Platinum(II)-Based Supramolecular Scaffold-Templated Side-by-Side Assembly of Gold Nanorods through Pt⋅⋅⋅Pt and π-π Interactions

The side-by-side assembly of gold nanorods (GNRs) was shown to be directed by the supramolecular scaffolds formed by sulfonate-containing alkynylplatium(II) terpyridine complexes. Driven by Pt⋅⋅⋅Pt and π-π stacking interactions, the Pt^II complex has a high propensity to assemble in water with the head-to-tail stacking arrangement to construct supramolecular scaffolds, in which the sulfonate groups on the terpyridine ligand at the peripheral position preferentially bind to the sides of the GNRs. The extent of the assembly of the GNRs into ladder rung-like nanostructures can be modulated by the concentration of the Pt^II complex. The Pt⋅⋅⋅Pt interaction-assisted formation of the scaffolds and its directed assembly of GNRs were characterized by UV/Vis spectroscopy, quantum-chemical modeling, electron microscopy, energy dispersed X-ray (EDX) analysis, and SERS. This work provides insights for the construction of higher-ordered nano-assemblies using both Pt⋅⋅⋅Pt interactions and template-directed approaches.