Competitive binding for triggering a fluorescence response in a hydrazodicarboxamide-based [2]rotaxaneElectronic supplementary information (ESI) available: Experimental procedures and spectroscopic data for all new compounds. See DOI: 10.1039/c3ob41807c

• Main Authors: Berná, José, Franco-Pujante, Carlos, Alajarín, Mateo
• Format: Article
• Language: English
• ISSN: 1477-0520; 1477-0539
• DOI: 10.1039/c3ob41807c

The design and synthesis of an interlocked receptor based on a hydrogen bonded [2]rotaxane containing a hydrazodicarboxamide binding site are reported. An anion recognition process with tetrabutylammonium benzoate triggers the submolecular translational movement of its benzylic amide macrocycle developing a progressive increase of the fluorescence intensity, effectively quenched at the original state. The binding of the anion competes with the hydrogen-bond-connected cyclic component for the bis(urea)-based station pushing it towards a stoppered alkyl chain. Moreover, this interlocked system is able to work as a molecular switch restoring its initial state in two ways, either by an ion exchange reaction or by a high yielding oxidation/reduction sequence. Fluorescence switching in a hydrazo [2]rotaxane through a reversible and competitive molecular recognition process.