Efficient and Selective Conversion of Phosphine-Protected (MAu) (M = Pd, Pt) Superatoms to Thiolate-Protected (MAu) or Alkynyl-Protected (MAu) Superatoms via Hydride Doping.

An efficient and selective method was developed for the synthesis of bimetallic clusters, MAuL (M = Pd or Pt; L = thiolates or alkynyls), by the reaction of Au(I)L oligomers with quasi-spherical superatoms [HMAu(PPh)] activated by hydride doping. This hydride-mediated conversion afforded previously known clusters MAu(SCHPh) having an icosahedral (M@Au) core at ∼200 mg scale, with a yield of >50%, and was successfully applied to a variety of primary thiols with good yields. Although the application to secondary and tertiary thiolates was limited, the conversion produced the novel cluster [PdAu(ScCH)] having a poorly symmetrical, flattened (Pd@Au) core. The conversion produced the new alkynyl-protected clusters [MAu(C≡CAr)] (Ar = 3,5-(CF)CH) having an icosahedral (M@Au) core, with a yield of >50%. The larger number of valence electrons in the M@Au core protected by alkynyls is ascribed to an increase in attractive potential of the M@Au core owing to the stronger electron-withdrawing nature of alkynyls than thiolates. This simple and versatile bottom-up approach will provide an opportunity to synthesize a variety of superatoms on a large scale for the promotion of materials science based on superatoms as building units.