title: Liquid crystalline phases induced by the hydroxyl group stereochemistry of amphiphilic carbohydrate bicatenary derivatives.
abstract: Liquid crystals (LCs) may exist in different phases depending upon the orientational and positional orders of molecules in the material. Here, we demonstrate that the class of LC state induced by amphiphilic carbohydrate bicatenary derivatives is strictly hydroxyl group stereochemistry-dependent. This statement results from the experimental and theoretical investigations of surface film (2D) and bulk solid (3D) thermal behavior of synthetic stereoisomers n-tetradecyl (α-D-n-tetradecyl) galacto- and gluco-pyranosiduronate, with an axial (GalA-C(14/14)) or equatorial (GlcA-C(14/14)) hydroxyl group at the fourth carbon, respectively. Surface pressure-area isotherms (283-310 K), differential scanning calorimetry thermograms (223-573 K), and polarized optical textures (298-363 K) reveal that GlcA-C(14/14) organizes as a smectic LC-like phase (positional or lateral order), whereas the analogous stereoisomer GalA-C(14/14) behaves as a nematic LC-like phase (orientational order). Thermodynamic investigations and molecular dynamics models computed under similar temperature conditions provide consistent data with physical properties resulting from experimental approaches.
authors.affiliation: Gembloux Agro-Bio Tech, University of Liege, Gembloux, Belgium. h.razafindralambo@ulg.ac.be
authors.forename: Hary L
authors.initials: HL
authors.lastname: Razafindralambo
authors.forename: Aurore
authors.initials: A
authors.lastname: Richel
authors.forename: Michel
authors.initials: M
authors.lastname: Paquot
authors.forename: Laurence
authors.initials: L
authors.lastname: Lins
authors.forename: Christophe
authors.initials: C
authors.lastname: Blecker
mesh_terms: D002241:Carbohydrates / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D006878:Hydroxides / Q000737:chemistry*; D050866:Liquid Crystals / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D010316:Particle Size; D013237:Stereoisomerism; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D002241:Carbohydrates; D006878:Hydroxides; C031356:hydroxide ion