Non-symmetrical bent-shaped liquid crystals with five ester groups

In this study a new series of bent-core liquid crystals based on laterally substituted 7-hydroxynaphthalene-2-carboxylic acid is presented. All compounds exhibit broken-layer type columnar phases. For CH3 laterally substituted compounds with a longer chain we found a smectic A above a columnar phase on cooling from the isotropic phase. Additionally, for CH3-substituted compounds with the longest chains (C14H29) two switchable columnar phases (B1RevT) occurred below the SmA phase. Two columnar phases were also found for Cl-substituted homologues with the long chain C12H25 and C14H29. For the Cl-substituted materials we found significant lowering of transition temperatures and a very steady columnar phase in a broad temperature interval of up to 130K.