The crystal structure of a 1:1 complex of n-octyl α- and β- d-glucopyranoside at 123 K

Abstract

The 1:1 complex of n-octyl α- and β- d-glucopyranoside, (C 14H 28O 6) 2, is triclinic, P1, with a = 5.021(1) [5.058(1)], b = 7.984(2) [7.996(3)], c = 20.848(3) [20.987(4)] Å, α = 79.06(2) [78.95(2)], β = 81.99(1) [83.36(2)], γ = 71.30(2) [72.57(2)], Z =1, V = 774.47 [787.30] Å 3 at 123 [293] K. The crystal structure is composed of ordered layers of each isomer, with hydrogen bonding across the α,β bilayer and interdigitizing alkyl chains. The molecular packing is therefore the same as that observed in the crystal structures of other mesogenic n-alkyl O- or S-pyranosides, except for the presence of the two isomers. The molecules differ in the orientation of the primary alcohol groups, being g/g in the a isomer and g/t in the β isomer. Otherwise the ring and alkyl chain conformations and dimensions are almost identical.