Osmium nuclear properties

The elements will be discussed in the order of increasing atomic number in the Periodic Table, i.e. nickel, zinc, technetium, ruthenium, silver, hafnium, tantalum, tungsten, rhem um, osmium, iridium, platinum, gold, and mercury. Full numerical data of the relevant nuclear properties are summarized, as for other elements, in Appendix 1. 

Plutonium-noble metal compounds have both technological and theoretical importance. Modeling of nuclear fuel interactions with refractory containers and extension of alloy bonding theories to include actinides require accurate thermodynamic properties of these materials. Plutonium was shown to react with noble metals such as platinum, rhodium, iridium, ruthenium, and osmium to form highly stable intermetallics. 

Chemical Properties. Compound 2 is readily decarbonylated upon exposure to UV irradiation.5 Irradiated solutions of 2 readily yield addition products of sulfur containing small molecules such as COS, CS2, and H2S. In the absence of reagents it will form the hexanuclear compound Os6(CO)17(/r4-S)2. It reacts with other metal complexes to form higher nuclearity osmium clusters and heteronuclear metal cluster compounds.5,11,12... 

This survey of higher Os clusters covers their direct formation from Os3 clusters only. Studies of the structures, properties, and reactions of high nuclearity osmium clusters encompass a large area, too big to be considered in this article. 

Plutonium-noble metal compounds have both technological and theoretical importance. Modeling of nuclear fuel interactions with refractory containers and extension of alloy bonding theories to include actinides require accurate thermodynamic properties of these materials. Plutonium was shown to react with noble metals such as platinum, rhodium, iridium, ruthenium, and osmium to form highly stable intermetallics. Vapor pressures of phases in these systems were measured by the Knudsen effusion technique. Use of mass spectrometer-target collection apparatus to perform thermodynamic studies is discussed. The prominent sublimation reactions for these phases below 2000 K was shown to involve formation of elemental plutonium vapor. Thermodynamic properties determined in this study were correlated with corresponding values obtained from theoretical predictions and from previous measurements on analogous intermetallics. 

It seems that one of the future developments in cluster chemistry lies in the production of nanosized particles (1 nm = 10 A) with well defined stoichiometries, which can be used as catalysts or as catalyst precursors. In this context, high nuclearity mixed-metal clusters are particularly useful because two or more metal atoms with different chemical properties can be combined in the same unit. The Cambridge group has spent the last few years designing rational synthetic routes to mixed-metal high nuclearity clusters of ruthenium and osmium with the coinage elements, which produce cluster cores of up to one nanometer in size. ... 

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