Ruthenium complexes oxalic acid

Ruthenium, iridium and osmium Baths based on the complex anion (NRu2Clg(H20)2) are best for ruthenium electrodeposition. Being strongly acid, however, they attack the Ni-Fe or Co-Fe-V alloys used in reed switches. Reacting the complex with oxalic acid gives a solution from which ruthenium can be deposited at neutral pH. To maintain stability, it is necessary to operate the bath with an ion-selective membrane between the electrodes . 

Ruthenium(IlI) Reaction of [Ru(OH)(NH3)5]C12 with acetic anhydride followed by acid hydrolysis and treatment with Ag+ gives [Ru(oAc)(NH3)5]2+.397 Oxalic acid with [Ru(OH)(NH3)5]2+29° or [RuCl(NH3)5]2 + 404a affords c/s-[Ru(ox)(NH3)4]+. Carboxylato complexes can be prepared generally by treatment of [RuCl(NH3)5]2+ with Ag(02CCF3) followed by addition of carboxylate buffer in DMF.402 Charge transfer bands for the complexes [Ru(02CR)(NH3)5]2+ are observed near 300 nm, and are related to the El/2 values for reduction of the complexes.405... 

An additional pathway for the formation of solvento-complexes is the decomposition by probe acids of coordinated carbonate or oxalate ligands. There are several examples of such reactions reported in the literature. Thus, the ruthenium(II) bis(aqua)-complex has been prepared by the reaction shown in Eq. 3.20 ... 

Carboxylic acids and their salts, as well as alcohols and alkoxides, are common ligands and this has limited their use as reductants in synthesis. Potassium hexachloroplatinate(IV), for example, is reduced by ammonium oxalate.63 Che and coworkers 4 have shown that the reaction of aqueous solutions of ascorbic acid with the complex, [Ru02(NH3)4]Cl2, in the presence of NaX (X = Cl, I, CNS) yields the complexes, [RuX2(NH3)4]X. The reduction of a mixture of hydrated ruthenium(III) chloride and ruthenium(IV) chloride by glucose or ascorbic acid in water in the presence of 2,2 -bipyridyl results in the formation of [Ru(bipy)3]Cl2 7H20. 5 Additionally, the reduction of the [Tc04] anion by gluconic acid has been studied. ... 

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