Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan, Canada.
Langmuir. 2009 Nov 17;25(22):12954-61. doi: 10.1021/la9018053.
Dithiolate ligands based on (+/-)-alpha-lipoic acid derivatives have been investigated as ligands for both Au monolayer-protected clusters (MPCs) and mixed alkanethiol/dithiolate Au MPCs. The oxidative and thermal stability of the MPCs were investigated by a combination of UV-vis spectroscopy, TEM, and (1)H NMR experiments. Results show that the dithiolate-protected MPCs are much more prone to oxidation by oxygen under ambient conditions than their alkanethiolate-protected MPC analogues; in addition, the Au core of the dithiolate-protected Au MPCs could be etched by KCN at much faster rates than both alkanethiolate-protected and mixed monolayer MPCs. These results suggest that strategies to increase ligand-metal interactions by incorporating more thiolate linkers into the ligand must also take into account the packing efficiency and/or stability of such ligands on the metal surface, which can make them much more prone to oxidation under ambient conditions.
基于 (+/-)-α-硫辛酸衍生物的二硫醇配体已被研究为金单层保护簇 (MPC) 和混合烷硫醇/二硫醇金 MPC 的配体。通过结合紫外-可见光谱、TEM 和 (1)H NMR 实验研究了 MPC 的氧化和热稳定性。结果表明，与烷硫醇保护的 MPC 类似物相比，二硫醇保护的 MPC 在环境条件下更容易被氧气氧化；此外，二硫醇保护的 Au MPC 的 Au 核可以比烷硫醇保护的和混合单层 MPC 更快地被 KCN 刻蚀。这些结果表明，通过将更多的硫醇配体链接到配体中来增加配体-金属相互作用的策略，还必须考虑配体在金属表面上的组装效率和/或稳定性，这会使它们在环境条件下更容易氧化。
