Ligand-induced change of the crystal structure and enhanced stability of the Au11 nanocluster

Abstract

In this paper, we report a highly stable gold nanocluster co-protected by the selenophenol and 1,5-bis(diphenylphosphino)pentane (L⁵ for short) ligands, formulated as [Au₁₁(L⁵)₄(SePh)₂]⁺. The structure of this nanocluster is determined by X-ray crystallography. The L⁵-ligands are in the form of “Au–PPh₂(CH₂)₅Ph₂P–Au”, similar to the “staple motif” in the Au_n(SR)_m nanoclusters. The purity of this nanocluster is confirmed by electrospray ionization mass spectrometry (ESI-MS) and the thermogravimetric analysis (TGA). Moreover, we have also systematically investigated the stability of the [Au₁₁(L⁵)₄(SePh)₂]⁺ (Au₁₁-Se for short). The results show that Au₁₁-Se is significantly more stable than both Au₁₁(PPh₃)₇Cl₃ (Au₁₁-7 for short) and [Au₁₁(PPh₃)₈Cl₂]Cl (Au₁₁-8 for short), even in the presence of excess thiol (RSH). This work will provide a new opportunity for future wide research on gold nanoclusters.