Thiacalixarenes

As a result of the discovery of a practical method for the synthesis of sulfur-bridged calixarenes, studies on their modification and development of the functions are now vividly progressing. These new members of the calix family are open to oxidation of the bridging sulfur moiety and chelation-assisted S_NAr substitution of the phenolic hydroxy groups in addition to the common transformations applicable to the conventional methylene-bridged calixarenes. Furthermore, the sulfur functional groups provide the thiacalixes characteristic abilities for recognition of organic molecules as well as metal ions.