22337-23-1Relevant academic research and scientific papers
Solvation and Reactivity of Iron(II)-Diimine Complexes in Dimethyl Sulfoxide-Water Mixtures
Al-Alousy, Ahmad,Alshehri, Saad,Blandamer, Michael J.,Blundell, Nicholas J.,Burgess, John,et al.
, p. 1041 - 1048 (1993)
Kinetics of the base hydrolysis of several iron(II)-diimine complexes, including two with terdentate ligands and one with an encapsulating ligand, and of the peroxodisulfate oxidation of three ternary iron(II)-diimine-cyanide complexes, are reported for reaction in dimethyl sulfoxide (DMSO)-water mixtures at 298.15 K.Solubilities of simple and complex salts have been determined in these mixtures, both to extend the range of simple and complex ion-transfer chemical potentials and to provide the basis for initial-state/transition-state analyses of reactivity trends for several of the base hydrolysis and peroxodisulfate oxidations.Cases are identified where the destabilisation of hydroxide ions, OH(-)(aq), by added DMSO increases the rate of base hydrolysis.We also identify cases where compensation effects result in only a small change in rate constant for oxidation by peroxodisulfate where DMSO is added.
Radiolytic study of the reactions of hydroxyl radical with cobalt(III), iron(II), and ruthenium(II) complexes containing 2,2′-bipyridyl and cyano ligands
Maliyackel,Waltz,Lilie,Woods
, p. 340 - 348 (2008/10/08)
The reactions of hydroxyl radical with the complex ions [Co(bpy)3]3+, [Fe(bpy)3]2+, [Fe(bpy)2(CN)2], [Fe(bpy)(CN)4]2-, [Fe(CN)6]4-, [Fe(Me2bpy)3]2+, and [Ru(bpy)3]2+ and with bpy and Hbpy+, where bpy = 2,2′-bipyridine and Me2bpy = 4,4′-dimethyl-2,2′-bipyridine, have been investigated in N2O-saturated aqueous media. The results from time-resolved studies, carried out by using pulse radiolysis in conjunction with conductivity and near-UV-visible optical detection methods, show that the OH reactions occur with rate constants in the range (2-17) × 109 M-1 s-1. For the reactions of bpy and the tris(bipyridyl) complex ions, the absence of significant conductivity movements accompanying the initial optical changes demonstrates that the processes are ones involving OH addition to the systems. The products are reactive toward hexacyanoiron(III) and molecular oxygen, and the associated findings clearly implicate these species to be of a ligand-radical type; however, the evidence also indicates in several cases the occurrence of more than one initially observed product. The reaction of ferrocyanide involves electron transfer whereas for the mixed cyano-bipyridyl complexes of iron(II) both electron-transfer and OH-addition processes are encountered, and the predominant process for [Fe(bpy)(CN)4]2- proceeds by an inner-sphere electron-transfer mechanism. Determinations for some of the final products arising from the pulse and γ-ray radiolysis of the mixed cyano-bipyridyl complexes, [Co(bpy)3]3+, and [Fe(bpy)3]2+ have been undertaken in order to obtain insight into the overall sequence of events, and the natures of the mechanisms are discussed.
The Oxidation of Dithiocarbamate Anion by Substitution Inert Metal Complexes
Nichols, Peter J.,Grant, Michael W.
, p. 1085 - 1102 (2007/10/02)
The kinetics of oxidation of dithiocarbamate anions to thiuram disulfides in aqueous acetone by 3- and 11 other substitution inert metal complexes have been investigated.Outer-sphere electron transfer, resulting in the formation of dithiocarbamate thio radicals, is the rate determining step.A Marcus cross reaction treatment allows an estimate for the redox potential for the dithiocarbamate radical/anion couple.For diethyldithiocarbamate, Edeg(edtc./edtc-) = 425+/-33 mV ν.s.c.e. and the outer-sphere electron self-exchange rate constant is logkex = 7.0+/-0.3.A comparison with thiophenolate oxidation is also given.
Temperature Dependence of Quenching Rates and Efficiencies of Net Forward and Reverse Electron Transfer in the Quenching of Protonated Triplet Methylene Blue by Complexes of Iron(II)
Kamat, Prashant V.,Lichtin, Norman N.
, p. 351 - 353 (2007/10/02)
The temperature dependence of kq, the specific rate of quenching of protonated triplet methylene blue, 3MBH+, and of ket and kret, the specific rates of net forward and reverse electron transfer, respectively, have been measured by laser flash photolysis-kinetic spectrometry using 1.0-J, 694.3-nm flashes from a Q-swiched ruby laser.The sum of the efficiencies of net forward and reverse electron transfer, F1 and F2, respectively, in the quenching of 3MBH2+ by FeII(CN)4bpy2- in 30 vol percent CH3CN - 70 vol percent H2O has been found to be indistinguishable from unity at 291.0, 298.0, 305.5, 313.0, and 321.0 K.This result supports the prior conclusion that the only significant mechanism of this quenching reaction is reversible electron transfer.In contrast, for quenching of 3MBH2+ by FeII(H2O)62+ in water over the same temperature range, F1 + F2 *, ΔH*, and ΔS*, have been determined for these processes and their implications for mechanism are discussed.
