Dinuclear complexes ruthenium

Alternatively, arene displacement can also be photo- rather than thermally-induced. In this respect, we studied the photoactivation of the dinuclear ruthenium-arene complex [ RuCl (rj6-indane) 2(p-2,3-dpp)]2+ (2,3-dpp, 2,3-bis(2-pyridyl)pyrazine) (21). The thermal reactivity of this compound is limited to the stepwise double aquation (which shows biexponential kinetics), but irradiation of the sample results in photoinduced loss of the arene. This photoactivation pathway produces ruthenium species that are more active than their ruthenium-arene precursors (Fig. 18). At the same time, free indane fluoresces 40 times more strongly than bound indane, opening up possibilities to use the arene as a fluorescent marker for imaging purposes. The photoactivation pathway is different from those previously discussed for photoactivated Pt(IV) diazido complexes, as it involves photosubstitution rather than photoreduction. Importantly, the photoactivation mechanism is independent of oxygen (see Section II on photoactivatable platinum drugs) (83). 

Fig. 18. The dinuclear complex [ RuCl(ri6-indane)>2(p-2,3-dpp)]2+ (21) can be photoactivated to yield highly reactive and potentially cytotoxic ruthenium species and the arene indane, which could be used as a fluorescent probe.

The iron subgroup exhibits a plethora of nonclassical M H Si interactions both for mono- and dinuclear complexes. Iron in the high formal oxidation states IV and ruthenium in the high formal oxidation states IV-VI are particularly prone to form such species. Some of them having three or more hydrides will be discussed in Section IV. 

Bielawski et al. have developed Janus-head dicarbene ligands which are able to act as a bridge between two metal centers, thereby leading to dinuclear complexes of type 96 [58-60] (Fig. 32). More recently homonuclear bimetallic ruthenium(II) and iron(II) complexes 97 have been synthesized. It was hoped that the dicarbene ligand would interconnect the redox-active metal centers, but the... 

Ruthenium(iv).—Several novel Ru compounds have been isolated from the reaction sequence shown in Scheme 9. These diamagnetic complexes are assumed to be mononuclear with two trans oxide groups. In addition, the dinuclear complex [Ru(0H)3(phen)]20 was reported to be formed by evaporating a methanolic solution of [Ru03(phen)]20. A study of the mechanism... 

The dinuclear complex (CpNiCO)2 is a source of NiCp fragments. Their addition to clusters occurs with Os3(CO),2 to form 88 (163) or with the hydrocarbon bridged ruthenium clusters 89 to form 90 (164). The clusters... 

Besides mononuclear, dinuclear complexes were also applied successfully as Kharasch addition catalysts (Fig. 38) [200, 201]. Ruthenium amidinate complex... 

The bisacetato ruthenium complex 28, on heating in 2-propanol, leads to the bridged hydrido dinuclear complexes 73 and 74. The bistrifluoroacetato complex 28 also leads to complex 73. The Tj2-acetato complex 39 was transformed in hot 2-propanol to another bridged hydrido derivative (75, arene = durene, mesitylene, p-cymene, hexamethylbenzene 60-70%). The introduction of alkyl substituents on the benzene ring is reflected by a shift of the p FI resonance toward high field (14,53). 

Arene)ruthenium(II) complexes 120-124, having a planar chirality, have been obtained recently (71,72). Complexes 121-123 are formed by addition of optically active amines (L1 and L2) or phosphine (L3) to the dinuclear complex 120 (Scheme 10). They exist as a mixture of two configurationally stable diastereoisomers. The absolute configuration of one of the diastereoisomers of 123 has been determined, and complex 124 containing a chelating optically active diamine has also been isolated (71,72). 

There are very few examples of exchange coupled dinuclear ruthenium complexes and a clear opportunity exists for further study. All dinuclear complexes that possess anionic bridging ligands 76, 81-85,... 

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