Cyclodextrin-based ordered rotaxane-monolayers at gold surfaces

Abstract

Decorating metal surfaces with well-defined architectures can be categorized as one of the currently interesting fields of nanomaterials and supramolecular chemistry, since the leading hybrid materials assembled in specific patterns exhibit unprecedented excellent properties which is different from their individual components and subunits. In this work a class of cyclodextrin based redox-active hemi-rotaxane structures were synthesized. After an investigation of their complexation properties in solution, the successful preparation of corresponding rotaxane monolayers with different orderliness on gold surfaces was demonstrated. Due to the complexation-to-deaggregation effect of the macrocyclic ring, construction of the monolayers with each unit encircled by one or two α-cyclodextrin rings has been accompanied with an increased orderliness at the surface. Such a system was suggested to be potentially useful as components for redox driven molecular electronics and optical controlling devices.