Macrocyclic liquid crystals

The synthesis of macrocycle-containing liquid crystals is reviewed with particular emphasis on derivatives of synthetic aza crowns. The synthesis of the C-functionalized thioether crowns (HO)(2)[14]aneS(4) and (HO)(2)[16]aneS(4) is described, and their derivatization to give oligobenzoate esters discussed. The formation of mesogens and metallomesogens in these systems has been achieved, and structural studies have been utilized to probe ionophore and tail-group conformation(s). Structural studies of functionalized thioether crowns suggests a relationship between potential mesogen formation and the conformational flexibility of the incorporated crown thioether.