Hosier Christopher A, Anderson Ian D, Ackerson Christopher J
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
Nanoscale. 2020 Mar 19;12(11):6239-6242. doi: 10.1039/d0nr00869a.
Acetylide-protected gold nanoclusters represent a recently described class of nanocluster compounds that are computationally predicted to be more stable than well-studied thiolate-protected clusters. Ligand exchange of thiolates-for-acetylides on these clusters as well as the reverse reaction are so-far unknown. Such reactions can inform a practical understanding of stability and other differences between thiolate- and acetylide-protected gold clusters. Here it is shown that acetylide-for-thiolate ligand exchange is facile when using either a lithium phenylacetylide or a gold(i)-phenylacetylide complex as incoming ligand to thiolate-protected gold clusters, whereas the reaction fails when using phenylacetylene. Both partial and full exchange are possible, as is the reverse reaction. While the overall reaction resembles ligand exchange, it may be better described as a metathesis reaction. Notably, while the simple thiolate-for-acetylide exchange reaction is enthalpically unfavorable, metathesis reactions between these ligands are enthalpically favorable. Intercluster exchange is also observed between thiolate-protected and acetylide-protected clusters.
乙炔基保护的金纳米团簇是最近描述的一类纳米团簇化合物，通过计算预测其比研究充分的硫醇盐保护的团簇更稳定。到目前为止，这些团簇上硫醇盐与乙炔基的配体交换以及逆反应尚不清楚。此类反应有助于切实理解硫醇盐保护和乙炔基保护的金团簇之间的稳定性及其他差异。本文表明，当使用苯基乙炔锂或金（I）-苯基乙炔配合物作为硫醇盐保护的金团簇的引入配体时，乙炔基与硫醇盐的配体交换很容易进行，而使用苯乙炔时反应则失败。部分和完全交换都是可能的，逆反应也是如此。虽然整体反应类似于配体交换，但或许更好地将其描述为复分解反应。值得注意的是，虽然简单的硫醇盐与乙炔基交换反应在焓变上不利，但这些配体之间的复分解反应在焓变上是有利的。在硫醇盐保护的团簇和乙炔基保护的团簇之间也观察到了团簇间交换。
