Ruthenium cluster

Figure 46 Formation of a POSS-based ruthenium cluster.

Fig. 6.2 Schematic representation of a Mo-containing ruthenium-clustered material. The indicated reaction paths represent (1) adsorption, (2) electrocatalysis, (3) desorption. (Adapted from [18])...

Fig. 6.3 Cluster model structure for Ru99Se54 showing the selenium bonding onto the ruthenium clusters (a) with a statistical distribution (b) with an ordered positioning. (Adapted with permission from [24]. Copyright 2009, American Chemical Society)...

There has been great interest in the preparation of bimetallic transition metal cluster complexes containing palladium.899-902 Bimetallic palladium-ruthenium clusters have been shown to be good precursors to supported bimetallic catalysts.903,904... 

Synthesis and characterization of a new class of anti-angiogenic agents based on ruthenium clusters... 

How to cite this article Nazarov, A. A. et al. Synthesis and characterization of a new class of anti-angiogenic agents based on ruthenium clusters. Sci. Rep. 3, 1485 DOL10.1038/ srep01485 (2013). 

Ruthenium cluster compounds (143) and (144) have been identified that may play a role in the catalysis when Ru3(CO)12 was used as the precursor.540-543 The use of [(dppe)Ru(CO)3] as a catalyst including the intermediates (145) and (146) in the catalytic cycles, have been studied in detail by Gladfelter and co-workers.544-550... 

Scheme 8.4 Mechanism for the hydrogenation of alkenes catalyzed by ruthenium clusters stabilized by edge-bridging diphosphine ligands (CO ligands omitted for clarity).

The Elsevier system has since been shown to carry out several ester hydrogenations that were previously deemed impossible [114]. The hydrogenation of dimethyl phfhalate to phfhalide with ruthenium cluster catalysts has already been discussed (Table 15.15, Entry 4). The application of [Ru(acac)3] and triphos -this time with a 20-fold excess of Et3N as additive - delivers good yields of phthalide. However, the use of isopropanol (I PA) as solvent and 24% HBF4 allows further hydrogenation to 1,2,-bis-hydroxylmethyl benzene for the first time. Both of these reactions were carried out under milder conditions (100°C, 85 bar H2, 16 h) than those reported previously. 

The ruthenium cluster [Ru4H4(//6-C6H6)4]2+ was also employed for the hydrogenation of arenes in a biphasic water/l-butyl-3-methylimidazolium tetrafluoro-borate biphasic system. At 90°C and 60 bar H2, benzene was reduced to cyclohexane with a TOF of 364. 

As previous studies by Ford32 had suggested that both tri and tetranuclear ruthenium clusters were important for the catalysis, Shore et al.64 tested the decomposition rate of H3Ru4(CO)12 , and samples were examined by H NMR... 

Several X-ray structural studies have been made on hydrido-ruthenium clusters (see Table... 

Ruthenium-(O) and -(i).—Apart from the ruthenium clusters discussed separately, only a few new ruthenium(O) complexes have been reported. The isocyanide complexes [Ru(CO)2(CNRKPPh3)2] and [Ru(CO)(CNR)(PPh3)3] have been prepared as shown in Scheme 1. Use of oxygen in the final step gave... 

More recently, the ruthenium-catalyzed hydrogenation of sorbic acid to cis-hex-3-enoic acid. Scheme 16, was achieved in a biphasic bmim-PF6-methyl tert- miy ether (MTBE) system. The ruthenium cluster [H4Ru(q -C6H6)4] [Bp4]4, in [bmim][BF4], was shown to be an effective catalyst for the hydrogenation of arenes to the corresponding cycloalkanes at 90 °C and 60 bar. The cycloalkane product formed a separate phase, which was decanted and the IL phase, containing the catalyst, could be repeatedly recycled. 

Decomposition of the trimethylsilyl diazoacetate 133 with a ruthenium cluster in the presence of benzaldehyde and dimethylfumarate led to formation of the THE derivative 135 in 54% isolated yields. The ruthenium catalyst proved superior to all standard rhodium complexes for this transformation. 

Submitted by MICHAEL 1. BRUCE and MICHAEL L. WILLIAMS Checked by GUY LAVIGNE and TH RESE ARLIGUIEt This tetranuclear ruthenium carbonyl hydride was described on several occasions,5 but early preparations were usually contaminated with Ru3(CO)12, giving rise to suggestions of the existence of two isomeric forms. The situation was clarified by the work of Kaesz and coworkers,6 who discovered the direct route from Ru3(CO)12 and hydrogen, which is described below. The compound is often obtained from reactions between Ru3(CO)12 and substrates containing hydrogen (hydrocarbons, ethers, alcohols, water, etc.) and by acidification of anionic ruthenium cluster carbonyls.7... 

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

TRI- AND TETRANUCLEAR CARBONYL-RUTHENIUM CLUSTER COMPLEXES CONTAINING ISOCYANIDE, TERTIARY PHOSPHINE, AND PHOSPHITE LIGANDS. RADICAL ION-INITIATED SUBSTITUTION OF METAL CLUSTER CARBONYL COMPLEXES UNDER MILD CONDITIONS... 

---