Ruthenium carbonyl clusters osmium

Although C-S bond cleavage reactions between thiophenes and osmium clusters have not been observed, selenophene and tellurophene undergo ring opening reactions with [Os3(CO)io(NCMe)2] to give complexes 28a and 28b (Scheme T). " It is likely that the sulfur-extrusion reactions of iron and ruthenium carbonyl clusters with thiophenes proceed via ring-opened intermediates of this type. 

Retaining the theme of metal carbonyl clusters, capping considerations in transition-metal clusters have been discussed with reference to [Sb2Co4(CX))] g( A-CX))], and [Bi2Co4(CO)jQ( i-CO)]" 28. An infrared spectroscopic study of the formation of carbonyl rhodium clusters on a rhodium electrode produced by oxidation reduction cycles in acidic solution 2 has also been published. Electrochemistry with ruthenium carbonyls >21 osmium carbonyls 2 jg also reported. Muon spin rotation in a metal-cluster carbonyl compound has been communicated and, lastly, a proton spin-lattice NMR relaxation study of hydride carbonyl clusters has been reported. This provides a method for determining distances involving hydrido ligands... 

Many carbonyl and carbonyl metallate complexes of the second and third row, in low oxidation states, are basic in nature and, for this reason, adequate intermediates for the formation of metal— metal bonds of a donor-acceptor nature. Furthermore, the structural similarity and isolobal relationship between the proton and group 11 cations has lead to the synthesis of a high number of cluster complexes with silver—metal bonds.1534"1535 Thus, silver(I) binds to ruthenium,15 1556 osmium,1557-1560 rhodium,1561,1562 iron,1563-1572 cobalt,1573 chromium, molybdenum, or tungsten,1574-1576 rhe-nium, niobium or tantalum, or nickel. Some examples are shown in Figure 17. 

The formation of carbido-carbonyl cluster compounds with ruthenium and osmium appears to be common in pyrolysis reactions the basic reaction may be viewed as the transformation of the coordinated carbon monoxide to carbide and carbon dioxide. Small variations in... 

Metal carbonyl cluster compounds which contain three ruthenium or three osmium atoms in the cluster core are common.1 Potentially useful reagents for syntheses of these compounds are the triruthenium and triosmium dianions [M3(CO)h]2 (M = Ru, Os).2 Therefore, it is desirable to develop good synthetic routes to obtain [M3(CO)11]2- (M = Ru, Os) of high purity in high yields. A method that is particularly useful for generating [M3(CO)n]2 (M = Ru, Os) is the designed stoichiometric reduction of M3(CO)12 (M = Ru, Os) using an electron carrier such as potassium-benzophenone.3... 

A considerable range of iron carbonyl clusters is now known to contain antimony or bismuth, and later developments have seen this extended to ruthenium and osmium complexes. Whitmire (711) has described the reaction between NaBi03 and methanolic [Fe(CO)5], which affords the anionic triiron cluster [BiFe3(CO)10] (108), which contains a tetrahedral BiFe3 core. Cluster 108 is an example of a closo tetrahedral cluster with three first-row... 

The osmium analog was obtained in moderate yield by pyrolysis of Os CO) or Os3(CO),2 (20). Both the ruthenium (29) and osmium clusters (31) are isostructural with the original iron analog, 1 (2), the metal atoms describing a square pyramid, each vertex bearing three terminal carbonyls. The carbon atom lies fractionally below the center of the basal plane of the cluster, protruding 0.11 A below the Ru4 plane in 10 and 0.12 A below the Os4 plane in 11 [cf. a value of 0.08 A for Fe5C(CO)15 (2)] (see Fig. 11). 

Platinum nanoparticles, preparation, 12, 78 Platinum-nitrogen bonds, in platinacycles, 8, 508 Platinum-osmium carbonyl clusters, characteristics, 8, 420 Platinum-oxygen bonds, in platinacycles, 8, 505 Platinum particles, surface reactivity, 12, 542 Platinum-phosphorus bonds, in platinacycles, 8, 508 Platinum-rhenium carbonyl clusters, characteristics, 8, 420 Platinum(II)-ruthenium(II) binary complexes, preparation,... 

Ruthenium and, particularly, osmium form a great many high nuclearity carbonyl clusters. Only a few illustrative examples can be mentioned here. Figure 18-F-6 shows some of the topological relationships among the osmium compounds. The scope of the ruthenium chemistry has been extended recently with the preparation of the [RuioH2(CO)25]2 and [RunH(CO)27]3 ions.137... 

Osmium forms stronger metal-metal bonds than either iron or ruthenium consequently, there are a large number of osmium carbonyl clusters see Cluster) and these complexes have a large body of reaction chemistry. The triosmium cluster are prepared from Os3(CO)i2. Most are diamagnetic... 

Bridges between trinuclear metal clusters [of Ru, Os] Synthesis of ruthenium and osmium carbonyl clusters with unsaturated organic rings Oxyligand derivatives of triosmium dodecacarbonyl... 

For the osmium and ruthenium carbonyl systems, replacement of carbonyl groups by effective leaving groups, such as acetonitrile, has resulted in the development of synthetic procedures leading to the designed synthesis of cluster derivatives. Thus for... 

Wider possibilities are also available with cluster-t)T3e MCMs. They are molecular compounds that include a framework of metal atoms, which are separated by short distances (not more than 3.5 A) permitting direct metal-metal interaction. Such a framework is enclosed within a set of polymerizable ligand groups. The first report in this regard relates to MCMs based on Co2(CO)g or Fc2(CO)9 and the methyl ester of j7-vinyldithiobenzoic acid as well as Wcyclohexyl-4-vinylthiobenzamide [57]. MCMs based on a carbonyl cluster of osmium 89, ruthenium [58] and rhodium [59] with 4-VPy 90 and allyldiphenylphosphine 91 are stable compounds (see Experiments 4-9 and 4-10, Section 4.6) [59,60]. 

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