Dissociative electron transfer on ionic surfaces

A theory of electron transfer between adsorbed ions and electrically charged ionic surfaces is developed. Electron transfer from a charged AgBr surface to an Ag⁺ ion, as well as from Br^? ion to AgBr surface holes is studied. The Ag and Br atoms resulting from the process are shown to be dissociated from the surface.     

Characterization of Nested Hollow Inorganic Fullerene-like Tungsten Disulfide Nanoparticles Prepared by Solid-Gas Reaction

Non-carbon inorganic fullerene-like(IF) nanoscale materials have recently attracted intense interest due to their nested hollow and nanotube structures,In this letter,IF-WS2 nanoparticles prepared by solid-gas reaction were characterized by X-ray diffraction,Scanning electron microscopy and transmission electron microscopy.The results show that the IF-WS2 nanoparticles have a nested hollow closed spherical structure with diameter of 100-150mm.     

A Hybrid Ring‐Opening Metathesis Polymerization Catalyst Based on an Engineered Variant of the β‐Barrel Protein FhuA

A β‐barrel protein hybrid catalyst was prepared by covalently anchoring a Grubbs–Hoveyda type olefin metathesis catalyst at a single accessible cysteine amino acid in the barrel interior of a variant of β‐barrel transmembrane protein ferric hydroxamate uptake protein component A (FhuA). Activity of this hybrid catalyst type was demonstrated by ring‐opening metathesis polymerization of a 7‐oxanorbornene derivative in aqueous solution.     

Catalytic oxidative coupling of diols by Ru3(CO)12

Ru₃(CO)₁₂ acts as a homogeneous catalyst precursor for the transformation of αω-diols to polyesters and lactones.     

Experimental evidence of surface-plasmon coupling in anisotropic hollow nanoparticles

We report on the investigation of surface-plasmon excitation of anisotropic WS(2) hollow nanoparticles in a near-field geometry by means of a scanning transmission electron microscope. The shell thickness influence on the electron-energy-loss-spectroscopy spectra is experimentally observed and is analyzed within a classical dielectric formalism. As for the isotropic case, we evidence one symmetric (tangential) and one antisymmetric (radial) mode. We point out the intriguing fact that, for the anisotropic case, one can relate these modes to the interband transition of the in-plane component of the dielectric tensor and to the bulk-plasmon energy of the out-of-plane component.     

Multichannel laser resonators — an experimental study

The output characteristics of several large-area multichannel unstable resonators are presented. The conventional unstable resonator and a novel toric unstable resonator, in both confocal and nonconfocal configurations, have been studied. Output beam profiles, optical energy extraction, beam focusability, resonator alignment properties and polarization states of the various resonators have been analysed in depth.     

Scaled particle theory of mixtures of hard spheres with negatively non-additive diameters

The scaled particle theory is solved for mixtures of hard spheres with arbitrary negative non-additive diameters in three dimensions. The results obtained with the Gibbs—Duhem relation show excellent agreement with the Monte-Carlo calculations. The results from the virial relation for high densities and high non-additivity are less satisfactory.     

H-transfer catalysis with Ru3(CO)12

Ru₃(CO)₁₂ , in the presence of tolane, catalyzes the formation of esters from the following three systems: alcohol + aldehyde, alcohol and aldehyde.     

Structure and stability of molybdenum sulfide fullerenes

MoS2 nanooctahedra are believed to be the smallest stable closed-cage structures of MoS2, i.e., the genuine inorganic fullerenes. Here a combination of experiments and density functional tight binding calculations with molecular dynamics annealing are used to elucidate the structures and electronic properties of octahedral MoS2 fullerenes. Through the use of these calculations MoS2 octahedra were found to be stable beyond nMo > 100 but with the loss of 12 sulfur atoms in the six corners. In contrast to bulk and nanotubular MoS2, which are semiconductors, the Fermi level of the nanooctahedra is situated within the band, thus making them metallic-like. A model is used for extending the calculations to much larger sizes. These model calculations show that, in agreement with experiment, the multiwall nanooctahedra are stable over a limited size range of 104-105 atoms, whereupon they are converted into multiwall MoS2 nanoparticles with a quasi-spherical shape. On the experimental side, targets of MoS2 and MoSe2 were laser-ablated and analyzed mostly through transmission electron microscopy. This analysis shows that, in qualitative agreement with the theoretical analysis, multilayer nanooctahedra of MoS2 with 1000-25 000 atoms (Mo + S) are stable. Furthermore, this and previous work show that beyond approximately 105 atoms fullerene-like structures with quasi-spherical forms and 30-100 layers become stable. Laser-ablated WS2 samples yielded much less faceted and sometimes spherically symmetric nanocages.