Ruthenium Cluster Complexes

T. Hasegawa, T. Yonemura, K. Matsuura, and K. Kobayashi, Tris-bipyridine ruthenium complex-based glyco-clusters Amplified luminescence and enhanced lectin affinities, Tetrahedron Lett., 42 (2001) 3989-3992. 

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... 

However upon standing at ambient conditions the solutions precipitate Ru3(CO)i2 in nearly quantitative yields. Infrared spectra under reaction conditions (400 atm of 1 1 H2/CO, 200°C) also correspond to the spectrum of Ru(CO)5 no acetate or cluster complexes are observed. However, there is evidence for the presence of small amounts of Ru3(CO) 2 under somewhat lower pressures (ca. 200 atm) Many other ruthenium complexes were used as catalyst precursors, and were found to be converted to the same ruthenium products under reaction conditions. For example, H4Ru4(CO)12 (13), [Ru(CO)2(CH3C02)2ln (14) ... 

Cabeza, J.A., in Braunstein, P., Oro, L.A., Raithby, P.R. (Eds.), Homogeneous Catalysis with Ruthenium Carbonyl Cluster Complexes Metal Clusters in Chemistry, Vol. 2. Wiley-VCH GmbH, Weinheim,... 

Mononuclear ruthenium complexes were found to be superior to carbonyl clusters during a comprehensive comparison of a variety of catalysts in the reduction of acetone [49]. Without solvent, most catalysts were highly selective, although the activity was quite low. The addition of water to the system vastly increased yields, in agreement with Schrock and Osborrfs observations into rhodium-catalyzed hydrogenations (Table 15.9) [41],... 

Coordination to two or three of the double bonds of a hexagon was found in various osmium, rhenium, iridium or ruthenium complexes, but these complexes do not exhibit a T -complexation. In fact metal clusters, not single metal atoms, bind to CgQ such that the metals are T -bound to adjacent bonds of a Cg face (Section 7.3). 

Osmium-Carbonyl-Hydride Clusters and Related Ruthenium Complexes. Our investigation of these species began with a study of the species (/i2-H)(H)Os3(CO)n, prepared from Os3(CO)i2 via the unsaturated species (M2-H)20s3(CO)io (33) (see Reaction 1). 

Dahl (175). The basic structure is defined by an octahedral core with trans-tellurium atoms and is isoelectronic with the ruthenium complex 183. Both clusters may also be compared with the ruthenium and osmium bismuth complexes, 125 and 129, which, although octahedral, contain two less electrons. A complex containing an additional carbonyl group, viz. [Te2Co4(CO)u], 185, has been described by Rauchfuss (172) as resulting from the reaction... 

The derivative of 1,4-diphosphepane 158 was obtained from the hydroxylmethyl-alkynyl ruthenium complex 157, which underwent dehydratation upon treatment with HBF4 in CH2CI2. Subsequently, the generated alkene endured a double nucleophilic attack by bidentate (diphenylphosphino) ethane to give cationic cluster 158 in 94% yield <2006IGA(359)938>. The structure of 158 was confirmed by the X-ray data. 

There are two examples of alkyne-substituted clusters in which there is an interaction between the alkyne and five-metal centers. Both occurrences are found in the related pentanuclear ruthenium complexes Ru5(CO)14(/i-PPh2)(C=CPh) (431) and Ru5(CO)12(p-... 

---