The conformational landscape of 1,2-propanediol was investigated by quantum chemical calculations from
(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. The g'Ga conformer is the fourth one in energy, calculated to be 305 K above the lowest.
Several higher lying conformers of 1,2-propanediol were studied recently by
(2) O. Zakharenko, J.-B. Bossa, F. Lewen, S. Schlemmer, and H. S. P. Müller, 2017, J. Mol. Spectrosc. 333, 23.
This analysis also included data from (1) and from
(3) W. Caminati, 1981, J. Mol. Spectrosc. 86 193.
The present analysis includes for completeness reason data from
(4) B. E. Arenas, S. Gruet, A. L. Steber, and M. Schnell, 2017, J. Mol. Spectrosc. 337, in press.
As there are uncertainties concerning the exact energy differences among the conformers, we treat each conformer as isolated species.
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 a- and c-dipole moment components are experimental values from (1), the b-component from a quantum chemical calculation also from that work.