Overall Structures of Two Metal Nanoclusters: Chloride as a Bridge Fills the Space between the Metal Core and the Metal Shell.

In addition to using common ligands (phosphine, thiol, or acetylene ligands) to protect metal nanoclusters, halogens can also be used to participate in the formation of nanoclusters. In this study, we reported the formation of two new nanoclusters promoted by chlorides released from HAuCl: one [AuAg(SR)Cl] with an icosahedral AuAg kernel, which is surrounded by the shell of Ag(SR), and the special chlorine atom fills the space between the metal core and the metal shell; the other [AuAg(Dppf)(SR)Cl] with the kernel consisted of two icosahedral AuAg units by sharing one vertex Ag atom, which is protected by the complicated shell of Ag(Dppf)(SR)Cl, two special chlorine atoms also fill the space between the metal core and the metal shell. Thus, both two nanoclusters suggest that the chlorine atoms can exist in the space between the metal kernel and out shell, playing a critical role in maintaining the stability of the overall structures.

Postmodified Dual Functional UiO Sensor for Selective Detection of Ozone and Tandemly Derived Sensing of Al.

Development of highly sensitive and selective fluorescent sensors toward hazardous analytes represents great progress in fabricating sensing devices for practical applications. In this work, a highly selective sensor with dual functions has been fabricated via facile postmodification of the UiO-MOF. Butene modified salicylaldehyde is covalently linked to the UiO-66 scaffold via an efficient Schiff-base reaction, resulting in a highly fluorescent ozone sensor of UiO-66-butene.

Doping Copper Atoms into the Nanocluster Kernel: Total Structure Determination of [CuAg(SAdm)S](BPh).

Doping active metal (i.e., Cu) into the kernel of noble metal nanoclusters (i.

Design and Remarkable Efficiency of the Robust Sandwich Cluster Composite Nanocatalysts ZIF-8@Au@ZIF-67.

Heterogeneous catalysts with precise surface and interface structures are of great interest to decipher the structure-property relationships and maintain remarkable stability while achieving high activity. Here, we report the design and fabrication of the new sandwich composites ZIF-8@Au@ZIF-67[tkn] and ZIF-8@Au@ZIF-8[tkn] [tkn = thickness of shell] by coordination-assisted self-assembly with well-defined structures and interfaces. The composites ZIF-8@Au@ZIF-67 efficiently catalyzed both 4-nitrophenol reduction and terminal alkyne carboxylation with CO under ambient conditions with remarkably improved activity and stability, compared to the simple components Au/ZIF-8 and Au@ZIF-8, highlighting the highly useful function of the ultrathin shell.

The mechanism of metal exchange in non-metallic nanoclusters.

We substituted gold atoms in fcc structured Au and Au nanoclusters with a Ag(i)SR complex and obtained Ag Au and Ag Au nanoclusters, respectively. The positive electrostatic potential (ESP) and dual descriptor (Δ) values were calculated for the metal cores of both nanoclusters, which indicated that the metal exchange is an electrophilic reaction.

Reversible nanocluster structure transformation between face-centered cubic and icosahedral isomers.

Structural transformations between isomers of nanoclusters provide a platform to tune their properties and understand the fundamental science due to their intimate structure-property correlation. Herein, we demonstrate a reversible transformation between the face-centered cubic (FCC) and icosahedral isomers of PtAg nanoclusters accomplished in the ligand-exchange processes. Ligand-exchange of 1-adamantanethiolate protected PtAg by cyclohexanethiolate could transform the FCC kernel to the icosahedral isomer.

Light-Induced Size-Growth of Atomically Precise Nanoclusters.

A photo-induced transformation from [Au(S--C)](TOA) to Au(S--C) nanocluster was first reported in this work. The [Au(S--C)](TOA) nanocluster is first excited to [Au(S--C)](TOA) by photons with energy higher than its ( = HOMO - LUMO energy gap), and then, the negatively charged [Au(S--C)] nanocluster was oxidized to the neutral state by transfering one electron to O. The unstable neutral cluster [Au(S--C)] obtained was decomposed into smaller nanocluster and finally reassembled into the Au(S--C) nanocluster.

Stabilization of a new nanocomposite family by reduction of gold nanoclusters with electron-reservoir complexes.

Four stable 19-electron Fe and Co sandwich electron-reservoirs and three hydride reservoir complexes reduce the prototypal nanocluster Au25(SR)18 (R = CH2CH2Ph) leading to a largely increased kinetic stabilization of the anionic nanocluster form compared to previously known nanocluster anion salts; these salts represent new and robust nanocomposite anionic gold clusters with 18-electron sandwich complexes as counter cations.

Free Valence Electron Centralization Strategy for Preparing Ultrastable Nanoclusters and Their Catalytic Application.

Metal nanoclusters have attracted extensive interests owing to their atomically precise structures as well as intriguing properties. However, silver nanoclusters are not as stable as their gold counterparts, impeding the practical applications of Ag nanoclusters. In this work, a strategy of free valence electron centralization was exploited to render parent Ag nanoclusters highly stable.

Mechanistic Study on Decarbonylative Phosphorylation of Aryl Amides by Nickel Catalysis.

The phosphorylation of amide represents an unprecedented environmentally friendly and easily achievable method to constitute C-P bonds in organic synthesis. In this study, the mechanisms for the nickel-catalyzed direct decarbonylative phosphorylation of amides recently reported by Szostak's team were systematically studied with density functional theory calculations. The reaction mainly undergoes four steps: oxidative addition (rate-determining step), phosphorylation, decarbonylation, and reductive elimination.

Density Functional Theory Investigations on the Mechanism of Formation of Pa(V) Ion in Hydrous Solutions.

Due to the enormous threat of protactinium to the environment and human health, its disposal and chemistry have long been important topics in nuclear science. [PaO(H₂O)₆] is proposed as the predominant species in hydrous and acidic solutions, but little is known about its formation mechanism. In this study, density functional theory (DFT) calculations demonstrate a water coordination-proton transfer-water dissociation mechanism for the formation of PaO in hydrous solutions.

Atomically Precise Noble Metal Nanoclusters as Efficient Catalysts: A Bridge between Structure and Properties.

Improving the knowledge of the relationship between structure and properties is fundamental in catalysis. Recently, researchers have developed a variety of well-controlled methods to synthesize (NCs). NCs have shown high catalytic activity and unique selectivity in many catalytic reactions, which are related to their ultrasmall size, abundant unsaturated active sites, and unique electronic structure different from that of traditional nanoparticles (NPs).

Zirconium based metal-organic framework in-situ assisted hydrothermal pretreatment and enzymatic hydrolysis of Platanus X acerifolia exfoliating bark for bioethanol production.

Metal-organic framework (MOF) assisted hydrothermal pretreatment and co-catalysis strategy based on UiO-66 MOF is developed for the first time. The Planetree exfoliating bark was pretreated with or without UiO-66 assisted hydrothermal method at a temperature ranging from 160 to 240 °C for 1-3 h residence. With the rise of pretreatment severity, the total reducing sugar (TRS) was increased till reached maximum, 180 mg g, in the presence of UiO-66.

Real-time visualization of autophagy by monitoring the fluctuation of lysosomal pH with a ratiometric two-photon fluorescent probe.

A benzimidazole-decorated two-photon fluorescent probe (Lyso-MPCB) based on the p-methoxyphenylacetylene-substituted carbazole was developed for detecting lysosomal pH with a double-channel signal, which can be used to visualize autophagy by real-time imaging the fluctuation of the pH in the lysosomes.

Rational design of a ratiometric two-photon fluorescent probe for real-time visualization of apoptosis.

A dialdehyde-functionalized ratiometric two-photon fluorescent probe (Mito-DCHO) based on a symmetric carbazole-containing two-dimensional ICT system was rationally designed for cysteine-specific detection in mitochondria, which was utilized for real-time assessing and dual-channel visualization of the early stage of apoptosis by monitoring mitochondrial oxidative stress levels.

Large-Scale Synthesis, Crystal Structure, and Optical Properties of the AgBr(SR) Nanocluster.

Solving the atomic structure of large-sized metal nanoclusters is a highly challenging task yet critically important for understanding the properties and developing applications. Herein, we report a stable silver nanocluster-AgBr(SR) (where SR = 4-isopropylbenzenethiolate)-with its structure solved by X-ray crystallography. Gram-scale synthesis with high yield has been achieved by a one-pot reaction, which offers opportunities for functionalization and applications.

Switching the subcellular organelle targeting of atomically precise gold nanoclusters by modifying the capping ligand.

Here, we have achieved the target switching fluorescence imaging and photodynamic activity of hydrosoluble AuNCs from lysosomes to mitochondria through ligand exchange. This work unveils the ligand-regulated subcellular distribution of AuNCs by which new strategies to improve their bio-applications such as precise nanotheranostics could be realized.

Au(SR): the captain of the great nanocluster ship.

Noble metal nanoclusters are in the intermediate state between discrete atoms and plasmonic nanoparticles and are of significance due to their atomically accurate structures, intriguing properties, and great potential for applications in various fields. In addition, the size-dependent properties of nanoclusters construct a platform for thoroughly researching the structure (composition)-property correlations, which is favorable for obtaining novel nanomaterials with enhanced physicochemical properties. Thus far, more than 100 species of nanoclusters (mono-metallic Au or Ag nanoclusters, and bi- or tri-metallic alloy nanoclusters) with crystal structures have been reported.

Two-Photon Fluorescent Probe for Monitoring Autophagy via Fluorescence Lifetime Imaging.

We reported the first lysosome targeted two-photon fluorescent probe (Lyso-NP) as a viscosity probe for monitoring autophagy. The fluorescence lifetime of Lyso-NP exhibited an excellent linear relationship with viscosity value ( R = 0.99, x = 0.

Observation of a new type of aggregation-induced emission in nanoclusters.

The strategy of aggregation-induced emission (AIE) has been widely used to enhance the photo-luminescence (PL) in the nanocluster (NC) research field. Most of the previous reports on aggregation-induced enhancement of fluorescence in NCs are induced by the restriction of intramolecular motion (RIM). In this work, a novel mechanism involving the restriction of the "dissociation-aggregation pattern" of ligands is presented using a Ag(BDT)(TPP) NC (BDT: 1,3-benzenedithiol; TPP: triphenylphosphine) as a model.

pH-Independent two-photon fluorescent lysotrackers for real-time monitoring autophagy.

Two carbazole-based two-photon fluorescent lysotrackers with different electron-donating groups (a methoxyl group for Lyso-MCO and a dimethylamino group for Lyso-NCO, respectively) have been developed from simple starting materials via an only 2-step procedure. Both of them exhibit pH-independent and specific lysosome location with a rapid staining rate, high photostability and deep issue penetration along with large two-photon absorption action cross-sections. By virtue of the better two-photon absorption properties of Lyso-NCO, it was chosen to visually monitor lysosomal tracking and autophagy.

X-ray crystal structure and doping mechanism of bimetallic nanocluster AuCu(m-MBT) (x = 1-3).

A novel AuCu(m-MBT) (x = 1-3, m-MBT = 3-methylbenzenethiolate) nanocluster has been prepared. According to the X-ray single crystal diffractometer, the structure of AuCu(m-MBT) is similar to that of Au(SPhBu). The AuCu(m-MBT) nanocluster contains a face-centered cubic (FCC) M core, which is protected by 4 MS (M = Au/Cu) staple motifs and 12 bridging SR ligands.

A mitochondria-targeted ratiometric two-photon fluorescent probe for detecting intracellular cysteine and homocysteine.

A novel mitochondria-targeted ratiometric two-photon fluorescent probe (Mito-MQ) for detecting intracellular cysteine (Cys) and homocysteine (Hcy) has been designed. Mito-MQ showed the ratiometric fluorescent detection signal (the green-to-blue emissionfrom 517nm to 460nm) to cysteine (Cys) and homocysteine (Hcy) over glutathione (GSH), along with the fast response rate (10min). The detection mechanism was illustrated by H NMR, ESI-MS and theoretical calculation.