Metallacarboranes are a class of inorganic boron clusters that have recently been recognized as biologically active compounds. Herein, we report on the host-guest complexation of several cobalt bis(1,2-dicarbollide) anions (COSANs) with cyclodextrins (CDs) in aqueous solution. The binding affinities reach micromolar values, which are among the highest known values for native CDs, and exceed those for neutral hydrophobic organic guest molecules. The entrapment of the COSANs inside the cavity of CDs was confirmed using NMR and UV-visible spectroscopy, mass spectrometry, cyclic voltammetry, and isothermal titration calorimetry. Complexation by CDs greatly influences the photophysical and electrochemical properties of COSANs. In combination with indicator displacement assays, a label-free fluorescence-based method was developed to allow real-time monitoring of the translocation of COSANs through lipid bilayer membranes.

Department of Chemistry Faculty of Science Al Balqa Applied University Al Salt 19117 Jordan

Department of Life Sciences and Chemistry Jacobs University Bremen Campus Ring 1 D 28759 Bremen Germany

Institute of Inorganic Chemistry Czech Academy of Sciences v v i Hlavní 1001 CZ 250 68 Řež Czech Republic

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Chemistry of Carbon-Substituted Derivatives of Cobalt Bis(dicarbollide)(1-) Ion and Recent Progress in Boron Substitution

Metallacarborane Cluster Anions of the Cobalt Bisdicarbollide-Type as Chaotropic Carriers for Transmembrane and Intracellular Delivery of Cationic Peptides

Cobalt Bis-Dicarbollide Enhances Antibiotics Action towards Staphylococcus epidermidis Planktonic Growth Due to Cell Envelopes Disruption

Electrochemistry of Cobalta Bis(dicarbollide) Ions Substituted at Carbon Atoms with Hydrophilic Alkylhydroxy and Carboxy Groups

Face-Fusion of Icosahedral Boron Hydride Increases Affinity to γ-Cyclodextrin: closo,closo-[B21 H18 ]- as an Anion with Very Low Free Energy of Dehydration