Chelate Effects and Preorganization Entropy Factors

A binding event in which one complex forms from two molecules is entropically disfavored. The entropic costs need to be paid from the reaction enthalpy released upon host-guest binding. However, strategies exist which can reduce these costs to a minimum. 

One approach is to incorporate more than one binding site in one host molecule. When the first bond is formed, the entropic costs of combining two molecules are taken care of. The second and all following binding events between the same two 

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