Simple and Selective Synthesis of Copper-Containing Metal Nanoclusters Using (PPh3 )2 CuBH4 as Reducing Agent.

A simple and selective synthetic protocol, using (PPh3 )2 CuBH4 as reducing agent, for Cu-containing mixed metal nanoclusters (NCs) is reported. Representative NCs include alkynyl-protected [Ag25 Cu4 (PhCC)12 (PPh3 )12 Cl6 H8 ]3+ (1), thiolate-capped [AuCu14 (SR)12 (PPh3 )6 ]+ (R = 4-flurothiophenol) (2), and phosphine-stabilized [Au9 Cu2 (PPh3 )8 Cl2 ]+ (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 (PPh3 )2 CuBH4 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.