The crystal structures of octyl alpha-D-glucopyranoside monohydrate and hemihydrate: mesogenic structures with interdigitizing alkyl chains.
The crystal structure of octyl alpha-D-glucopyranoside monohydrate, C14H28O6.H2O, is monoclinic, C2, with Z = 4, a = 17.896(2), b = 5.154(1), c = 18.303(2) A, beta = 90.30(1) degrees. The hemihydrate, C14H28O6.0.5 H2O, is also monoclinic, C2, with Z = 4, a = 15.190(5), b = 5.136(3), c = 19.944(7), beta = 92.74(3) degrees. The crystal structures were solved using SHELXTL and refined to R values of 0.037 and 0.052 for 1224 and 1231 observed structure amplitudes, respectively. The crystal structures have bilayer head-to-head molecular packing with interdigitizing alkyl chains similar to those observed in other long-chain alkyl pyranosides. The carbohydrate moieties are hydrogen-bonded in infinite chains which exclude the ring and glycosidic oxygen atoms. Both crystal structures transform to a smectic A liquid crystal at 72.3 degrees, which has a clearing point at 116.5 degrees.
Department of Crystallography, University of Pittsburgh, Pennsylvania 15260.
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D002236:Carbohydrate Conformation; D005960:Glucosides; D006027:Glycosides; D006860:Hydrogen Bonding; D008958:Models, Molecular; D013329:Structure-Activity Relationship
D005960:Glucosides; D006027:Glycosides; C018619:octyl-beta-D-glucoside