Symmetrical Pillar-shaped Macrocyclic Compound

Crystal structure of 1 from the side view (a) and the upper view (b).

Dimethoxypillar[5]arene (1) is a ring-shaped molecule developed by T. Ogoshi et al. in 2008, and has a symmetric pillar structure differing from basket-shaped calixarenes. 1 can capture electron-accepting molecules and linear n-alkanes selectively because the internal cavity (diameter ca. 0.5 nm) is an electron-rich space enclosed by benzene rings. The applications using the structual properties of 1 for host-guest chemistry and supramolecular materials such as rotaxanes are now in progress.