Structure and Properties of Au5Cu6(Dppf)2(SAdm)6)(BPh4)

Phosphine ligand can also effectively regulate the overall structures. Changing the phosphorus ligand from bis­(diphenylphosphino)­methane (Dppm) to bis­(diphenylphosphino)­ferrocene (dppf), a new atomically precise Au–Cu alloy nanocluster Au5Cu6(Dppf)2(SAdm)6(BPh4) (Au5Cu6 for short) was synthesized, whose structure was determined by single-crystal X-ray diffraction (SCXRD) and further confirmed by electrospray ionization mass spectrometry (ESI-MS) and X-ray photoelectron spectrospray (XPS). Like the structure of Au2Cu6, the structure of Au5Cu6 was formed via (DppfAu2)-Au-(DppfAu2) core interpenetrating a closed hexagon (CuSR)6 complexes. The time-dependent density functional perturbation theory (TD-DFT) and partial density of states (PDOS) calculations figured out the atomic contributions to the related optical transitions. Meanwhile, metal engineering and stability tests in thermal, oxidizing, and reducing environments as well as in C6H11SH showed that the Au5Cu6(Dppf)2(SAdm)6(BPh4) was particularly stable. This novel Au5Cu6(Dppf)2(SAdm)6(BPh4) will enrich the small-size gold–copper alloy clusters and contribute to the application and theoretical analysis of gold–copper alloy clusters.