Journal of the American Chemical Society, Vol.120, No.37, 9541-9544, 1998
Synthesis, structure, and properties of a helical columnar liquid crystal
Helicene 2b can be prepared by acylating the disproportionation product formed by combining 1 with the bis-hydroquinone that 1 gives when it is reduced. At room temperature, the nonracemic material forms a liquid crystalline phase, which upon heating becomes isotropic at 85 degrees 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 : the circular dichroisms, specific rotations, fluorescent emission shifts, and H-1 NMR shieldings. The material is the first columnar mesophase with a nonracemic helical core.