Carbodiphosphorane as an Electron-Donating Ligand for Gold Nanoclusters

A variety of organic ligands such as thiolates, phosphines, alkynyls, N-heterocyclic carbenes, and halides have been widely used to protect gold nanoclusters (AuNCs). The ligands not only determine the stability and solubility but also affect the physicochemical properties of AuNCs. In this regard, the exploration of new ligands is important to further expand the range of properties. In this work, we successfully applied carbodiphosphoranes, known as unique ligands with σ and π donor capabilities, to protect small (<2 nm) AuNCs. X-ray photoelectron spectroscopy and theoretical calculations indicate that AuNCs are negatively charged by electron donation from carbodiphosphorane. These results suggest that novel electron-rich AuNCs can be synthesized by using carbodiphosphoranes as ligands.

硫醇盐、膦配体、炔基配体、氮杂环卡宾（N-heterocyclic carbenes）以及卤化物等多种有机配体，已被广泛用于保护金纳米团簇（AuNCs）。此类配体不仅决定了金纳米团簇的稳定性与溶解性，还会对其理化性质产生影响。有鉴于此，开发新型配体对于进一步拓展金纳米团簇的性能范围具有重要意义。本研究成功将兼具σ与π给电子能力的独特配体碳二膦烷（carbodiphosphoranes），应用于保护尺寸小于2 nm的金纳米团簇。X射线光电子能谱（X-ray photoelectron spectroscopy）与理论计算结果表明，碳二膦烷通过电子给体作用使金纳米团簇带负电。上述结果表明，以碳二膦烷作为配体，可合成新型富电子金纳米团簇。