How Carbene Ligands Transform AuAg Alloy Nanoclusters for Electrocatalytic Urea Synthesis.

Metal nanoclusters stabilized by N-heterocyclic carbene (NHC) ligands have attracted increasing interest for their special structures and diverse applications. However, developing synthetic strategies and extending the database of NHC-protected nanoclusters are still challenging tasks. In this work, a novel and rapid synthetic method is developed to prepare AuAg alloy nanocluster ligated by carbene based on the reactivity of nanoclusters.

Atomically precise copper dopants in metal clusters boost up stability, fluorescence, and photocatalytic activity.

The structurally precise alloy nanoclusters have been emerged as a burgeoning nanomaterial for their unique physical/chemical features. We here report a rod-like nanocluster [AuCu(PPh)I](SbF) (AuCu), which was generated through a transformation of a [Au(PPh)] intermediate in the presence of CuI, unveiled by time-dependent UV-vis spectroscopy, electrospray ionization mass spectrometry as well as single crystal X-ray diffraction. AuCu is comprised of two pentagonal bipyramids AuCu units and a pentagonal prism Cu unit, where the copper and gold species are presented in +1 and 0 chemical states.

Identification of Differentially Expressed Genes in the Longissimus Dorsi Muscle of Luchuan and Duroc Pigs by Transcriptome Sequencing.

The Duroc pig originated in the United States and is a typical lean-meat pig. The breed grows fast, and the body size is large, but the meat quality is poor. The Luchuan pig is one of eight excellent local breeds in China; it has tender meat but is small in size.

Self-Assembly of Silver Clusters into One- and Two-Dimensional Structures and Highly Selective Methanol Sensing.

The development of new materials for the design of sensitive and responsive sensors has become a crucial research direction. Here, two silver cluster-based polymers (Ag-CBPs), including one-dimensional {[Ag(L1)(CFCO)](CHOH)} chain and two-dimensional {[Ag(L2)(COCF)(HO)(AgCOCF)](HNEt)} film, are designed and used to simulate the human nose, an elegant sensor to smells, to distinguish organic solvents. We study the relationship between the atomic structures of Ag-CBPs determined by x-ray diffraction and the electrical properties in the presence of organic solvents (e.

Photo-Induced Cluster-to-Cluster Transformation of [AuAg(PPh)Cl] into [AuAg(PPh)Cl]: Fragmentation of a Trimer of 8-Electron Superatoms by Light.

We present the photoinduced size/structure transformation of [AuAg(PPh)Cl] (M37) into [AuAg(PPh)Cl] (M25) cluster. Single-crystal X-ray diffraction revealed that M37 has a tri-icosahedron M metal core assembled via the fusion of three AuAg icosahedrons in a cyclic fashion and that the M core is further protected by phosphine and chloride ligands. The M37 cluster is found to be highly sensitive toward ambient light, and the M37 → M25 transition is observed with 530 nm irradiation, monitored by time-dependent UV-vis spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and femtosecond transient absorption spectroscopy.

On the redox property of AgAu clusters: One-way conversion from anionic [AuAgL] to charge neutral [AuAgL].

The redox property of metal nanoclusters plays a pivotal role and is of particular interest in catalysis and other applications, such as aerobic oxidation, hydrogenation, and singlet oxygen generation, over intact nanoclusters. In this study, we report a one-way conversion process of the anionic [AgAuL] nanocluster into a charge neutral nanocluster of [AgAuL] via oxidation in a solution phase using HO as the oxidant. Three-electron loss of [AgAuL] occurred during the oxidation process, which was confirmed by electron paramagnetic resonance and electrospray ionization mass spectrometry methods.

Recent Progress in Heterogeneous Catalysis by Atomically and Structurally Precise Metal Nanoclusters.

The feasibility to synthesize the ligand-protected atomically precise nanoclusters with various compositions in sub-nanometer range (≤2 nm) and the determination of their structures is an important step in long-pursuit of well-defined heterogeneous catalysis. Such types of precise catalysts provide an opportunity to understand the fundamentals of catalysis better in terms of: 1) activity and selectivity by metal-core and metal-ligand interface, 2) size-dependent activity, 3) reaction mechanism and 4) active-site identification and activation. It motivated us to develop the novel metal nanoclusters with precise structures as the new catalytic systems, which led to the several significant findings on above mentioned points.

Atomically precise nanoclusters with reversible isomeric transformation for rotary nanomotors.

Thermal-stimuli responsive nanomaterials hold great promise in designing multifunctional intelligent devices for a wide range of applications. In this work, a reversible isomeric transformation in an atomically precise nanocluster is reported. We show that biicosahedral [AuAg(PPh)Cl]SbF nanoclusters composed of two icosahedral AuAg units by sharing one common Au vertex can produce two temperature-responsive conformational isomers with complete reversibility, which forms the basis of a rotary nanomotor driven by temperature.

A Homoleptic Alkynyl-Ligated [Au Ag L ] Cluster as a Catalytically Active Eight-Electron Superatom.

A new alkynylated cluster [Au Ag (C H NO) ] is prepared by a NaBH mediated reduction method. The AuAg clusters are confirmed by sophisticated characterization techniques. It has a unique "Au @Ag @Au Ag " metal framework which is protected by 24 atypical alkyne ligands L (L=C H NO).

Alkynyl- and phosphine-ligated quaternary AuAg clusters featuring an Alkynyl-AuAg motif for multicomponent coupling.

The coordination motif of alkynly with a metal atom is versatile and plays a pivotal role in tailoring the kernel configuration of the atomically precise metal nanoclusters. In this study, we synthesized a new mono-valent Au(I)Ag(I)(CHNO)(PhP) alloy cluster with a very high yield of >90%, which is well characterized by a serial of technologies, UV-vis, X-ray single crystal diffraction (SCXRD) and FT-IR. The SCXRD analysis shows the alloy cluster is composed of a quadrangular AuAg kernel protected by four alkynyl and two phosphine ligands.

Pyridine as a trigger in transformation chemistry from Au(SR) to aromatic thiolate-ligated gold clusters.

Transformation chemistry is a systematic methodology for achieving new atomically precise gold nanoclusters with specific physical and chemical properties. In this work, we have developed a new synthetic approach to prepare an aromatic thiolate-capped Au38(SNap)24 nanocluster via ligand exchange, size and structure transformation from the aliphatic thiolate-capped Au144(SC6H13)60 parent clusters triggered by the addition of a pyridine additive in the presence of excess 2-naphthalenethiol at thermal conditions (80 °C for 6 h). The Au38(SNap)24 nanoclusters have been well characterized by UV-vis spectroscopy and electrospray ionization mass spectrometry.

[MWO] clusters: unprecedented central heteroatoms atomically dispersed in the eight coordination state bridging the 1 : 12 polyoxometalate family of Keggin and Silverton.

A general synthetic protocol is developed to afford a series of [MW12O44] (M = Ni2+, Co2+ and Fe3+) clusters with diverse central heteroatoms, by employing [W12O44]16- as the structure-directing precursor. The structures of the [MW12O44] clusters are definitively confirmed by single crystal X-ray diffraction (XRD). The central heteroatoms are monodispersed and capture the "empty" cavity of [W12O44]16- with an 8 coordination number state, as demonstrated by the combination of single crystal structure extended X-ray absorption fine structure (EXAFS) fitting analysis and wavelet transform EXAFS (WTEXAFS).

Heterogeneous Cross-Coupling over Gold Nanoclusters.

Au clusters with the precise numbers of gold atoms, a novel nanogold material, have recently attracted increasing interest in the nanoscience because of very unique and unexpected properties. The unique interaction and electron transfer between gold clusters and reactants make the clusters promising catalysts during organic transformations. The AuL nanoclusters (where L represents organic ligands and and mean the number of gold atoms and ligands, respectively) have been well investigated and developed for selective oxidation, hydrogenation, photo-catalysis, and so on.

Tailoring the stability, photocatalysis and photoluminescence properties of Au nanoclusters doping engineering.

Dopants in gold nanoclusters have been proved to mediate the intrinsic electronic properties of homo-clusters. In this work, we report the precise synthesis of atomically precise AuAg(PPh)Cl alloy nanoclusters with multiple Ag dopants for the first time. Their structure was resolved by single-crystal X-ray crystallography.

Supramolecular topology design of silver(i) and copper(ii) coordination polymers through a new semi-rigid sulfonyl ligand with different anion templates.

A series of metal organic coordination polymers (MOCPs) of silver(i) and copper(ii) coordinated with a novel multifunctional semi-rigid sulfonyl ligand with different anion templates and oxidation states were designed for the first time. In addition, their atomically precise molecular structure was determined by single crystal X-ray diffraction analysis. In comparison, the topology of silver(i)-based MOCPs is affected significantly by different anion templates.

Cloning of Porcine Pituitary Tumor Transforming Gene 1 and Its Expression in Porcine Oocytes and Embryos.

The maternal-to-embryonic transition (MET) is a complex process that occurs during early mammalian embryogenesis and is characterized by activation of the zygotic genome, initiation of embryonic transcription, and replacement of maternal mRNA with embryonic mRNA. The objective of this study was to reveal the temporal expression and localization patterns of PTTG1 during early porcine embryonic development and to establish a relationship between PTTG1 and the MET. To achieve this goal, reverse transcription-polymerase chain reaction (RT-PCR) was performed to clone porcine PTTG1.

The effect of buffalo CD14 shRNA on the gene expression of TLR4 signal pathway in buffalo monocyte/macrophages.

CD14 plays a crucial role in the inflammatory response to lipopolysaccharide (LPS), which interacts with TLR4 and MD-2 to enable cell activation, resulting in inflammation. Upstream inhibition of the inflammation pathway mediated by bacterial LPS, toll-like receptor 4 (TLR4) and cluster of differentiation antigen 14 (CD14) was proven to be an effective therapeutic approach for attenuating harmful immune activation. To explore the effect of CD14 downregulation on the expression of TLR4 signaling pathway-related genes after LPS stimulation in buffalo (Bubalus bubalis) monocyte/macrophages, effective CD14 shRNA sequences were screened using qRT-PCR and FACS analysis with buffalo CD14 shRNA lentiviral recombinant plasmids (pSicoRGFP-shRNA) and buffalo CD14 fusion expression plasmids (pDsRed-N1-buffalo CD14) co-transfected into HEK293T cells via liposomes.