Structural Characterization of β-Glycolaldehyde Dimer

Vlasta Mohaček-Grošev, Biserka Prugovečki, Stjepan Prugovečki
2020 Croatica Chemica Acta  
Structural characterization of the β-polymorph of glycolaldehyde dimer by powder X-ray diffraction, Raman and infrared spectroscopies is described. The previously described α-polymorph and the β-polymorph both crystallize in the monoclinic crystal system, space group P21/c, but with different cell parameters. There are no significant differences in the glycolaldehyde dimer molecular structure, the molecules in both polymorphs are trans-isomers with the hydroxyl groups in axial positions. The
more » ... polymorphs have a different arrangement of the glycolaldehyde dimer molecules. In the previously reported α-polymorph the molecules are arranged in hydrogen bonded layers parallel to (100) while in the β-polymorph the hydrogen bonded molecules are arranged in a three-dimensional network. Theoretically calculated Gibbs free energy as well as differential scanning calorimetry indicate β-polymorph to be the stable crystal phase of glycolaldehyde.
doi:10.5562/cca3606 fatcat:mvvgrmlkkvccpb2erc43w4za4e