title: Threading-followed-by-shrinking protocol for the synthesis of a [2]rotaxane incorporating a Pd(II)-salophen moiety.
abstract: This communication describes a new protocol for the construction of [2]rotaxanes: "threading-followed-by-shrinking". This approach involves the threading of a rodlike unit through a crown ether-like macrocycle and then shrinking the size of the macrocycle's cavity through coordination of a transition-metal ion by a salophen moiety in the macrocycle. The self-assembly of the macrocycle and a thread, followed by addition of palladium acetate, afforded the [2]rotaxane, which contains a palladium(II)-salophen moiety, after counterion exchange. This [2]rotaxane was characterized fully by NMR and IR spectroscopic, mass spectrometric, and elemental and X-ray crystallographic analyses.
authors.affiliation: Nanoarchitectonics Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba Ibaraki 305-8565, Japan.
authors.forename: Il
authors.initials: I
authors.lastname: Yoon
authors.forename: Mamiko
authors.initials: M
authors.lastname: Narita
authors.forename: Toshimi
authors.initials: T
authors.lastname: Shimizu
authors.forename: Masumi
authors.initials: M
authors.lastname: Asakawa