Substitution kinetics, supramolecular

The constant C has units of concentration and denotes the concentration at which intramolecular and intermolecular reactions have the same rate. In the 1970s, the term effective molarity (EM) was widely adopted to describe this parameter and characterize the rate enhancements observed for intramolecular reactions. The EM defined by Eq. (1) is a kinetic EM, because it is based on the ratio of two reaction rates, but it is possible to define a thermodynamic EM in the same way, if equibbrium constants are substituted for rate constants (Eq. (2)). In this review, we will use thermodynamic EM to quantify the chelate cooperativity associated with multivalent noncovalent interactions in supramolecular systems. 

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