The crystal structure of the title compound [5; space group P2,; a = 8.375(5). b = 51.52(2), c = 5.647(3) A; p = 89.64( 4)"] was determined by X-ray diffraction methods and refined to R = 0.107. There are two molecules in the asymmetric unit, which adopt nearly identical conformations. Each molecul
The crystal structure and thermotropic liquid-crystal properties of N-n-undecyl-d-gluconamide
β Scribed by George A. Jeffrey; Hanna Maluszynska
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 725 KB
- Volume
- 207
- Category
- Article
- ISSN
- 0008-6215
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β¦ Synopsis
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.
π SIMILAR VOLUMES
N-(n-Octyl)-6-deoxy-D-gluconamide crystallizes in the orthorhombic space group P212121, with a = 5.4524(5), b = 16.662(3), and c = 36.897(5) ,~. The structure was determined by X-ray diffraction and refined to R = 9.2%. The asymmetric crystal unit contains two molecules (A,B) with significantly diff
The crystal structure of N-(1-hexadecyl)-D-gluconamide [a = 4.8072(6) A, b = 46.771(5) A, c = 5.2885(7) ,~, /3 = 94.37(1)Β°; monoclinic P21, Z = 2] displays the same molecular conformation and the same monolayer packing-arrangement as its lower homologues described previously. This is at seeming vari