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Periodic Table of Elements: Los Alamos National Laboratory

Periodic Table of Elements: Los Alamos National Laboratory

Organotin chemistry Organotin compounds are those with tin linked to hydrocarbons. Structure of organotin compounds[edit] Organotin compounds are generally classified according to their oxidation states. Tin(IV) compounds are much more common and more useful. Organic derivatives of tin(IV)[edit] The entire series R4−nSnCln are known for many R groups and values of n up to 4. With bulky R groups, diorganotin oxides adopt cyclic trimeric or dimeric structures consisting of Sn3O3 and Sn2O2 rings, respectively. Hypercoordinated stannanes[edit] Unlike their carbon(IV) analogues but like silicon compounds, tin(IV) can also be coordinated to five and even six atoms instead of the regular four. Tin radicals (organic derivatives of tin(III))[edit] Tin radicals, with the formula R3Sn, are called stannyl radicals.[6] They are invoked as intermediates in certain atom-transfer reactions. Organic derivatives of tin(II)[edit] Organotin(II) compounds are somewhat rare. 2 R2Sn (R2Sn)2 Organic derivatives of tin(I)[edit] [edit]

Meteorite impact and PGEs in Scotland | The Traveling Geologist The northwest coast of Scotland is an incredibly geologically diverse stretch of coastline. In less than 150 kilometers the rocks span over 2.8 billion years of Earth history, from the Archaean Lewisian gneiss to the Tertiary volcanic province on Skye with little missing in between. Such a wide temporal spread means that any particular age of rocks is restricted to a relatively small area. The Stoer Formation is a sedimentologist's dream land. However the highlight of the Stoer Formation is the Stac Fada member. Although initial investigators assumed this to be volcanic in origin it was bizzare in context of the surrounding geology. Recently, my colleagues at the University of St Andrews found that much of this iridium is focused in the rims of this accretionary lapilli.

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C&EN: IT'S ELEMENTAL: THE PERIODIC TABLE - INTRODUCTION National Chemistry Week, October 19-24, 2009 NCW kicks off this week with the theme "Chemistry—It's Elemental!" Visit for more information. The Periodic Table is nature’s rosetta stone. That’s not to say, of course, that all of chemistry is obvious from the periodic table. Indeed, as John Emsley notes in his invaluable book, “Nature’s Building Blocks: An A–Z Guide to the Elements,” Mendeleyev never accepted that electrons came from atoms because he was convinced that atoms were indivisible. No matter. The periodic table is so central to chemistry that it seemed natural to devote a special issue to it and the elements that compose it as we celebrate C&EN’s 80th anniversary. Top Chemical & Engineering News Copyright © 2003 American Chemical Society

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