The crystal structure and thermotropic liquid-crystal properties of N-n-undecyl-D-gluconamide.
N-n-Undecyl-D-gluconamide, C17H35O6, crystallizes in space group P1, with one molecule in a unit cell a = 5.2267(6), b = 19.628(9), c = 4.7810(4) A, alpha = 93.23(2), beta = 95.60(1), gamma = 89.58(2) degrees, V = 487.35 A3, Dx = 1.19 g.cm-3. The crystal lattice is isostructural with N-n-heptyl-D-gluconamide having monolayer head-to-tail molecular packing. The molecules have a V-shaped conformation. The hydrogen bonding of the gluconamide moieties includes a four-link homodromic cycle. The transition to a smectic A liquid-crystal phase at 156.7 degrees is preceded by two crystal-to-crystal phase transitions at 77.2 degrees and 99.4 degrees. The long d-spacing of the intermediate crystal phase of 39 A, and the d-spacing of the liquid-crystal phase of 32 A, are consistent with a transition to a bilayer head-to-head molecular packing.
Jeffrey
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Department of Crystallography, University of Pittsburgh, Pennsylvania 15260.
Maluszynska
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D002236:Carbohydrate Conformation; D005942:Gluconates / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D013816:Thermodynamics; D014961:X-Ray Diffraction
D005942:Gluconates; C067907:N-n-undecylgluconamide