title: Triple-ion interactions for the construction of supramolecular capsules.
abstract: A novel type of [2+4] capsules based on triple-ion interactions was obtained. Four monovalent anions (bromide, nitrate, acetate, and tosylate) bring together two tetrakis(pyridiniummethyl)tetramethyl cavitands by pyridinium-anion-pyridinium interactions. ESI-MS experiments have confirmed the capsule structure due to different fragmentation pathways of triple ions, cations, and ion-pairs. Each capsule encapsulates one or two anions, depending on its size. The capsules exist in equilibrium with hemicapsules containing three walls. The latter form complexes with phenols and anilines to give new unsymmetrical capsules containing both pyridinium-anion-pyridinium and pyridinium-guest-pyridinium walls.
authors.affiliation: Laboratory of Supramolecular Chemistry and Technology, MESA Research Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Gennady V
authors.initials: GV
authors.lastname: Oshovsky
authors.forename: David N
authors.initials: DN
authors.lastname: Reinhoudt
authors.forename: Willem
authors.initials: W
authors.lastname: Verboom