Triruthenium Complexes

Triruthenium Complexes from Axial Ligand Substitution... 

Triruthenium Complexes with Ortho-Metallated Ligands... 

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... 

N-heterocycles are a class of neutral ligands with strong coordination affinity to many metal ions. Since a number of neutral N-donors ligands are available, a wide range of oxo-centered triruthenium complexes with various N-heterocyclic ligands have been prepared through axial ligand substitution. By judicious selection of the N-heterocyclic type and modification of the substituents with different electronic and steric effects, the electronic, redox, and spectroscopic properties in these oxo-centered triruthenium derivatives are controllable. 

Using solvent-containing triruthenium species 1 as a synthetic precursor, a series of pyridyl-substituted triruthenium derivatives [Ru30(0Ac)6(py)2(L)]+ (L = 4,4 -bpy 5, BPE 6, BPA 7) were prepared by Meyer et al. [9]. Electrochemical studies showed that these triruthenium complexes exhibit four to five reversible one-electron redox waves in the potential range of +2.0 to —2.0 V, suggesting that these complexes can... 

By introducing redox-active N-methyl-4,4/-bipyridinium ion (mbpy+) to the oxo-centered triruthenium cores, a series of triruthenium derivatives bearing two or three axially coordinated mbpy+ were prepared by Abe et al. [12, 13]. Electrochemical studies indicated that these mbpy+-containing triruthenium complexes afforded a total of seven to nine reversible or quasi-reversible redox waves in acetonitrile solutions at ambient temperature. Of these redox waves, four or five one-electron redox processes arise from RU3 -based oxidations or reductions involving five or six formal oxidation states, including... 

Triruthenium Complexes with Ortho-Metallated 2,2 -bipyridine or 1,10-Phenanthroline... 

The reactions of methanol-coordinated triruthenium complex 2 with diimine ligands such as 2,2 -bipyridine and 1,10-phenanthroline at ambient temperature induced isolation of a series of oxo-centered triruthenium derivatives [Ru30(0Ac)s p.-T 1(C),T 2(N,N)-bipyridine (py)2]+ (bipyridine = dbbpy 31 dmbpy 32 bpy 33 Br2bpy 34 phen 35) containing an ort/zo-metallated bipyridine [8]. Formation of triruthenium derivatives 31-35 is involved in substitution of the coordinated methanol as well as one of the six bridging acetates in the precursor complex 2 by an orf/jo-metallated bipyridine in a p.-r 1(C),r 2(N,N) bonding fashion. 

The CV and DPV of bpym-substituted triruthenium complex 36 (Fig. 5) exhibit three reversible redox waves at +0.75, —0.39, and —1.73 V, ascribed to redox... 

Fig. 8 Plots of cyclic voltammograms of abcp-substituted triruthenium species 48 and the parent triruthenium complex [Ru30(0Ac)6(py)3]+ in chloromethane solution of (Bu4N)(PFg), showing anodic shifts of redox potentials in 48 relative to those in [Ru30(0Ac)6(py)3] +...

Ruthenium complexes of a novel silsesquioxane-based tridentate phosphine ligand have been prepared and characterized by Mitsudo et al The synthesis of the ligand 178 is depicted in Scheme 60. Reactions of 178 with several late transition metal complexes were examined. A typical example is the reaction with three equivalents of [RuCl2(cymene)]2, which produced the red triruthenium complex (c-C5H9)7Si709[0SiMe2CH2CH2PPh2RuCl2(cymene)]3 (179) in almost quantitative yield. 

James and coworkers2 reported a method for the synthesis of dodecacar-bonyltriuthenium from hexakis(ji-acetato)-trisaquooxotriruthenium(III) acetate, which requires only ambient pressures of carbon monoxide. The reaction time can be long and the yield is 59% based on the starting triruthenium complex. 

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