Synthesis of Antiferroelectric Host Materials

The synthesis of the first achiral host material that exhibits a smectic Cau phase [36] (achiral version of the antiferroelectric phase) is shown in Fig. 42. It can be seen that this material has three aromatic rings and two ester groups, but in addition it has a swallow-tail unit. This unit (for no apparent reason at the moment) stabilizes the formation of smectic Cai, phases. The material like a ferroelectric host can be doped with a chiral dopant to give an antiferroelectric mixture. 

The synthesis of the novel achiral host material can be achieved in a variety of ways. Using the Corey-Fuchs method, which involves a modified Wittig reaction of 4-alkoxybenzaldehydes with carbon tet-rabromide, phenylpropiolic acids can be prepared by lithiation and treatment with solid carbon dioxide (see center of Fig. 42). Alternatively, this can also be achieved using a palladium(O) mediated coupling between 3-methyl-3-hydroxybutyne and an 

The area of the synthesis of smectic liquid crystals is too large to cover in a single article of this type. Nevertheless, a number of common areas of interest in the synthesis of 

Szczucinski, R. Dabrowski, Biul. Wojsk. Acad. Techn. 1981, 30, 109. 

Kriicke, F. Kuschel, H. U. Noth-nick, G. Pelzl, H. Zaschke, Mol. Cryst. Liq. Cryst. Lett. 1979,56,115 D. Demus, H. Zaschke, Mol. Cryst. Liq. Cryst. 1981, 63, 129 R. Paschkonene, Yu. Daugwila, Abstracts of the 4th Liq. Cryst. Conf. of Soviet Countries 1981, C36. 

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