title: Silver ion shuttling in the trimer-mimic thiacalix[4]crown tube.
abstract: Novel 1,3-alternate calix-thiacalix[4]crown trimers bearing crown-5 and crown-6 were prepared. As proven by X-ray diffraction, in a 1:2 mole ratio of ligand to metal ion, the Cs(+) and K(+) ions prefer to be encapsulated in the trimeric thiacalix[4]crown-6 and crown-5, respectively. On the contrary, the Ag(+) ion was found to be entrapped in the central thiacalix spacer as a 1:1 complex confirmed by (1)H NMR spectrosocpy. Variable-temperature (1)H NMR studies for the trimeric thiacalix[4]crown-6 encapsulating the silver ion revealed that the Ag(+) ion oscillates through the central thiacalix spacer with the aid of cation-pi interactions.
authors.affiliation: Department of Chemistry, Institute of Nanosensor and Biotechnology, Dankook University, Seoul 140-714, Korea.
authors.forename: Sung Kuk
authors.initials: SK
authors.lastname: Kim
authors.forename: Jae Kwang
authors.initials: JK
authors.lastname: Lee
authors.forename: Seoung Ho
authors.initials: SH
authors.lastname: Lee
authors.forename: Mi S
authors.initials: MS
authors.lastname: Lim
authors.forename: Soon W
authors.initials: SW
authors.lastname: Lee
authors.forename: Wonbo
authors.initials: W
authors.lastname: Sim
authors.forename: Jong Seung
authors.initials: JS
authors.lastname: Kim