Simple and Selective Synthesis of Copper-Containing Metal Nanoclusters Using (PPh 3 ) 2 CuBH 4 as Reducing Agent.

A simple and selective synthetic protocol, using (PPh 3 ) 2 CuBH 4 as reducing agent, for Cu-containing mixed metal nanoclusters (NCs) is reported. Representative NCs include alkynyl-protected [Ag 25 Cu 4 (PhCC) 12 (PPh 3 ) 12 Cl 6 H 8 ] 3+ (1), thiolate-capped [AuCu 14 (SR) 12 (PPh 3 ) 6 ] + (R = 4-flurothiophenol) (2), and phosphine-stabilized [Au 9 Cu 2 (PPh 3 ) 8 Cl 2 ] + (3), which are fully characterized by single-crystal X-ray diffraction analysis, electrospray ionization mass, nuclear magnetic resonance ( 1 H, 2 H, 13 C, and 31 P NMR), and optical measurements, respectively. This work demonstrates the advantages of using (PPh 3 ) 2 CuBH 4 as a reducing agent in the synthesis of Cu-containing heterometallic NCs in terms of versatility as well as high yield and high purity of the products. This work may open the door to utilizing functional metal borohydride, as a new generation of reducing agent for the simple and selective synthesis of metal NCs.