New phase sequences in banana-shaped mesogens: influence of fluorine substituent in compounds derived from 2,7-dihydroxynaphthalene

Abstract

The synthesis and characterization of several new banana-shaped mesogens derived from 2,7-dihydroxynaphthalene are described. Some new phase sequences such as N → B₆ → B₁, N → X₁ → X₂ → B₆, N → X₁ → X₂ → B₁ → Col? have been observed in these bent-core compounds. The influence of a lateral fluorine substituent on the occurrence as well as mesophase type have been investigated. The mesophases have been characterized using polarized light optical microscopy, differential scanning calorimetry, X-ray diffraction studies and electro-optical switching studies.