Carbido-Clusters

The reaction with [Mn(CO)5]2 or [Co(CO)4]2 also led to mixed-metal clusters.962,963 Osmium-palladium mixed-metal carbonyl clusters were made using the unsaturated cluster [Os3(CO)io(/r-H)2] and the carbido cluster [Os5(/U5-C)(CO)15].964 970 Treatment of [Os3(CO)10Gu-H)2] with [Pd2(/u-dppm)2Cl2] afforded the novel high-nuclearity osmium-palladium mixed-metal carbonyl clusters [Os5Pd6(CO)13( -CO)5(/u-H)2(/u-dppm)2], [Os5Pd6(CO)13(//-CO)6(/u-dppm)2], and... 

Interest in the high nuclearity carbonyl clusters of ruthenium has centered around the hexanuclear carbido-cluster Ru6C(CO)17 and its derivatives, Ru5C(CO)15 and, more recently, [Ru C CO) ]2-.1 The chemistry of both Ru6C(CO)17 and Ru5C(CO)15 has been investigated in some detail. Their syntheses are described below. 

The parent neutral carbido-cluster of this class, Fe4C(CO)t3, 5, is most readily synthesized from 4 by protonation [Eq. (4)] (11). 

In clusters with octahedrally encapsulated carbon atoms, the observed values for the radius of the interstitial atom are much smaller. An illuminating comparison is provided by contrasting the optimum carbon radius in [Co8C(CO)l8]2- (0.74 A) with that for Co6C(CO)fr (0.56 A) 63), which has an octahedral core. Indeed all the octahedral carbido clusters have similarly compressed interstitial cavities (Table IV) and as has been pointed out previously, this fact militates against invoking minimum steric requirements of the carbon atom to explain distortions in octahedral carbido clusters. 

The iron analog of (86) has been obtained by oxidative degradation of the anionic carbido cluster [Fe4(//4-C)(CO)12]2- with silver(I) ion (133). 

The syntheses of MeOH, Me20 and HCHO take place in the CO/H2 reaction on the supported carbido-clusters in contrast to the preferential formation of methane and... 

Aryl crown ethers, in hexaruthenium carbido clusters, 6, 1008 Aryl cyanides, with Ni(0) complexes, 8, 47 Aryldiazoalkanes, with bis-Gp Ti, 4, 580-581 a-Arylenamides, asymmetric hydrogenation, 10, 28 Arylenes, with platinum(II), 8, 491 Aryl ethers, via cross-coupling with copper, 10, 650 with palladium, 10, 654 Aryl fluorides... 

Biaryl bisphosphines, atropisomeric, in hydrogenation, 10, 2 Biaryl-bridged bis(iminooxazolidine) complexes, with Zr(IV) and Hf(IV), 4, 811-812 Biaryl compounds, directed synthesis, 10, 145 Bicyclic arenes, in hexaruthenium carbido clusters,... 

Hexa(—)menthyldistannane, preparation, 3, 856 Hexamethylbenzenes, with titanium, 4, 246 Hexamethylcyclotrisiloxane, in polymerization, 3, 654 Hexamethyldigermane, terminal alkyne reactions, 10, 747 1,1,2,2,3,3-Hexamethylindane, metallation, 9, 15—16 Hexanuclear arenes, in hexaruthenium carbido clusters,... 

Hydrothermal methods, for molecuarlar precursor transformation to materials, 12, 47 Hydrotris(3,5-diisopropylpyrazolyl)borate-containing acetylide, in iron complex, 6, 108 Hydrotris(3,5-dimethylpyrazolyl)borate groups, in rhodium Cp complexes, 7, 151 Hydrotris(pyrazolyl)borates in cobalt(II) complexes, 7, 16 for cobalt(II) complexes, 7, 16 in rhodium Cp complexes, 7, 151 Hydrovinylation, with transition metal catalysts, 10, 318 Hydroxides, info nickel complexes, 8, 59-60 Hydroxo complexes, with bis-Cp Ti(IV), 4, 586 Hydroxyalkenyl complexes, mononuclear Ru and Os compounds, 6, 404-405 a-Hydroxyalkylstannanes, preparation, 3, 822 y-Hydroxyalkynecarboxylate, isomerization, 10, 98 Hydroxyalkynes, in hexaruthenium carbido clusters, 6, 1015 a-Hydroxyallenes... 

Polysulfanides, in Ru and Os half-sandwich complexes, 5-Gp and 7 5-indenyl compounds, 6, 496 Polysulfide rings, with germanium, 3, 742-743 Polysulfides, in Ru and Os half-sandwich complexes, rjS-Cp and ]5-indenyl compounds, 6, 496 Polysulfido nitrosyl complexes, with chromium, 5, 303 Polytetrafluoroethylene valves, in high vacuum lines, 1, 198 Polythiaether macrocyclic ligands, in hexaruthenium carbido clusters, 6, 1018-1019... 

Cluster Compounds.—Following the recent108 preparation of [Rh6C(CO)5]2 , the first carbido-cluster of the cobalt subgroup, two related species have now been obtained (Scheme 10).109 Preliminary single-crystal X-ray studies were carried out... 

In the realm of all-carbon ligands in the formation of transition-metal complexes, the naked carbon atom holds a special position. Based on the geometry of metal-carbon interaction, these compounds can be divided into four classes terminal carbide (I), 1,3-dimetallaallene (II), C-metalated carbyne (III), and carbido cluster (IV) ... 

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