Ruthenium binuclear

Recently mononuclear ruthenium(II) and binuclear ruthenium(III) complexes of 5 and its iV-phenyl derivative have been isolated [214], Although many of the complexes were not soluble in the culture medium, both ruthenium(II) and ruthenium(III) complexes showed considerably more activity against E. coli than the uncomplexed thiosemicarbazones. Similar results were found for the oxovanadium(IV) complexes of the same ligands [VO(L)2Br]Br, where L is the deprotonated 2-formylpyridine N-phenylthiosemicarbazone, was the most potent inhibitory activity [215]. 

Binuclear ruthenium compounds, with hydrocarbon bridges without M-M bonds, 6, 619... 

Barigelletti F et al (1993) Luminescence properties of rigid rod-like binuclear ruthenium(II)-osmium(II) terpyridine complexes - electronic interaction through phenyl bridges. JCS Chem Commun 942-944... 

Very recently, the water-soluble binuclear ruthenium allenybdene complex [ RuCl(ju-Cl)(C=C=CPh2)(Ph2P(2-0S(0)2C6H4))2 2] Na4 was used to perform selective transetherification of substituted vinyl ethers into acetals and aldehydes according to the solvent (Scheme 23) [110]. 

The first attempt seems to have been promoted by binuclear ruthenium alkene metathesis catalyst for the ROMP of cyclooctene followed by hydrogenation (50 °C, 30 psi H2) in the presence of 10 equiv. of triethylamine [72] (Scheme 31). It was motivated by the observed capability of [RuCl2(arene)]2... 

In this section we consider the complexes of mono-, di- and poly-carboxylato complexes. There appear to be marked differences from ruthenium carboxylato chemistry particularly in respect of the II/III and III states. A number of osmyl complexes are known with monodentate or bidentate carboxylates (p. 582) but apparently none of ruthenium(VT). On the other hand, the binuclear ruthenium species [Ru30(OCOR)6L3]"+, in which OCOR functions as a bidentate ligand, does not appear to have an osmium counterpart both elements form lantem -like species containing [M2(OCOR)4]"+ cores, but again with marked differences between ruthenium and osmium. This is clearly an interesting and rewarding field for further study. 

Backvall et al. [10] have recently reported substantial improvements in the described process. A range of 1 -phenylethanol derivatives can be synthesized from the raeemates in excellent yields and >99 % ee by using a binuclear ruthenium complex combined with an immobilized lipase and a specifically designed acyl donor (4-Cl-PhOAc). Even aliphatic alcohols and diols... 

TABLE 13. Formal electrode potentials (vs. SCE) and relative separations for the sequential oxidations and reductions of the binuclear ruthenium complexes [112] in CH2CI2 solution as a function of the spacer... 

R = cyclohexyl Scheme 5.17 Synthesis of chiral NHC-based mono- and binuclear ruthenium carbenes. 

Water oxidation is a thermodynamically unfavorable process which involves the transfer of four electrons. Several catalysts have been developed and simultaneously several mechanisms for these types of chemical transformations have been proposed [13]. Binuclear ruthenium complexes have drawn considerable attention in the context of water oxidation. The anthracene-bridged binuclear Ru bis-hydroxide bis-quinone... 

The importance of hydroxycarbonyl intermediates is well illustrated in a recent study of the stepwise oxidation of CO to CO2 by binuclear ruthenium complexes". Deprotonation of a diruthenium(I) aquo species yields a hydroxy intermediate which rearranges to an isolable hydroxycarbonyl complex, equation (h). Deprotonation of the hydroxycarbonyl with NEts in dichloromethane results in a formally diruthenium(O) ii-CO complex, equation (i). 

Simkhovich L, Luobeznova I, Goldberg I, Gross Z (2003) Mono- and binuclear ruthenium corroles synthesis, spectroscopy, electrochemistry, and structural characterization. Chem Eur J 9 201-208... 

Collman JP, Barnes CE, Swepston PN, Ibers JA (1984) Synthesis, proton NMR spectroscopy, and structural characterization of binuclear ruthenium porphyrins. J Am Chem Soc 106 3500-3510... 

The use of Me3NO to induce substitution of dppm (bis(diphenylphosphino)-methane) for CO molecules on dinuclear iron complexes led to insertion of CO into C-C bonds of alkyne-derived metallacycles. Similar behavior was observed when [PPNJCl salts were used to favor the formation of alkyne-substituted triruthenium dppm-containing clusters.I This behavior should be compared with the insertion of CO into allenylidene and phosphido-bridging ligands occurring when dppm coordinates to binuclear ruthenium complexes as shown in Fig. 3. This reaction is a nucleophilic attack of the coordinated allenylidene and phosphido groups on a coordinated CO (see Section 2.8.2.2). 

Of particular interest are the cases where, by a suitable design of the complex, the factors (a) to (d) above can be eliminated so that the departure of the electrochemical response from the purely statistical behaviour arises solely from cause (e). Two examples of such complexes which have been well studied are binuclear ruthenium complexes bridged by 4,4 -bipyridyl type ligands, and binuclear complexes where L, the binucleating macrocyclic ligand, is a symmetric... 

Scbeme 19. Synthesis of Chiral AtHeterocyclene-Based Mono- and Binuclear Ruthenium Carbenes... 

CD study shows that the configuration of the octahedral chiral element is controlled by that of the hgand, being (A) for the hgand (—)-[ctpy-x-ctpy] (6.54). The chemistry of these coordination polymers is directly related to the work of von Zelewsky on the enantioselective formation of chiral mono- and binuclear ruthenium (II) complexes. 

---