Liquid-crystalline pillar[5]arene-based [2]rotaxanes

Liquid-crystalline mechanically interlocked molecules have been prepared from a clickable pillar[5]arene-containing [2]rotaxane building block incorporating ethynylated stoppers and dendritic mesogenic subunits of generation 0, 1 and 2 under copper-catalysed alkyne-azide cycloaddition conditions. The liquid-crystalline properties of the resulting pillar[5]arene-based rotaxanes bearing 4, 8 and 16 peripheral cyanobiphenyl units have been investigated and compared to those of corresponding model compounds lacking the macrocyclic component.