title: Photolockable ratiometric viscosity sensitivity of cyclodextrin polypseudorotaxane with light-active rotor graft.
abstract: A prototype, based on light-active fluorescent rotor grafted to beta-cyclodextrin, shows a good solvent viscosity-sensitive behavior due to the environment-dependent nonradiative decay. With the reversible photoisomerization of the cyanostilbene unit, the viscosity sensitivity of the molecular rotor could be locked and activated, and the two switchable states can be distinguished by fluorescent signals. This cyclodextrin derivative was threaded to form a novel polypseudorotaxane. Such supramolecular assembly displays a lockable ratiometric fluorescent viscosity sensitivity with two emission channels: one aroused by fluorophore's intramolecular excimer without influenced by viscosity is used to gauge the concentration of the compound, while the other corresponding to the monomer's rotor fluorescence acts as a viscosity-sensitive signal and it can be shut off by UV irradiation.
authors.affiliation: Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science & Technology, Shanghai 200237, PR China.
authors.forename: Liang-Liang
authors.initials: LL
authors.lastname: Zhu
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Feng-Yuan
authors.initials: FY
authors.lastname: Ji
authors.forename: Xiang
authors.initials: X
authors.lastname: Ma
authors.forename: Qiao-Chun
authors.initials: QC
authors.lastname: Wang
authors.forename: He
authors.initials: H
authors.lastname: Tian
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D003505:Cyclodextrins / Q000737:chemistry*; D008027:Light; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008968:Molecular Conformation; D010777:Photochemistry / Q000379:methods; D043862:Rotaxanes / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods; D013267:Stilbenes / Q000737:chemistry; D043823:Taxoids / Q000737:chemistry*; D014466:Ultraviolet Rays; D014783:Viscosity; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D003505:Cyclodextrins; D043862:Rotaxanes; D012997:Solvents; D013267:Stilbenes; D043823:Taxoids; D047392:beta-Cyclodextrins; C031215:betadex