Strategic synthesis of FLPClusters toward catalysis

FLPClusters, which are structurally precise metal clusters incorporating Frustrated Lewis Pairs (FLPs), represent a promising class of FLP catalysts. Although FLPClusters have emerged only recently, their precise and strategic synthesis remains underdeveloped. Herein, we report the approach for the strategic synthesis of FLPClusters featuring well-defined, tailorable, and accessible FLP active sites. Our approach utilizes bis(2-(diphenylphosphino)phenyl)ether (DPEphos) as a rigid surface ligand. The two phosphine termini of DPEphos bridge adjacent metal atoms, while the central ether oxygen atom (Lewis base) is geometrically constrained, enabling the formation of stable FLPs with copper atoms (Lewis acid) on the cluster surface. By modulating the structure of ancillary thiolate ligands, we successfully synthesized three FLPClusters. These FLPClusters demonstrate high catalytic activity in the hydrolytic oxidation of organosilanes to silanols. Both theoretical and experimental studies confirm that the catalysis is FLP-driven. Crucially, their catalytic performance scales with the number of FLP sites present. FLPClusters, which are structurally precise metal clusters incorporating Frustrated Lewis Pairs (FLPs), represent a promising class of catalysts, but their tendency to undergo neutralization limits catalytic efficiency. Herein, the authors report the synthesis of FLPClusters featuring well-defined, tailorable, and accessible FLP active sites.