Synthesizing [2]Rotaxanes and [2]Catenanes through Na(+)-Templated Clipping of Macrocycles around Oligo(ethylene glycol) Units.

Di-, tri-, and tetra(ethylene glycol) units in both dumbbell-shaped and macrocyclic molecules can be used as primary recognition units for the clipping of macrocycles in the presence of templating Na(+) ions to form corresponding [2]rotaxanes and [2]catenanes. One such tri(ethylene glycol)-containing [2]catenane behaves as a Na(+) ion-controllable molecular switch.

Self-sorting under solvent-free conditions: one-pot synthesis of a hetero[3]rotaxane.

The one-pot synthesis of a hetero[3]rotaxane, assembled from five different molecular components under solvent-free conditions, through "self-sorting" of the bead and stopper units during the threading and stoppering processes, is reported.

Design and synthesis of iridium(III) azacrown complex: application as a highly sensitive metal cation phosphorescence sensor.

A new metal cation probe bearing a central Ir(III) element and 1-aza-15-crown-5-ether substituted pyridyl pyrazolate as the chelate was synthesized. The octahedral molecular structure of was confirmed using single crystal X-ray diffraction analyses. Subsequent photophysical study showed yellow-green emission at approximately 560 nm in both fluid solution and solid state at room temperature. Remarkable differentiation in spectral properties upon metal cation (e.g. Ca2+) complexation makes complex a highly sensitive phosphorescence probe.