The synthesis, characterization and investigation of mesomorphic properties of assymmetric banana-shaped mesogens with 4-cyano resorcinol central unit

"Bent-core" or banana-shaped molecules represent a distinct and novel class of thermotropic liquid crystals as they form new types of mesophases. The remarkable behaviour of "bent-core" liquid crystalline materials is the formation of polar order without molecular chirality. The structure-property relationship in "bent-core" molecules is an important factor for the system of the mesophase and development of polar order and chirality. The formation of the mesophase in "bent-core" molecules much more depends on structural variations than in calamitic compounds. The variation of the central cores as well as the diversity of the terminal units and linking groups can cause a considerable change of the mesomorphism. Terminal chains play a significant role in the emergence of particular phase structures for banana-shaped mesogens. In this study, the design, synthesis and characterization of 4-cyanoresorcinol central unit based non-symetric "bent-core" compounds with a (S)-2-methylbutoxy and (S)-3,7-dimethyloctyloxy substitued phenylbenzoate based rod-like unit attached to one of the two sides of the molecular structure have been carried out. The main focus in this study is the investigation of the effect of length of alkoxy terminal chain, molecular chirality and the non-symmetry in molecular structure on the mesomorphic properties of "bent-core" mesogens derived from 4-cyanoresorcinol. The structures of synthesized compounds have been characterized by spectroscopic methods (IR, 1H-NMR and 13C-NMR). The mesomorphic properties have been investigated using polarized optical microscopy (POM) and differential scanning calorimetry (DSC).