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Abstract: Catalytic properties of superparamagnetic γ-ferric oxide nanoclusters, which are uniform in terms of size and magnetic properties were studied. The catalysts were supported on the activated silica gel matrix (AGM) prepared from the KSK-2 silica gel of globular structure and on the activated silica matrix (ASM) prepared from layered natural vermiculite. The clusters are active in some reactions of chloroolefin conversions: isomerization of dichlorobutenes and alkylation of benzene with allyl chloride. Their activity in these reactions is many times higher that of usual supported catalysts based on α-ferric oxide. Analysis of the Mssbauer spectra of the 2.5 wt.% Fe/AGM and 2.5 wt.%Fe/ASM samples before and after the reaction at T = 3–300 K shows that during the reaction some FeIII ions arranged in ∼2–3-nm γ-Fe2O3 nanoclusters magnetically ordered at 6 K are reduced to form a high-spin FeII complex in the paramagnetic state. According to the macroscopic magnetization data (SQUID) of the initial clusters, curves with hysteresis are observed at 2 K in the plots of forward and backward magnetization, while the 2.5 wt.%Fe/ASM catalyst after the reaction at T = 2 K demonstrates a linear field dependence of the magnetization passing through the coordinate origin. Analysis of the Mssbauer spectra and magnetic properties suggests that during the catalytic reaction the FeIII ions in the γ-Fe2O3 nanoclusters interact with chloroolefin with the allylic structure to be partially reduced to the FeII ions that are bound in a complex containing chloride ions and OII ion(s) of the silicate matrix as ligands. This is a reason, probably, for the high catalytic activity of γ-Fe2O3 nanoparticles.

Iodine doping of polyferrocenylenesilylene(germylene) thin films, [(η⁵-R2EC5H4)Fe(η⁵-C5H4)]n, E = Si, Ge, transforms them from insulators to conducting materials. The process was monitored by IR, Raman, and UV/vis spectroscopy and occurs via irreversible electron transfer to form of ferrocenium ion centers with [I3]^- counteranions. The latter further react with I2 to form [I5]^- polyiodide anions in a reversible manner. A Mössbauer spectrum of the doped polymer suggests that alternate Fe centers have been oxidized. Treatment of the doped films with NH3 results in a typical compensation process.

Conclusions 1.The modifying H2 and CO treatment of the Fe-Cr and Fe-Cr-Cu conversion and desulfurization catalysts is accompanied by the formation of a nonstoichiometric magnetite structure which is catalytically active in the synthesis of organic compounds from CO and H2O. The stability of the phase to oxidation in air is apparently due to the stabilizing effect of the incorporated carbon atoms. The oxides of chromium and copper perform primarily the function of the structure-forming promoters.2.During the modifying action of H2 and CO on the finely dispersed iron oxide phases localized in the pores of the substrates (kieselguhr, kaolin), the iron ions aggregate and form large blocks of a substituted ferrite phase stable to oxidation. The catalytic activity of ferrite in the synthesis reactions is greater than the activity of the above-mentioned catalysts.

This paper reports Rayleigh scattering experiments on metmyoglobin crystals and freeze dried myoglobin which was exposed to air with different partial pressure of water vapor. While dry myoglobin shows no fluctuations between conformational substates such “breathing modes” are rearly seen in water covered myoglobin. Larger amounts of water increase the average mean square displacements. In crystals the dynamic behaviour is hindered by the crystal packing. The results are analysed by a theory describing the motion within the molecule by a Langevin equation with restoring forces corresponding to a square well potential.

Thermal decomposition of the [FeCp(SPh)CO]2 complex and its reaction with the surface of activated silica gel were investigated by Mössbauer spectroscopy. A small amount of a complex with properties similar to ferrocene is separated in the first stage of thermal decomposition (120–130°C). The starting carbonyl complex totally disappears in the second stage (165–210°C), and two compounds are present among the products: a derivative of ferrocene and the final product, an x-ray amorphous, iron-containing structure with an ionic-covalent type of chemical bond (CB) and a 25 and 5 wt. % concentration of oxygen and sulfur, respectively. The Mössbauer parameters of this product and the compound formed in the reaction of [FeCp(SPh)CO]2 with the surface of activated silica gel at 4.2–300 K are identical. The analysis of the data suggested that both structures are highly disperse clusters of iron oxide with the structure of an inverted spinel with superparamagnetic properties.

Abstract: The interaction of Fe(CO)5 with the acidically etched mica was studied Fe(CO)5 reacts with disrupted bonds defects of the structure with incorporation of iron as Fe2+ and Fe3+ ions in oxide matrix. The flaky structure of the original mica is preserved.

Abstract: The bimetallic catalysts obtained by the deposition of a Fe−Co binuclear cluster on the dehydroxylated γ-Al2O3 are studied and compared to some other relative systems. These bimetallic catalysts are found to be active and selective in olefin synthesis. This is connected with the formation of Fe−Co contact which is detectable by Mssbauer spectroscopy.

The sintering of finely dispersed, supported iron oxide particles in H2S has been studied by Mössbauer spectroscopy, X-ray diffraction and magnetization measurements. Particles treated in air at 873 K, are shown to sinter at much lower temperatures.