19052-44-9Relevant articles and documents
Electron Transfer. 134. Reduction of Bound Ruthenium(III) by Indium(I)
Chandra, Swapan K.,Gould, Edwin S.
, p. 3485 - 3487 (1997)
Aqueous solutions of the hypovalent state indium(I) react with oxidants of the type [(NH3)5RuIII(Lig)]3+, in which the sixth ligand, Lig , is devoid of groups allowing inner-sphere bridging. Reaction stoichiometry conforms to the relationship InI + 2RuIII → InIII + 2RuII. Kinetic profiles are consistent with a two-step sequence initiated by the formation of metastable InII, which then reacts rapidly with RuIII. Rate constants for the rate-determining steps in this series (kRu,In values) are proportional to those for reductions of the corresponding (NH3)5CoIII oxidants with V2+(aq), Cr2+(aq), Eu2+(aq), and U3+(aq), even though, for each comparison, no metal center is common to the two series chosen. This implies that changes in ΔG?redox arising from substitution of one N-donor ligand for another are nearly independent of the metal centers involved in the net transfer. The rate for the reduction of (NH3)6Ru3+, considered in the framework of the Marcus model, leads to an estimated rate constant of 10-9 M-1 s-1 for electron self-exchange in the system In2+/+. This value lies well below the range characteristic of the most usual aqua-substituted cationic couples, suggesting a more severe H2O-metal bond contraction in going from the uni- to the dipositive cation.
Hydration of the carbonyl groups in 1,10-phenanthroline-5,6-dione induced by binding protons or metal cations to the pyridine nitrogen sites
Lei, Yabin,Anson, Fred C.
, p. 9849 - 9854 (1995)
In acidic solutions, the chemical or slow electrochemical reduction of the organic ligand - oxidant 1,10-phenanthroline-5,6-dione consumes two electrons and two protons. However, when the electrochemical reduction is examined on shorter time scales using cyclic or rotating disk voltammetry, fewer than two electrons are consumed in the reduction. The magnitude of the electron deficit depends upon pH and the deficit is eliminated at pH values where the pyridine nitrogen sites on the molecule are not protonated. Complexation of metal cations, e.g., Os(II) or Ni(II), to the 1,10-phenanthroline portion of the molecule also produces an electron deficit in electrochemical reductions of the dione. A proton- or metal ion-induced addition of H2O to the quinone carbonyl groups is shown to be responsible for the observed behavior. Rate and equilibrium constants for the hydration - dehydration equilibrium were evaluated by fitting experimental and calculated parameters in a digital simulation. The possible consequences of the results to studies in which the dione is used to oxidize amines and other organic reductants are pointed out.
Studies of electron transfer through self-assembled monolayers using impedance spectroscopy
Protsailo, Lesia V.,Fawcett, W. Ronald
, p. 3497 - 3505 (2000)
An investigation of the kinetics of reduction of Ru(NH3)3+6 has been carried out at single crystal electrodes modified by alkanethiols of varying chain lengths. Careful study of the impedance of the modified electrode system in the absence of the reaction has shown that there is a highly resistive path in parallel to the capacitance due to the self-assembled monolayer. Analysis of the kinetic data and extrapolation of the Tafel plots show that the standard rate constant for the Ru(NH3)3+/2+6 system is 1.7 cm s-1 at an unmodified Au surface with a transfer coefficient close to 0.5. These parameters are expected for a very fast simple heterogeneous electron transfer reaction. The present results are compared with whose reported previously in the literature.
Lomis, Thomas J.,Martin, Jennifer,McCloskey, Barbara,Zhang, Songsheng,Siddiqui, Shirin,et al.
, p. 99 - 116 (1989)
Study of nitrosation of hexaammineruthenium(II): Crystal structure of trans-[RuNO(NH3)4Cl]Cl2
Il'in,Emel'Yanov,Baidina,Alferova,Korol'Kov
, p. 62 - 70 (2008/10/09)
The nitrosation of [Ru(NH3)6]2+ in hydrochloric acid and alkaline ammonia media has been studied; the patterns of interconversion of ruthenium complexes in reaction solutions have been proposed. In both cases, nitrogen(II) oxide acts as the nitrosation agent. The procedure for the synthesis of [Ru(NO)(NH3)5]Cl3 ? H2O (yield 75-80%), the main nitrosation product of [Ru(NH 3)6]2+, has been optimized. Thermolysis of [Ru(NO)(NH3)5]Cl3 ? H2O in a helium atmosphere has been studied; the intermediates have been identified. One of these products is polyamidodichloronitrosoruthenium(II) whose subsequent decomposition gives an equimolar mixture of ruthenium metal and dioxide. The structure of trans-[RuNO(NH3)4Cl]Cl2, formed in the second stage of thermolysis and as a by-product in the nitrosation of [Ru(NH3)6]Cl2, has been determined by X-ray diffraction. Nauka/Interperiodica 2007.
