Rotaxanes with Chiral Stoppers and Complexation of Cations by Podand Axles with Sugar Terminal Groups
✍ Scribed by Archut, Andreas ;Müller, Walter Manfred ;Baumann, Sven ;Habel, Mathias ;Vögtle, Fritz
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 476 KB
- Volume
- 1997
- Category
- Article
- ISSN
- 0947-3440
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✦ Synopsis
Abstract
The new π‐donor/π‐acceptor type rotaxanes 15, 16 bearing chiral sugar units as blocking groups have been synthesized in 2% and 6% yield, starting from acetobromo glucose 10 and the podands 8 or 9, followed by the reaction of the resulting axles 11 and 12 with the dicationic bis(bipyridinio) wheel precursor 13 and the bis(bromomethyl) compound 14. The capability of the podands 11 and 12 and of the rotaxanes 15 and 16 to form podate‐like complexes with metal salts was investigated by NMR; the effect of metal thiocyanate salt addition was monitored. Distinct changes of proton shifts that indicate complex formation were only observed between the free axles 11, 12 and the metal salts, whereas no major effects were found in case of the rotaxanes 15, 16. Glucose entities were chosen as stopper units in order to support metal complexation as terminal groups and to introduce a source of chirality into the molecules.