Au₁₁Ag₆ nanocluster: Controllable preparation, structural determination, and optical property investigation

The structure/composition of nanoclusters has a decisive influence on their physicochemical properties. In this work, we obtained two different Au-Ag nanoclusters, [Au₉Ag₁₂(SAdm)₄(dppm)₆Cl₆]³⁺ and Au₁₁Ag₆(dppm)₄(SAdm)₄(CN)₄, via controlling the Au/Ag molar ratios by a one-pot synthetic approach. The structure of nanoclusters was confirmed and testified by single-crystal x-ray diffraction, electrospray ionization time-of-flight mass spectrometry, XPS, powder x-ray diffraction, and electron paramagnetic resonance. The Au₁₁Ag₆ nanocluster possessed a M₁₃ core caped by four Au atoms and four dppm and four AdmS ligands. Interestingly, four CN are observed to locate at the equator of the M₁₃ core. Both nanoclusters contain a similar icosahedral M₁₃ core, whereas their surface structures are totally different. However, the Au₁₁Ag₆ nanocluster exhibits good stability and strong red photoluminescence in solution.