Motor proteins, whose locomotion is driven by catalytic ATP hydrolysis in their active sites, are vital components of nature's molecular machinery that convert chemical energy into mechanical work. Wholly synthetic systems that accomplish similar feats are currently being developed on account of their potential to power artificial molecular machines. We are targeting (Figure 1a) an interlocked system which, by virtue of the orientational asymmetry and 'catalytic activity' of its ?-cyclodextrin (?-CD, Figure 1b) ring component, can undergo catalytically-driven unidirectional shuttling. We intend to exploit the well-known rate enhancement of anthracene photodimerization in the presence of ?-CD � formation of a highly stable ternary complex aligns two molecules of anthracene face-to-face. By analogy to motor proteins, the ?-CD 'active site' in this design would move (Figure 1a) along the dumbbell with directional bias which is linked to a catalytic reaction, and it would do so autonomously whilst fuel is supplied, in the form of anthracene and light.In order to test this strategy, we have explored the photodimerization of supramolecular complex 1 . This complex is composed of a ?-CD ring component and two anthracene-containing polyether chains � each of which is terminated at one end by a bulky carbazole group. Upon dimerization, the rings orientation is frozen as it is trapped between one of the carbazole groups and the sterically bulky anthracene dimer at the center of the dumbbell.

Catalytically-driven unidirectional loading of ?-cyclodextrin onto a symmetrical molecular dumbbell

248th National Meeting (2014)

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