Thermotropic Ionic Liquid Crystals. 6. Structural Parameters of Solid and Liquid Crystal Phases of Anhydrous Short-Chain Sodium Alkanoates

摘要

Unit cell constants were determined from powder X ray diffraction photographs taken of several anhydrous short chain sodium alkanoates at room temperature. The temperature dependence of the bilayer spacing in the alkanoates was determined over the range 25-300 C. Overall changes in bilayer spacing between the solid and the neat phase were found to be much smaller than in long chain alkanoates. A correspondence was noted between the room temperature lateral packing area and the 23Na quadrupole coupling constant in the mesophase. The mesophase bilayer spacing was consistent with a structural model in which the tilted anion chain rotates on a cone. X ray diffraction; Thermotropic ionic liquid crystals; Short chain; Sodium alkanoates. Reprints. (mjm)