A bowl-shaped supramolecular structure has been designed and made by scientists in China and Japan.
Shu-Yan Yu at the Chinese Academy of Sciences, Beijing, and colleagues created the nano-sized container by using metal-directed self assembly of organic ligands. This synthetic approach has already been used to make molecular squares and grids; however, there are few examples of bowl-shaped arrangements.
The upper hydrophilic part of the structure is functionalised with crown ether molecules and can encapsulate ions. Also, including this functionality on the 'lip' of the bowl makes the cavity bigger. In contrast, the cavity base is hydrophobic, and made from aromatic molecules.
These nano-sized cavities could be used as sensors for binding large cluster anions, such as polyoxometalate anions, and as microreactors.
Metal-organic container molecules are of particular interest because their properties might allow them to be mimics of calixarenes and cyclotriveratrylenes (CVT). Yu hopes that by adding the crown ether rings, his supramolecules will resemble the structure of CVT.
S-H Li et al, Dalton Trans., 2005, 2346 (DOI: 10.1039/b504639d)