Ethylenediamine ruthenium complexes

Besides the tris ruthenium complexes, other complexes can be made (Figure 1.20), while ethylenediamine (en) complexes exist ... 

TRIS(ETHYLENEDIAMINE)RUTHENIUM(II) AND TRIS(ETHYLENEDIAMINE)RUTHENIUM(III) COMPLEXES... 

A series of ruthenium compounds has been obtained by replacing ammonia by ethylenediamine in the complex. These bring ruthenium completely into line with the other metals of the platinum group as far as co-ordination number is concerned. 

Chen H, Parkinson JA, Morris RE, Sadler PJ (2003) Highly selective binding of organometallic ruthenium ethylenediamine complexes to nucleic acids novel recognition mechanisms. J Am Chem Soc 125 173-186... 

As far as we are aware the first example of a ruthenium(II)-arene compound to be evaluated for anticancer activity was described by Tocher and co-workers in 1992 [18]. The field remained essentially dormant until the explosion in interest led largely by our group and that of Sadler, who has extensively studied ruthenium(II)-arene complexes with ethylenediamine and related ligands, and describes these compounds in the Chapter X in this book. It should be noted that other groups have also contributed to the field as will become clear in the course of this Chapter. 

There are now a substantial number of nitrido complexes of osmium(VI) and osmium(IV) as well as the osmiamate ion [OsVII 03N]. In addition to the ammine and ethylenediamine complexes, much recent work has been carried out on the bipy, phen and terpy complexes, often in connection with research into the photodissociation of water. The nitrosyl chemistry of the element, though seemingly not as extensive as that of ruthenium, has received much attention, and there has been considerable work on the phosphine, arsine and stibine complexes. 

Within the Hush formalism of electron transfer [129], the electronic coupling through hydrogen bond interfaces may be deduced from the intensity of a mixed-valence transition between juxtaposed donor-acceptor pairs. We highlight the only such detailed study in this section. Curtis and coworkers have studied a collection of hydrogen-bonded mixed-valence adducts formed between ruthenium(II) electron-donor and ruthenium(III) electron-acceptor complexes in solution [130]. Using acetonitrile or nitromethane as a solvent, hydrogen-bonded assemblies of the type [(tpy)(bpy)Ru (CN)]2, (en)2Ru (bpy) 5+ 45 (bpy = 2,2 -bipyridine, tpy = 2, 6", 2 -terpyridine, en = ethylenediamine) and [(bpy)2Ru (CN)2]2, (en)2Ru (bpy) +... 

More recent studies, also including in vivo evaluations, have been undertaken on ruthenium(ll)-arene complexes with the l,3,5-triaza-7-phosphatricyclo-[3.3.1.1]decane (PTA) co-ligand, viz. [Ru(77 -arene)Cl2(PTA)] 11 and ethy-lenediamine co-ligand, viz. [Ru(77 -arene)Cl(dien)] (dien = ethylenediamine) 12." ... 

Asymmetric transfer hydrogenation of ketones in the presence of soluble transition metal catalysts has been developed [8-10], enantioselectivities up to 99% ee being obtained using a ruthenium catalyst bearing mono-N-tosylated diphenyl-ethylenediamine as a ligand. Iridium complexes associated with fluorous chiral diimines 3a-3c or diamines 4a—4b have also been shown to be effective catalysts in hydrogen-transfer reduction of ketones [11,12]. 

Arakawa, R., Matsuda, F, Matsubayashi, G., Matsuo, T. (1997) Structural Analysis of Photo-oxidized (Ethylenediamine)bis(2,2 -bipyridine)ruthenium(II) Complexes by Using On-line Electrospray Mass Spectrometry of Labeled Compounds. J. Am. Soc. Mass Spectrom. 8 713-717. 

The reaction using C10 is not quantitative. When alkaline [Fe(CN)e] is used, however, four equivalents of oxidant are required. The ruthenium(ii) complexes may, however, be oxidized to Ru both by cyclic voltammetry and by titration with Ce . In the latter case, however, some over-oxidation occurs since five moles of oxidant are necessary for complete reaction. Dinitrogen complex formation has been postulated from the cleavage of a C—N bond in a co-ordinated ethylenediamine of ruthenium(iii). Treatment of [Ru(en)3] + with NO in alkaline media yields as one product [(en)aRu(N2)(OH2)] +. An initial rapid reaction may be associated with reduction of the metal to the + 2 oxidation state and the reaction may proceed via either (4) or (5) as intermediates. 

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