Osmium IV chloride

Pentachloride und -bromide konnten bisher noch nicht hergestellt werden. Bei der Bildungunddem chemischen Transport von Osmium(IV)-chlorid (106) und Ruthenium(III)-chlorid wurden jedoch Hinweise auf die Existenz hoherer, fltichtiger Halogenide gefunden. Es konnte sich jedoch auch um Oxidchloride handeln, wie sie bereits seit langerer Zeit bekannt sind (144, 148). 

Mit Nickel(II)-, Osmium(IV)-, Iridium(III)- und Platin(II)-chlorid werden ahnliche Ergebnisse erzielt. In Gegenwart von Raney-Nickel geniigt ein 100°/oiger Natriumbora-nat-t)berschu63. 

Trimethylsilyldiazomethane, 327 Silyl substituted arenes Bis(trimethylsilyl)acetylene, 97 Chromium carbene complexes, 82 Titanium(IV) chloride-Diethylalu-minum chloride, 309 Other organosilanes Osmium tetroxide-Trimethylamine N-oxide-Pyridine, 223 Tributyltin chloride, 315 Di- x-carbonylhexacarbonyldicobalt, 99 Trimethylsilyl trifluoromethanesul-fonate, 329... 

The chloride-, bromide-, and thiocyanate complexes of ruthenium(IIl) and osmium(IV) can be extracted from acid solutions by oxygen-containing solvents, also in the presence of TBP or amines [10,12-15]. Osmium has been separated from Ru after conversion into Osle and extraction with TO A [16]. From mixtures of thiocyanate complexes of Ru and Os, only the Os complex can be extracted into diethyl ether containing a small amount of peroxide [14]. Poljmrethane foam has also been used for separating Ru and Os as their thiocyanate complexes [17,18]. 

There are however several substituted ethylenediamine complexes, the most unusual being the hydride [Os(en)2H2] " which can be obtained as a [ZnCl4] salt (by reaction of [0s02(en)2]Cl2 with zinc in HCl) or as a chloride. The salts are diamagnetic or almost so ( efr 0.22 BM at 298 K and O.IOBM at 183K for the [ZnCl4] salt). Although this is formally an osmium(IV) complex there seems to be no abnormality in the HNMR shift ((Sqsh = 15.4p.p.m.) the Os—H stretch lies at 2150 cm in the IR. ... 

All four halide ions from octahedral complexes with the metal. Fluorides or fluoro complexes are known for osmium(VII) to osmium(IV) inclusive, with rather tenuous evidence for OsFj OsF is a rare example of seven coordination for the metal. The other halides prefer the IV and III states, though osmium(V) chloride and chloro complexes have recently been made and also [OsBr ]". Although [RuFs] " is well known there is no osmium analogue, in keeping with the general tendency of third-row elements to display higher oxidation states than their second-row partners. 

The PGM concentrate is attacked with aqua regia to dissolve gold, platinum, and palladium. The more insoluble metals, iridium, rhodium, mthenium, and osmium remain as a residue. Gold is recovered from the aqua regia solution either by reduction to the metallic form with ferrous salts or by solvent-extraction methods. The solution is then treated with ammonium chloride to produce a precipitate of ammonium hexachloroplatinate(IV),... 

Using chromium-based oxidants 2,4-Dimethylpentane-2,4-diol chromate(VI) diester, 122 Trimethylsilyl chlorochromate, 327 Using other oxidizing agents Bis(tributyltin) oxide, 41 Hydrogen hexachloroplatinate(IV)-Copper(II) chloride, 145 4-Methoxy-2,2,6,6-tetramethyl-1 -oxopiperidinium chloride, 183 Osmium tetroxide, 222 Potassium nitrosodisulfonate, 258 Samarium(II) iodide, 270 From alkenes by addition or cleavage reactions... 

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