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The Microwave Spectrum of the C3 Sugars: Glyceraldehyde and 1,3-Dihydroxy-2-Propanone and the Dehydration Product 2-Hydroxy-2-Propen-1-Al



Francis J. Lovas, R D. Suenram, David F. Plusquellic, H Mollendal


The triose sugars with empirical formula, C3H6O3, consist of the aldehyde form, glyceraldehyde, and the ketone form, 1,3-dihydroxy-2-propanone. Recently, the simplest sugar, glycolaldehyde (CH2OHCHO) was identified in the Sgr B2 (N)molecular cloud by Hollis, Lovas, and Jewell (Astrophys. J. (Letters) 540, L107-L110 (2000)), providing the incentive to pursue the present study. The microwave spectra of the triose sugars were obtained with the NIST Fourier-transform pulsed-nozzle microwave spectrometers equipped with heated nozzles. A few tenths of a gram of solid sample was placed in the nozzle base, which was heated to between 105 C and 135 C and pressurized with inert carrier gas. Broad spectral survey scans were carried out from 10 GHz to 20 GHz for samples of both compounds. In the glyceraldehyde sample study, three conformers of the parent species were identified as well as 1,3-dihydroxy-2-propanone. In addition, three decomposition products were also identified: formic acid, trans-methyl glyoxal, and a previously unknown compound; 2-hydroxy-2-propen-1-1l. Ab initio calculations were carried out with the Gaussian 98 program at the MP2/6-311++G** level to aid in the identification of each of the new species. The survey scan of a 1,3-dihydroxy-2-propanone sample confirmed the identification of this species initially assigned in the glyceraldehyde study. The 1,3-dihydroxy-2-propanone survey also exhibited spectra from the same three decomposition products initially observed in the glyceraldehyde work. However, the three conformers of glyceraldehyde were not present in the spectra of 1,3-dihydroxy-2-propanone.
Journal of Molecular Spectroscopy
No. 2


1, 3-dihydroxy propanone, 2-hydroxy propenal microwave spectra, ab initio calculations, dipole moments, glyceraldehyde, molecular structure, rotational spectra, sugars


Lovas, F. , Suenram, R. , Plusquellic, D. and Mollendal, H. (2003), The Microwave Spectrum of the C<sub>3</sub> Sugars: Glyceraldehyde and 1,3-Dihydroxy-2-Propanone and the Dehydration Product 2-Hydroxy-2-Propen-1-Al, Journal of Molecular Spectroscopy (Accessed June 16, 2024)


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Created December 1, 2003, Updated February 17, 2017