title: Thallium pi-cation complexation by calix[4]tubes: (205)Tl NMR and x-ray evidence.
abstract: Thallium cation complexation by calix[4]tubes has been investigated by a combination of (205)Tl, (1)H NMR and ES MS demonstrating the solution formation of a dithallium complex in which the cations are held in the calix[4]arene cavities. In addition, the structure of the complex has been determined in the solid state revealing the cations to be held exclusively by pi-cation interactions. Furthermore, this crystal structure has been used as the basis for molecular dynamics simulations to confirm that binding of the smaller K(+) cation in the calix[4]tube cryptand like array occurs via the axial route featuring a pi-cation intermediate.
authors.affiliation: Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Matthews
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: Rees
authors.forename: Vitor
authors.initials: V
authors.lastname: Felix
authors.forename: Michael G B
authors.initials: MG
authors.lastname: Drew
authors.forename: Paul D
authors.initials: PD
authors.lastname: Beer