Oxalate ruthenium complexes

Kanoufi F, Bard AJ (1999) Electrogenerated Chemiluminescence. 65. An investigation of the oxidation of oxalate by tris(polypyridine) ruthenium complexes and the effect of the electrochemical steps on the emission intensity. J Phy Chem B 103(47) 10469-10480. doi 10.1021/jp992368s... 

The effect of the polymer-coating of the electrode appears to be not only the immobilisation of the ruthenium complex but also adsorption of the oxalate ions on the polymer layer. Possible practical applications of such polymer-coated electrodes are in the electrochemical analysis of trace compounds by concentration in the film [24, 25] and electroanalysis of slow reactions, e.g. mediation of enzyme redox processes [22]. 

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 . 

Os forms many complexes with nitnte. oxalate, carbon monoxide, amines, and thio ureas. The latter arc important analytically Osmium forms the interesting aromatic sandwich" compound, osmocene. A metallocene is described under Ruthenium. See also Chemical Elements and Platinum and Platinum Group. 

Despite the considerable body of knowledge now available on the extraction chemistry of ruthenium, it remains a problematic element for fuel reprocessors. A variety of means10 may be used to render the ruthenium less extractable. These include the addition of reagents such as oxalate or thiourea, the oxidation of Ru111 to inextractable RuIV or the addition of nitrogen dioxide to retain more Ru(NO) 3+ in the form of nitrito complexes of low DRu. However, such treatments may have undesirable effects on plant operation. It is possible to attain high decontamination factors for ruthenium over several process cycles, the penalty being that the ruthenium will appear in several waste streams, not just the HAW from the first decontamination cycle. 

The analysis has subsequently been extended to other Co(L)3 complexes [331] as well as M(bipy)32+ and M(phen)32+ complexes [332]. In the former study, L represents the unsaturated ligands acetylacentonate (acac), oxalate (ox), malonate (mal), and dithioxalate (diox). In the latter study, M represents the metals iron, ruthenium, and osmium. For the cobalt complexes, BP86/TZP computed spectra were in acceptable agreement with their experimental counterparts. The unsaturated ligands cause more complicated spectra due to the presence of both a and % orbitals, and therefore the analysis was somewhat more challenging. The distortions of the geometry away from an idealized octahedral metal environment resulted not... 

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... 

Electrochemical oxidation of the tris(2,2-bipyridyl)ruthenium(II) complex to the corresponding ruthenium(lll) species in the presence of reducing agents such as oxalate anions gives rise to emission from the excited ruth-enium(II) complex, (Rubinstein and Bard, 1981). 

Further work on the use of the gcm-dimorpholine derivative of 2-thienylgly-oxal for the synthesis of gem-di(acylamino)- and other derivatives has appeared. In connection with work on surfactant complexes of ruthenium, thiophen-2-aldehydes were condensed with 4,4 -dimethyl-2,2 -bipyridyls. From the easily available 2,3,4-trichlorothiophen, the 5-formyl- and 5-acetyl-derivatives have been prepared, and from them a large number of derivatives. ... 

Ruthenium(ni) acetylacetonate [Ru(acac)3] [14284-93-6] M 398.4, m 240"(dec). Purify the complex by reciystallisation from benzene. [Wilkinson 7Aw Chem Soc 74 6146 1952, Beilstein 1IV 3677.] It catalyses the hydrogenation of dimethyloxalate to ethylene glycol under mild conditions [70bar H2 pressure at 100°] and the best ligand is MeC(CH2PPh2)3 with a trace of Zn (0.07% of oxalate) in MeOH with yields of >84% and with turnover numbers of 875 (turnover frequency/hour of 53.5) [Teunissen Elsevier 7 Chem Soc, Chem Commun 667 1997]. 

Ruthenium(IV), d, forms a more limited number of complexes involving mainly the halides (except the iodide), oxalate, and sulfate, together with r-acceptor nitrogen donor ligands. RUO2 is used as a catalyst and as an electrode material. 

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