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High-pressure crystal growth and synthesis of selected solid-state osmium oxides, many of which are perovskite-related types, are briefly reviewed, and their magnetic and electrical properties are introduced. Crystals of the osmium oxides, including NaOsO 3 , LiOsO 3 , and Na 2 OsO 4 , were successfully grown under high-pressure and high-temperature conditions at 6 GPa in the presence of an appropriate amount of flux in a belt-type apparatus. The unexpected discovery of a magnetic metal–insulator transition in NaOsO 3 , a ferroelectric-like transition in LiOsO 3 , and high-temperature ferrimagnetism driven by a local structural distortion in Ca 2 FeOsO 6 may represent unique features of the osmium oxides. The high-pressure and high-temperature synthesis and crystal growth has played a central role in the development of solid-state osmium oxides and the elucidation of their magnetic and electronic properties toward possible use in multifunctional devices.

A compositionally new osmium oxide, Ca2InOsO6, which crystallizes in a double-perovskite structure, was synthesized through a high-pressure and high-temperature synthesis method. The crystal structure of Ca2InOsO6 was determined by X-ray diffraction to be monoclinic with the space group P21/n, like other double-perovskite osmium oxides. Magnetic measurements revealed that Ca2InOsO6 is antiferromagnetic below 14K.

Na2OsO4 crystals were grown by a NaCl flux method under high pressure. It crystallizes in the Ca2IrO4-type structure without having additional elements or metal vacancies, which are usually accommodated. It appears that Na2OsO4 is a metal-stoichiometric Ca2IrO4-type compound never been synthesized to date. Na2OsO4 has the octahedral environment of Os6+O6 so that the electronic configuration is 5d2, suggesting the magnetic S=1 ground state. However, magnetization, electrical resistivity, and specific heat measurements indicated that the non-magnetic S=0 state is much likely for Na2OsO4 than the S=1 state. Band structure calculations and the structure analysis found that the disagreement is probably due to the statically uniaxial compression of the OsO6 octahedra, resulting in splitting of the t 2 g band.

Particles of osmium or an inorganic polymeric film of osmium oxide-ruthenium cyanide (OsO-RuCN) electrodeposited on glassy carbon (GC) electrocatalyze the oxidation of dopamine (DA), adrenaline (AD), and noradrenaline (NAD). It is found that these biogenic amines are determined with a high sensitivity by oxidation at an electrode with an OsO-RuCN film. Procedures for the voltammetric determination of DA, AD, or NAD at a composite film electrode are developed. The currents of the substrate oxidation are linear functions of the concentrations in the ranges from 5 × 10−7 to 1 × 10−3 M for DA and from 1 × 10−6 to 1 × 10−3 M for AD and NAD.

Interlocked supramolecular dendrimers were spontaneously self-assembled from molecular components, metallocycles, and dumbbells bearing benzyl ether repeating units. Here, the metallocycles were in situ self-assembled from L-shaped ligands with dendritic branches, 2,3-dimethyl-2-butene and osmium tetraoxide. The supramolecular dendrimers were stabilized by hydrogen-bonding interactions between the pyridine-2,6-dicarboxamide unit in the metallocycle and the adipamide unit in the dumbbell.

Recently prepared layered double hydroxides (LDH)-supported OsO 4 , developed by the ion-exchange technique, was employed for catalytic asymmetric aminohydroxylation (AA) of olefins of varied nucleophilicity using Chloramine-T and (DHQ) 2 PHAL to afford chiral vicinal N-protected amino alcohols, important building blocks for many biologically active compounds and precursors for chiral ligands with moderate yields and ee's for the first time. Strong electron deficient olefins undergo AA reaction offering better yields than the less electron deficient and electron rich olefins due to the greater polarization of Os=NTs group in the former. The catalyst could be reused without any loss of enantioselectivity albeit a reduced activity.

A new catalyst derived from osmium has been prepared, fully characterized and tested in the dihydroxylation of alkenes. The catalyst was prepared by wet impregnation methodology of OsCl3·3H2O on a commercial micro-magnetite surface. The catalyst allowed the reaction with one of the lowest osmium loadings for a heterogeneous catalyst and was selective for the monodihydroxylation of 1,5-dienes. Moreover, the catalyst was easily removed from the reaction medium by the simple use of a magnet. The selectivity of catalyst is very high with conversions up to 99%. Preliminary kinetics studies showed a first-order reaction rate with respect to the catalyst. This work was supported by the Spanish Ministerio de Economía y Competitividad (CTQ2011-24151). J. M. P. thanks the M.E.C. for a fellowship through the FPI program.

Phase structures of binary and ternary blends of polycarbonate (PC) with poly(styrene-co-acrylonitrile) (PSAN), and poly(methyl methacrylate-co-styrene) (PMMAS) were examined by transmission (TEM) and/or scanning transmission electron microscopy (STEM). Osmium or ruthenium tetroxides were applied to ultrathin sections and significant differences in the staining of phases were observed: PC was stained most intensely, while staining of the PSAN- and PMMAS-rich phases was affected by the concentration of the dissolved (partially miscible) PC. The blends within the phase inversion interval contained both PC continuous and PC dispersed phases, which were observed at different places on the sample cross-section. Three-phase structure, found in ultrathin sections of binary blends and confirmed on plasma-etched cut surfaces, is discussed from the point of view of likely artefacts; a possible interpretation considers non-uniform blending in the melt.

The frequency of picking occurrence in off-set printing depends on surface strength, namely, resistance of coated paper to ink tack. In this study, the surface strength was assumed to be determined by the adhesive area of pigment/binder interface. Thus, a new method of the adhesive area measurement was proposed. The method follows the steps : SB -latex of a dry coating is hardened with osmium oxide, a network structure of only the latex film is preserved by dissolving the pigment, and the adhesive area is calculated from the specific surface areas of the residual latex film and of the pure pigment powder.It was found that no picking occurred on a RI printability tester above an adhesive area of 3. 5 g/m2 both for coated papers with different SB-latex contents and for those dried at different temperatures. On the other hand, there was no threshold regarding the pore volume of the dry coatings. This concluded that the adhesive area between pigment and binder better explained the surface strength than the pore volume of a dry coating.

Polymer-supported oxidic osmium catalysts based on cross-linked poly(4-vinyl pyridine) were synthesized by various routes and characterized by a number of physical techniques (Raman, IR, XPS, 13 C and 15 N solid-state NMR spectroscopy). Model compounds of type Os 2 O 6 L 4 (L = pyridine, 4- iso -propyl pyridine, and 4- tert -butyl pyridine) were obtained under the conditions of the catalyst synthesis. The catalytic systems were successful in the dihydroxylation of alkenes.

Sidewall osmylation of individual metallic single-walled carbon nanotubes has been achieved by exposing the tubes to osmium tetroxide vapor under UV photoirradiation. The covalent attachment of the osmium oxide leads to an increase in the electrical resistance by up to several orders of magnitude. The cycloaddition product can be cleaved by UV light in vacuum or under an oxygen atmosphere, whereby the original resistance is restored. Single-walled carbon nanotubes (SWCNTs), with a diameter in the nanometer scale range and a length of several micrometers, represent attractive components for nanoscale electronic devices because of their unique electronic, mechanical, and chemical properties. 1 Depending on their chirality, SWCNTs are either metallic or semiconducting nanowires. 2 It is well documented that the electronic properties of SWCNTs are sensitive to the environment, 3,4 which constitutes the basis for using nanotubes in chemical sensors. 4-6 Recently, considerable effort has been directed toward chemical modification of the nanotube sidewall by attaching organic or inorganic functional groups. 6-16 Methods for sidewall functionalization include electrochemical attachment of phenyl groups, 7a,b decoration with selenium nanoparticles, 8 covalent attachment of nitrenes, 9 fluorination, 10a-c,11a,b ozonolysis, 12a,b and noncovalent attachment of

Pressure dependence of superconducting transition temperature $T_{\rm c}$ has been determined through the DC magnetic measurements under pressure up to $P$=10 GPa for $\beta$-pyrochlore oxides AOs$_2$O$_6$ with A=Cs ($T_{\rm c}$=3.3 K), Rb (6.3 K) and K (9.6 K). Both for A=Rb and Cs, $T_{\rm c}$ increases with increasing $P$ and shows a saturation at $T_{\rm cm}$$\sim$8.8 K, which is considered as the upper limit of $T_{\rm c}$ inherent in AOs$_2$O$_6$. In contrast, the $T_{\rm c}-P$ curve for KOs$_2$O$_6$ shows a sharp maximum of $\sim$10 K at $P$$\sim$0.5 GPa, and $T_{\rm c}$ is higher than $T_{\rm cm}$ for 0$\leq$$P$$\leq$1.5GPa, suggesting the enhanced superconductivity due to the rattling of K ions., Comment: 4 pages, 4 figures, to be published in J. Phys. Soc. Jpn. Vol. 77, No. 4 (2008)

5d Solid-state oxides K0.84OsO3 (Os5.16+; 5d 2.84) and Bi2.93Os3O11 (Os4.40+; 5d 3.60) were synthesized under high-pressure and high-temperature conditions (6 GPa and 1500–1700 °C). Their crystal structures were determined by synchrotron x-ray diffraction and their 5d electronic properties and tunnel-like structure motifs were investigated. A KSbO3-type structure with a space group of Im-3 and Pn-3 was determined for K0.84OsO3 and Bi2.93Os3O11, respectively. The magnetic and electronic transport properties of the polycrystalline compounds were compared with those obtained theoretically. It was revealed that the 5d tunnel-like structures are paramagnetic with metallic charge conduction at temperatures above 2 K. This was similar to what was observed for structurally relevant 5d oxides, including Bi3Re3O11 (Re4.33+; 5d 2.66) and Ba2Ir3O9 (Ir4.66+; 5d 4.33). The absence of long-range magnetic order seems to be common among 5d KSbO3-like oxides, regardless of the number of 5d electrons (between 2.6 and 4.3 per 5d atom).

A three-dimensional networked osmium nanomaterial (N-Os) was prepared by a thermal decomposition of Os3(CO)12 within mesopores of MCM-48. The novel N-Os species shows high catalytic activity and excellent reusability in the oxidation reactions of unsaturated compounds under mild conditions.

The periodic table provides a classification of the chemical properties of the elements. But for the heaviest elements, the transactinides, this role of the periodic table reaches its limits because increasingly strong relativistic effects on the valence electron shells can induce deviations from known trends in chemical properties. In the case of the first two transactinides, elements 104 and 105, relativistic effects do indeed influence their chemical properties, whereas elements 106 and 107 both behave as expected from their position within the periodic table. Here we report the chemical separation and characterization of only seven detected atoms of element 108 (hassium, Hs), which were generated as isotopes (269)Hs (refs 8, 9) and (270)Hs (ref. 10) in the fusion reaction between (26)Mg and (248)Cm. The hassium atoms are immediately oxidized to a highly volatile oxide, presumably HsO(4), for which we determine an enthalpy of adsorption on our detector surface that is comparable to the adsorption enthalpy determined under identical conditions for the osmium oxide OsO(4). These results provide evidence that the chemical properties of hassium and its lighter homologue osmium are similar, thus confirming that hassium exhibits properties as expected from its position in group 8 of the periodic table.

Magnetic and lattice properties of the pyrochlore NaxOs2O6?H2O were studied by a synchrotron X-ray diffraction method, measurements of magnetic susceptibility, electrical resistivity, and specific heat. The results indicated little change in the properties over the Na range 0.5 ? x ? 1.4. Any trace of superconductivity was undetected to 2 K.

Inelastic neutron scattering and neutron powder diffraction experiments were carried out to investigate a localized mode, proposed from various bulk measurements, in the beta-pyrochlore AOs2O6 (A=K, Rb, Cs). The localized mode was identified in all the three compounds as well as another beta-pyrochlore CsW2O6. The anharmonicity of the mode is weak in RbOs2O6 and CsOs2O6 but substantial in KOs2O6., Comment: 12 pages, 6 figures; typos and graph corrected

The emission spectrum of OsO has been photographed in the region 405–875 nm where many new bands have been observed. In favorable cases the 190 OsO 192 OsO isotopic splittings have been resolved and aid in vibrational assignments. Three visible bands in the region 433–470 nm have been assigned as (1,0), (0,0), and (0,1) of a ΔΩ = 0 electronic transition. The (0,0) and (0,1) bands have been rotationally analyzed, yielding principal constants (cm−1) for the visible system of ν0 = 22 273.3, B′0 = 0.3657, D′0 = 2.8 × 10−7, B″e = 0.4023, D″e = 3.2 × 10−7, Δ G″( 1 2 ) = 780.7 , and Δ G″( 1 2 ) = 884.9 . A band at 825.4 nm has been found to be a ΔΩ = +1 (0,0) band with the same lower state as in the analyzed visible bands. Constants for the upper state of the ir system are ν0 = 12 109.7, B′0 = 0.3845, and D′0 = 3.1 × 10−7 cm−1.

The fine structure of Chinon fibers treated with some proteases was examined. Under optical microscope, the cross sections of Chinon fiber stained with C. I. Acid Red 249 revealed that Pronase P (Pro) and Proteoliquifase (Plf) both eliminated the protein component of the fiber progressively from its surface region to the center, while the distribution of protein was apparently uniform in the intact fibers. On the other hand, Papain C-400 (Pap) seemed to digest the protein uniformly under the same conditions. Under transmission electron microscope, the cross sections stained with osmium oxide revealed that the protei component distributed uniformly in Chinon fiber as fine units of less than 200 A in diameter. Furthermore, it was observed that Pro and Plf decreased not only the diameter but also the density of the protein units according to the progress of the proteolysis, while Pap seemed to decrease only the density but not the diameter of the components. Thus, introduction of certain micro-void spaces was expected at the positions corresponding to those stainable by osmium oxide before but unstainable after the proteolysis. However, direct observation by a scanning electron microscope was unable to detect the micro-void spaces probably because of their dimension out of the resolution.