Triruthenium dodecacarbonyl

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,... 

Triptycyl ring systems, 17 60 Triruthenium dodecacarbonyl, 16 63 Tris... 

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... 

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... 

The synthetically useful dianions [M3(CO)u]2- were first isolated by Shore and co-workers as the Ca2+ (M=Ru) and the K+ (M=Os) salts by the reduction of M3(CO)12 using alkali metal benzophenone solutions in THF.1 [Ru3(CO) J2 reacts with Ru3(CO) 2 to form the higher nuclearity clusters [Ru4(CO)13]2- and [Ru6(CO)i8]2- but the triruthenium anion can be obtained in high purity by slowly adding triruthenium dodecacarbonyl to an excess of reducing solution using vacuum-line techniques.2 Vacuum-line syntheses of both dianions have been described in detail.1... 

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. 

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]. 

M. Hidai Yuki Gosei Kagaku Kyokai Shi 27, 1243 (1969) Triruthenium dodecacarbonyl 3 (13) Japan. 

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... 

The search for new reactivity and new reactions is an important target in homogeneous catalysis. A declared goal is the selective activation of C-H bonds under mild conditions. Although there are numerous examples of stoichiometric C-H bond oxidative additions to transition metal centers, successful examples regarding catalytic functionalization of C-H bonds have been made only during the last five years. Notable advances have been achieved by Moore and coworkers who described in 1992 the ortAo-acylation of pyridine with olefins and carbon monoxide. The cluster compound triruthenium dodecacarbonyl has been used as catalyst (Scheme 10). 

New hydration-dehydration reactions of propargyl alcohols coordinated to triruthenium dodecacarbonyl... 

Balch and coworkers have reported that triruthenium dodecacarbonyl reacts with a N,N -vinyl bridged porphyrin to yield structure E. Ru-N bond distances range from 2.068 to 2.257 A. 

Ru supported on silica is prepared by grafting of triruthenium dodecacarbonyl RU3CO12 onto the support followed by decomposition in vacuo at 373 K to form metallic ruthenium particles covered by adsorbed CO. Adsorbed CO is then removed at 673 K in vacuo. The procedure was described by TheoUer et al. [95]. Ni/alumina is a commercial catalyst supplied by IFP. Ni supported on silica is prepared by the cationic exchange technique, using an aqueous solution of hex-amine nickel hydroxide Ni(NH3)6(OH)2, following the procedure already described [96]. Ir supported on silica is prepared by decomposition of Ir(Acac)3 absorbed on the silica surface, following the procedure already described [97]. 

A more detailed study into the mechanism of ruthenium bimetallic melt catalysis for alcohol/ester production has been undertaken for the ruthenium-cobalt combination. Specifically, for the triruthenium dodecacarbonyl-dicobalt octacarbonyl couple, dispersed in tetrabutyl-phosphonium bromide, we have defined the experimental limits of this catalysis, demonstrated multiple catalyst recycle (7) and most importantly, identified some of the relationships linking catalyst productivity, alcohol-ester carbon distributions, and certain key operating parameters with the catalytically active metal carbonyl species present in these reaction media. 

Solution Spectra. The typical crude product solutions from these triruthenium dodecacarbonyl-dicobalt octacarbonyl/tetrabutyl-phosphonium bromide catalyzed CO hydrogenations to Ci C alcohols and their acetate esters display three band sets in the metal carbonyl spectral region. The strong band at ca. 1888 cm is characteristic (57) of [Co(C0)4l. The group of bands at 1955, 1990, and 2017 cm is characteristic (32) of the hydridoruthenium carbonyl anion,... 

Among the complexes studied, the rathenium carbonyls were found to be significantly more active than their iridium, osmium, and platinum analogs. The activity reached for triruthenium dodecacarbonyl [Ru3(CO)j2] is stiU one of the highest ever reported in homogeneous WGS. Based on infrared studies of the less reactive iron carbonyl systems, they postulated a mechanism for the WGS reaction that involves addition of a hydroxide anion as the rate-determining step (RDS), as depicted in Figure 16.3. 

Treatment of 5,8-bis(trimethylsilyl)cyclo-octa-l,3,6-triene or 3,5,8-tris(trimethyl-silyl)cyclo-octa-l,3,6-triene with triruthenium dodecacarbonyl gave the pentalene complexes (352 X = H or SiMe ). Tricarbonyl(Ti-cyclo-octa-l,5-diene)ruthenium and tricarbonyl(T)-cyclo-octa-l,3-diene)osmium have been prepared. They react with trityl fluoroborate to give cyclo-octadienylium complexes [(CgHn)M(CO)3] which react with anionic nucleophiles to give neutral compounds, some of which... 

Triruthenium dodecacarbonyl (Ru3(CO)i2) orange solid, was first (276) prepared by decomposition of Ru(CO)5 but initially incorrectly identified as Ru2(CO)g. This error was first rectified in 1961 when Ru3(CO)i2 was shown (87) to be isomorphous to OS3(CO)i2 and the crystal structure of the latter was determined by x-ray diffraction. Later the structure of Ru3(CO)i2 was determined to be 11 (M = Ru) with the ruthenium triangle having 2.85-A edges (282). In 1966 (48, 50) an improved preparation of Ru3(CO)i2 was developed, utilizing the reductive carbonylation of hydrated ruthenium(III) chloride with carbon monoxide at 10-atm pressure in the presence of zinc, according to the following reaction ... 

Meijer RH, Ligthart GBWL, Meuldijk J, Vekemans JAJM, Hulshof LA, Mills AM, Kooijman H, Spek AL (2004) Triruthenium dodecacarbonyl/triphenylphosphine-catalyzed dehydrogenation of primary and secondary alcohols. Tetrahedron 60 1065-1072... 

Figure 16.9 Structure of triruthenium dodecacarbonyl, Ru3(CO)i2 [65], HCOOH, RuCl2(PPh3)3,180 °C, 6 h...

The ability of sol-gel entrapped compounds to catalyze reactions that do not take place by the non-entrapped materials is even more pronounced when an alumina sol-gel matrix is used. For example, while dihydrogen treated of triosmium- and triruthenium dodecacarbonyls [i.e., H40s4(C0)i2 andH4Ru4(CO)i2] are poor hydrogenation catalysts (see e.g., Ma, 1990) their immobilized versions in alumina sol-gel are highly active catalysts for the reduction ofalkenes and nitro groups at 60°C under 20-25 atm, H2 (Schemes 24-27 and 24-28). The alumina sol-gel entrapped ruthenium carbonyl complex even catalyzes... 

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