Anchoring Frustrated\nLewis Pair Active Sites on Copper\nNanoclusters for Regioselective Hydrogenation

In\nrecent years, the concept of Frustrated Lewis Pairs\n(FLPs),\nwhich consist of a combination of Lewis acid (LA) and Lewis base (LB)\nactive sites arranged in a suitable geometric configuration, has been\nwidely utilized in homogeneous catalytic reactions. This concept has\nalso been extended to solid supports such as zeolites, metal oxide\nsurfaces, and metal/covalent organic frameworks, resulting in a diverse\nrange of heterogeneous FLP catalysts that have demonstrated notable\nefficiency and recyclability in activating small molecules. This study\npresents the successful immobilization of FLP active sites onto the\nsurface of ligand-stabilized copper nanoclusters with atomic precision,\nleading to the development of copper nanocluster FLP catalysts characterized\nby high reactivity, stability, and selectivity. Specifically, thiol\nligands containing 2-methoxyl groups were strategically designed to\nstabilize the surface of [Cu<sub>34</sub>S<sub>7</sub>(RS)<sub>18</sub>(PPh<sub>3</sub>)<sub>4</sub>]<sup>2+</sup> (where RSH = 2-methoxybenzenethiol),\nfacilitating the formation of FLPs between the surface copper atoms\n(LA) and ligand oxygen atoms (LB). Experimental and theoretical investigations\nhave demonstrated that these FLPs on the cluster surface can efficiently\nactivate H<sub>2</sub> through a heterolytic pathway, resulting in\nsuperior catalytic performance in the hydrogenation of alkenes under\nmild conditions. Notably, the intricate yet precise surface coordination\nstructures of the cluster, reminiscent of enzyme catalysts, enable\nthe hydrogenation process to proceed with nearly 100% selectivity.\nThis research offers valuable insights into the design of FLP catalysts\nwith enhanced activity and selectivity by leveraging surface/interface\ncoordination chemistry of ligand-stabilized atomically precise metal\nnanoclusters.