title: pH Control on the Sequential Uptake and Release of Organic Cations by Cucurbit[7]uril.
abstract: Cucurbit[7]uril (CB7) is a macrocycle with the ability to form the most stable supramolecular complexes in water ever reported for an artificial receptor. Its use for the design of advanced functional materials is, however, very limited because there is no example of a fully reversible CB7 based supramolecular complex enabling repetitious dissociation/association controlled by external stimuli. We report the synthesis of a new ferrocene amino acid that forms with CB7 a 1:1 inclusion complex that is stable in submicromolar concentration at low pH but dissociates at high pH. This reversible process was used for the sequential uptake and release of bispyridinium and antraquinone guests by CB7, which is controlled by adjusting the pH of the solution.
authors.affiliation: Department of Chemistry, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.
authors.forename: Lukas
authors.initials: L
authors.lastname: Mikulu
authors.affiliation: Department of Chemistry, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.
authors.forename: Romana
authors.initials: R
authors.lastname: Michalicova
authors.affiliation: Center for Supramolecular Science and Department of Chemistry, University of Miami, Coral Gables, FL, 33124-0431, USA.
authors.forename: Vivian
authors.initials: V
authors.lastname: Iglesias
authors.affiliation: Department of Chemistry, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.|RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.
authors.forename: Mirza A
authors.initials: MA
authors.lastname: Yawer
authors.affiliation: Center for Supramolecular Science and Department of Chemistry, University of Miami, Coral Gables, FL, 33124-0431, USA.
authors.forename: Angel E
authors.initials: AE
authors.lastname: Kaifer
authors.affiliation: Department of Chemistry, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.|Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.
authors.forename: Premysl
authors.initials: P
authors.lastname: Lubal
authors.affiliation: Department of Chemistry, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.|RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Sindelar
keywords: cage compounds; drug delivery; macrocycles; molecular devices; supramolecular chemistry