Shape-Assisted Self-Organization in Highly Disordered Liquid Crystal Phases.

In achiral rod-like molecules, a nematic phase is the most disordered liquid crystal phase, which only has one-directional order in the direction of the molecular long axis. A dumbbell-shaped molecule (compound 3: R-C6 H10 -CH=CH-C6 H4 -CH=CH-C6 H10 -R, (R=nC5 H11 )), and its liquid crystal phase (X phase) are reported, which exhibit high scattering without thermal fluctuation between two nematic phases under a polarized light optical microscope. The X phase was investigated by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and molecular dynamics simulation. A layered structure was ascertained for which a molecular self-organization mechanism was postulated in which the super-structure is based on lateral intermolecular interlocking. A second nematic phase above the X phase consisted of "rice grain"-shaped particles.