Ruthenium ligand-bridged

Figure 4. Ruthenium and osmium hetero-bi- and trinuclear complexes with bis(terpyridine) ligands bridged by one and two phenylene groups (98).

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... 

Although mechanistic details are still unclear, an open-form triruthenium complex 43, which adopted a ruthena-benzene structure, was derived from the bimetallic 1,4-cyclohexadiene complex 42 (Equation (14)). On the basis of the fact that complex 43 was dicationic, the trimetallic skeleton is most likely formed by the reaction of 42 with a cationic monometallic species, [Cp Ru], generated by the partial decomposition of 42. The X-ray diffraction study of 43 showed that the central ruthenabenzene moiety was coordinated to one of the peripheral ruthenium atoms in an 7 -fashion and to the other in an 7 -fashion. This nonsymmetrical structure arises from the hydrido ligand bridging on one of the Ru-Ru bonds. 

A variety of RU2- and Rug-complexes containing silicon-substituted cyclic polyolefins have been prepared and one of these, [RugCCgHgSiMegCHg-CH3iMe2)(CO)s], has been shown to contain an unusual -hydrocarbon ligand bridging both ruthenium atoms. The reactions of [Ru2(CO)e(DAB)]... 

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