Liquid crystal trimers containing secondary amide groups

We report the synthesis and phase behaviour of a series of liquid crystalline trimers containing secondary amide groups. These materials form nematic, smectic and twist-bend nematic phases and their liquid crystal behaviour appears to be primarily driven by their molecular shape, with little evidence for the influence of hydrogen bonding between the amide groups. The results show that suitable molecular design can allow for amides to be included into mesogenic materials in an analogous manner to more commonly used linking groups, such as esters and imines, offering new synthetic routes to liquid crystalline materials.