A Mixture-Induced Nematic Phase

We report on an unusual variant in liquid crystal polymorphism where a nematic phase is created from a binary mixture of two compounds, neither one of which in its pure state exhibits the nematic phase. One of the compounds in its pure form exhibits only a smectic A phase which is stabilized by an extended alkyl chain. The other compound in its pure form exhibits a smectic A and a smectic B phase which are stabilized by a terminally substituted halogen. When mixed, a wide-temperature-range nematic is created. This induced nematic is studied by x-rays, differential scanning calorimetry, and by varying the terminal halogen.