Iron ethoxide

In the first study of hydrolysis of Fe(OEt)3 carried out by Thiessen et al. [1577], the precipitate of cubic crystals Fe203 4H20 was obtained after refluxing of diluted alcoholic solution of iron ethoxide for a few hours. Hydrolysis of iron ethoxide by excess of water results in amorphous precipitate, which on thermal treatment at first gives y-Fe203 and then a-Fe203 (in contrast to the precipitates of (X-FeOOH, which precipitate from aqueous solutions) [1776]. 

An X-ray single crystal study of the repeatedly reported crystals of iron ethoxide has shown that this compound (as well as isomorphous to it crystalline aluminium ethoxide ) is actually an oxocomplex- [Fe502(0Et)11]2,3Et0H (Fig. 6.4) [1365, 1785], The fragmentation products of such big molecules... 

The thermal instability of iron ethoxide is related to the degree of association of the ethoxide molecule in the solid state. It is known that the corresponding aluminum compound is an infusible solid due to the extensive polymerization of Al(OEt)3 through alkoxy bridging. The bridging tendency in alkoxide species is governed by the propensity of the metal centers to increase their coordination state,which can be tuned either by increasing the steric bulk... 

Hydrolysis of metal alkoxides. It is used in the synthesis of garnets. A typical procedure to prepared yttrium garnet (YIG) nanoparticles can be mixing iron ethoxide andytfrium butoxide in a 5 3 molar ratio, and then hydrolyzing with an excess of water. It results in amorphous YIG nanoparticles that yield crystalline YIG after heating at 650-700"C. 

Chlorins (2) are undoubtedly the most important dihydroporphyrins, since the chlorin chromophore is found in chlorophylls and some bacteriochlorophylls and, as the magnesium complex, is the catalyst in photosynthesis. The method of choice for formation of trans-chlorins involves reduction of iron porphyrins with sodium in boiling isopentyl alcohol (57JCS3461), but methods involving photochemical reduction of tin(IV) porphyrins, isomerization of phlorins, reduction of metalloporphyrins with sodium anthracenide followed by protonolysis, heating with sodium ethoxide, and photoreductions of zinc(II) porphyrins in the presence of ascorbic acid have also been employed. The best method for formation of c/s-chlorins (note that all natural chlorophylls possess the trans arrangement) appears to... 

The preparation of iron (IH) ethoxide was first reported in 1929 simultaneously by Meerwein [1101] and Thiessen [1577]. The aim of the first of these studies was to obtain anew reagent for reduction of carbonyl compounds, and the aim of the second was to obtain a precursor for the preparation of iron hydroxydes and their colloid solutions. The derivatives of the Fe(OAlk)3 series were obtained then by Bradley et al. in 1958 [228], and their magnetic properties and UV-vis spectra were studied in detail in the 1960s by the group of... 

Polymer-inorganic composites with 25 mol% Fe on a cation basis were prepared using a sol of GLYMO and Al(OsBu)3 mixed with a solution of the structure-directing PI-/7-PEO diblock copolymer (see Table 21.1, F and G) and iron(m) ethoxide powder. For the production of a crystalline magnetic iron-oxide phase, the as-made composites were calcined at elevated temperatures in air. SAXS and TEM were performed to determine the structure and order in the materials. Figure 21.17a shows SAXS data for the pure diblock copolymer (1), the as-made polymer-inorganic composite (2), and material calcined to 750°C (3). 

A common feature of the complexes [Nac Fe6(L13)6 ]Cl (36) and [Csc- Fe8(L13)g ]Cl (37, Sect. 6) is that one p -OT ethoxide donor of the triethano-lateamine ligands [N(CH2CH20)iCH2CH20 ] of (L13) 3 does not participate in the formation of the ferric wheels. They function solely as ligands for the coordi-native saturation of the iron centers. Therefore, any monoanionic donor, such as a chloride ion, could also be a candidate for this function. As expected, reaction of /V-alkyldiethanolamines H2L14 17 (38) with calcium hydride and iron(III) chloride yielded the neutral iron coronands [Fe6Cl6(L14 17)6] (39) with unoccupied centers (Scheme 14) [114-116],... 

Zeise had formulated this salt as a compound of ethylene, namely KCl-PtCl2 -H20. Liebig disagreed, considering it rather to contain an ethoxide group (165, 252). Since the compound usually formed as a monohydrate and since the water of hydration could be removed fairly easily, analytical results could be used to justify either viewpoint. Zeise s view prevailed, and was verified by later work. Zeise s last paper (295), by an ironical juxtaposition, appeared right next to Bunsen s first paper on cacodyl (39) ... 

In 1989, a novel, electrochemical process developed jointly with the Max-Planck-Institut fiir Kohlenforschung at Miilheim/Ruhr (Germany) went into operation. The process is based on earlier work of Lehmkuhl and Eisenbach [7] and follows eq. (4). An iron anode is first used to form the reactive intermediate iron(II) ethoxide Fe(OC2H5)2 as an ethanol adduct. (The ethanol serves as solvent and reactant.) Due to the Lewis-basic ethoxy ligands, (monomeric) cyclopentadiene is deprotonated under mild conditions to form high-purity ferrocene directly. This process has the advantage that the iron(II) precursor compound is not to be synthesized but is rather formed in situ without further purification. Typical conditions of electrolysis are 120 A at 13 V at 0.8 m X 10 mm iron anodes. A pilot plant converts 2.5 kg of iron per day. The working temperature is 60 °C. 

NaBr (0.15 m) is used as the conducting salt. The iron(II) ethoxide must be separated from the electrolyte. The work-up by sublimation follows. A flow scheme of the technical process is shown in Figure 1 [7d]. 

Except for HDPM, all the additives decrease the stoichiometric ratio. Oxidation in the presence of CsHuN and HDPM leads to precipitation of bis (dipivaloylmethanato) iron (III) ethoxide (38), and a small amount of acetaldehyde (0.2-0.5y) was also detected. Tests for peroxides were negative. Consequently, we believe that the chelating agents themselves (HAA, AA", and DPM") are oxidized by some transient involved in the reaction. 

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