Biaxial Nematic and Smectic A Phases in a “Peelable Banana-Shaped” Molecule

ABSTRACT

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.

Keywords:

• bent core molecule
• biaxial nematic
• biaxial smectic A
• conoscopy, X-ray

Notes

†Dedicated to Prof. S. Chandrasekhar