16397-91-4Relevant articles and documents
Oxidation of NIII and N-I by an {Mn4O 6}4+ core in aqueous media: Proton-coupled electron transfer
Das, Suranjana,Mukhopadhyay, Subrata
, p. 4500 - 4507 (2007)
[Mn4(μ-O)6(bipy)6]4+ (1 4+; bipy = 2,2′-bipyridine) and its conjugate acid [Mn 4(μ-O)5(μ-OH)(bipy)6]5+ (1H5+) quantitatively oxidise NIII (HNO2 and NO2-) and N-1 (NH3OH+ and NH2OH) to NV (nitrate) and NI (nitrous oxide), respectively, in aqueous solution (pH 2.0-6.0), with 1H5+ reacting much faster than 14+. An uncommon feature of these reactions is the kinetic superiority of HNO2 over its conjugate base NO 2-. NH2OH, however, behaves normally - the conjugate acid NH3OH+ is less reactive than NH 2OH. These reactions show remarkable kinetic isotope effects: the observed rate of NIII oxidation increases in D2O media whereas the N-I oxidation rate slows down in media enriched with D2O. A search of the available data on the redox kinetics of multinuclear oxidants suggests that the title {Mn4O6} 4+ reduction by NIII, the rate of which is accelerated in D2O, is the only one established so far. A hydrogen atom transfer (HAT) mechanism (1e, 1H+; electroprotic) is proposed. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Redox chemistry of metal-catechol complexes in aprotic media. 2. 3,5-Di-tert-butylcatecholato complexes of manganese(IV) and manganese(III)
Jones, Stephen E.,Chin, Der-Hang,Sawyer, Donald T.
, p. 4257 - 4262 (1981)
When mixtures of manganese(II) and 3,5-di-tert-butyl-o-quinone (DTBQ) with mole ratios of 1:3 and 1:2 are reduced in aprotic solvents, stable MnIV(DTBC)32- and MnIII(DTBC)2- complexes are formed, respectively (DTBC represents the dianion of di-tert-butylcatechol). These complexes and their oxidation-reduction products have been characterized by cyclic voltammetry, controlled-potential electrolysis, optical spectroscopy, ESR spectroscopy, and magnetic susceptibility measurements in dimethylformamide, dimethyl sulfoxide, and acetonitrile solvents. On the basis of these results, a self-consistent redox mechanism is presented for the interconversion of the various species of manganese(II)-DTBQ systems with mole ratios of 1:1, 1:2, and 1:3. The catechol complexes of manganese(II), -(III), and -(IV) are versatile electron-transfer agents and should be effective redox catalysts and oxygen activators.
Malati, M. A.,Sear, A.
, p. 1874 - 1875 (1989)
Kinetics of the Permanganate-Iron(II) Reaction in Aqueous Acid Medium
Sutter, John R.,Park, Kee B.
, p. 770 - 772 (1984)
The kinetics of the permanganate-iron(II) redox reaction has been studied in aqueous perchloric acid at 20 deg C by using stopped-flow techniques.The disappearance of permanganate was followed at 525 nm, with use of excess iron, and consisted of two consecutive first-order decays.A mechanism consistent with the data is MnO4- + Fe2+ O3MnOFe+ (k1, k-1), O3MnFe+ -> Mn(VI) + Fe(III) (k2).The rate constants are k1 = 9.97E4 M-1 s-1, k-1 = 16.4 s-1, and k2 = 12.9 s-1.No dependence on H+ or salt was observed in either step.
The kinetics and mechanism of the decomposition reaction of the bis(oxalato)manganese(III) complex in an aqueous solution
Kimura,Ohota,Tsukahara
, p. 151 - 155 (1990)
The kinetics and mechanism of the decomposition of the bis(oxalato)manganase(III) complex ion ([Mn(ox)2]-) were studied in acid solution in the absence and in the presence of oxygen at temperatures from 10 to 35°C. The decomposition reaction of [Mn(ox)2]- in the absence of oxygen was described by the first-order rate law of -d[[Mn(ox)2]-]/dt=k(obsd)[[Mn(ox)2]-], where the observed rate constant, k(obsd), increased proportionally with the increasing hydrogen-ion concentrations, being expressed as k(obsd)=k[H+] in the [H+] range of 0.006-0.1 M. The enthalpy and entropy changes of activation (ΔH≠ and ΔS≠) were 73.4±2.0 kJ mol-1 and -8.6±0.2 J K-1 mol-1 respectively. The rate of the decomposition of [Mn(ox)2]- decreased greatly upon the addition of a radical scavenger for CO2-. such as [Co(NH3)6]3+, [CoCl(NH3)5]2+, or molecular oxygen. In the presence of oxygen, the rate deviated greatly from the first-order rate law. On the other hand, the addition of [Co(NH3)6]3+ or [CoCl(NH3)5]2+ in the absence of oxygen did not change the first-order rate law, but did decrease the rate of reaction up to 40% of that in the absence of the radical scavenger. The mechanisms for the decomposition reaction of [Mn(ox)2]- are discussed in the light of the results obtained.
