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We have reported several precisely designed metal‐oxo clusters on lacunary polyoxometalate (POM) tetra‐n‐butylammonium (TBA) salts in organic solvents. However, owing to their low thermostability and/or low effective surface area, POM TBA salts are not amenable to heterogeneous catalysts for gas‐phase reactions at high temperature. To avoid this problem, we developed a new preparation method that obtains highly dispersed supported‐POM Cs salts (Cs−POM/support) via cation exchange from the corresponding TBA salts on supports. In this study, a model Keggin‐type POM called TBA4PVMo11O40 (TBA−PVMo11) is supported on oxides (TBA−PVMo11/support) using an incipient wetness method in acetonitrile. This TBA−PVMo11/support was cation‐exchanged with cesium trifluoromethanesulfonate in ethanol to obtain supported‐POM Cs salts (Cs−PVMo11/support). Various characterizations revealed that the TBA−PVMo11/support maintained the original Keggin structure during cation exchange and that Cs−PVMo11 was highly dispersed on the supports. Furthermore, Cs−PVMo11/support maintained the Keggin structure even after calcination at 573 K under an aerobic condition. [ABSTRACT FROM AUTHOR]

Polyoxometalates (POMs), anionic metal‐oxygen nanoclusters that possess various composition‐dependent properties, are widely used to modify the existing properties of metal nanoparticles and to endow them with new ones. Herein, we present an overview of recent advances in hybrid materials that consist of metal nanoparticles and POMs. Following a brief introduction on the inception of this area and its development, representative properties and applications of these materials in various fields such as electrochemistry, photochemistry, and catalysis are introduced. We discuss how the combination of two classic inorganic materials facilitates cooperative and synergistic behavior, and we also give personal perspectives on the future development of this field. [ABSTRACT FROM AUTHOR]

The biological reduction of nitrite ions to gaseous nitrogen monoxide (N[O.sub.2].sup.-] + 2[H.sup.+] + [e.sup.-] → NO + [H.sub.2]O) is catalysed by two very different enzymes called haem [cd.sub.1]-containing nitrite [...], Recent earth science studies have pointed out that massive acceleration of the global nitrogen cycle by anthropogenic addition of bio-available nitrogen has led to a host of environmental problems (1). Nitrous oxide ([N.sub.2]O) is a greenhouse gas that is an intermediate during the biological process known as denitrification (2). Copper-containing nitrite reductase (CuNIR) is a key enzyme in the process; it produces a precursor for [N.sub.2]O by catalysing the one-electron reduction of nitrite ([N.sub.2]O to nitric oxide (NO) (3). The reduction step is performed by an efficient electron-transfer reaction with a redox-partner protein (4-6). However, details of the mechanism during the electron-transfer reaction are still unknown. Here we show the high-resolution crystal structure of the electron-transfer complex for CuNIR with its cognate cytochrome c as the electron donor. The hydrophobic electron-transfer path is formed at the docking interface by desolvation owing to close contact between the two proteins. Structural analysis of the interface highlights an essential role for the loop region with a hydrophobic patch for protein protein recognition; it also shows how interface construction allows the variation in atomic components to achieve diverse biological electron transfers.

Regioselective transformations of tertiary amines, which are ubiquitously present in natural products and drugs, are important for the development of novel medicines. In particular, the oxidative α-C–H functionalisation of tertiary amines with nucleophiles via iminium cations is a promising approach because, theoretically, there is almost no limit to the type of amine and functionalisation. However, most of the reports on oxidative α-C–H functionalisations are limited to α-methyl-selective or non-selective reactions, despite the frequent appearance of α-methylene-substituted amines in pharmaceutical fields. Herein, we develop an unusual oxidative regiospecific α-methylene functionalisation of structurally diverse tertiary amines with alkynes to synthesise various propargylic amines using a catalyst comprising Zn salts and hydroxyapatite-supported Au nanoparticles. Thorough experimental investigations suggest that the unusual α-methylene regiospecificity is probably due to a concerted one-proton/two-electron transfer from amines to O2 on the Au nanoparticle catalyst, which paves the way to other α-methylene-specific functionalisations.The selective α-methylene functionalization of tertiary amines is challenging. Here, the authors report the gold nanoparticles-catalyzed α-methylene alkynylation of tertiary amines via concerted one-proton/two-electron transfer to O2. [ABSTRACT FROM AUTHOR]

The X-ray crystal structures and kinetic studies of methanol dehydrogenase (Hd-MDH) and its physiological electron acceptor cytochrome c(super L) (Hd-Cyt c(super L)) from a methylotrophic denitrifying bacterium Hyphomicrobium denitrificans A3151 are described. Kinetic investigations indicate that these proteins tightly interact with each other at pH 5.5.

The synthesis of a novel dititanium-substituted gamma-Keggin polyoxometalates (POM), [{gamma-SiTi2W10O36(OH)(sub 2)}(sub 2)(mu-O)(sub 2)](super 8-) (1), containing an edge-shared dinuclear Ti site, and its molecular structure are described. The results have shown that the dinuclear titanium core of 1 catalyzes mono-oxygenation reactions, such as epoxidation of olefins and sulfoxidation of sulfides with hydrogen peroxide.

The field trapping and shielding experiments are performed using high-T(sub c) bulk superconductor with a cylindrical hole in it. The trapping of magnetic field in the hole is accomplished by cooling the bulk superconductor in the presence of an applied field and then gradually reducing the applied field to zero.

A catalyst prepared by modifying the surface of Au nanoparticles (NPs) on Al2O3 with [Nb6O19]8− clusters had specific base and reduction abilities, and the reduction of p-nitrophenol to p-aminophenol using H2 as a reductant proceeded efficiently with the dual functional catalyst. At the interface between Au NPs and basic [Nb6O19]8−, heterolytically cleaved hydrogen species are generated, which can efficiently react with nitrophenolate ions generated by base catalysis. Moreover, this surface modification strategy was applicable to the reduction of other nitro compounds. [ABSTRACT FROM AUTHOR]