Reversible Cu–S Motif Transformation and Au₄ Distortion via Thiol Ligand Exchange Engineering

Abstract

Au 4 Cu 4 (SAdm) 5 (Dppm) 2 ]Br and [Au 4 Cu 5 (C 6 H 11 S) 6 (Dppm) 2 ](BPh 4 ) (SAdmH = 1-adamantane mercaptan, C 10 H 15 SH; C 6 H 11 SH = cyclohexyl mercaptan; Dppm = bis-(diphenylphosphino)methane, Ph 2 PCH 2 PPh 2 ), which was well characterized by single-crystal X-ray crystallography (SCXC) and monitored by time-dependent UV−vis absorption spectroscopy. Surprisingly, by etching with cyclohexyl mercaptan (C 6 H 12 S), [Au 4 Cu 4 (SAdm) 5 (Dppm) 2 ] + was converted to [Au 4 Cu 5 (C 6 H 11 S) 6 (Dppm) 2 ] + , accompanied by the transformation of Cu 4 (SAdm) 5 to Cu 5 (C 6 H 11 S) 6 . Besides, a reversible transformation reaction can be achieved via HSAdm etching with [Au 4 Cu 5 (C 6 H 11 S) 6 (Dppm) 2 ] + . These reversible Cu−S motif transformations via thiol ligand engineering between [Au 4 Cu 4 (SAdm) 5 (Dppm) 2 ] + and [Au 4 Cu 5 (C 6 H 11 S) 6 (Dppm) 2 ] + present a new desirable model to tailor the structure of Au−Cu alloy nanoclusters capped with Dppm and thiol ligands at the atomic level.

Structure and Properties of Au5Cu6(Dppf)2(SAdm)6)(BPh4)

“…In terms of the electrochemical properties, the HOMO–LUMO gaps in NCs are primarily determined by the size and structure of nanocluster. , The electrochemical measurements were carried out for [Au 5 Cu 6 (Dppf) 2 (SAdm) 6 ] + . Figure represented the DPV behavior of it.…”

“…Furthermore, the ligand and the overall framework affect the overall stability of the cluster. ,, The time-dependent UV–vis spectra of [Au 4 Cu 4 (SAdm) 5 (Dppm) 2 ]Br and [Au 4 Cu 5 (C 6 H 11 S) 6 (Dppm) 2 ]­(BPh 4 ) indicated that both nanoclusters were not stable in CH 2 Cl 2 solution at room temperature (Figure ). Dissolved in the DCM, the solution of [Au 5 Cu 6 (Dppf) 2 (SAdm) 6 ]­(BPh 4 ) can remain green, and the optical spectra clearly display the characteristic absorption peaks of [Au 5 Cu 6 (Dppf) 2 (SAdm) 6 ]­(BPh 4 ) after 80 h. The solid state can be stably stored at room temperature for more than 0.5 year (Figure S6).…”

“…Therefore, there are various strategies for controlling the structures of Au–Cu alloy clusters. Recently, the [Au 4 Cu 4 (SAdm) 5 (Dppm) 2 ] + with a quadrilateral Cu 4 ring could be converted into [Au 4 Cu 5 (CHT) 6 (Dppm) 2 ] + with Cu 5 ring via ligand engineering . Inspired by these two nanoclusters and early reported Au 2 Cu 6 (SAdm) 6 (PPh 2 Py) 2 , we look forward to regulating the synthesis strategy to obtain new gold–copper clusters with similar structures and sizes, which would facilitate comprehension of structure-performance relationships.…”

Rapid Conversion of a Au9Ag12 into a AuxAg16‐x Nanocluster via Bisphosphine Ligand Engineering

“…Electrospray ionization mass spectra (ESI‐MS) is often performed to analyse transformation mechanism for ligand exchange induced size transformation, such as thiol ligand‐induced transformation of Au 38 (SC 2 H 4 Ph) 24 to Au 36 (SPh‐ t Bu) 24 [7,11] . Compared with studies on thiol ligands as exchange ligands, [7,12,13] fewer studies on phosphine ligands as inducers to reconstruct clusters are reported, let alone studies on bisphosphine ligands [14] . How does the bisphosphine ligand reconstruct the surface structures of the nanoclusters, especially for alloy clusters [15]…”

Polystyrene Microspheres Decorated with Au4Cu5 Nanoclusters and their Application in Catalytic Reduction of 4‐Nitrophenol

“…nanoclusters was successfully synthesized according to our previous report. [32] The UV-vis absorption spectrum showed that the final product exhibited three peaks centered at 440, 500, and 580 nm, respectively (Figure 1a). The final product was further analyzed by electrospray ionization mass spectrometry (ESI-MS).…”