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. Herein 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 well 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 site 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.

Advances in Cu nanocluster catalyst design: recent progress and promising applications

“…Recently Luo et al introduced a novel metal-deficient chiral Cu NC, denoted as [Cu 57 H 20 (PET) 36 (PPh 3 ) 4 ] + (PET: phenylethanethiolate) NC, composed of a unique architecture featuring a Cu 8 cubic kernel and a Cu 49 (PET) 36 (PPh 3 ) 4 shell. 62 The outermost shell exhibits a distinct Cu atom deficiency, as evidenced by the total symmetric structure of reported [Cu 58 H 20 (S-CH 2 CH 2 CH 3 ) 36 (PPh 3 ) 8 ] 2+ NC. 63 Despite the presence of eight PPh3 units capping the outermost cubic shell in the reported nanocluster, a single copper atom vacancy defect emerges at one corner of this shell in the [Cu 57 H 20 (PET) 36 (PPh 3 ) 4 ] + NC, leading to alterations in the PPh 3 ligand attachments.…”

A thiolated copper-hydride nanocluster with chloride bridging as a catalyst for carbonylative C–N coupling of aryl amines under mild conditions: a combined experimental and theoretical study

“…The interconnectivity between metals and ligands creates a different core configuration that preferentially governs the geometric architecture of the overall NCs and creates active catalytic sites with fewer coordination bonds, which are inaccessible in any other contemporary materials. 18–24…”

Thiacalix[4]arene Etching of an Anisotropic Cu70H22 Intermediate for Accessing Robust Modularly Assembled Copper Nanoclusters

“…Atomically precise coinage-metal nanoclusters (NCs) have attracted much attention because of their intriguing esthetic structures, unique properties, and potential applications in various research areas such as optics, catalysis, biochemistry, new energy sources, sensors, etc. − With the advancements in synthetic approaches and X-ray diffraction technology, a series of high-nuclearity Au and Ag NCs (such as Au 99 , Au 144 , Au 279 , Ag 100 , Ag 141 , Ag 307 ) have been successfully isolated and structurally characterized, which are significant for understanding the process of formation and growth of metal nanoparticles (NPs). − In contrast, the access and precise characterization of their Cu analogs remain deficient because of the susceptibility to air oxidation and challenge in single-crystal growth, despite the pivotal role played by copper and copper-based nanomaterials in energy conversion. − Over the past decades, only limited large-sized Cu NCs (Cu 53 , Cu 57 , Cu 61 , Cu 81 , Cu 92 , etc.) have been structurally determined, which impeded the comprehensive understanding of the evolutionary mechanisms underlying Cu nanoparticles. − Therefore, the development of new methods and approaches to access high-nuclearity Cu NCs with diverse structures is of great significance.…”