New Fluorine Substituted Liquid Crystal Containing Bicyclo[2.2.2]Octane Unit

We have designed and synthesized a new series of liquid crystalline compounds with hybridized three-ring system based on bicyclo[2.2.2]octane unit together with fluorine substituted phenyl and biphenyl fragments. The key stages of the synthesis are alkylation of substituted benzene in concentrated sulfuric acid by bicyclo[2.2.2]octanoles and further cross-coupling between 3,4-difluorophenylboronic acid and the alkylation product. The influence of bicyclo[2.2.2]octane unit position in mesogenic core and fluorine substituents onto a phase transitions of the liquid crystals is discussed.