Osmium ruthenium

At the start of the nineteenth century, platinum was refined in a scientific manner by William Hyde WoUaston, resulting in the successful production of malleable platinum on a commercial scale. During the course of the analytical work, WoUaston discovered paUadium, rhodium, indium, and osmium. Ruthenium was not discovered until 1844, when work was conducted on the composition of platinum ores from the Ural Mountains. 

Metals other than iron which catalyze the ammonia synthesis such as osmium, ruthenium, uranium, and molybdenum can also be promoted by added substances. However, several of these metals do not show improvements of the same magnitude as does iron. Further-... 

Howe JL, Holtz HC (1919) Bibliography of the platinum group platinum, palladium, iridium, rhodium, osmium, ruthenium 1748-1917. Government Printing Office, Department of the Interior, U.S. Geological Survey, Washington, DC... 

Two different kinds of metals are found in chondrites. Small nuggets composed of highly refractory siderophile elements (iridium, osmium, ruthenium, molybdenum, tungsten, rhenium) occur within CAIs. These refractory alloys are predicted to condense at temperatures above 1600 from a gas of solar composition. Except for tungsten, they are also the expected residues of CAI oxidation. 

On the other hand, iridium yields a tetrachloride, IrCl4, and this, with chlorides of the alkali metals, produces a series of salts known as hexachlor-iridates, of general formula M2IrClG, isomorphous with the analogous derivatives of osmium, ruthenium, palladium, and platinum. These form an interesting link between these metals. 

Two kinds of metal are found in chondrites grains composed of refractory elements (iridium, osmium, ruthenium, molybdenum, tungsten, and rhenium), which condense along with the refractory oxides above —1,600 K at 10 atm, and grains composed predominantly of iron, cobalt, and nickel, which condense with forster-ite and enstatite at —1,350-1,450 K. The former are associated with CAIs (Palme and Wlotzka 1976) and the latter with chondrules, typically type I or FeO-poor chondrules (B J 1998, pp. 244-278). Unfortunately, few chondrites preserve a good record of the formation history... 

Many normal oxides are formed on burning the element in air or oxygen. This is true not only of the non-metals boron, carbon, sulphur and phosphorus, but also for the volatile zinc, cadmium, indium and thallium, the transition metals cobalt and iron, in finely divided condition, and the noble metals osmium, ruthenium and rhodium. With some elements, limiting the supply of oxygen produces the lower oxide (e,g, P40g in place of P4O40 (p. 332)). 

Using a modified Epson ink-jet printer, they printed metal salt solutions of platinum, rhodium, osmium, ruthenium, and iridium to form 220 compositions in the phase space of ternary and quaternary alloys of these metals. They were converted to metallic form after printing the metal salt solutions and screened for performance using a pH-sensitive fluorescence indicator. This led to identification of new fuel cell catalysts Pt 2l h250s,3 and Pt44Ru4jOjoIr5, which provided 40% higher current densities. 

Cleare MJ, Fritz HP, Griffith WP (1972) Vibrational spectra of nitrosyl and carbonyl complexes nitrosylpentahalogeno complexes of osmium, ruthenium and iridium. Spectrochim Acta A Mol Spectrosc 28 2013-2018... 

The following metal compounds are used for the preparation of the catalysts oxides, metal carbonyls, halides, alkyl and allyl complexes, as well as molybdenum, tungsten, and rhenium sulfides. Oxides of iridium, osmium, ruthenium, rhodium, niobium, tantalum, lanthanum, tellurium, and tin are effective promoters, although their catalytic activity is considerably lower. Oxides of aluminum, silicon, titanium, manganese, zirconium as well as silicates and phosphates of these elements are utilized as supports. Also, mixtures of oxides are used. The best supports are those of alumina oxide and silica. 

Nitroso-2,6-pyridinediol, 850 analytical reagent for determination of osmium, ruthenium and palladium, 850... 

Properties Platinum Palladium Iridium Rhodium Osmium Ruthenium Gold Silver Units... 

Fullerene-Organometallics. Also recently investigated are the organo-metallic exohedral complexes of osmium, ruthenium, and platinum which are readily attached to the external framework of the C o molecule by solution chemistry.I X I An osmylated-Ceo compound is shown in Fig. 15.8.P1]... 

Vinylic polymerization of monomers containing first row transition elements has been studied extensively but little has been done with the second and third row transition elements because of their greater cost. This paper reports the synthesis of monomers containing lead, osmium, ruthenium and tungsten, attempts to polymerize them and a method for assessing the potential machinability of the polymers. 

The polymerization of 5,5-dimethylnorbornene in the presence of various metathesis catalysts based on molybdenum, tungsten, rhenium, osmium, ruthenium, and iridium compounds to ring-opened polymers having 0-100% CIS content has been reported [138] [Eq. (68)]. 

---