Iron catalysts acetylacetonate

Chemical Treatment of Paper. Test samples were treated with aqueous copper(II) or iron(II) sulfate solutions or with nonaqueous copper(II) or iron(III) acetylacetonate solutions. All chemical treatments were designed to obtain extensive and uniform penetration into the paper structure. To facilitate contact between paper and solution and to provide physical support, test samples were interleaved with fibrous sheets of nonwoven polyester. Sorption of metal species from aqueous media was achieved by immersion of paper samples into the solution of choice for 16-18 h. The metal-catalyst content of paper was varied by adjusting the solution concentration. The concentration ol the aqueous metal salt solutions was varied from 10 3 to 10 1 M. One liter of solution was used for every 25 sheets of paper. At the end of the treatment period, paper samples treated in aqueous media were washed with water. 

Rates of degradation observed in the presence of ionic iron and copper systems have been compared with those obtained for the respective acetylacetonate chelate systems in Tables X and XI. Lower relative lifetime and relative stability values are observed for the copper(II) acetylacetonate catalyzed system than those obtained in the presence of higher concentrations of the ionic copper species. A similar increase in the catalytic efficiency of copper upon coordination has been reported by Ericsson et al. (10). However, iron(III) acetylacetonate shows no catalytic effect at all. This observation of contrary effects on the stability of paper with the same chelates of two highly active transition metal catalysts is most interesting. Unlike the relatively stable octahedral iron(III) acetylacetonate molecule, the tetrahedral, tetracoordinate copper(II) chelate could accept two more ligands if it were to assume an... 

Iron(lll) acetylacetonate is a curing catalyst for polymethane binders with combustion-modifying abilities for - AP containing - Composite Propellants. 

Mixtures of homogeneous rhodium and iron catalysts were tested in the hydroformylation of 1-hexene by Trzeciak and Zidtkowski [146]. In the absence of a rhodium complex, Fe(CO)5 did not show any catalytic activity at 80 °C and 10 atm of syngas pressure. Addition of Rh(acac)(CO)2 (acac = acetylacetonate) led to the formation of 2-hexene and eventually 3-hexene, but no aldehyde was formed. Hydroformylation commenced only in the presence of Rh(acac)(CO)(PPh3). The bimetallic catalyst benefited from the presence of additional PPhg. At a ratio of P/Rh = 3, a rate acceleration of 2 times was observed, and eventually an 83% yield of aldehyde was obtained. No change in the Ub ratio was observed as a result of these modifications. 

In order to provide the homogeneous catalyst deposition, silicas were treated with volatile cobalt(II), nickel(II), and iron(II) acetylacetonates at the moderate temperatures. At these conditions acetylacetonates of metals are chemisorbed on the silica surface due to reaction with surface silanol groups with eliminating one of ligands. 

Recently, the already-known polymers of (5)-3-methyl-pentyne and (5 )-4-methyl-l-hexyne [27, 28] as well as of (5)-5-methyl-l-heptyne, (iS)-6-methyl-l-octyne and (S )-3,4-dimethylpentyne (Xlla—e) have been prepared in the presence of iron tris(acetylacetonate)-aluminum triisobutyl catalyst [29]. 

The oxidation reaction between butadiene and oxygen and water in the presence of CO2 or SO2 produces 1,4-butenediol. The catalysts consist of iron acetylacetonate and LiOH (99). The same reaction was also observed at 90°C with Group (VIII) transition metals such as Pd in the presence of I2 or iodides (100). The butenediol can then be hydrogenated to butanediol [110-63-4]. In the presence of copper compounds and at pH 2, hydrogenation leads to furan (101). 

The acetylacetonates are stable in air and readily soluble in organic solvents. From this standpoint, they have the advantage over the alkyls and other alkoxides, which, with the exception of the iron alkoxides, are not as easily soluble. They can be readily synthesized in the laboratory. Many are used extensively as catalysts and are readily available. They are also used in CVD in the deposition of metals such as iridium, scandium and rhenium and of compounds, such as the yttrium-barium-copper oxide complexes, used as superconductors. 1 1 PI Commercially available acetyl-acetonates are shown in Table 4.2. 

Ziegler-type catalysts obtained from an organic acid salt or acetylacetone salt of nickel, cobalt, iron, or chromium which reacts with a reducing agent such as an organic aluminum compound. 

Among group 8 transition metal catalysts, iron-based Ziegler-type catalysts such as Fe(acac)3-Et3Al(l 3) (acac = acetylacetonate) have been well known from the early stage of the catalyst investigation, which are readily prepared in situ to polymerize sterically unhindered terminal acetylenes such as -alkyl-, r f-alkyl-, and phenylacetylenes. The formed poly(phenylacetylene) has red color and r-cisoidal structure, and is insoluble and crystalline. 

Twenty-five years later, a dramatic improvement was reported by Fiandanese, Marchese and coworkers ° . They discovered that excellent yields of ketone were obtained when diethyl ether is replaced by THF. Moreover, iron acetylacetonate is used as a catalyst instead of iron(III) chloride because it is not hygroscopic and easier to handle. The scope of the procedure is very large and the reaction occurs highly chemoselectively under mild conditions (0 °C). It should be noted that excellent yields are obtained from stoichiometric amounts of Grignard reagents (Table 3). 

The first report on the coordination polymerisation of epoxide, leading to a stereoregular (isotactic) polymer, concerned the polymerisation of propylene oxide in the presence of a ferric chloride-propylene oxide catalyst the respective patent appeared in 1955 [13]. In this catalyst, which is referred to as the Pruitt Baggett adduct of the general formula Cl(C3H60)vFe(Cl)(0C3H6),CI, two substituents of the alcoholate type formed by the addition of propylene oxide to Fe Cl bonds and one chlorine atom at the iron atom are present [14]. A few years later, various types of catalyst effective for stereoselective polymerisation of propylene oxide were found and developed aluminium isopropoxide-zinc chloride [15], dialkylzinc-water [16], dialkylzinc alcohol [16], trialkylalumi-nium water [17] and trialkylaluminium-water acetylacetone [18] and trialkyla-luminium lanthanide triacetylacetonate H20 [19]. Other important catalysts for the stereoselective polymerisation of propylene oxide, such as bimetallic /1-oxoalkoxides of the [(R0)2A10]2Zn type, were obtained by condensation of zinc acetate with aluminium isopropoxide in a 1 2 molar ratio of reactants [20-22]. 

Because oxidations with oxygen are free-radical reactions, free radicals should be good initiators. Indeed, in the presence of hydrogen bromide at high enough temperatures, lower molecular weight alkanes are oxidized to alcohols, ketones, or acids [5 7]. Much more practical are oxidations catalyzed by transition metals, such as platinum [5, 6, 55, 56], or, more often, metal oxides and salts, especially salts soluble in organic solvents (acetates, acetylacetonates, etc.). The favored catalysts are vanadium pent-oxide [3] and chlorides or acetates of copper [2, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66], iron [67], cobalt [68, 69], palladium [60, 70], rhodium [10], iridium [10], and platinum [5, 6, 56, 57]. 

Iron(III) and cobalt(II) complexes of these polymeric ligands were found to be effective catalysts for the oxidation of cyclohexane and ethylbenzene with H2Oz or 02 in biphasic media. The authors proposed that the oxidation takes place inside polymer micelles which can be regarded as microreactors. However, no recycle experiments were performed to ascertain the stability of these catalysts. A priori one would expect acetylacetonate ligands to undergo facile degradation under oxidizing conditions. 

Oxalic acid Oxalic acid dihydrate catalyst, nylon Manganese acetate (ous) catalyst, olefin isomerization Iron pentacarbonyl catalyst, olefin polymerization Acetylacetone Ammonium lactate Chromium carbonyl Chromium chloride (ic) Ethylacetoacetate... 

The acetylacetonate complexes of cobalt(II) and manganese(111) are efficient catalysts for the thermally intiated oxidation of tetralin, but do not influence the photoinitiated process. The reverse situation is observed for the iron(III) and cobalt(III) complexes [70a]. The thermal oxidation can be influenced by the addition of free-radical initiators like t-butyl hydroperoxide or 2,2 -azobisisobutyronitrile [70b]. 

In 2010 [95], Ozaki and collaborators mixed a furan resin with iron, cobalt, or nickel acetylacetonates and carbonized the mixture in N2 at 600 to 1,000 °C. The resulting material was ball milled and then acid washed to remove excess metal. The best catalyst was obtained with the Co complex carbonized at 800 °C. Its Fonset in 0.5 M H2SO4 was 0.62 V vs. RHE. The catalyst had a specific surface area of 211 m /g and its N/C ratio was 0.035. Its ORR activity was explained by the formation of carbon nanoshells, but also by N doping of the catalyst carbonaceous material. 

Hiatt, Irwin and Gould [328] studied the decomposition of terU mXyX hydroperoxide in the presence of cobaltous and cobaltic stearates (St), octanoates (Oct) and acetylacetonates as well as iron phthalocyanine. They found that the acetylacetonates of Ni(II), Co(III) and Fe(III) were inert toward terUh xiyX hydroperoxide at room temperature. In chlorobenzene or alkanes at 25-45 °C, half lives for decomposition of O.IM ferf-butyl hydroperoxide by 10 M catalyst ranged from 1-10 min with the active catalysts. Products included approximately 88% tert-huXyX alcohol, 11% di-rer -butyl peroxide, 1% acetone and 93% O2. These authors reported that in general, the choice of metal ion, as long as it can undergo a facile one-electron redox reaction, had little effect on products or reaction rates [328]. 

Base-catalyzed elimination of -acetoxy sulfones is highly stereoselective, leading to ( )-alkenyl sulfones which undergo transition metal-catalyzed coupling with Grignard reagents with retention of configuration to provide a stereoselective synthesis of trisubstituted alkenes. Either nickel(II) acetylacetonate, tris(acetylacetonato)iron(III), or iron(III) chloride can be used as the catalyst (eq 17). ... 

PO can be made degradable by means of additives. The types of additives include aromatic ketones (benzo-phenone and substituted benzophenones [47], qui-none), aromatic amines (trisphenylamine), polycyclic aromatic hydrocarbons (anthracene, certain dyes such as xanthene dyes), or transition metal organic compounds. The transition metal compounds of Fe, Co, Ni, Cr, Mn are widely used. Organo-soluble acetyl acetonates of many transition metals are photooxidants and transition metal carboxylates are also thermal pro-oxidants. Co acetylacetonate appears to be an effective catalyst for chemical degradation of PP in the marine environment. The preferred photoactivator system is ferric dibutyldithiocarbamate with a concentration range of 0.01. 1%. Scott has patented the use of organometallic compounds hke iron (ferric) dibutyldithiocarbamate or Ni-dibutyl-dithiocarbamate [48]. Cerium carboxylate [49] and carbon black are also used in such materials [50]. 

A pressure bottle charged with fruns-stilbene and chromium (III) acetylacetonate as the transition metal compound, evacuated, flushed with N2, pressured with Hg, Ng-flushed toluene and triisobutylaluminum as the catalyst alkylation agent in n-heptane injected by syringe, the resulting soln. stirred 20 hrs. at room temp, and 3.7 atm. bibenzyl. Y 78%. F. e., also with the more active catalysts prepared from iron (III) and cobalt (III) acetylacetonates, s. M. F. Sloan, A. S. Matlack, and D. S. Breslow, Am. Soc. 85, 4014 (1963). 

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