title: Installation of a ratchet tooth and pawl to restrict rotation in a cyclodextrin rotaxane.
abstract: Eight new [2]rotaxanes have been prepared, incorporating an alpha-cyclodextrin as the rotor, a stilbene as the axle, and trinitrophenyl substituents as capping groups. Strategies have been devised to elaborate these by linking the rotor to the axle, to produce two new [1]rotaxanes. Rotational motion in a selection of these rotaxanes has been investigated through the application of two-dimensional NMR spectroscopy by performing TOCSY, DQF-COSY, ROESY and HMQC experiments. This has shown that a methoxyl group incorporated on the stilbene and a succinamide joining the stilbene and the cyclodextrin behave analogously to a ratchet tooth and pawl, respectively, to restrict rotation.
authors.affiliation: Research School of Chemistry, Institute of Advanced Studies, Australian National University, Canberra ACT 0200, Australia.
authors.forename: Hideki
authors.initials: H
authors.lastname: Onagi
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Blake
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Easton
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Lincoln
mesh_terms: D000577:Amides / Q000737:chemistry; D003505:Cyclodextrins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol / Q000737:chemistry; D008958:Models, Molecular; D020409:Molecular Motor Proteins / Q000737:chemistry*; D012399:Rotation; D043862:Rotaxanes / Q000737:chemistry*; D013267:Stilbenes / Q000737:chemistry; D013386:Succinates; D047391:alpha-Cyclodextrins
chemical_list: D000577:Amides; D003505:Cyclodextrins; D020409:Molecular Motor Proteins; D043862:Rotaxanes; D013267:Stilbenes; D013386:Succinates; D047391:alpha-Cyclodextrins; D000432:Methanol; C011116:succinamide; C032613:alpha-cyclodextrin