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Ligand-protected metal nanoclusters provide an ideal platform for investigating photoredox catalysis. The central challenge is balancing their stability and catalytic activity. Here we show a photochemical reduction–oxidation cascade method for synthesizing an Au8Cu6 nanocluster, which features a robust structure and active surface. Photoredox catalytic activity of Au8Cu6 is developed for the functionalization of alkynes under oxidative conditions. Mechanism studies based on the precise structure reveal the catalytic process of the Au8Cu6 nanocluster. Oxidant-dependent selectivity of Au8Cu6 catalysis is developed for chemodivergent synthesis of mono- and di-functionalized products in high efficiency. The results will stimulate more research on metal nanocluster synthesis and catalysis. Ligand-protected metal nanoclusters provide an ideal platform for investigating the balance of stability and activity in photoredox catalysis. Here, the authors apply a photochemical reduction–oxidation cascade method to synthesize an Au8Cu6 nanocluster with a robust structure and active surface. [ABSTRACT FROM AUTHOR]

A gold nanocluster Au17Cd2(PNP)2(SR)12 (PNP=2,6‐bis(diphenylphosphinomethyl)pyridine, SR=4‐MeOPhS) consisting of an icosahedral Au13 kernel, two Au2CdS6 staple motifs, and two PNP pincer ligands has been designed, synthesized and well characterized. This cadmium and PNP pincer ligand co‐modified gold nanocluster showed high catalytic efficiency in the KA2 reaction, featuring high TON, mild reaction conditions, broad substrate scope as well as catalyst recyclability. Comparison of the catalytic performance between Au17Cd2(PNP)2(SR)12 and the structurally similar single cadmium (or PNP) modified gold nanoclusters demonstrates that the co‐existence of the cadmium and PNP on the surface is crucial for the high catalytic activity of the gold nanocluster. This work would be enlightening for developing efficient catalysts for cascade reactions and discovering the catalytic potential of metal nanoclusters in organic transformations. [ABSTRACT FROM AUTHOR]

Thiolates endow metal nanoclusters with stability while sometimes inhibit the catalytic activity due to the strong M−S interaction (M: metal atom). To improve the catalytic activity and keep the stability to some extent, one strategy is the partial phosphorization of thiolated metal nanoclusters. This is demonstrated by successful partial phosphorization of Au23(SC6H11)16 and by revealing that the products Au22(SC6H11)14(PPh3)2 and Au22(SC6H11)12(PPh3)4, with varied degree of phosphorization, both show excellent activity in the photocatalytic oxidation of thioanisole without notable reduction of stability. Furthermore, Au22(SC6H11)12(PPh3)4 exhibits better photoluminescence performance than the mother nanocluster Au23(SC6H11)16, indicating that partial phosphorization can also improve some other performance(s) except for the catalytic performance. The intermediates Au22‐xCux(SC6H11)12(PPh3)4 (x=1, 2) in the transformation from Au23(SC6H11)16 (Au22(SC6H11)14(PPh3)2) to Au22(SC6H11)12(PPh3)4 were captured and identified by mass spectrometry and single crystal X‐ray diffraction, which throws light on the understanding of the non‐alloyed anti‐galvanic reaction. [ABSTRACT FROM AUTHOR]

Tuning the nanoclusters' compositions and structures is critical for the performance improvement of nanoclusters. Herein, a well-known Au25( SCH2CH2Ph)18 (Au25 for short) nanocluster has been transformed to a rare cadmium doped gold nanocluster [ Au13Cd2( PPh3)6( SC2H4Ph)6( NO3)2] 2Cd( NO3)4 ( Au26Cd5 for short) by peeling and doping. Although Au25 exhibits no catalytic activity toward A3-coupling reaction under the investigated conditions, the novel cadmium doped gold nanocluster Au26Cd5 shows high catalytic activity, as well as good recyclability and substrate tolerance for the same reaction. The high catalytic activity is attributed to the cooperation between the exerted cadmium atoms and the neighbor gold atoms on the surface of Au13 icosahedron. This work has important implication for the tuning of nanoclusters' compositions and structures targeting the improvement of catalytic performance by some unusual but effective strategies. [ABSTRACT FROM AUTHOR]

A new nanocluster of atomic precision, Au44(SC2H4Ph)32, is obtained by an oxidation–decomposition–recombination (ODR) process from Au25(SC2H4Ph)18 under mild conditions with high yield (75%). Among the investigated gold nanoclusters, Au44(SC2H4Ph)32 exhibits the highest catalytic activity for the reduction of 4-nitrophenol, especially at low temperature, indicating that the catalytic properties of gold nanoclusters are not only size-dependent, but also structure-sensitive. [ABSTRACT FROM AUTHOR]

[Display omitted] • An efficient strategy to incorporate Cu2+ into nanoclusters was developed. • The incorporation induced enhancement in nanocluster catalysis was revealed. • The atomically precise composition/structure of the nano-catalyst was determined. • The Au 13 Cu 2 catalyst outperforms the classic bicatalyst for Sonogashira reaction. • Mechanism of Au 13 Cu 2 catalyzed-Sonogashira reaction was proposed. Pd together with CuI has been well known as the catalyst towards Sonogashira reaction, which provides an effective route to functional alkynes. However, the achievement of high activity and selectivity of this catalytic system is still challenging in some cases. Illustrative examples include their low activity for aryl chloride substrates, and switched selectivity to oxidative coupling products in air atmosphere. In this work, a Cu-incorporated Au 13 nanocluster [Au 13 Cu 2 (PPh 3) 6 (SC 2 H 4 Ph) 6 ]+[NO 3 ]- (Au 13 Cu 2) was designed and prepared in high yield via rapid synthesis. This atomically precise nanocluster shows the potential to be a novel catalytic system for Sonogashira reaction, featuring high activity and selectivity, as well as good recyclability even in air atmosphere. [ABSTRACT FROM AUTHOR]