6533b7d8fe1ef96bd1269853
RESEARCH PRODUCT
Water Structure Recovery in Chaotropic Anion Recognition: High-Affinity Binding of Dodecaborate Clusters to γ-Cyclodextrin
Merve S. UralKhaleel I. AssafKari RissanenFangfang PanTony GeorgievWerner M. NauDetlef GabelSvetlana Simovasubject
AnionsBoron CompoundsModels MolecularHofmeister seriesInorganic chemistrySupramolecular chemistrysyklodekstriinithost–guest complexes010402 general chemistry01 natural sciencessupramolecular chemistryCatalysissupramolekulaarinen kemiaMoleculeBinding siteta116Binding SitescyclodextrinsAqueous solutionMolecular Structure010405 organic chemistryChemistryDodecaborateWaterBorclusterGeneral MedicineGeneral ChemistryAffinitiesCommunicationsboron clusters0104 chemical sciencesCrystallographyChaotropic agentThermodynamicsgamma-CyclodextrinsHofmeister seriesdescription
Dodecaborate anions of the type B12X12(2-) and B12X11Y(2-) (X=H, Cl, Br, I and Y=OH, SH, NH3(+), NR3(+)) form strong (K(a) up to 10(6) L mol(-1), for B12Br12(2-)) inclusion complexes with γ-cyclodextrin (γ-CD). The micromolar affinities reached are the highest known for this native CD. The complexation exhibits highly negative enthalpies (up to -25 kcal mol(-1)) and entropies (TΔS up to -18.4 kcal mol(-1), both for B12I12(2-)), which position these guests at the bottom end of the well-known enthalpy-entropy correlation for CDs. The high driving force can be traced back to a chaotropic effect, according to which chaotropic anions have an intrinsic affinity to hydrophobic cavities in aqueous solution. In line with this argument, salting-in effects revealed dodecaborates as superchaotropic dianions.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2015-05-07 | Angewandte Chemie International Edition |