Single Cu Atom Doping on Au11 Nanocluster: Its Implication toward Selectivity in C-C Coupling Reaction

Abstract

Atom precise metal nanoclusters with customized surface structures are important for understanding the mechanism of surface engineering for appropriate applications. We are reporting a single copper doping on a very widely studied Au11(PPh3)7Cl3 nanocluster, in which one chloride ligand is replaced by one Cu atom. Accordingly, a new bimetal nanocluster Cu1Au11(PPh3)7Cl2 is produced, which consisted of a unique Au-Cu surface motif where the Cu is only bonded with an Au atom. In such a motif, the unsaturated Cu atom acts as an active catalyst for the Sonogashira reaction in contrast to the catalytically inactive Au11 nanocluster. Moreover, it demonstrated a reversed selectivity in the Sonogashira cross-coupling reaction, where the major product obtained was homocoupled Glaser products in contrast to the selectivity of previously reported cluster/bimetallic clusters toward Ullmann or Sonogashira products. Theoretical calculations support the unsaturated Cu to be the active site on the nanocluster (NC) and act like a single-atom catalyst. This highlights the effect of mono copper atom doping on the unique selectivity in the Sonogashira cross-coupling reaction. © 2023 American Chemical Society.