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Selective Host–Guest Binding of Anions without Auxiliary Hydrogen Bonds: Entropy as an Aid to Design


  • We gratefully acknowledge the generous financial support of this research by the Hans-Fischer-Gesellschaft München. We are also indebted to Prof. H. Mayr and Dr. A. Ofial, LMU München, for their collegial help and permission to use their ITC instrument. We also thank Prof. Vladimir Král, Technical University of Prague, for directing our attention to the unique properties of COSAN dioxanate.


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Entropy matters! In contrast to classic host–guest design, which employs dedicated enthalpic interactions of the binding partners, the novel electroneutral host 1 binds its anionic guests by virtue of an overwhelmingly positive entropy of association. The prime driving force is guest desolvation. Despite the total omission of hydrogen bonding, host 1 is one of the best electroneutral receptors known for binding anions in polar solution.