title: Variable ion selectivity in [N.3.3](1,3,5)crownophanes: the "breathing" process.
abstract: [reaction: see text] A series of dithia[n.3.3](1.3.5)crownophanes were synthesized by cesium carbonate-assisted intramolecular cyclization reactions in 10-31% yields. Their complexation behavior exhibits an unusual ion-selectivity preference due to the presence of a "breathing" process of the dithia[3.3]metacyclophane moiety, which indirectly controls the ion selectivity through the adjustment of the cavity size of the crown unit. This breathing mechanism is also supported by observation made in X-ray crystallographic analysis.
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Xu
authors.forename: Yee-Hing
authors.initials: YH
authors.lastname: Lai
authors.forename: Weiling
authors.initials: W
authors.lastname: Wang