Supramolecular cryptate effect

In the beginning of the increased cognizance of the different types of chemical influences that mnltiple binding sites can impart, the focus was totally on transition metal coordination complexes. Indeed, for the majority of these effects (with the exception perhaps of the cryptate effect), supramolecular chemistry was not even on the radar screen. Now, however, decades after the term snpramolecular was coined by the now Nobel Laureate Jean-Marie Lehn, ... 

The following sections provide examples of cooperativity as it relates to the chelate, macrocyclic, and cryptate effects for supramolecular complexes of both cations and anions. 

Perhaps the most apparent similarities with transition metal complexes are the main group metal ions and their supramolecular complexes. Here, the progression from the chelate to macrocyclic to cryptate effect can be readily recognized and the thermodynamics are, for the most-part, established. The term ionophore is often used for this class of hosts, originating from its use in biology for lipid-soluble molecules that serve as vehicles for transporting ions across membranes. 

Cooperativity is also seen for anion coordination chemistry in terms of the chelate, macrocyclic and cryptate effects. However, the area has been less extensively studied than for the transition metals and supramolecular metal ion host-guest chemistry. Some examples, primarily structural with a smattering of binding constants, which illustrate the importance of cooperativity in anion coordination chemistry are provided below. 

Jost, R, Galand, P.J.N., Schurhammer, R., Wipff, G. 2007. Supramolecular interactions of cryptates in concentrated solutions The effect of solvent and counterions investigated by MD simulations. Solvent Extr. Ion Exch. 25 (2) 257-271. 

Sabbatini, N., S. Perathoner, V. Balzani, B. Alpha and J.-M. Lehn, 1987b, Antenna effect in Eu and Tb + cryptates, in Supramolecular Photochemistry, ed. 

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