Ru IV Complexes with O- or N-Donors

Cs [Ru 05(0H)(Hj0) Y-PWj 03 j].17H20 Strictly this lies outside the terms of reference of this book as it has so far only been used as a water oxidant. It is made from [ y-PWj Oj ] in aqueous RuClj at pH 6 in air. The X-ray crystal structure was determined and cyclic voltammetric properties were measured. The system [RuP3(OH)(Hp)Jy-PW, 03, 3] -/[Ru(bpy)3] Vaq. Na CSp ) pH 5.8/UV oxidised water to [651]. 

Much work has been carried out with this species, and although the majority of the oxidations studied with it of a variety of organic substrates were stoicheiometric rather than catalytic, investigation of the mechanisms involved has been illuminating for an understanding of Ru oxidation chemistry. The many possible pathways of organic oxidations by [Ru(0)(py)(bpy)2] have been reviewed [43]. 

Thymidine-specific depyrimidination of DNA by this and other Ru(lV) 0x0 complexes, e.g. electrocatalytically by [Ru(0)(py)(bpy)2] Vaq. formate buffer was studied and related to their Ru(IV)/Ru(ll) redox potentiis [664]. Oxidation of formate and of formic acid to CO by stoich. aT-[Ru(0)(py)(bpy)2] Vwater was studied kinetically, and a two-electron hydride transfer mechanism proposed [665]. 

Cis-A-[Ru(0)(py)(bpy)J(C10 )j is made from d5-[Ru(py)j(bpy)j]Cl2 resolved with disodium-f0,0 -dibenzoyl-(A,/ )-tartrate, and the resulting salt converted to CM-A-[Ru(H20)(py)(bpy)2](C10 )2 and oxidised by cerium(lV). The system stoich. cd-A-[Ru(0)(py)(bpy)2] dwater-CH3CN oxidised methyl-p-tolyl sulfide to (R)-methyl-/i-tolyl sulfoxide [666]. 

7 a s-[Ru(0)(bpy)(tpy)](C10 )2 This light green salt is made from [Ru(H30) (bpy)(tpy)] and Br electronic spectra and cyclic voltammograms were recorded. Much mechanistic work has been carried out with this species, often in parallel with studies on ctT-[Ru(0)(py)(bpy)3] , mainly by Meyer et al. and principally with stoicheiometric oxidations [667]. 

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