Assessing cooperativity in supramolecular systems

This tutorial review summarises different aspects of cooperativity in supramolecular complexes. We propose a systematic categorisation of cooperativity into cooperative aggregation, intermolecular (allosteric) cooperativity, intramolecular (chelate) cooperativity and interannular cooperativity and discuss approaches to quantify them thermodynamically using cooperativity factors. A brief summary of methods to determine the necessary thermodynamic data is given with emphasis on isothermal titration calorimetry (ITC), a method still underrepresented in supramolecular chemistry, which however offers some advantages over others. Finally, a discussion of very few selected examples, which highlight different aspects to illustrate why such an analysis is useful, rounds up this review.