Dichroism in indigoid and thiodigoid colorants

摘要

Organic materials which are composed of long, rod-like and fairly rigid dipolar molecules form one or more liquid crystal phases between the crystalline solid and the amorphous isotropic liquid. The credit of recognition of the first liquid crystal phase goes to the botanist Reinitzer in 1988 in the molecule cholesterol benzoate; however, this effect was considered a strange curiosity until the 1960's. The importance of these molecular materials gained momentum is the 1970's because of their application in liquid crystal displays of watches, desk calculators and other such appliances.