Liquid-Crystalline Polymorphism of Symmetrical Azobananas: bis(4-(4-alkylphenyl)azophenyl) 2-nitroisophtalates

In this paper we present a series of novel compounds, bis(4-(4-alkylphenyl)azophenyl) 2-nitroisophtalates, which exhibit nematic and banana-type liquid-crystalline phases. The alkyl chain length varies from 1 to 18 carbons. The first ten members of this series exhibit nematic phase. The last eleven compounds exhibit banana-type liquid crystalline phases. The propyl and pentyl derivatives have extra second type of banana mesophase.