Rotational spectra of several conformers of 1,2-propanediol have been studied very recently by
(1) F. J. Lovas, D. F. Plusquellic, B. H. Pate, J. L. Neill, M. T. Muckle, and A. J. Remijan, 2009, J. Mol. Spectrosc. 257, 82.
The aG'g conformer was found to be the lowest one with the gG'a conformer calculated to be 106 K higher in energy and the g'G'g conformer 165 K higher. Other conformers were calculated to be more than 300 K higher.
With respect to the first entry from Mar. 2011, extensive new data were reported by
(2) J.-B. Bossa, M. H. Ordu, H. S. P. Müller, F. Lewen, and S. Schlemmer, 2014, Astron. Astrophys. 570, Art. No. A12.
In addition, low frequency data from (1) were used. One apparent typographical error in one transition frequency was corrected. Three further transitions were omitted, and for three transitions more the uncertainties were increased as outlined in (2).
The predictions are expected to be sufficient for all astronomical observations. Predictions with uncertainties larger than 0.3 MHz should be viewed with caution.
The ab initio dipole moment was published in (1).