Light-driven exchange between extended and contracted lasso-like isomers of a bistable rotaxane†
The synthesis of a set of benzylic amide rotaxanes via a self-templating clipping approach is described. This methodology supposes the 1 + 1 coupling of isophthaloyl dichloride with an acyclic diamine precursor incorporating a templating arm. The structure of the threaded compounds was determined both in solution and in the solid state. The conversion into the corresponding unthreaded isomers, also obtained by deslipping of rotaxane models, was evaluated in competitive and non-competitive hydrogen-bonding solvents. The switch of the extended and contracted lasso-like isomers of a bistable rotaxane by an olefin isomerization promoted by UV light irradiation was also accomplished and their ring positional integrity was examined.
- This article is part of the themed collection: Supramolecular chemistry in OBC