Novel zigzag-shaped compounds exhibiting apolar columnar mesophases with oblique and rectangular lattices

Abstract

The design, synthesis and characterisation of some compounds whose constituent molecules have a completely new shape have been carried out. A total of eight different series/part of series of these zigzag-shaped compounds that are either symmetrical or unsymmetrical were synthesised. Only two mesophases were observed, and on the basis of polarising optical microscopy, differential scanning calorimetry, X-ray diffraction and electro-optical studies, these have been characterised as columnar phases with a rectangular or an oblique lattice. Perhaps, these represent the first examples of a rigid zigzag-shaped compound exhibiting a mesophase.

Keywords:

• zigzag-shaped
• columnar rectangular
• columnar oblique
• apolar

Acknowledgements

The authors thank Mrs. K.N. Vasudha for the technical support and Mr. Santosh Prasad Gupta for XRD measurements. The authors also thank the NMR Research Centre, Indian Institute of Science, Bangalore and Dr. D. Vijayaraghavan for recording the NMR spectra. BKS thanks the Indian National Science Academy, New Delhi, for the financial support.