Monofluorinated unsymmetrical bent‐core mesogens

Abstract

The synthesis and mesomorphic properties of 30 bent‐core compounds with a fluorine substituent in one of the outer rings are reported. The banana‐shaped compounds are all derived from resorcinol and contain esters as linking groups between the five aromatic rings. The different mesophases have been characterized by polarizing optical microscopy, differential scanning calorimetry, X‐ray diffraction studies and electro‐optical investigations. The compounds with the longer terminal chains exhibit an antiferroelectric SmCP phase. Upon introduction of a fluorine substituent the layer spacing increases, as compared with the corresponding unsubstituted compound. The introduction of one terminal vinyl group in the mono‐substituted bent‐core mesogens has no significant influence on the liquid crystalline properties and the switching remains antiferroelectric. Due to the introduction of the terminal double bond, these banana‐shaped compounds are suitable for the preparation of siloxane polymers or attachment to a hydrogen‐terminated silicon surface.