Crown ethers, one of host macrocycles, are known to selectively capture various alkali metal ions with different sizes according to their own cavity sizes. In order to improve the complexing ability of the crown ethers, lariat ethers and cryptands having three-dimensional coordination sites have been developed.  

In addition, Crown ethers with plural fluorescent moieties on the different type of sidearms were discussed about the synthesis and their complexation properties toward metal cations for the purpose of molecular fluorescent sensors.

On the other hands, macrocycles were prepared to realize various interlocked molecules with the supramolecular structures such as rotaxanes and catenanes.  This interlocked molecules was investigated as molecular machines and switches.

This presentation will introduce recent development of macrocyclic and supramolecular chemistry based on the design and synthesis of macrocycles and molecular recognition.