The Structure of Mesophases of Cholesteryl Esters

Abstract

Abstract The mesophases and the isotropic melt phase of several cholesteryl esters of saturated aliphatic acids have been studied by X-ray diffraction. The data are presented and briefly analyzed in terms of the angular position of the diffraction lines, their intensity, their integral width, and their shape. Both the cholesteric and the smectic phases are characterized by layerstructures with the long molecular axes perpendicular to the layers. Within the layers of the mesophases, the molecules are arranged anti-parallel to each other; the lateral order is nearly random. The isotropic phase is also characterized by groups of parallel molecules. Just above the temperature of transition into this phase, the molecules are still in their extended form.