The Reactivity of Pt Clusters With NO Facilitated by Dual Lewis-Acid Sites.

The size dependence of metal cluster reactions frequently reveals valuable information on the mechanism of nanometal catalysis. Here, the reactivity of the Pt (n = 1-40) clusters with NO is studied and a significant dependence on the size of these clusters is noticed. Interestingly, the small Pt clusters like Pt and Pt are inclined to form NO complexes; some larger clusters, such as Pt , Pt , and Pt , appear to be unreactive; however, the others such as Pt and Pt are capable of decomposing NO.

Tailoring Titanium Carbide Clusters for New Materials: from Met-Cars to Carbon-Doped Superatoms.

Tailoring materials with prescribed properties and regular structures is a critical and challenging research topic. Early transition metals were found to form supermagic MC metallocarbohedrenes (Met-Cars); however, stable metal carbides are not limited to this common stoichiometry. Utilizing self-developed deep-ultraviolet laser ionization mass spectrometry, here, we report a strategy to generate new titanium carbides by reacting pure Ti clusters with acetylene.

Unusually High-Spin FeC Metallo-Carbohedrene Clusters.

Ferromagnets constructed from nanometals of atomic precision are important for innovative advances in information storage, energy conversion, and spintronic microdevices. Considerable success has been achieved in designing molecular magnets, which, however, are challenging in preparation and may suffer from drawbacks on the incompatibility of high stability and strong ferromagnetism. Utilizing a state-of-the-art self-developed mass spectrometer and a homemade laser vaporization source, we have achieved a highly efficient preparation of pure iron clusters, and here, we report the finding of a strongly ferromagnetic metal-carbon cluster, FeC, simply by reacting the Fe clusters with acetylene in proper conditions.

Rh: A high-spin super-octahedron cluster.

Probing atomic clusters with magic numbers is of supreme importance but challenging in cluster science. Pronounced stability of a metal cluster often arises from coincident geometric and electronic shell closures. However, transition metal clusters do not simply abide by this constraint.

Weak Interactions Initiate C-H and C-C Bond Dissociation of Ethane on Nb Clusters.

The conversion of ethane into value-added chemicals under ambient conditions has attracted much attention but the mechanisms remain not fully understood. Here we report a study on the reaction of ethane with thermalized Nb clusters based on a multiple-ion laminar flow tube reactor combined with a triple quadrupole mass spectrometer (MIFT-TQMS). It is found that ethane reacts with Nb clusters to form both products of dehydrogenation and methane-removal (odd-carbon products).

Catalysis of dinitrogen activation and reduction by a single Fe cluster and its doped systems.

Catalyzing N reduction to ammonia under ambient conditions is known to be significant both in the fertilizer industry and life sciences. To unveil the synergy of multiple sites, here, we have studied the catalysis of ammonia synthesis using a typical Fe cluster and its doped systems, FeX (X = V, Cr, Mn, Co, Ni, Cu, Zn, Nb, Mo, Ru, and Rh). The energetics analysis showed that center substitution (X@Fe) was favored while doping single V, Cr, Co, and Mo atoms, whereas Mn, Ni, Cu, Zn, Nb, Ru, and Rh tended to form shell-doped structures (FeX).

Plasma-Assisted Dinitrogen Activation on Small Cobalt Clusters: Co N with Enhanced Stability.

We have performed a study on the accommodation of nitrogen doping toward superatomic states of transition metal clusters. By reacting cobalt clusters with N in the presence of plasma radiation, a large number of odd-nitrogen clusters were observed, typically Co N (m=1-5) and Co N (m=1-6) series, showing N≡N bond cleavage in the mild plasma atmosphere. Interestingly, the Co N , Co N , and Co N clusters exhibit prominent mass abundances.

Gas-Phase Synthesis of Metal Olefins: Plasma-Assisted Methane Dehydrogenation and C═C Bond Formation.

Methane dehydrogenation and C-C coupling under mild conditions are very important but challenging in chemistry. Utilizing a customized time of flight mass spectrometer combined with a magnetron sputtering (MagS) cluster source, here, we have conducted a study on the reactions of methane with small silver and copper clusters simply by introducing methane in argon as the working gas for sputtering. Interestingly, a series of [(CH)] ( = Cu and Ag; = 2-12) clusters were observed, indicating high-efficiency methane dehydrogenation in such a plasma-assisted chamber system.

Reactivity of Cobalt Clusters Co with Dinitrogen: Superatom Co and Superatomic Complex CoN.

We report a joint experimental and theoretical study on the reactions of cobalt clusters (Co) with nitrogen using the customized reflection time-of-flight mass spectrometer combined with a 177.3 nm deep-ultraviolet laser. Comparing to the behaviors of neutral Co ( = 2-30) and anionic Co clusters ( = 7-53) which are relatively inert in reacting with nitrogen in the fast-flow tube, Co clusters readily react with nitrogen resulting in adducts of one or multiple N except Co which stands firm in the reaction with nitrogen.

An oxygen-passivated vanadium cluster [V@VO] with metal-metal coordination produced by reacting V with O.

Vanadium cluster anions are highly reactive making the preparation of pure Vn- and the observation of their reactivity extremely challenging. Herein, well-resolved anionic Vn- clusters are prepared enabling an in-depth study on their reactions with O2 in the gas phase. While pure metal clusters of a magic number are not identified due to the strong V-O bonding, interestingly an unexpected oxide V11O15- was experimentally observed in surviving O2 etching reactions.

Plasma-Assisted Chain Reactions of Rh Clusters with Dinitrogen: N≡N Bond Dissociation.

Dinitrogen activation is known as one of the most challenging subjects in chemistry. A number of well-defined metal complexes, nitrides, and clusters have been studied that show catalysis for dinitrogen activation. However, direct evidence of a complete cleavage of the N≡N triple bond at mild conditions is rather limited to date.

CoO-metalloxocubes: a new class of perovskite-like neutral clusters with cubic aromaticity.

Exploring stable clusters to understand structural evolution from atoms to macroscopic matter and to construct new materials is interesting yet challenging in chemistry. Utilizing our newly developed deep-ultraviolet laser ionization mass spectrometry technique, here we observe the reactions of neutral cobalt clusters with oxygen and find a very stable cluster species of CoO that dominates the mass distribution in the presence of a large flow rate of oxygen gas. The results of global-minimum structural search reveal a unique cubic structure and distinctive stability of the neutral CoO cluster that forms a new class of metal oxides that we named as 'metalloxocubes'.

Ligand accommodation causes the anti-centrosymmetric structure of AuCu clusters with near-infrared emission.

We synthesized an [AuCu(PPh)(SPy)] nanocluster co-capped by phosphine and thiolate ligands. Interestingly, this AuCu cluster corresponds to an anti-centrosymmetric structure with the four copper atoms coordinated to the mixed ligands on the same side of the Au icosahedron, which is in sharp contrast to the [AuCu(PPhPy)(SPhtBu)] and [AuCu(PPh)(SPy)] clusters which possess highly symmetric structures with well-separated Cu adatoms. Both [AuCu(PPh)(SPy)] and [AuCu(PPh)(SPy)] clusters correspond to 8 valence electron superatoms with large HOMO-LUMO gaps, respectively.

Reactivity of Cobalt Clusters Co with Ammonia: Co Cluster Catalysis for NH Dehydrogenation.

A customized reflection time-of-flight (Re-TOF) mass spectrometer combined with a 177 nm deep-ultraviolet laser has enabled us to observe well-resolved cobalt clusters Co and perform a comprehensive study of their reactivity with ammonia (NH). The anions Co are found to be inert, the neutrals allow the adsorption of multiple NH molecules, while the cationic Co clusters readily react with NH giving rise to dehydrogenation. However, incidental dehydrogenation of NH on Co is only observed for ≥ 3.

A small bimetallic AgCu nanocluster with dual emissions within and against Kasha's rule.

Single crystals of a small bimetallic AgCu nanocluster protected by six ligands of 2,4-dimethylbenzene thiol are synthesized by a one-pot procedure of wet chemistry. This AgCu nanocluster bears a trigonal bipyramid metallic core with two copper atoms located on both sides of a triangular Ag. Interestingly, the six Cu-Ag side edges of the trigonal bipyramid are fully protected by the six ligands giving rise to reinforced stability and high chemical purity.

Correction: A hexagonal Ni cluster protected by 2-phenylethanethiol for catalytic conversion of toluene to benzaldehyde.

Correction for 'A hexagonal Ni cluster protected by 2-phenylethanethiol for catalytic conversion of toluene to benzaldehyde' by Anthony M. S. Pembere et al.

A hexagonal Ni cluster protected by 2-phenylethanethiol for catalytic conversion of toluene to benzaldehyde.

We have synthesized single crystals of a 2-phenylethanethiol-protected Ni6 nanocluster, namely Ni6(C8H9S)12, which shows a hexagonal metallic core structure and reasonable stability. Interestingly this cluster is found to be an excellent candidate for the catalytic oxidation of toluene to benzaldehyde, with 100% conversion and 91% selectivity, showing application potential as an aromatic aldehyde in industry. Using DFT calculations, we rationalize the catalytic reaction mechanism for the conversion of toluene to benzaldehyde, and demonstrate that the presence of H2O2 initiates the Ni6 cluster via a highly exothermic step to form a Ni6O* intermediate which then results in active sites for the oxidation of toluene.

The Doping Effect of 13-Atom Iron Clusters on Water Adsorption and O-H Bond Dissociation.

Understanding the interactions between water and Fe-based clusters is necessary to unravel the micromechanics of the surface hydrophilic property and the corrosion process of iron-related materials. Herein, a theoretical study is conducted of water adsorption and dissociation on icosahedral Fe and FeX (X = Ti, V, Cr, Mn, Co, Ni) clusters. It is found that the doping atoms have significant influence on the geometric structures, magnetic moments, and electronic states of FeX clusters.

Ultrafast Deep-Ultraviolet Laser Ionization Mass Spectrometry Applicable To Identify Phenylenediamine Isomers.

The application of low-fragmentation mass spectrometry to identify chemicals has been recognized to be of particular importance in chemistry, biomedicine, and materials science. Utilizing a customized all-solid-state picosecond-pulsed deep-ultraviolet (DUV) laser, here we present new advances into photoionization mass spectrometry. The DUV laser ionization mass spectrometry (DUV-LIMS) results in very clean spectra pertaining to minimized structure relaxation and fragmentation under the ultrafast ionization process.

Direct C-C Coupling of CO2 and the Methyl Group from CH4 Activation through Facile Insertion of CO2 into Zn-CH3 σ-Bond.

Conversion of CO2 and CH4 to value-added products will contribute to alleviating the green-house gas effect but is a challenge both scientifically and practically. Stabilization of the methyl group through CH4 activation and facile CO2 insertion ensure the realization of C-C coupling. In the present study, we demonstrate the ready C-C coupling reaction on a Zn-doped ceria catalyst.