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The Cu‐glutathione (GSH) redox system, essential in biology, is designed here as a supramacromolecular assembly in which the tetrahedral 18e Cu(I) center loses a thiol ligand upon adsorption onto ZIF‐8, as shown by EXAFS and DFT calculation, to generate a very robust 16e planar trigonal single‐atom Cu(I) catalyst. Synergy between Cu(I) and ZIF‐8, revealed by catalytic experiments and DFT calculation, affords CO2 conversion into high‐value‐added chemicals with a wide scope of substrates by reaction with terminal alkynes or propargyl amines in excellent yields under mild conditions and reuse at least 10 times without significant decrease in catalytic efficiency. [ABSTRACT FROM AUTHOR]

In this work, a gold nanocluster [Au14(2-SAdm)9(Dppe)2]+ was synthesized and structurally determined by X-ray crystallography. The crystals of this cluster exhibit a 50-fold enhancement in quantum yield (5.05% for crystals) compared with its solution. Crystallographic analysis reveals that the weak intermolecular interactions (C–H⋯π, π⋯π) can inhibit the molecular vibration and thus generate the crystallization-induced emission enhancement phenomenon. [ABSTRACT FROM AUTHOR]

Recently, CO2 hydrogenation had a new breakthrough resulting from the design of catalysts to effectively activate linear CO2 with symmetry‐breaking sites. However, understanding the relationship between symmetry‐breaking sites and catalytic activity at the atomic level is still a great challenge. In this study, a set of gold‐copper alloy Au13Cux (x=0–4) nanoclusters were used as research objects to show the symmetry‐controlled breaking structure on the surface of nanoclusters with the help of manipulability of the Cu atoms. Among them, Au13Cu3 nanocluster displays the highest degree of symmetry‐breaking on its crystal structure compared with the other nanoclusters in the family. Where the three copper atoms occupying the surface of the icosahedral kernel unevenly with one copper atom is coordinately unsaturated (CuS2 motif relative to CuS3 motif). As expected, Au13Cu3 has an excellent hydrogenation activity of CO2, in which the current density is as high as 70 mA cm−2 (−0.97 V) and the maximum FECO reaches 99 % at −0.58 V. Through the combination of crystal structures and theoretical calculations, the excellent catalytic activity of Au13Cu3 is revealed to be indeed closely related to its asymmetric structure. [ABSTRACT FROM AUTHOR]

The preparation of 2-Oxazolidinones using CO2 offers opportunities for green chemistry, but multi-site activation is difficult for most catalysts. Here, A low-nuclear Ag4 catalytic system is successfully customized, which solves the simultaneous activation of acetylene (-C≡C) and amino (-NH-) and realizes the cyclization of propargylamine with CO2 under mild conditions. As expected, the Turnover Number (TON) and Turnover Frequency (TOF) values of the Ag4 nanocluster (NC) are higher than most of reported catalysts. The Ag4* NC intermediates are isolated and confirmed their structures by Electrospray ionization (ESI) and 1H Nuclear Magnetic Resonance (1H NMR). Additionally, the key role of multiple Ag atoms revealed the feasibility and importance of low-nuclear catalysts at the atomic level, confirming the reaction pathways that are inaccessible to the Ag single-atom catalyst and Ag2 NC. Importantly, the nanocomposite achieves multiple recoveries and gram scale product acquisition. These results provide guidance for the design of more efficient and targeted catalytic materials. The preparation of 2-Oxazolidinones using carbon dioxide offers a productive yet clean synthesis route. Here, a low-nuclear Ag4 nanocluster catalytic system helps the simultaneous activation and the cyclization of propargylamine with CO2. [ABSTRACT FROM AUTHOR]

The redox property of the ultrasmall coinage nanoclusters (with several to tens of Au/Ag atoms) has elucidated the electron-transfer capacity of nanoclusters, and has been successfully utilized in a variety of redox conversions (such as from CO2 to CO). Nevertheless, their biological applications are mainly restricted by the scarcity of atomically precise, water-soluble metal nanoclusters, and the limited application (mainly on the decomposition of H2O2 in these days). Herein, mercaptosuccinic acid (MSA) protected ultrasmall alloy AuAg nanoclusters were prepared, and the main product was determined [Au3Ag5(MSA)3]− by electrospray ionization mass spectrometry (ESI-MS). The clusters can not only mediate the decomposition of H2O2 to generate hydroxyl radicals, but is also able to mediate the reduction of nicotinamide adenine dinucleotide (NAD) to its reduced form of NADH. This is the first time that the atomically precise metal nanoclusters were used to mediate the coenzyme reduction. The preliminary mechanistic insights imply the reaction to be driven by the hydrogen bonding between the carboxylic groups (on the surface of MSA) and the amino N—H bonds (on NAD). In this context, the presence of the carboxylic groups, the sub-nanometer size regime (∼ 1 nm), and the synergistic effect of the Au-Ag clusters are pre-requisite to the NAD reduction. [ABSTRACT FROM AUTHOR]