Functionalized Hydrogen-Bonded Assemblies as Templates for Metal-Containing Arrays of Nanorods

We report on the synthesis and characterization of metal-containing multicomponent, hydrogen-bonded rosette assemblies and their ordered arrangement on graphite surfaces. The introduction of gold atoms into the architecture of double rosettes was achieved using the coordination of phosphane groups to Au(I)Cl moieties. Transmission electron microscopy studies on gold-functionalized double rosettes deposited from dilute solution onto amorphous graphite revealed isolated features with a diameter of 1.0-1.2 nm, assigned to individual double rosettes. Highly ordered 2-D nanorod domains with an inter-row spacing of 5.1 ± 0.1 nm were obtained by deposition of the gold-labeled double rosettes on highly oriented pyrolytic graphite, as demonstrated by atomic force microscopy (AFM) experiments. Two sets of domains with different mutual orientations were resolved in high-resolution images, indicating the resolution of the racemic rosette mixture into enantiomerically pure domains on the substrate. Our strategy for the formation of metal-containing nanorod arrays, involving well-defined surface-immobilized self-assembled systems as scaffolds, will contribute to the development of templated functional nanoarchitectures via bottom-up approaches.