We report the results of AMI semi-empirical electronic structure calculatio
ns on a prototype photochemically driven molecular shuttle based on a rotax
ane. As inferred experimentally, the ring component of the rotaxane is show
n to favor a different position about the shaft component depending on whet
her the shaft is in the trans or cis conformation. The calculations show th
at the shuttling action of the cyclodextrin ring is accompanied by the (de)
formation of a kink in the shaft. Published by Elsevier Science B.V.