Liquid Crystal (LC) Building Blocks
The first nematic liquid crystal materials, the Schiff base types, were sensitive to moisture, while the azoxybenzene types were sensitive to light. Therefore, research to improve the stability of liquid crystals to moisture and light had been undertaken. The chemically stable biphenylcarboxylates and cyanobiphenyls were developed one after another. The cyanobiphenyls were found to be exceptional in possessing the necessary properties of display material. They exhibited low viscosity and low voltage operation, leading to many reports on the cyanobiphenyls. The phenylcyclohexane-based liquid crystals also have low viscosity and high response speeds, thus drawing to attention their use as display material. Furthermore, these bicylic liquid crystals were modified by the addition of benzene and cyclohexane rings to produce tricyclic and tetracyclic liquid crystals. As a result, the upper range of temperature was increased. Further improvements in the various physical properties were made by introduction of fluorine and other functional groups to the liquid crystals. The optically active compounds are important components of chiral nematic liquid crystals, chiral smectic liquid crystals, and blue phase. Antiferroelectric liquid crystals of the chiral smectic liquid crystal type are undergoing vigorous synthetic studies to develop novel liquid crystal compounds. Larger high-resolution displays are the target for the next generation of liquid crystal materials.
Following are listed building blocks for liquid crystals. These products enable you to develop new liquid crystal materials.
- 1) T. Kitamura, Zairyo Kagaku 1992, 29, 72.
- 2) H. Numata, Kogyo Zairyo 1998, 46, 40.
- 3) Y. Suzuki, Kino Zairyo 1995, 15, 8.
- 4) T. Inukai, K. Miyazawa, Ekisho 1997, 1, 9.
- 5) G. W. Gray, G. R. Luckhurst, in The Molecular Physics of Liquid Crystal, Academic Press 1979, pp.1-29, pp.263-284.
- 6)P. G. Gennes, J. Prost, in The Physics of Liquid Crystals, Second Edition, Oxford University Press 1993.