Platinum(II)-Based Supramolecular Scaffold-Templated Side-by-Side Assembly of Gold Nanorods Through Pt···Pt and π–π Interactions and Their Photophysical Study

Abstract

Side-by-side assembly of gold nanorods (GNRs) has been demonstrated to be directed by the supramolecular scaffolds formed by sulfonate-containing alkynylplatium(II) terpyridine complexes. Driven by Pt···Pt and − stacking interactions, the Pt(II) complex has demonstrated a high propensity to assemble in water with the plausible 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. Interestingly, the plasmonic properties and the extent of the assembly of the GNRs into ladder rung-like nanostructures can be readily modulated by the concentration of the Pt(II) complex. The photophysical and spectroscopic properties of the alkynylplatinum(II) complex and its supramolecular scaffold obtained from Pt···Pt interaction assisted formation as well as the directed side-by-side assembly of GNRs have been investigated by UV−vis absorption spectroscopy, NMR spectroscopy, energy dispersed X-ray (EDX) analysis and surface-enhanced Raman scattering (SERS). This work provides important insights for the construction of higher-ordered nanoassemblies using both Pt···Pt interactions and template-directed approaches. Acknowledgement(s) Financial supports from the UGC funding administered by The University of Hong Kong (HKU), HKU University Research Committee (URC) Strategically Oriented Research Theme (SORT) on Functional Materials for Molecular Electronics, University Grants Committee Areas of Excellence (AoE) Scheme (AoE/P-03/08) and a General Research Fund (GRF) grant from the Research Grants Council of the Hong Kong Special Administrative Region, People’s Republic of China (HKU17334216) are highly acknowledged. References: [1] Y.-S. Wong, F. C.-M. Leung, M. Ng, H.-K. Cheng, V. W.-W. Yam, Angew. Chem., Int. Ed., 2018, in press DOI: 10.1002/anie.201810302.