Synthesis and Photophysical Properties of Light‐Harvesting Gold Nanoclusters Fully Functionalized with Antenna Chromophores

Abstract

The development of efficient light‐harvesting systems is important to understand the key aspects of solar‐energy conversion processes and to utilize them in various photonic applications. Here, atomically well‐defined gold nanoclusters are reported as a new platform to fabricate artificial light‐harvesting systems. An efficient amide coupling method is developed to synthesize water‐soluble Au22 clusters fully protected with pyrene chromophores by taking advantage of their facile phase‐transfer reaction. The synthesized Au22 clusters with densely packed 18 pyrene chromophores (Au22–PyB18) exhibit triple‐emission in blue, green, and red wavelength regions arising respectively from pyrene monomer, pyrene excimer, and Au22 emission, producing bright white light emission together. The photoluminescence of Au22 is enhanced by more than tenfold, demonstrating that pyrenes at the periphery efficiently channel the absorbed energy to the luminescent Au22 at the center. A combination of femtosecond transient absorption and anisotropy measurements of Au22–PyB18 explicitly reveals three main decay components of 220 fs, 3.5 ps, and 160 ps that can be assigned to energy migration between pyrenes and energy transfer processes from pyrene monomer and excimer to the central Au22, respectively.

Anisotropic Evolution of Nanoclusters from Ag40 to Ag45: Halogen- and Defect-Induced Epitaxial Growth in Nanoclusters

“…Metal nanoclusters, as ultrasmall nanoparticles, have attracted extensive research interest because of their precise structures and excellent optical, − catalytic, − and electrochemical properties. − The precise structures of metal nanoclusters offer opportunities to explore the relationship between structure and properties in nanoscience. − Notably, minor structural changes in nanomaterials often cause important improvements in their properties. ,,,,− In this context, structural manipulation at the atomic level is highly important but remains extremely challenging. In the past decade, great efforts have been made to tailor the surface patterns and specific locations of metal nanoclusters and many inducing compounds (like thiolate and metal–thiolate complexes) have been employed to induce changes in the size and structure of metal nanoclusters. ,,− The “surgery” and “graft on” approaches involving changes of a few surface metal atoms and the specific surface motif variety were evaluated and afforded enhanced emission properties.…”

“…The UV−vis spectra show that there are no significant changes before and after S-acid ligand exchange for Ag 40 -II or Ag 45 nanoclusters (Figure S19), indicating the size and structure of Ag 40 -II and Ag 45 are unchanged after S-acid exchange. 1 H NMR spectra indicate that the benzoic acid ligands on Ag 40 -II and Ag 45 have been entirely replaced by the S-acid (Figures S20−S25), as in the case of acetic acid ligands in Ag 40 -I. 50 CD spectra show five pronounced peaks at 332 nm (+), 411 nm (+), 462 nm (−), 503 nm (+), and 593 nm (−) for the mixed solution of Ag 40 -II and S-acid, similar to that in Ag 40 -I (Figure 5a, red and black lines) but different with only a peak at 232 nm in S-acid ligands.…”

Facile one-pot synthesis of white emitting gold nanocluster solutions composed of red, green and blue emitters

“…46–48 A similar emission can be obtained from perylene-coated AuNCs. 49 A broadband excitation of our emitter system is simulated by summing up the emission spectra shown in Fig. 1a for 400 ≤ λ ex ≤ 700 nm as shown in Fig.…”

Atomically precise thiolate‐protected gold nanoclusters: Current status of designability of the structure and physicochemical properties

“…Reproduced with permission: Copyright 2021, Wiley‐VCH GmbH. [ 380 ] (B) A scheme showing the model click reaction of [Au 28 (SPhN 3 ) 20 ] 0 (SPhN 3 = 4‐azidobenzenethiol). Au, orange.…”