The crystal structures of octyl α-d-glucopyranoside monohydrate and hemihydrate: Mesogenic structures with interdigitizing alkyl chains

✍ Scribed by George A. Jeffrey; Younghee Yeon; Jaime Abola

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 527 KB
• Volume: 169
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(87)80237-9

✦ Synopsis

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.