kK·l10 < –11 should be viewed with some caution.
The dipole moment is assumed to be the same as for the v = 0 state, e040502.cat.
The nuclear spin-weight ratio is 2 : 1 for A-CH3CCH with k + l10 > 0 and all other states, respectively. The A state levels are described by k = 3n + l10, those of E state by k = 3n + l10 ± 1.
Besides the ground vibrational state, the partition function takes into account the states v10 = 1, v9 = 1, and v10 = 2. Their respective contributions are given in parentheses as long as they are different from 0 within the quoted digits.

Lines Listed2962
Frequency / GHz< 1620
Max. J95
log STR0-10.5
log STR1-8.5
Isotope Corr.-0.0
Egy / (cm-1)330.95
 µa / D0.784
 µb / D 
 µc / D 
 A159078.
 B8569.816
 C = B
 Q(300.0)17826.0720 (4518.3010; 1040.8925, 1412.0356)
 Q(225.0)9357.5685 (1740.3447; 245.6071, 322.7121)
 Q(150.0)4209.3392 (333.2663; 17.6501; 21.7571)
 Q(75.00)1362.3596 (5.1339; 0.0144; 0.0146)
 Q(37.50)481.7197 (0.0035)
 Q(18.75)176.2982
 Q(9.375)68.7664
detected in ISM/CSMnot yet


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