Synthesis and conformational analysis of an a-cyclodextrin [2]-rotaxane
Date
1999
Authors
Easton, C.
Lincoln, S.
Meyer, A.
Ongani, H.
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Advisors
Journal Title
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Volume Title
Type:
Journal article
Citation
Journal of the Chemical Society. Perkin transactions 1, 1999; (17):2501-2506
Statement of Responsibility
Christopher J. Easton, Stephen F. Lincoln, Adam G. Meyer and Hideki Onagi
Conference Name
DOI
Abstract
An a-cyclodextrin [2]-rotaxane has been prepared in 10% yield, by threading a-cyclodextrin (a-CD) with (£)-4, 4'diaminostilbene in aqueous solution and capping the included guest through reaction with 2, 4, 6-trinitrobenzene-lsulfonate. ID 'H NMR spectroscopy and DQCOSY and ROES Y experiments show that the a-CD rotates freely around the axle of the rotaxane, but is localised over the olefinic moiety of the stilbene. The pA"a values of the a-CD [2]-rotaxane were found to be 9.3 and 9.6, which are attributable to deprotonations of the (£')-4)4'-bis(2, 4, 6-trinitrophenylamino)stilbene moiety. NMR experiments show that these deprotonations do not perturb the conformation of the rotaxane.