Iron electronic properties

Interaction of iron(II) chloride with the lithium salt of R4B2NJ (R = Me, Et) gives sandwiches 61 (R = Me, Et) (67ZAAC1, 96MI4), resembling in electronic properties those of ferrocene (99ICA(288)17). The n- rf-) complex stems from the further complex-formation of 61 (R = Me, Et) with mercury(II) salts via the unsubstituted nitrogen atom. 

During the past 20 years, considerable progress has been made toward understanding the electronic properties of iron-sulfur centers thanks to the fruitful interplay between various approaches such as synthetic analog chemistry, theoretical modeling, and of course spectroscopic studies. Modeling studies have been strongly stimulated by the permanent supply of complementary data provided especially by EPR, Mossbauer, ENDOR, MCD, and NMR experiments. However,... 

Catalysis has not been established with these DNICs until now nevertheless, these complexes are interesting low-valent iron complexes that lit into the class of ferrates from which one can learn a lot about reactivity, stability, and electronic properties. 

The reactivity of iron(II) cations [FeX]+, where X = H, Me, C3H5, NH2, OH, F, Cl, Br, and I, have been examined by reactions with acetone (177). The C-C bond activation was the major process for the iron halide cations. The [FeF]+ ion promoted C-H bond activation as well as C-C bond activation and C-H bond activation was also promoted by the other [FeX]+ ions. The relative reactivities of the [FeX]+ ions toward acetone have been correlated with the thermochemical and electronic properties of the substituents X. 

In particular, Fitzgerald s new route for the preparation of alkyl substituted dinitriles was used to prepare ethyl appended porphyrazines that were centrally metalated with iron and rhodium (Schemes 4 and 5). The main focus of Fitzgerald s work was on the magnetic and electronic properties of the metalated octaethylpor-... 

Contamination of silicon wafers by heavy metals is a major cause of low yields in the manufacture of electronic devices. Concentrations in the order of 1011 cm-3 [Ha2] are sufficient to affect the device performance, because impurity atoms constitute recombination centers for minority carriers and thereby reduce their lifetime [Scl7]. In addition, precipitates caused by contaminants may affect gate oxide quality. Note that a contamination of 1011 cnT3 corresponds to a pinhead of iron (1 mm3) dissolved in a swimming pool of silicon (850 m3). Such minute contamination levels are far below the detection limit of the standard analytical techniques used in chemistry. The best way to detect such traces of contaminants is to measure the induced change in electronic properties itself, such as the oxide defect density or the minority carrier lifetime, respectively diffusion length. 

Previous studies in conventional reactor setups at Philip Morris USA have demonstrated the significant effectiveness of nanoparticle iron oxide on the oxidation of carbon monoxide when compared to the conventional, micron-sized iron oxide, " as well as its effect on the combustion and pyrolysis of biomass and biomass model compounds.These effects are derived from a higher reactivity of nanoparticles that are attributed to a higher BET surface area as well as the coordination of unsaturated sites on the surfaces. The chemical and electronic properties of nanoparticle iron oxide could also contribute to its higher reactivity. In this work, we present the possibility of using nanoparticle iron oxide as a catalyst for the decomposition of phenolic compounds. 

In 2002, Kiindig et al. [23, 24] developed catalytic DCR between diaryl nitrones and a,(3-unsaturated aldehydes in the presence of Binop-F iron and ruthenium complexes as chiral Lewis-acid catalysts (Scheme 6). The corresponding cycloadducts were obtained in good yields with complete endo selectivity and up to 94% ee. The isoxazolidine products were obtained as a mixture of regioi-somers in molar ratios varying from 96 4 to 15 85. Experimental and computational data show that the regioselectivity correlates directly with the electronic properties of the nitrone. 

By use of appropriate sterically demanding carboxylates it is possible to generate four-, five-, and six-coordinated mononuclear iron(III) complexes. Ligand flexibility and electronic properties provide fine-tuning. These complexes are subunits of the models for di-iron(II) sites in metallo-proteins mentioned in the following section. 

We describe some recent work in which we have studied how the magnetic and electronic properties of heme iron vary when it is occluded by a polymer ligand. 

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