Carboranealkynyl‐Protected Gold Nanoclusters: Size Conversion and UV/Vis–NIR Optical Properties

Abstract

Structure evolution has become an effective way to assemble novel monolayer‐protected metal nanomolecules. However, evolution with alkynyl‐stabilized metal clusters still remains rarely explored. Herein, we present a carboranealkynyl‐protected gold nanocluster [Au28(C4B10H11)12(tht)8]3+ (Au28, tht=tetrahydrothiophene) possessing an open‐shell electronic structure with 13 free electrons, which was isolated by a facile self‐reduction method with 9‐HC≡C‐closo‐1,2‐C2B10H11 as the two‐in‐one reducing and protecting agent. Notably, Au28 undergoes a complete transformation in methanol into a stable and smaller‐sized nanocluster [Au23(C4B10H11)9(tht)6]2+ (Au23) bearing 12 valence electrons and crystal‐field‐like split superatomic 1D orbitals. The transformation process was systematically monitored with ESI‐MS and UV/Vis absorption spectra. Au28 and Au23 both display optical absorption covering the UV/Vis–NIR range and NIR emission, which facilitates their potential application in the biomedical and photocatalytic fields.

Developing tiny-sized particles, different modification behaviors of gold atoms, and nucleating distorted particles

“…Tiny particles other than gold have also been discussed in the literature, and some reports are cited here. 33–40 The work discussed here presents the science on different topics not previously reported.…”

Recent Advances in Ligand Engineering for Gold Nanocluster Catalysis: Ligand Library, Ligand Effects and Strategies

“…Besides the incorporation of new ligating units into AuNC formation, the versatility of organic molecules/super molecules provides countless changes of skeletons that can enrich ligand engineering in AuNCs [59,60] . These efforts deserve another review article and will be partially involved in the following discussion.…”

[Pt1Ag37(SAdm)21(Dppp)3Cl6]2+: intercluster transformation and photochemical properties

“…The Zang group reported the size conversion of a carboranealkynyl-protected gold nanocluster Au 28 into a stable and smaller-sized nanocluster Au 23 . 36 Indeed, the ligand exchange can be partial or complete, with or without altering the metallic kernel.…”