title: A new photo-switchable "on-off" host-guest system.
abstract: A new photo-switchable "on-off" host-guest system comprising cucurbit[7]uril (CB[7]) and a photoresponsive cinnamamide derivative (trans-(3-phenyl-acryloylamino)-acetic acid, E-1) is studied. The cinnamamide derivative and CB[7] forms a stable 1 : 1 host-guest complex (CB[7]·E-1) with a high binding constant (K = 2.1 × 10(4) M(-1)). Irradiation of UV light (300 nm) to an aqueous solution of CB[7]·E-1 induces the E- to Z-conformational change of the cinnamamide derivative, which then leads to the dissociation of the complex as evidenced by UV-visible and (1)H-NMR spectroscopy. The reverse process, photo-induced host-guest complex formation between CB[7] and Z-1 is achieved by irradiation of UV light at 254 nm. The photo-switchable "on-off" host-guest system shows high reversibility and switching efficiency, which makes it potentially useful in designing photoresponsive gating systems.
authors: National Creative Research Initiative Center for Smart Supramolecules, Department of Chemistry, Pohang University of Science and Technology, Korea.
authors: Youngkook
authors: Y
authors: Kim
authors: Young Ho
authors: YH
authors: Ko
authors: Minseon
authors: M
authors: Jung
authors: Narayanan
authors: N
authors: Selvapalam
authors: Kimoon
authors: K
authors: Kim
mesh_terms: D001952:Bridged-Ring Compounds / Q000737:chemistry*; D002934:Cinnamates / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D014466:Ultraviolet Rays; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils
chemical_list: D001952:Bridged-Ring Compounds; D002934:Cinnamates; D007093:Imidazoles; C456276:cucurbit(7)uril; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils; C411088:cinnamamide