HYDROGEN BONDING OF CATECHOL GROUPS IN THE CRYSTAL STRUCTURE OF DIHYDROCAFFEIC ACID
T. N. Drebushchak1,2, E. V. Boldyreva1,2, K. Fucke3,4
1Institute of Solid State Chemistry and Mechanochemistry, Siberian Division, Russian Academy of Sciences, Novosibirsk, Russia
tanya@xray.nsu.ru
2Research and Education Center Molecular Design and Ecologically Safe Technologies, Novosibirsk State University, Novosibirsk, Russia
3Department of Chemistry, Durham University, United Kingdom
4Institute of Pharmacy, Innsbruck University, Innsbruck
Keywords: catechol compounds, hydrogen bonds, dihydrocaffeic acid, single-crystal X-ray diffraction
Abstract
Dihydrocaffeic acid С9H10O4 is a natural antioxidant. The crystal structure of dihydrocaffeic acid is determined; the crystallographic data at 100 K are: a = 11.3189(4) Å, b = 5.5824(1) Å, c = 13.8431(4) Å, b = 109.248(4)°, and V = 825.80(4) Å3; the space group is P21/c, Z = 4. In addition to the formation of hydrogen bonds that are typical of acids, the compound has features that are important from the viewpoint of reactivity of dihydrocaffeic acid molecules. The position of one of the hydroxyl hydrogen atoms in the catechol group is disordered even at 100 K. The crystal structure of caffeic acid does not show such a disordering.
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