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A Light‐Driven Pseudo[4]rotaxane Encoded by Induced Circular Dichroism in a Hydrogel
Author(s) -
Ma X.,
Wang Q.,
Qu D.,
Xu Y.,
Ji F.,
Tian H.
Publication year - 2007
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200600981
Subject(s) - rotaxane , circular dichroism , materials science , dumbbell , cyclodextrin , crystallography , azobenzene , photochemistry , polymer , chemistry , supramolecular chemistry , organic chemistry , crystal structure , medicine , composite material , physical therapy
A light‐driven pseudo[4]rotaxane 1 , based on α‐cyclodextrin (α‐CyD) and cucurbit[7]uril (CB[7]), is prepared in an easy and convenient manner. The reference pseudo[2]rotaxane 2 and pseudo[3]rotaxane 2 ′ are obtained via the insertion of α‐CyD and CB[7] onto the dumbbell 3 , thus including an azobenzene unit and two viologen moieties, respectively. The CyD macrocycle in pseudo[4]rotaxane 1 can be photochemically stimulated to shuttle accompanied with obvious induced circular dichroism (ICD) signals. The ICD performances of these pseudorotaxanes, including ICD in aqueous solution, variable‐temperature ICD, ICD in confected hydrogel systems and in solid‐state films, are investigated for their conformational identification. The photo‐driven shuttling of the CyD macrocycle in pseudo[4]rotaxane 1 is easier than in the CyD‐based pseudo[2]rotaxane 2 , especially in non‐solution media. This can be attributed to the space exploitation of CB[7]‐included parts, which aid the movement of α‐CyD.