Pyridine-functionalised C4 symmetric resorcinarenes

Racemic mixtures of C4 symmetric resorcinarenes have been functionalised by adding 2- and 3-picolyl ether functional groups. Three of the resulting macrocycles were structurally characterised. The aim of the work was to enable the resolution of the racemic mixture by forming salts with chiral acids. While the formation of diastereomers was demonstrated using NMR spectroscopy, isolation of the salts was not successful. Metal complexation was also investigated. The pyridine-functionalised ligands solubilise copper and nickel salts in dichloromethane, and form insoluble products with silver and palladium. A copper complex was structurally characterised, and shown to form a linear polymer containing two structurally distinct copper bridges.