Osmium halides

Pseudohalides of Se in which the role of halogen is played by cyanide, thiocyanate or selenocyanate are known and, in the case of Se are much more stable with respect to disproportionation than are the halides themselves. Examples are Se(CN)2, Se2(CN)2, Se(SeCN)2, Se(SCN)2, Se2(SCN)2. The selenocyanate ion SeCN is ambidentate like the thiocyanate ion, etc., p. 325), being capable of ligating to metal centres via either N or Se, as in the osmium(IV) complexes [OsCl5(NCSe)], [OsCl5(SeCN)], and trans-[OsCU(NCSe)(SeCN)]2-.920) Tellurium and polonium pseudohalogen analogues include Te(CN)2 and Po(CN)4 but have been much... 

Ruthenium(IV) produces few other complexes of interest but osmium(IV) yields several sulfito complexes (e.g. [0s(S03)6] and substituted derivatives) as well as a number of complexes, such as [Os(bipy)Cl4] and [Os(diars)2X2] (X = Cl, Br, I), with mixed halide and Group 15 donor atoms. The iron analogues of the latter complexes (with X = Cl, Br), are obtained by oxidation of... 

Osmium carbonyl (Os3(CO)i2) acts as a photoinitiator of vinyl polymerization [20], which can function without a halide additive. The mechanism of photoinitiation is by a hydrogen abstraction from monomer to pho-... 

Fluorination of a mixture of alkali metal halide and an appropriate ruthenium or osmium halide affords cream MRuF6 (M = alkali metal, Ag /ieff = 3.5—3.8 /l b) or white MOsF6 ... 

Halide complex ions of ruthenium and osmium in the +3 state are known for all except OsFg" [39], Syntheses include ... 

The halides in mer-OsCl3(PR3)3 can be replaced by a thiolate ligand to give paramagnetic Os(SC6F5)3(PR3)2 an agostic Os—F—C interaction is believed to complete the coordination sphere of osmium [156]. 

A particularly interesting case is that of the platinum metal group which, in addition to platinum (Pt), comprises ruthenium (Ru), osmium (Os), rhodium (Rh), iridium (Ir), and palladium (Pd). These carbonyl halides are usually the most practical precursors for metal deposition because of their high volatility at low temperature. Indeed two of them, palladium and platinum, do not form carbonyls but only carbonyl halides. So does gold. 

Osmium tetroxide is obtained as an intermediate during recovery of osmium metal from osmiridium or other noble metal minerals (See Osmium). In general, oxidation of an aqueous solution of an osmium salt or complex, such as sodium osmate with nitric acid, yields the volatile tetroxide which may be distilled out from the solution. In the laboratory, the compound can be prepared by oxidation of the osmium tetrachloride, OsCh, or other halide solutions with sodium hypochlorite followed by distdlation. 

Alkylations, osmium(ll), 37 348 Alkyl azides, UV spectra, 26 178 Alkylbarium halides, solvated, 11 390 Alkylbery Ilium alkoxides, 11 395 alkylperoxides, 11 395 amides, 11 401 03 anions, 11 369-370 crystal structure of, 11 369 halides, solvated, 11 389 hydrides, 11 371-373 B-Alkylborolane, 16 241... 

Alkylcadmium alkoxides, 11 399-400 alkylperoxides, 11 399-400 anions, 11 370-371 halides, 11 377 solvated, 11 392-394 Alkylcalcium halides, solvated, 11 390 Alkyl complexes, osmium, 37 239-242 Alkyl copper compounds, 17 140, 142, 143 Alkyl derivatives, phosphoniuilic halides and, 1 363... 

Alkylstrontium halides, solvated, 11 390 Alkylsulfonato complexes, osmium, 37 286-287... 

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