(1) K. Bolton, D. G. Lister, and J. Sheridan,
1974, J. Chem. Soc. Faraday Trans. 2 70, 113
determined the s-trans conformer to be higher than the
s-cis conformer by 58 (17) cm1
or 0.7 (2) kJ/mol or 83 (24) K.
The experimental data were taken from (1) and
from
(2) C. Calabrese, A. Vigorito, G. Feng, L. B. Favero, A. Maris,
S. Melandri, W. D. Geppert, and W. Caminati,
2014, J. Mol. Spectrosc. 295, 37.
With respect to the first entry of Dec. 2013, extensive
microwave and millimeter wave data were added. These
were published by
(3) E. R. Alonso, L. Kolesniková, I. Peña,
S. T. Shipman, B. Tercero, J. Cernicharo, and J. L. Alonso,
2015, J. Mol. Spectrosc. 316, 84.
Uncertainties of individual data sets were tested and
adjusted if necessary. A small number of transitions
with large residuals from (3) were omitted.
These were almost exclusively transitions with
Δ(Ka > 0. Moreover, the number of
spectroscopic parameters was reduced with respect to
that work. An estimate of HK was
kept fixed in the fit.
The calculations should be sufficient for all observational
purposes. Transitions with calculated uncertainties larger
than 0.1 MHz should be viewed with caution.
The partition function values were calculated summing up
the ground state contributions of both conformers.
The uncertainty of the energy of the trans
conformer leads to some probably modest uncertainty
in the partition function and to uncertainties in
the relative intensities between the conformers,
in particular at low temperatures.
The dipole moment components were measured in (1).
|