Circularly Polarized Luminescence from Atomically Precise Gold Nanoclusters Helically Assembled by Liquid‐Crystal Template

Abstract

Chiral plasmonic gold nanoparticles assemblies are known for their strong circular dichroism. However, little is known about the creation of helical assemblies from atomically precise nanoparticles like gold nanoclusters (AuNCs) and the optical properties of the final structures. Herein, a new approach is proposed to helically assemble atomically precise gold nanoclusters and enable circularly polarized luminescence using a liquid‐crystal template creating helical nanofilaments. The problem of nanoclusters miscibility is resolved with the liquid crystal matrix by functionalizing nanoclusters with two different ligands: dodecanethiol and specially designed liquid crystal‐like ligand. Additionally, the authors explore how functionalization, heating, and helical assembly affect optical properties of gold nanoclusters. The findings prove that assembly incorporating thermotropic liquid crystals and double functionalization of nanocluster surface can be successfully applied to assemble ultrasmall nanoparticles in a helical manner while preserving their atomically precise structure. Moreover, the assembly tunes the nanocluster luminescence and generates new chiroptical effects.

Ligand-correlated crystalline assembly of nanoclusters with atomic precision

“…The supramolecular arrangements of metal nanoclusters in their crystalline lattices were mainly supported by intra-and inter-cluster noncovalent interactions [50][51][52][53][54]. The interactions of the two Au 9 Ag 6 nanoclusters were investigated to reveal the cluster assembly mechanism.…”

Circular dichroism and circularly polarized luminescence of ligand-protected molecular metal clusters: insights into structure–chiroptical property relationships

“…13. 54 CPL from these clusters with high g lum values reaching maximally 0.32 and −0.37 for the domains of opposite handedness were observed. This is arguably the highest g lum value reported for a noble metal cluster reported so far.…”

Parasitism in Metal Nanoclusters: A Case Study of (AuAg)25·(AuAg)27

“…Metal nanoclusters are of great ongoing interest due to their atomically precise structures and intriguing properties. − To date, a large number of nanoclusters have been controllably synthesized and structurally determined with the help of improved synthesis strategies and advanced characterization techniques. − Because of their well-defined compositions and highly ordered surface structures, nanoclusters have served as nanomodels for investigating the surface coordination chemistry of nanoparticles at the atomic level; − for example, thiolated metal nanoclusters have been employed to study the coordination modes of metal–sulfur interactions.…”