Hydrido complexes osmium

The formation of the first osmium hydrido(alkoxo) complex, a yellow air-stable and thermally stable hydrido(methoxo)osmium(II) complex, trans-[OsH(OMe)(Cl) (NO) (P Pr3)2] (72), by the oxidative addition of MeOH to a 16-electron complex, trans-[OsCl(NO)(P Pr3)2] (71) was briefly reported (Eq. 6.22) [51]. 

Schemes 6-17 Reaction of hydrido(carboxylato)osmium(IV) complexes with alkynes...

In the solid state, the equilibrium is in favor of the hydrido complex (III), and its crystal structure and that of the osmium(II) analog have been determined (38). Chatt also observed that, on heating the equilibrium mixture of (II) and (III), naphthalene was eliminated and the product Ru(dmpe)2 was also a tautomeric mixture. Here the tautomer-ism involves breaking and re-formation of carbon-hydrogen bonds in the methyl groups of the phosphine ligands (IV and V) ... 

The feverish interest in hydrido complexes has, as its main cause, the tremendous potential of these reactions in catalytic systems. In a relatively short span of time, hydrido complexes have been found to play a role in a significant number of catalytic processes (6, 9)—e.g., oligomerization of olefins (rhodium), decarboxylation reactions (rhodium), and hydrogenation reactions (ruthenium, osmium, rhodium, iridium, and platinum). Discussion of these applications would go beyond the scope of the present treatment. 

Hydrido complexes, gold-osmium, 27 209 iridium, 26 117, 27 19 iron, 26 244, 27 168 iron-tungsten, 26 336 manganese, 26 226 mercury-molybdenum-ruthenium,... 

Complexes with other Carbon-donor Ligands. The naphthyl hydrido Complexes of the type [MH(CioH,)(MejP CHg CHa-PMe2)2] (46), where M = Ru or Os , are isomorphous and isostructural. They are octahedral and contain a naphthyl ligand o-bonded to the metal atom and in a position cis to the hydrido hydrogen. The respective Ru-C, Os-C, and Ru-H distances are 2.16(1), 2.13(2), and 1.7 A in the osmium compound the hydrido hydrogen atom has not been located. The M-P distances range... 

Osmium.— In general alkyl hydrido-complexes are much less stable than dihydro and dialkyl derivatives and undergo alkane elimination readily. Kinetic studies of the decomposition of tOsH(Me)(CO)4], equation (8), were undertaken in an attempt to... 

Schemes 6-14 Reactions of osmium hydrido (hydroxo) complex 2 with several substrates...

The reactions of a neutral 10 as well as a cationic dihydrido(acetato)osmium complex 12 with acetylenic compounds were examined (Scheme 6-17) [11-13]. A vinyU-dene 99, an osmacyclopropene 100, or a carbyne complex 101 were obtained, depending on the starting hydrido(acetato) complexes or the kind of acetylene used. In any case, the reaction proceeded by insertion of a C C triple bond into one of the two Os-H bonds, but the acetato ligands do not take part in the reaction and act as stabilizing ligands. 

HjNiOcjOsjCuHs, Osmium, nonacarbonyl-( tl -cyclopentadienyl )tri- x-hydridonickeltri-, 26 362 H,NiO,Ru,C14H5, Ruthenium, nonacar-bonyl-f-rf-cyclopentadienyl)-tri-p.-hydridonickeltri-, 26 363 H4N, Hydrazine ruthenium(II) complexes, 26 72 H40 20sjCi , Osmium, dodecacarbonyl-tetra- x-hydrido-te/rahedro-tetra-,... 

S04PC Hi , 2-Butenedioic acid, 2-(dimethyl-phosphinothioyl)-dimethyl ester, manganese complex, 26 163 SO Ci H i, Thiophenetetracarboyxlic acid, tetramethyl ester, 26 166 SO (,OsiC , Osmium, p,4-carbonylnona-car-bonyl-p,-thio-tri-, 26 305 SO ,OsiC 6H, Osmium, (p.-benzenethio-lato)-(decacarbonyl-p-hydrido-tri-, 26 304... 

Osmium(n).—Group VII Donors. Hydrido- and halogeno-carbonyl complexes. Carbonylation of [OsHX(CO)(PCy3)2] has produced the novel dicarbonyl hydride [OsHX(CO)2(PCy3)2] (X = Cl or Br Cy = tricyclohexyl).17 I.r. and n.m.r. data indicate the geometry (17). Addition of other ligands to the five-co-ordinate... 

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