a-n-C3H7CN, v30 = 2
a-n-Propyl cyanide, a-n-butyronitrile, cyano-a-n-propane, v30 = 2
Species tag 069513
Version1*
Date of EntryDec. 2016
ContributorH. S. P. Müller

The anti conformer is about 58 K higher than the gauche conformer and the later is doubly degenerate with respect to the former. It has CS symmetry. Among the 30 vibrational modes, 18 are totally symmetric (a') and 12 belong to a". The state v30 = 3 is third lowest in energy. The transition frequencies were taken from
(1) H. S. P. Müller, A. Walters, N. Wehres, A. Belloche, O. H. Wilkins, D. Liu, R. Vicente, R. T. Garrod, K. M. Menten, F. Lewen, and S. Schlemmer, 2016, Astron. Astrophys., 595 Art. No. A87.
Data of v30 = 1 and 2 were fit together which reduces the number of spectroscopic parameters for the latter. In addition, v18 = 1 was included in the fit because of interaction with v30 = 2. The two states can be separated because there are only few transitions between the states which have very large uncertainties.
14N hyperfine splitting as well as CH3 are unlikely to be resolved in astronomical observations.
The predictions may be sufficient for astronomical observations, but should be viewed with caution if the uncertainties are larger than 0.3 MHz. In addition, b-type transitions with Ka ≥ 2 should be viewed with caution.
Note: the statistical weight of the anti and gauche conformers is 1 : 2 because of symmetry. We have estimated vibrational corrections in the harmonic oscillator approximation using fundamental vibrations of the gauche-conformer from
(2) J. R. Durig, B. R. Drew, A. Komer, and S. Bell, 2001, Phys. Chem. Chem. Phys., 3 766,
as commented in (1). Additional information on vibrational states is also available.
The dipole moment components were assumed to agree with those in the ground vibrational state of the respective conformer, see e069505.cat.

Lines Listed12268
Frequency / GHz< 600
Max. J139
log STR0-8.0
log STR1-7.0
Isotope Corr.-0.0
Egy / (cm–1)238
 µa / D4.00
 µb / D0.984
 µc / D 
 A22140.1
 B2271.215
 C2163.133
 Q(300.0)2527732.
 Q(225.0)723913.
 Q(180.0)322479.
 Q(150.0)180907.
 Q(120.0)96932.
 Q(75.00)32698.
 Q(37.50)9113.9
 Q(18.75)2969.2
 Q(9.375)1032.07
detected in ISM/CSMyes


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