Total Structure, Electronic Structure and Catalytic Hydrogenation Activity of Metal-Deficient Chiral Polyhydride Cu57 Nanoclusters.

Abstract

Accurate identifying and in-depth understanding of the defect sites in a working nanomaterial could hinge on establishing specific defect-activity relationships. Yet, atomically precise coinage-metal nanoclusters (NCs) possessing surface vacancy defects are scarce primarily owing to challenges in the synthesis and isolation of such defective NCs. We report a mixed-ligand strategy to synthesizing an intrinsically chiral and metal-deficient copper hydride-rich NC [Cu57H20(PET)36(TPP)4]+ (Cu57H20). Its total structure (including hydrides) and electronic structure are established by combined experimental and computational results. Crystal structure reveals Cu57H20 features a cube-like Cu8 kernel embedded in a corner-missing metal-ligand shell of Cu49(PET)36(TPP)4. Single Cu vacancy defect occurs at one corner of the shell, evocative of mono-lacunary polyoxometalates. Theoretical calculations demonstrate that the above-mentioned point vacancy causes one surface hydride exposed as an interfacial capping μ3-H-, which is accessible in chemical reaction, as proved by deuterated experiment. Moreover, Cu57H20 shows catalytic activity in the hydrogenation of nitroarene. The success of this work opens the way for the research on well-defined chiral metal-deficient Cu and other metal NCs, including exploring their application in asymmetrical catalysis.