Constructing perfect cubic Ag-Cu alloyed nanoclusters through selective elimination of phosphine ligands.

The aspiration of chemists has always been to design and achieve control over nanoparticle morphology at the atomic level. Here, we report a synthesis strategy and crystal structure of a perfect cubic Ag-Cu alloyed nanocluster, [Ag 55 Cu 8 I 12 (S-C 6 H 3 2,4 (CH 3 ) 2 ) 24 ][(PPh 4 )] (Ag 55 Cu 8 I 12 for short). The structure of this cluster was determined by single-crystal X-ray diffraction (SCXRD) and further validated by X-ray photoelectron spectroscopy (XPS), inductively coupled plasma (ICP), Energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), and 1 H and 31 P nuclear magnetic resonance (NMR). The surface deviation of the cube was measured to be 0.291 Å, making it the flattest known cube to date.