Biaxial nematic and smectic A phases in a "peelable banana-shaped" moleculet

The article discusses the observation of a fluid phase having three-dimensional orientational order and its transformation to a similar phase but with an additional one-dimensional positional order in a low molar system. X-ray and optical observations establish the phases to be biaxial nematic and biaxial smectic A respectively. The organic system used is a unique combination of a bent core molecule linked to a rod-like unit through a flexible aliphatic spacer. We argue that this special combination is responsible for the observation of especially the biaxial nematic phase and propose possible molecular arrangements in the two phases.