Calixarenes
Calix[n]arenes represent macrocyclic compounds widely used in supramolecular chemistry for the construction of various receptors for the complexation of charged or neutral molecules [1]. Their unique three-dimensional structures with almost unlimited derivatization abilities and a tunable shape of the molecules make calixarenes ideal candidates for building blocks and/or molecular scaffolds in the design of new more sophisticated molecules. Calixarenes have several attractive features as macrocycles of higher degree of preorganization. They are formed by para-phenolic units linked by methylene bridges ortho to the OH functions. Calixarene can be chemically modified by substitution of the phenolic hydrogens with various types of functions [2]. Furthermore, phenolic groups can be functionalized on the para position to make the calixarene either lipophobic or lipophilic. Calixarenes lend themselves well to many applications because of the multiplicity of options for such structural elaboration.
[1] J. Vicens, Calixarenes. A Versatile Class of Macrocyclic Compounds. Topics in Inclusion Science, ed. V. Bohmer (Dordrecht: Kluwer Academic Publishers, 1991).
[2] Z. Asfari, V. Bohmer, J. Harrowfield, J. Vicens, Calixarenes 2001, ed. J. Vicens (Dordrecht: Kluwer Academic Publishers, 2001).
![Calix[4]arene (CX 001)](/storage/compounds/90/structures/CX001.svg)
![4-tert-Butylcalix[4]arene (CX 002)](/storage/compounds/91/structures/CX002.svg)