Magnetite in mixture with metallic iron in indoor dust samples was examined using several magnetic analyses, thermomagnetic curves of the magnetic susceptibility and the induced magnetization vs. temperature, hysteresis loops, and first-order reversal curves. The study of the magnetic properties was supplemented by the analysis of chemical elements and electron microscopic observation. The meta...

Friedreich's ataxia is associated with a deficiency in frataxin, a conserved mitochondrial protein of unknown function. Here, we investigate the iron binding and oxidation chemistry of Escherichia coli frataxin (CyaY), a homologue of human frataxin, with the aim of better understanding the functional properties of this protein. Anaerobic isothermal titration calorimetry (ITC) demonstrates that ...

Utilization of dioxygen as the terminal oxidant at ambient temperature is always a challenge in redox chemistry, because it is hard to oxidize a stable redox metal ion like iron(III) to its high oxidation state to initialize the catalytic cycle. Inspired by the dioxygenation and co-oxidase activity of lipoxygenases, herein, we introduce an alternative protocol to activate the sluggish iron(III)...

Synthetic modeling studies of non-heme iron proteins continue to contribute to our understanding of the mechanism of these proteins. Recently, mononuclear Fe(IV)=O complexes have been prepared and characterized to model the same species that are proposed to be the reactive intermediates in reactions involving mononuclear non-heme iron proteins. Generation of such species for the oxidation of or...

The synthesis of two molecular iron complexes, a dinuclear iron(iii,iii) complex and a nonanuclear iron complex, based on the dinucleating ligand 2,2'-(2-hydroxy-5-methyl-1,3-phenylene)bis(1H-benzo[d]imidazole-4-carboxylic acid) is described. The two iron complexes were found to drive the oxidation of water by the one-electron oxidant [Ru(bpy)3](3+).

The corrosion of zero-valent iron (Fe0(s)) by oxygen (O2) can lead to the oxidation of organic compounds. To gain insight into the reaction mechanism and to assess the nature of the oxidant, the oxidation of methanol, ethanol, 2-propanol, and benzoic acid by the reaction of nanoparticulate zero-valent iron (nZVI) or ferrous iron (Fe[II]) with O2 in the absence of ligands was studied. At pH valu...

Acidophilic iron-oxidizing bacteria were enriched from mine water samples with ferrous sulfate as the substrate at incubation temperatures in the range of 4 to 46 degrees C. After several subcultures at each test temperature except 46 degrees C, which was prohibitive to growth, the rates of iron oxidation were determined in batch cultures. The results yielded linear rates in a semilogarithmic s...

Iron (III) phthalocyanine complexes were employed for the first time as a mild and efficient Lewis acid catalyst in the selective oxidation of cyclohexene to cyclohexane-1,2-diol. It was found that the catalyst FePcOTf shown excellent conversion and moderate selectivity relative to other iron (III) phthalocyanine complexes. The optimum conditions of the oxidation reaction catalyzed by FePcOTf/H...

Oxidation of ferritic/martensitic steel P92 was investigated in pure oxygen and in pure steam at 600-800 °C by thermogravimetric analysis (TGA), optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results showed that the oxidation of P92 was significantly enhanced and multilayer scale with an outer iron oxides layer formed in pure steam. At 700 °C, the ...

conclusions changes of ph could remarkably affect the efficiency and oxidation rate of mtbe. in particular, the amount of kap in terms of oxidation declines substantially by moving away from the optimum ph range. in this study, ph 3.5 was considered as the optimal ph in h2o2/nzvi/ultrasonic oxidation process, with the elimination of about 89.56% of the high mtbe concentration. in general, we ca...