Satellite Pd Single-Atom Embraced AuPd Alloy Nanoclusters for Enhanced Hydrogen Evolution.

The fabrication of hybrid active sites that synergistically contain nanoclusters and single atoms (SAs) is vital for electrocatalysts to achieve excellent activity and durability. Herein, we develop a ligand-assisted pyrolysis strategy using nanoclusters (AuPd(SCHPh)) with alloy cores and protected ligands to build AuPd cluster sites embraced by satellite Pd SAs. In the thermal drive control process, different thermodynamic properties of the alloy atoms and the confinement effects of organic ligands allow for the mild spillover of the single-component metal Pd, resulting in the formation of AuPd alloy nanoclusters tightly encompassed by isolated Pd atoms.

Selectivity Modulation of Multistep Reduction Reactions by Gold Nanoclusters.

The selective synthesis of valuable azo- and azoxyaromatic chemicals via transfer coupling of nitroaromatic compounds has been achieved by fine-tuning the catalyst structure. Here, a direct method to modulate nitrobenzene reduction and selectively alter the product from azobenzene to azoxybenzene by employing the size effect of Au is reported. Au nanoclusters (NCs) with smaller sizes embedded in ZIF-8 controllably converted nitrobenzene into azoxybenzene, while supported Au nanoparticles (NPs) selectively catalyzed nitrobenzene reduction to azobenzene.

Single-atom tailored atomically-precise nanoclusters for enhanced electrochemical reduction of CO-to-CO activity.

The development of facile tailoring approach to adjust the intrinsic activity and stability of atomically-precise metal nanoclusters catalysts is of great interest but remians challenging. Herein, the well-defined Au nanoclusters modified by single-atom sites are rationally synthesized via a co-eletropolymerization strategy, in which uniformly dispersed metal nanocluster and single-atom co-entrenched on the poly-carbazole matrix. Systematic characterization and theoretical modeling reveal that functionalizing single-atoms enable altering the electronic structures of Au clusters, which amplifies their electrocatalytic reduction of CO to CO activity by ~18.

KOH-Enabled Axial-Oxygen Coordinated Ni Single-Atom Catalyst for Efficient Electrocatalytic CO Reduction.

Precise control of the coordination structure of metal centers is an ideal approach to achieve reasonable selectivity, activity, and stability in the electrochemical reduction of CO . In this work, the KOH activation strategy for preparation of hierarchically porous material containing Ni single-atoms with axial-oxygen coordination is reported. Spectroscopic measurements reveal the multiple roles of KOH as oxygen source, pore-making reagent and promoter for the formation of key phthalocyanine structure.

Catalytic Cyanation of C-N Bonds with CO/NH.

Cyanation of benzylic C-N bonds is useful in the preparation of important α-aryl nitriles. The first general catalytic cyanation of α-(hetero)aryl amines, analogous to the Sandmeyer reaction of anilines, was developed using reductive cyanation with CO/NH. A broad array of α-aryl nitriles was obtained in high yields and regioselectivity by C-N cleavage of intermediates as ammonium salts.

Recyclable Oxofluorovanadate-Catalyzed Formylation of Amines by Reductive Functionalization of CO with Hydrosilanes.

An efficient method has been developed for the reductive amination of CO by using readily available and recyclable oxofluorovanadates as catalysts. Various amines are transformed into the desired N-formylated products in moderate to excellent yields at room temperature in the presence of phenylsilane. Mechanistic studies based on in situ infrared spectroscopy suggest a reaction pathway initiated through F-Si interactions.

Ru-Catalyzed Switchable N-Hydroxyethylation and N-Acetonylation with Crude Glycerol.

Highly efficient Ru-catalyzed selective C-C or C-O bond cleavage of polyols (e.g., crude glycerol) for N-hydroxyethylation or N-acetonylation of amines was achieved through the hydrogen-borrowing approach.

Cu Cluster with Partial Cu(0) Character: Difference in Electronic Structure from Isostructural Silver Analog.

An atom-precise Cu-containing copper cluster, Cu(CBHS)(CHCN) (abbreviated as Cu-8CHCN) is reported, which is synthesized via a simultaneous reduction strategy and fully characterized by single-crystal X-ray diffraction, ESI-TOF-MS, and X-ray photoelectron spectroscopy. Cu-8CHCN is the only copper cluster that has a virtually identical silver structural analog, i.e.

Distinct photophysical properties in atom-precise silver and copper nanocluster analogues.

The synthesis of atom-precise analogues of homometallic nanoclusters remains a great challenge. Herein we report the first pair of atom-precise copper/silver-thiolate halide cluster analogues, namely [Cu17/Ag17I3S(C2B10H10S2)6(CH3CN)11] (Cu17 and Ag17), obtained by bottom-up self-assembly and complete-metal-exchange-induced cluster-to-cluster transformation, respectively. The differences in optical absorption and emission of these analogues were fully elucidated by experimental and theoretical methods.

Amino functionalized Zn/Cd-metal-organic frameworks for selective CO adsorption and Knoevenagel condensation reactions.

Two amino functionalized Metal-Organic Frameworks (MOFs), {[Zn(Py2TTz)(2-NH2-BDC)]·(DMF)}n (1) and {[Cd(Py2TTz)(2-NH2-BDC)]·(DMF)·0.5(H2O)}n (2) (where Py2TTz = 2,5-bis(4-pyridyl)thiazolo[5,4-d]thiazole, 2-NH2-BDC = 2-amino-1,4-benzenedicarboxylate, and DMF = N,N-dimethylformamide), were synthesized and characterized using the primary ligand 2-amino-1,4-benzenedicarboxylic acid (2-NH2-H2BDC) and the auxiliary ligand 2,5-bis(4-pyridyl)thiazolo[5,4-d]thiazole (Py2TTz). They possess similar 2-fold interpenetrated three-dimensional bipillared-layer framework structures composed of typical binuclear metal nodes, 2-NH2-BDC two-dimensional layers and Py2TTz bipillars.

Mn-Catalyzed Selective Double and Mono-N-Formylation and N-Methylation of Amines by using CO.

Functionalization of amines by using CO is of fundamental importance considering the abundance of amines and CO . In this context, the catalytic formylation and methylation of amines represent convenient and successful protocols for selective CO utilization as a C building block. This study represents the first example of selective catalytic double N-formylation of aryl amines by using a dinuclear Mn complex in the presence of phenylsilane.

Photoluminescence modulation of an atomically precise silver(i)-thiolate cluster via site-specific surface engineering.

A series of pyridyl ligand functionalized silver-thiolate nanoclusters with an identical cuboctahedron Ag12 core were prepared through site-specific surface engineering and fully characterized. Their wide-range photoluminescence modulation was systematically studied.

Towards Hydrogen Storage through an Efficient Ruthenium-Catalyzed Dehydrogenation of Formic Acid.

Hydrogen is of fundamental importance for the construction of modern clean-energy supply systems. In this context, the catalytic dehydrogenation of formic acid (FA) is a convenient method to generate H gas from an easily available liquid. One of the issues associated with current catalytic dehydrogenation systems is insufficient stability.

Regioselectivity inversion tuned by iron(iii) salts in palladium-catalyzed carbonylations.

Impactful regioselectivity control is crucial for cost-effective chemical synthesis. By using cheap and abundant iron(iii) salts, the hydroxycarbonylations of both aromatic and aliphatic alkenes were significantly enhanced in both reactivity and selectivity (iso/n or n/iso up to >99 : 1). Moreover, Pd-catalyzed carbonylation selectivity can be switched from branched to linear by using different Fe(iii) salts.

Hypersensitive dual-function luminescence switching of a silver-chalcogenolate cluster-based metal-organic framework.

Silver(i) chalcogenide/chalcogenolate clusters are promising photofunctional materials for sensing, optoelectronics and solar energy harvesting applications. However, their instability and poor room-temperature luminescent quantum yields have hampered more extensive study. Here, we graft such clusters to adaptable bridging ligands, enabling their interconnection and the formation of rigid metal-organic frameworks.

Hierarchical assembly of a homochiral triple concentric helical system in a novel 3D supramolecular metal-organic framework: synthesis, crystal structure, and SHG properties.

The hierarchical assembly of a homochiral triple concentric helical system in a novel 3D metal-organic framework with SHG activity has been observed. The result also provides a better understanding of host-guest chemistry and the process of water transport in biological systems.

Syntheses, structures and properties of two unusual silver-organic coordination networks: 1D→1D tubular intertwinement and existence of an infinite winding water chain.

Two unusual metal-organic frameworks {[Ag(2)(Hbtc)(bpy)(2)]·(H(2)O)(2)}(n) (1), {[Ag(3)(btc)(bpy)(3)(H(2)O)]·(H(2)O)(7)}(n) (2) (H(3)btc = 1,2,3-benzenetricarboxylic acid, bpy = 4,4'-bipyridine) have been synthesized and characterized by single crystal X-ray diffraction. Complex 1 features an infinite 1D→1D tubular intertwinement network, while complex 2 exhibits a double ladder structure which contains rare winding water chains. Both infinite 1D→1D tubular chains in complex 1 and double ladder in 2 are mutually interconnected by hydrogen bonding and π···π stacking interactions into three-dimensional (3D) supramolecular networks.

Diaquabis[2'-(4,5-diazafluoren-9-ylidene)picolinohydrazidato-kappa2N,O]zinc(II) tetrahydrate: a metal-water chain complex containing cyclic water hexamers.

In the title compound, [Zn(C17H10N5O)2(H2O)2].4H2O, cyclic water hexamers forming one-dimensional metal-water chains are observed. The water clusters are trapped by the co-operative association of coordination interactions and hydrogen bonds.