22541-63-5Relevant academic research and scientific papers
Recovery of radioactive cobalt from aqueous EDTA solutions using concentrated ozone
Seliverstov,Lagunova,Ershov,Gelis,Basiev
, p. 326 - 328 (2009)
Oxidative decomposition of EDTA in aqueous solution under the action of ozone was studied. Conditions providing complete decomposition of EDTA and precipitation of radioactive cobalt in the form of hydroxide were found.
Kinetics of manganese(III) acetate in acetic acid: Generation of Mn(III) with Co(III), Ce(IV), and dibromide radicals; reactions of Mn(III) with Mn(II), Co(II), hydrogen bromide, and alkali bromides
Jiao, Xiang-Dong,Espenson, James H.
, p. 1549 - 1554 (2008/10/08)
The reaction of cobalt(III) acetate with excess manganese(II) acetate in acetic acid occurs in two stages, since the two forms Co(IIIc) and Co(IIIs) are not rapidly equilibrated and thus react independently. The rate constants at 24.5 °C are k(c) = 37.1 ± 0.6 L mol-1 s-1 and k(s) = 6.8 ± 0.2 L mol-1 s-1 at 24.5 °C in glacial acetic acid. The Mn(III) produced forms a dinuclear complex with the excess of Mn(II). This was studied independently and is characterized by the rate constant (3.43 ± 0.01) x 102 L mol-1 s-1 at 24.5 °C. A similar interaction between Mn(III) and Co(II) is substantially slower, with k = (3.73 ± 0.05) x 10-1 L mol-1 s-1 at 24.5 °C. Mn(II) is also oxidized by Ce(IV), according to the rate law -d[Ce(IV)]/dt = k[Mn(II)]2[Ce(IV)], where k = (6.0 ± 0.2) x 104 L2 mol-2 s-1. The reaction between Mn(II) and HBr2·, believed to be involved in the mechanism by which Mn(III) oxidizes HBr, was studied by laser photolysis; the rate constant is (1.48 ± 0.04) x 108 L mol-1 s-1 at ~23 °C in HOAc. Oxidation of Co(II) by HBr2· has the rate constant (3.0 ± 0.1) x 107 L mol-1 s-1. The oxidation of HBr by Mn(III) is second order with respect to [HBr]; k = (4.10 ± 0.08) x 105 L2 mol-2 s-1 at 4.5 °C in 10% aqueous HOAc. Similar reactions with alkali metal bromides were studied; their rate constants are 17-23 times smaller. This noncomplementary reaction is believed to follow that rate law so that HBr2· and not Br· (higher in Gibbs energy by 0.3 V) can serve as the intermediate. The analysis of the reaction steps then requires that the oxidation of HBr2· to Br2 by Mn(III) be diffusion controlled, which is consistent with the driving force and seemingly minor reorganization.
Kinetics of Silver(II) Oxidation of Metal Cations
Arselli, Patrizia,Baiocchi, Claudio,Mentasti, Edoardo,Coe, John S.
, p. 475 - 478 (2007/10/02)
The oxidation of Fe2+, Mn2+, Co2+, Ce3+, and VO2+ by silver(II) has been investigated with a stopped-flow technique.The reactions of Mn2+ and Ce3+ occur through two competitive paths involving Ag2+ and AgOH+.For the other cations a single pathway with Ag2+ as oxidant has been observed.An inner-sphere interaction mechanism is proposed and discussed with reference to the electron configuration of the reductant and to the behaviour predicted by the Marcus cross relation.
Oxidation by aqueous fluoroxysulfate: Catalysis by silver(I)
Thompson, Richard C.,Appelman, Evan H.
, p. 2114 - 2118 (2008/10/08)
The oxidations of the ions Cr3+, Co2+, and VO2+ by the fluoroxysulfate ion, SO4F-, in aqueous solution are catalyzed by Ag+. The rate-determining step for all three catalyzed reactions is the bimolecular oxidation of Ag+ by SO4F-, which has a rate constant of (1.3 ± 0.2) × 103 M-1 s-1 at 17°C. Activation parameters for this reaction are ΔH≠ = 6.1 ± 0.5 kcal/mol and ΔS = -23 ± 2 cal/(mol deg). In the absence of Ag+, Co2+ and VO2+ react very slowly with SO4F-, while Cr3+ does not react at all. Despite its high thermodynamic oxidizing power, the fluoroxysulfate ion acts as a very selective oxidant.
Kinetics of Oxidation of Cobalt(II) by Iron(III) in Presence of 2,2'-Bipyridyl
Subbaiah, K. V.,Srinivas, K.,Subba Rao, P. V.
, p. 399 - 401 (2007/10/02)
The reaction between iron(III) and cobalt(II) in the presence of 2,2'-bipyridyl has been investigated spectrophotometrically.The rate-law has been found to be: .The added anions accelerate the reaction in the order: Cl(-) > Br(-) > ClO4(-).The activation energy and entropy of activation have been found to be 8.0 +/- 0.5 kcal mol-1 and -13 +/- 1.0 cal deg-1 mol-1, respectively.An outer-sphere electron-transfer mechanism has been proposed.
