Methods and techniques for the selective extraction and recovery of oxoanions.

An important goal in environmental chemistry is the extraction of metals that are toxic or radioactive from soils and waters. For many such metals, the problem is solved by designing compounds with coordination sites that are specific for that particular metal. For cases such as oxoanions, however, where the inorganic center is already fully coordinated by oxygens, different strategies need to be used.

Calixarenes Derivatized with Sulfur-Containing Functionalities as Selective Extractants for Heavy and Precious Metal Ions.

The calix[4]arenes 5,11,17,23-tert-butyl-25,26,27,28-(2-methylthioethoxy)calix[4]arene, 25,26,27,28-(2-methylthioethoxy)calix[4]arene, and 5,11,17,23-tert-butyl-25,26,27,28-(2-(2-thiophenecarboxy)ethoxy)calix[4]arene have been prepared. The structure of 25,26,27,28-(2-methylthioethoxy)calix[4]arene has been verified by X-ray crystallography. The crystals with the empirical formula C(40)H(48)O(4)S(4) are monoclinic C2/c with a = 20.