Figure 2.

Fabrication of mono- and multilayers of switchable rotaxanes. (a) Monolayers of covalently fixed Rot3 are made by first depositing an azide-terminated SAM of AUD from ethanol solution onto a HCl-cleaned gold surface. Afterward, acetylene-substituted rotaxane Rot3 is “clicked” to the azides. (b) On a PST SAM, first Pd^II ions are deposited from acetonitrile and mediate the connection to the first layer of Rot6 deposited from dichloromethane solution. Subsequently, this monolayer can be converted into multilayers by an alternating deposition of Fe^II ions and Rot6. Similarly, a 1:3 mixed monolayer of TDT and DT can serve as a templating SAM with Fe^II ions connecting the next layer to it.