II Acetylacetonate

Manganese (II) acetylacetonate 2-hydrate has been obtained by precipitation from aqueous solution.1 The anhydrous product was prepared from the hydrate by allowing it to stand in a vacuum over phosphorus (V) oxide. Although the 2-hydrate, in solution or wet with solvent, is reported to oxidize rapidly in air, the dry material is reported to be stable. 

To a solution of 49.5 g. (0.25 mol) of manganese(II) chloride 4-hydrate in 250 ml. of water at room temperature is added a solution of 50 g. (0.5 mol) of acetylacetone in 100 ml. methanol. The mixture is stirred during the addition with a magnetic stirrer. A solution of 68.1 g. (0.5 mol) 

If desired, the 2-hydrate can be purified by recrystallization. Sixteen grams of the dried material is stirred for a few minutes with 100 ml. of absolute ethanol, and the solution is then filtered with suction as rapidly as possible through coarse filter paper on a Buchner funnel. Sufficient ethanol is added to the filtrate to replace that lost by evaporation and to redissolve any solid which separates. Fifteen milliliters of water is added to the filtrate, and the solution is evaporated with a stream of nitrogen until reduced in volume by one-half. The mixture is then cooled for a few minutes. The yellow crystals are filtered off on a Buchner funnel and dried under the conditions specified for the unrecrystallized material. The yield is 30 to 50% of the quantity of unrecrystallized compound taken. Anal. Calcd. for Mn(C5Hv02)2-2H20 C, 41.5 H, 6.3 Mn, 19.0. Found C, 41.2 H, 6.1 Mn, 19.2. 

The anhydrous compound may be formed as a tan powder by heating the 2-hydrate 2 to 4 hours at 100° in a drying pistol or vacuum oven at a pressure of several mm. Hg. 

The dry compounds do not oxidize readily in air but the wet compounds do, more rapidly with higher temperature. 

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Cobalt(II) acetylacetonate [14024-48-7] cobalt(II) ethyUiexanoate [136-52-7] cobalt(II) oleate [14666-94-5] cobalt(II) linoleate [14666-96-7] cobalt(II) formate [6424-20-0], and cobalt(II) resinate can be produced by metathesis reaction of cobalt salt solutions and the sodium salt of the organic acid, by oxidation of cobalt metal in the presence of the acid, and by neutralization of the acid using cobalt carbonate or cobalt hydroxide. 

Manganese (II) acetylacetone [14024-58-9] M 253.2, m -250°. Purify by stirring 16g of reagent for a few min with lOOmL absolute EtOH and filter by suction as rapidly as possible through coarse filter paper. Sufficient EtOH is added to the filtrate to make up for the loss of EtOH and to redissolve any solid that separates. Water (15mL) is added to the filtrate and the solution is evapiorated with a stream of N2 until reduced to half its vol. Cool for a few min and filter off the yellow crystals, dry under a stream of N2, then in a... 

In addition to rhodium(III) oxide, cobalt(II) acetylacetonate or dicobalt octacarbonyl has been used by the submitters as catalyst precursors for the hydroformylation of cyclohexene. The results are given in Table I. 

In chelation complexes (sometimes called inner complexes when uncharged) the central metal ion coordinates with a polyfunctional organic base to form a stable ring compound, e.g. copper(II) acetylacetonate or iron(III) cupferrate ... 

CHROMIUM TRIOXIDE-PYRIDINE COMPLEX, preparation in situ, 55, 84 Chrysene, 58,15, 16 fzans-Cinnamaldehyde, 57, 85 Cinnamaldehyde dimethylacetal, 57, 84 Cinnamyl alcohol, 56,105 58, 9 2-Cinnamylthio-2-thiazoline, 56, 82 Citric acid, 58,43 Citronellal, 58, 107, 112 Cleavage of methyl ethers with iodotri-methylsilane, 59, 35 Cobalt(II) acetylacetonate, 57, 13 Conjugate addition of aryl aldehydes, 59, 53 Copper (I) bromide, 58, 52, 54, 56 59,123 COPPER CATALYZED ARYLATION OF /3-DlCARBONYL COMPOUNDS, 58, 52 Copper (I) chloride, 57, 34 Copper (II) chloride, 56, 10 Copper(I) iodide, 55, 105, 123, 124 Copper(I) oxide, 59, 206 Copper(ll) oxide, 56, 10 Copper salts of carboxylic acids, 59, 127 Copper(l) thiophenoxide, 55, 123 59, 210 Copper(l) trifluoromethanesulfonate, 59, 202... 

Smooth and efficient cyclopropanation also occurs with copper(II) triflate and diazomethane. Intra- and intermolecular competition experiments show that, in this case, the less substituted double bond reacts preferentially251. The same is true for CuOTf and Cu(BF4)2, whereas with CuX P(OMe)3 (X = Cl, I), CuS04 and cop-per(II) acetylacetonate, cyclopropanation of the more substituted double bond predominates. An example is given for cyclopropanation of 1. 

Palladium(II) acetate was found to be a good catalyst for such cyclopropanations with ethyl diazoacetate (Scheme 19) by analogy with the same transformation using diazomethane (see Sect. 2.1). The best yields were obtained with monosubstituted alkenes such as acrylic esters and methyl vinyl ketone (64-85 %), whereas they dropped to 10-30% for a,p-unsaturated carbonyl compounds bearing alkyl groups in a- or p-position such as ethyl crotonate, isophorone and methyl methacrylate 141). In none of these reactions was formation of carbene dimers observed. 7>ms-benzalaceto-phenone was cyclopropanated stereospecifically in about 50% yield PdCl2 and palladium(II) acetylacetonate were less efficient catalysts 34 >. Diazoketones may be used instead of diazoesters, as the cyclopropanation of acrylonitrile by diazoacenaph-thenone/Pd(OAc)2 (75 % yield) shows142). 

Catalytic homogeneous hydrogenation of cyclohexene has been claimed for simple systems such as nickel(II) acetylacetonate [39] or a nickel-chloride complex with two monodentate amines [40]. The latter complex was used as comparison for a heterogeneous catalyst obtained by impregnation of the complex on y-alu-mina [40]. SCRs of 100 were used at 30 atm. H2 and temperatures up to 100°C, resulting in conversions of only 20-35% after 1 h. 

Copper (II) -acetylacetonate complex (Resonating ring compound)... 

Mn(acac)3 reacts with ethylenediamine (L2) or other primary amines (L) to yield [Mn"(acac)2L2], which can also be prepared by the reaction of the amine or diamine with [Mn(acac)2(H20)2]. Allylamine reacts with [Mn(acac)2-(H20)2] in ether to give a second complex, [Mn(acac)2(H2NCH2==CH2)]2 which is dimeric both in the solid and vapour phases. This is the First example of a dinuclear manganese(ii) acetylacetonate complex. Thermodynamic data have been reported for the manganese(ii)-acetylacetone system in propan-1-ol-water. ... 

In the first reports by Ishii and coworkers , catalytic amounts of both HPI and Co(II)acetylacetonate, Co(acac)2, were employed for the oxidation of alkanes in AcOH at 100 °C, dioxygen being the terminal oxidant. The appeal of this procedure for the oxidative transformation of simple hydrocarbons into carbonyl derivatives is clear. Cycloalkanes were converted into a mixture of cyclic ketones plus open-chain a, )-dicarboxylic acids (Table 11), while linear alkanes yielded the corresponding alcohols plus ketones in significant amounts (40-80%), and alkylbenzenes could be oxidized in almost quantitative yields . 

Combined use of cobalt(II) acetylacetonate [Co(acac)2] and DiBAlH also gives selective... 

Nasibulin AG, Richard 0, Kauppinen El, Brown DP, Jokiniemi JK, Altman IS (2002) Nanoparticle synthesis by copper (II) acetylacetonate vapor decomposition in the presence of oxygen. Aerosol Sci Technol 36 899-911... 

Cobalt (III) acetylacetonate [Co(acac)3] (14), manganese (III) acetylacetonate [Mn(acac)3] (15), iron(III) acetylacetonate [Fe(acac)3] (30), chromium(III) acetylacetonate [Cr(acac)3] (13), nickel(II) acetylacetonate [Ni(acac)2] (8), and copper (II) acetylacetonate [Cu(acac)2] (18) were prepared and purified. Cobalt, manganese, iron, chromium, nickel, and copper naphthenates were all commercially available. 

Photoreduction of cobalt(III) complexes in nonaqueous solvent systems has been little studied because of the limited solubility of cobalt(III) complexes and their tendency to photooxidize the solvent. Irradiation with 365-mjj. light of cis- or trans-Co(en)2C 2 + and Co(en)2Cl(DMSO)2+ in dimethylsulfoxide (DMSO) leads rapidly to production of a green tetrahedral cobalt(II) product apparently with concurrent solvent oxidation.53,71 Irradiation with 365-mjx light of the molecular Co(acac)3 in benzene rapidly gives a red precipitate which may be the cobalt(II) acetylacetonate.53... 

It has been noted that for the ammonium ylide generation copper catalysts such as copper(ii) acetylacetonate [Cu(acac)2] and Cu(hfacac)2 are superior over Rh(ii) catalysts. Sweeney and co-workers have recently reported copper-catalyzed [2,3]-sigmatropic rearrangement of ammonium ylide generated from tetrahydropyridines 150 and diazo ester 129 (Equation (22)). A detailed study on the reaction conditions has revealed that Cu(acac)2 is the best catalyst for this reaction. 

Figure 14. Theoretical absorption and experimental first derivative for Cu(II) acetylacetonate in 60 per cent toluene and 40 per cent chloroform at 138°K. See Ref. (32).

Values of y are not given because there is some uncertainty as to the value of AE(Eg). In the case of copper(II) acetylacetonate, which is one of the few systems where the signs of A and B as well as the magnitudes have been determined, there are three bands observed in the visible spectrum at 14,900 cm-1, 18,200 cm-1 and 25,800 cm-1. It seems likely that AE(Blg) = 14,900 cm 1 and this value was used in computing values in Table IV. 

Nickel (II) acetylacetonate [3264-82-2] M 256.9, m 229-230°, h 220-235°/llmm, d 1.455. Wash the green solid with H2O, dry in a vacuum desiccator and recrystallise from MeOH. [JPC 62 440 1958]. The complex can be conveniently dehydrated by azeotropic distn with toluene and the crystals may be isolated by concentrating the toluene solution. [JACS 76 1970 1954]. 

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