SYNTHESIS, STRUCTURE, AND PROPERTIES OF A HELICAL COLUMNAR LIQUID-CRYSTAL

Helicene 2b can be prepared by acylating the disproportionation produc t formed by combining 1 with the bis-hydroquinone that 1 gives when it is reduced. At room temperature, the nonracemic material forms a liqu id crystalline phase, which upon heating becomes isotropic at 85 degre es C. Hexagonal columnar ordering in the pure material is demonstrated by X-ray diffraction, and columnar organization in dodecane solutions is indicated by all of the following increasing with concentration: t he circular dichroisms, specific rotations, fluorescent emission shift s, and H-1 NMR shieldings. The material is the first columnar mesophas e with a nonracemic helical core.