Chiral recognition in the crystal structure of a dichiral mesogen with a unique isotropic mesophase: 2-{4-[(R)-2-fluorohexyloxy]phenyl}-5-{4-[(S)-2-fluoro-2-methyldecanoyloxy]phenyl}pyrimidine

Abstract

The crystal structure of the title compound, which has an optically isotropic IsoX phase with an endothermic transition on cooling from an Sm*C phase, has been determined at 230 K. The crystal has a smectic-like layer structure composed of four crystallographically independent molecules. In the layer, one-dimensional chains of tightly fitted pyrimidine rings, with N... H distances shorter than the van der Waals radii, result in the large overlapping of core moieties and further induce close contacts and stereo-specific F-methyl interactions between the chiral groups; this is considered to be responsible for the uniquely organized IsoX phase.