Enthalpy molecular recognition

MOLECULAR RECOGNITION IN CHEMISTRY AND BIOLOGY AS VIEWED FROM ENTHALPY-ENTROPY COMPENSATION EFFECT ... 

Instead, a wide variety of spectroscopic and electrochemical titration methods are often employed to determine the equilibrium constants for a molecular recognition process at several different temperatures, which are then analyzed by the van t Hoff equation to give the thermodynamic parameters for the process. However, there is a critical tradeoff between the accuracy of the value obtained and the convenience of the measurement since the thermodynamic parameters, evaluated through the van t Hoff treatment, do not take into account the possible temperature dependence of the enthalpy change, i.e. heat capacity, and are less accurate in principle. In fact, it has been demonstrated with some supramolecular systems that the van t Hoff treatment leads to a curved plot and therefore the thermodynamic parameters deviated considerably from those determined by calorimetry.3132 Hence one should be cautious in handling thermodynamic parameters determined by spectroscopic titration and particularly in comparing the values for distinct systems determined by different methods. 

It is advised therefore that the extrathermodynamic analysis based on the enthalpy-entropy compensation effect should be restricted to the (supra)molecular recognition phenomena governed by cooperative weak interactions. 

Enthalpy-Entropy Compensation as a Practical Tool for a Global Understanding of Molecular Recognition... 

A Theoretical Approach to Enthalpy-Entropy Compensation in Molecular Recognition... 

Inoue Y, Hakushi T, Liu Y, Tong LH, Shen BJ, Jin DS, Thermodynamics of molecular recognition by cyclodextrins. 1. Calorimetric titration of inclusion complexation of naphthalenesulfonates with a-, f-, and y-cyclodextrins enthalpy-entropy compensation, J. Am. Chem. Soc. 1993 115 475-481. 

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