Biotin[6]uril Esters: Chloride-Selective Transmembrane Anion Carriers Employing C—H···Anion Interactions

Micke Lisbjerg, Hennie Valkenier, Bo M. Jessen, Hana Al-Kerdi, Anthony P. Davis *, and Michael Pittelkow*

J. Am. Chem. Soc., 2015, 137, 4948-4951


Biotin[6]uril hexaesters represent a new class of anionophores which operate solely through C—H···anion interactions. The use of soft H-bond donors favors the transport of less hydrophilic anions (e.g., Cl, NO3) over hard, stongly hydrated anions (e.g., HCO3 and SO42–). Especially relevant is the selectivity between chloride and bicarbonate, the major inorganic anions in biological systems.