title: Interconversion between [5]pseudorotaxane and [3]pseudorotaxane by pasting/detaching two axle molecules.
abstract: An acceptor-donor-acceptor-type linear molecule 1(2+) containing one electron-rich naphthoxy (NP) unit and two monocharged viologen (MCV) units was synthesized. Through the noncovalent interaction of cucurbit[8]uril (CB[8]) with one NP and one MCV in 1(2+), we first obtained a [2]pseudorotaxane ([1(2+)]⊂CB[8]), and the excess CB[8] included simultaneously the two bare MCV units of two [2]pseudorotaxanes to form a [5]pseudorotaxane ([1(2+)](2)⊂[CB[8]](3)). Its transformation to [3]pseudorotaxane was achieved through detaching the two axle molecules in the presence of acid, and then the addition of base may result in a reversible switch between two different pseudorotaxanes. This novel methodology elongating reversibly linear molecules by noncovalent interactions will benefit the development of stimuli-responsive functional molecular devices.
authors.affiliation: Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, PR China.
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Zhang
authors.forename: Heng-Yi
authors.initials: HY
authors.lastname: Zhang
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu