Cyclodextrins enthalpy-entropy compensation

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. 

Fig. 4.—Enthalpy-Entropy Compensation for Alpha Cyclodextrin Inclusion-Complexes. [The guest identification numbers are as given in Table II.]...

It is thus demonstrated that the inclusion behavior of cyclodextrins is similarly analyzed and interpreted in terms of the enthalpy-entropy compensation effect, although the major weak forces involved are quite different from those working in... 

Hauser, S.L., Johanson, E.W., Green, H.P., Smith, P.J. (2000) Aryl phosphate complexation by cationic cyclodextrins An enthalpic advantage of guanidinium over ammonium and unusual enthalpy-entropy compensation, Org.Lett. 2, 3575-3578 ... 

Rekharsky MV, Inoue Y, Chiral recognition thermodynamics of f-cyclodextrin The thermodynamic origin of enantioselectivity and the enthalpy-entropy compensation effect, J. Am. Chem. Soc. 2000 122 4418-4435. 

Interestingly, in a study of the binding of ditopic substrates to such cyclodextrin dimers we saw that the binding was dominated by an improved enthalpy, rather than entropy. The simplest ideas about chelate binding would have suggested an entropy advantage, but in solution enthalpy-entropy compensation can be seen if the binding or release of water molecules is also considered. 

The formation of enthalpically controlled 1 1 and 2 1 (host guest) complexes between a-cyclodextrin and Ph-Me sulfides has been observed in a kinetic and thermodynamic study of the a-cyclodextrin-mediated reaction of substituted Ph-Me sulfides with j-CPBA and peroxomonosulfate. The enthalpically controlled 1 1 cyclodextrin- j-CPBA complex is also formed. Peroxomonosulfate does not form any such complex. The reaction rates are analysed using the transition-state pseudoequilibrium approach. Enthalpy-entropy compensation plots for transition-state pseudoequilibrium constant Kjs give slopes close to unity." ... 

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