Anion host design shape selectivity

In the last few years there has been considerable interest in development of new aza and oxa-aza macrocyclic receptors. Macrocyclic molecules containing appropriate binding sites and cavities of suitable size and shape may be designed to form selective inclusion complexes. Actually, the molecular topology of the host molecule can be synthetically modulated in order to bind many different chemical species. To this purpose, aza or oxa-aza macrocyclic receptors able to bind different kinds of substrates, such as inorganic or organic cations,anionic species, " and neutral molecules have been studied to elaborate their use as selective recognizers, molecular carriers and catalysts. 

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