Ruthenium triruthenium

Nagashima reported the hydrogenation of di-, tri- and tetranuclear ruthenium complexes bearing azulenes below 100 °C revealed that only the triruthenium compounds reacted with H2 via triruthenium dihydride intermediates.398 This indicates that there exists a reaction pathway to achieve facile activation of dihydrogen on the face of a triruthenium carbonyl moiety.399... 

It has been several decades since oxo-centered triruthenium-carboxylate complexes with triangular cluster frameworks of Ru3(p3-0)(p-00CR)6 (R = alkyl or aryl) were first isolated [1,2]. In the early 1970s, the first oxo-centered triruthenium complex was structurally characterized by Cotton through X-ray crystal structural determination [3]. Since then, oxo-centered trinuclear ruthenium-carboxylate cluster complexes with general formula [Ru30(00CR)6(L)2L ]n+ (R = aryl or alkyl, L and... 

It appears that abpy- or abcp-substituted oxo-centered triruthenium derivatives exhibit a high stabilization on low-valence III,III,II and III,II,II species, which are usually unavailable through axial ligand substitution. The abpy or abcp exhibits a i-T 1(N),r 2(N,N) bonding mode, chelating one ruthenium center via azo N and pyridyl/pyrimidine N donors as well as bound to another ruthenium center via the other pyridyl/pyrimidine N donor. 

Effect of Catalyst Composition. Where acetic is the typical acid substrate, effective ruthenium catalyst precursors include ruthenium(IV) oxide, hydrate, ruthenium(III) acetyl-acetonate, triruthenium dodecacarbonyl, as well as ruthenium hydrocarbonyls, in combination with iodide-containing promoters like HI and alkyl iodides. Highest yields of these higher MW acids are achieved with the Ru02-Mel combination,... 

In many respects the apparently analogous reduction of nitroarenes with triruthenium dodecacarbonyl under basic phase-transfer conditions is superior to that of the iron carbonyl-mediated reductions. However, the difference in the dependence of the two processes on the concentration of the aqueous sodium hydroxide and the pressure of the carbon monoxide suggests that they may proceed by different mechanisms. Although the iron-based system is most effective under dilute alkaline conditions in the absence of carbon monoxide, the use of 5M sodium hydroxide is critical for the ruthenium-based system, which also requires an atmosphere of carbon monoxide [11]. The ruthenium-based reduction has been extended to the... 

Ruthenium complexes of a novel silsesquioxane-based tridentate phosphine ligand have been prepared and characterized by Mitsudo et al The synthesis of the ligand 178 is depicted in Scheme 60. Reactions of 178 with several late transition metal complexes were examined. A typical example is the reaction with three equivalents of [RuCl2(cymene)]2, which produced the red triruthenium complex (c-C5H9)7Si709[0SiMe2CH2CH2PPh2RuCl2(cymene)]3 (179) in almost quantitative yield. 

A PHOSPHINO BRIDGED RUTHENIUM CLUSTER NONACARBONYL-n-HYDRIDO-Oi-DIPHENYL-PHOSPHINO)TRIRUTHENIUM(O)... 

The heptane solvent should be dried over sodium wire and a few milliliters of heptane should be added to the autoclave outside the liner tube to improve thermal contact between the autoclave and the tube. Triruthenium dodecacar-bonyl is available commercially (Alpha and Strem) or may be made from hydrated ruthenium trichloride by well-known procedures.6... 

Tetrahydrofuran (THF) and diethyl ether are freshly distilled from sodium benzophenone ketyl under nitrogen. Hexane is freshly distilled from sodium metal under nitrogen. Triruthenium dodecacarbonyl is available commercially or it can be synthesized from ruthenium trichloride trihydrate (Alfa) using the procedure of Mantovani and Cenini,3a or alternately, by the procedure given in this volume.3b The [/r-nitrido-bis(triphenylphosphorus)(l+)] chloride can be purchased from Strem or synthesized according to the literature procedure4... 

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 number of unusual structural features have been noted. The ruthenium porphyrin formed by reaction of triruthenium dodecacarbonyl with an N, AT-vinyl-bridged tetraphenylporphyrin involves disruption of a pyrrole C-N bond to give a product in which the ruthenium is bound to two pyrrole N atoms, the C and N atoms of the ruptured pyrrole ring, and two mutually cis carbonyl ligands. The remaining pyrrole N is uncoordinated.613 Mutually cis configurations have also been found for the dicarbonyl complex of molybdenum tetraphenylporphyrin and for some dinitrosyl porphyrins. 

Some four-electron capping units enter as such. This is the case for the many reactions forming/t3-sulfur ligands from elemental sulfur (103). It also holds for the triruthenium /i3-nitrene cluster 45, formed from Me3SiN3 and Ru3(CO)i2 (104). A versatile four-electron ligand is the acetylene moiety, which can add facially to M3 units as a two-center capping group, as found in the clusters 46, which can be obtained from trinuclear carbonyls of iron, ruthenium, and osmium (105, 106). 

If Ru3(CO)12 is used, the product is again the porphyrin, in a mixture with its Ru2 + complex. The catalytic action of ruthenium in expanding the macrocycle core has not been further investigated. The yield of ruthenium porphyrinate increases with time this is not surprising since the reaction of triruthenium dodecacarbonyl with porphyrins is a standard procedure for the synthesis of such complexes [26]. 

Ruthenium and osmium analogs of the /r-oxo bound cluster are known. For example, (/r-H)Ru3(CO)io(/r-OSiEt3) and (/u.-H)Os3(CO)io(/r-OSiEt3) have been prepared, and the (/n-oxo)-bound triruthenium and the triosmium clusters can be selectively prepared on the surface of silica and alumina/ ... 

The first example of a symmetric triangular mixed-valent triruthenium complex 99 has been obtained by thermal treatment of Ru(acac)2(MeCN)2 with substituted 2-thiouracil (equation 66). Although the usual coordination mode of the acetylacetonate is present in the trinuclear compound, the y-carbon atom of one of the coordinated acetylacetonato units of the parent Ru(acac)2(MeCN)2 links to a ruthenium atom forming the trinuclear network. The factors which are primarily involved in the ruthenium-mediated C—S bond cleavage of the stable thiouracyl are not clear. It was suggested that the process starts with the initial coordination of thiouracyl to ruthenium followed by cleavage of the C—S bond and subsequent nucleation. ... 

A trinuclear ruthenium cluster blocked by three pentamethylcydopentadienyl ligands showed a unique reaction environment for C-C bond cleavage. C-C bonds in cydopentadiene and branched alkane are easily cleaved on the triruthenium cluster, giving organo(methylidyne)triruthenium complexes. For example, cydopentadiene coordinates to the trinuclear Ru cluster and cleaves a C-C bond to form ruthenacy-... 

Cgo bonds to transition metals primarily in a dihapto fashion, but at least one example of a hexahapto structure has been reported. The coordination mode of the Cgo in the triruthenium cluster in Figure 13-38(a) is perhaps best described as r, rather than iq -Ceo, because the C—C bonds bridged by the ruthenium atoms are slightly shorter than the other C—C bonds in the 6-membered ring. 

The starting material for preparation of these derivatives, [Ru2(00)4(11 -CsH5)2], has previously been obtained by the reaction of sodium cyclo-pentadienide with a dihaloruthenium(II) carbonyl [Ru(CO)2l2] (ref. 3) or [Ru(CO)3Cl2]2(ref. 4) prepared by carbonylation of the corresponding ruthenium(III) trihalide. A more facile synthesis was later reported, involving the reaction of triruthenium dodecacarbonyl with cyclopentadiene. The procedure described herein represents a modification of this second method, resulting in an improved yield. 

Asakura K, Yamada M, Iwasawa Y, Kuroda H (1985) Spectroscopic studies on the surface structures of ruthenium catalysts derived from triruthenium dodecacarbonyl/y-aluminum oxide or -silicon dioxide. Chem Lett 14 511... 

Ruthenium(II) has been complexed to each of the bidentate sites on the arms of 13, each ruthenium capped with two additional 2,2/-bipyridyl ligands.21 Each of these complexes, in particular the triruthenium species... 

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