Bent-core (BC) molecules have a ’banana’ shape. Though this shape is far from being rod like, some BC molecules can form liquid crystalline phases. Among these mesophases one can find nematic and smectic phases, as well as special ’banana’ phases (B1 – B8) characteristic only for BC materials. These latter occur due to the tendency for polar steric ordering which may lead to spontaneous chiral separation and ferroelectricity, even though the constituent molecules are achiral.
Even the nematic phase of BC compounds may exhibit unusual physical properties, like giant flexoelectric response, low frequency dielectric relaxation, unusual electroconvection scenarios, and huge viscosity, which may be related to the presence of polar smectic clusters in the nematic phase.
An example of a BC nematic (ClPbis10BB):
Our group is involved in the synthesis of BC compounds and in the investigation of the properties of BC nematics and of their mixtures with conventional rod like materials.