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High‐yield and large‐scale synthesis are highly demanded for the studies of gold nanoclusters. We developed a "cluster from cluster" approach to assemble gold nanoclusters with preformed atomically precise Au13 precursors. This facile approach has proved to be very effective in the synthesis of the well‐known magic cluster [Au25(SR)18]−, which could prepare the target cluster in high yield (overall yield up to ≈100 %) at large scale (gram‐scale based on gold). This method can be applied in the synthesis of 10 Au25 clusters with different R groups. This work presents an important approach that may be extended to high‐yield and large‐scale synthesis of other metal nanoclusters. [ABSTRACT FROM AUTHOR]

High‐yield and large‐scale synthesis are highly demanded for the studies of gold nanoclusters. We developed a "cluster from cluster" approach to assemble gold nanoclusters with preformed atomically precise Au13 precursors. This facile approach has proved to be very effective in the synthesis of the well‐known magic cluster [Au25(SR)18]−, which could prepare the target cluster in high yield (overall yield up to ≈100 %) at large scale (gram‐scale based on gold). This method can be applied in the synthesis of 10 Au25 clusters with different R groups. This work presents an important approach that may be extended to high‐yield and large‐scale synthesis of other metal nanoclusters. [ABSTRACT FROM AUTHOR]

Gold nanoclusters with surface open sites are crucial for practical applications in catalysis. We have developed a surface geometric mismatch strategy by using mixed ligands of different type of hindrance. When bulky phosphine Ph3P and planar dipyridyl amine (Hdpa) are simultaneously used, steric repulsion between the ligands will reduce the ligand coverage of gold clusters. A well‐defined access granted gold nanocluster [Au23(Ph3P)10(dpa)2Cl](SO3CF3)2 (Au23, dpa=dipyridylamido) has been successfully synthesized. Single crystal structural determination reveals that Au23 has eight uncoordinated gold atoms in the shape of a distorted bicapped triangular prism. The accessibility of the exposed Au atoms has been confirmed quantitatively by luminescent titration with 2‐naphthalenethiol. This cluster has excellent performance toward selective oxidation of benzyl alcohol to benzaldehyde and demonstrates excellent stability due to the protection of negatively charged multidentate ligand dpa. [ABSTRACT FROM AUTHOR]

An alkynyl‐protected gold nanocluster, Au22(tBuC≡C)18 (1), has been synthesized and its structure has been determined by single‐crystal X‐ray diffraction. The molecular structure consists of a Au13 cuboctahedron kernel and three [Au3(tBuC≡C)4] trimeric staples. The cluster 1 has strong luminescence in the solid state with a 15 % quantum yield, and it displays interesting thermochromic luminescence as revealed by temperature‐dependent emission spectra. The enhanced room‐temperature emission is characterized as thermally activated delayed fluorescence. [ABSTRACT FROM AUTHOR]

Two homoleptic alkynyl‐protected gold clusters with compositions of Na[Au25(C≡CAr)18] and (Ph4P)[Au25(C≡CAr)18] (Na⋅1 and Ph4P⋅1, Ar=3,5‐bis(trifluoromethyl)phenyl) were synthesized via a direct reduction method. 1 is a magic cluster analogous to [Au25(SR)18]− in terms of electron counts and metal‐to‐ligand ratio. Single‐crystal structure analysis reveals that 1 has an identical Au13 kernel to [Au25(SR)18]−, but adopts a distinctly different arrangement of the six peripheral dimer staple motifs. The steric hindrance of alkynyl ligands is responsible for the D3 arrangement of Au25. The introduction of alkynyl also significantly changes the optical absorption features of the nanocluster as supported by DFT calculations. This magic cluster confirms that there is a similar but quite different parallel alkynyl‐protected metal cluster universe in comparison to the thiolated one. Magic clusters Na[Au25(C≡CAr)18] and (Ph4P)[Au25(C≡CAr)18] (Ar=3,5‐bis(trifluoromethyl)phenyl) exhibit novel connection between staples and the Au13 core. Steric hindrance caused by rigid ligand coordination preference accounts for the different geometric and electronic structures. [ABSTRACT FROM AUTHOR]

Abstract: Total structure determination of a ligand‐protected gold nanocluster, Au144, has been successfully carried out. The composition of title nanocluster is Au144(C≡CAr)60 (1; Ar=2‐FC6H4‐). The cluster 1 exhibits a quasi‐spherical Russian doll‐like architecture, comprising a Au54 two‐shelled Mackay icosahedron (Au12@Au42), which is further enclosed by a Au60 anti‐Mackay icosahedral shell. The Au114 kernel is enwrapped by thirty linear ArC≡C‐Au‐C≡CAr staple motifs. The absorption spectrum of 1 shows two bands at 560 and 620 nm. This spectrum is distinctly different from that of thiolated Au144, which was predicted to have an almost identical metal kernel and very similar ligands arrangement in 1. These facts indicate the molecule‐like behavior of 1 and significant involvement of ligands in the electronic structure of 1. The cluster 1 is hitherto the largest coinage metal nanocluster with atomically precise molecular structure in the alkynyl family. The work not only addresses the concern of structural information of Au144, which had been long‐pursued, but also provides an interesting example showing ligand effects on the optical properties of ligand protected metal nanoclusters. [ABSTRACT FROM AUTHOR]

Abstract: Total structure determination of a ligand‐protected gold nanocluster, Au144, has been successfully carried out. The composition of title nanocluster is Au144(C≡CAr)60 (1; Ar=2‐FC6H4‐). The cluster 1 exhibits a quasi‐spherical Russian doll‐like architecture, comprising a Au54 two‐shelled Mackay icosahedron (Au12@Au42), which is further enclosed by a Au60 anti‐Mackay icosahedral shell. The Au114 kernel is enwrapped by thirty linear ArC≡C‐Au‐C≡CAr staple motifs. The absorption spectrum of 1 shows two bands at 560 and 620 nm. This spectrum is distinctly different from that of thiolated Au144, which was predicted to have an almost identical metal kernel and very similar ligands arrangement in 1. These facts indicate the molecule‐like behavior of 1 and significant involvement of ligands in the electronic structure of 1. The cluster 1 is hitherto the largest coinage metal nanocluster with atomically precise molecular structure in the alkynyl family. The work not only addresses the concern of structural information of Au144, which had been long‐pursued, but also provides an interesting example showing ligand effects on the optical properties of ligand protected metal nanoclusters. [ABSTRACT FROM AUTHOR]