Acetylacetone. extraction with

Much effort has been directed to finding extractants that would remove sulphur fractions from soils for a more precise analysis, but the production of artifacts has made this difficult. However, an extraction procedure using O.OIM acetylacetone with ultrasonic dispersion looks promising, extracting from 60-90% of the total sulphur in relatively unaltered form. Further separation of the acetylacetone extract with... 

After some hours the blue-green compound of copper and acetylacetone is separated by filtration with suction, washed twice with water, transferred directly from the filter funnel to a separating funnel, and, after being covered with ether, decomposed by continuous shaking with 50 c.c. of 42V-sulphuric acid. The ethereal solution is separated and the acid layer is extracted with ether the extract is then combined with the ethereal solution, which is now dried over calcium chloride. After the ether has been removed by distillation the diketone is likewise distilled. The bulk of the material passes over at 125°-140° and, on repeating the distillation, at 135°-140°. The boiling point of the completely pure substance is 139°. Yield 15-20 g. 

Saito, N., Ikushima, Y. and Goto, T. Bull. Chem. Soc. Japan 63 (1990) 1532-1534. Liquid-solid extraction of acetylacetone chelates with supercritical carbon dioxide. 

Ail equimolar mixture (10 mmol) of benzylidenemethylamine 1 (1.19 g) and acetylacetone 2a (1 g) was adsorbed onto montmorillonite K10 (5 g) and allowed to stand at room temperature for 3 days. The mixture was extracted with CH2C12, the clay separated by filtration and the solvent evaporated under reduced pressure. Pure compound 3 could be isolated by short-path distillation (81% yield). The equimolar mixture of enamino ketone 3 and alkene 4a (5 mmol) was allowed to stand at room temperature for a suitable time. Washing with suitable solvent afforded the pure solid product 5. 

Acetylacetone la (10 mmol), metliyl vinyl ketone 2a (10 mmol) and bismuth trichloride (0.32 g, 10% mol) were mixed together without solvent in an Erlen-meyer flask and placed in a commercial microwave oven (operating at 2450 MHz frequency) and irradiated for 15 min. The reaction mixture was allowed to reach room temperature and extracted with chloroform. Removal of solvent and the residue on purification by passing through a short column of silica gel using chloroform as eluent, affords the Michael adduct 4a in 90% yield without tlie formation of any side products. Similarly cadmium iodide (10% mol) was used in place of bismuth trichloride and the corresponding Michael adduct was isolated in 85% yields. 

Cr(VI) is a toxic element, and its environmental pollution should be monitored even in seawater. CrO - is a stable chemical species in seawater, while Cr(III) also exists in relatively high amounts. Therefore, a separation of Cr(VI) from Cr(III) is necessary in the analysis of Cr( VI). For this purpose, the solvent extraction technique can also be used, being followed by atomic absorption analysis. Many workers have investigated the solvent extraction of total Cr in seawater, where Cr was extracted with acetylacetonate, DDC, APDC and analysed by AAS [37—42]. Hiiro et al. examined in detail the separation of Cr(VI) from Cr(III) in seawater [42]. The effect of pH values on extraction of Cr(VI) is shown in Fig. 5. Cr( VI) is most effectively extracted near pH 5, while Cr(III) is increasingly extracted above pH 4. Therefore,... 

A 100-ml round bottomed flask containing 50 ml of glycerol was treated with the Step 1 product (1.0 mmol) and the iridium acetylacetone complex (0.2 mmol). The mixture was heated for 18 hours and then cooled to ambient temperature and poured into 300 ml of 1M HCl. The resulting precipitate was isolated, washed with water, and dissolved in chloroform and filtered. The material was subjected to Soxhlet extraction with acetone for 24 hours, and 0.50 g of a yellow powder was isolated. The product had a Mn of 13,000 daltons with a polydis-persity of 2.1. 

Extraction is used mainly for the preliminary separation of macro- and microquantities of metals which interfere in the determination of aluminium. After Fe(III), Ti, Zr, and Cu cupferronates have been extracted from dilute HCl into chloroform, aluminium cupferronate is extracted at pH 3.5 [5]. Some interfering metals are separated from Al by extraction with trifluoroacetylacetone in CHCI3 [6], and as chloride- or thiocyanate complexes in the presence of DAM [7]. Aluminium has been separated from various elements by extraction as chelates with BPHA [8], oxine [4,9], 8-hydroxyquinaldine [10], and acetylacetone [11]. 

Extraction with acetylacetone in CHCI3, CCI4 or CeHe enables to separate Be from Mg, Ca, and phosphate. In the presence of EDTA Fe(III) and A1 remain in the aqueous phase traces of Fe(III) and A1 are, however, also extracted. The beryllium can be back-extracted into hydrochloric acid (-5 M) [2-4]. Trifluoroacetylacetone and hexafluoroacetylacetone have also been used to extract beryllium [5]. 

The cobalt(ll) thiocyanate complex can be extracted with oxygen-containing solvents, such as a mixture of diethyl ether with isoamyl alcohol (1+1), MIBK, or acetylacetone [23,24], The molar absorptivity, e, of the complex in the ether-isoamyl aleohol mixture is about 30% smaller than in the aqueous acetone media. 

From weakly acid solutions, Fe(III) is extractable with acetylacetone [5], hexafluoroacetylacetone [6], and HTTA [7]. Iron(III) can be extracted with oxine in chloroform [8,9], HDEHP [10], dithiocarbamates [11,12], and Adogene 464 (in toluene) [13,14]. 

The polyitnide bead bearing a triazole residue was used to immobilize a stable and active Mo(VI) epoxidation catalyst. The polyimide was refluxed with molybdenyl acetylacetonate in ethanol for 3days. Upon completion, a polyimide-Mo complex catalyst was filtered and extracted with ethanol in a Soxhiet apparatus for 3 days. The supported complex was dried thoroughly under vacuum. The molybdenum content was measured by inductively coupled plasma (ICP) to be l.OSmmolg for PI-DAT.Mo and l. lOmmolg for CPI-DAT.Mo. 

The sol-gel titania-silica mixed oxide contained 20 wt% titania. The catalyst was synthesized imder acidic conditions [5]. The acidic hydrolysant was added to an isopropanohc solution of tetraisopropoxytitanitam(IV) modified by acetylacetone (molar ratio alkoxide acetylacetone =1 1) and tetramethoxysilicon(IV). The water alkoxide acid molar ratio was 5 1 0.09. The resulting gel was dried by semicontinuous extraction with supercritical COg at 40 °C and 240 bar, and stored in a closed vessel under Ar. After calcination in flowing air at 600 °C, the BET smface area was 648 m g and the specific pore volume 2.9 cm g". Details on the synthesis and characterization of the sol-gel titania-sihca by means of FTIR, Raman and UV-vis spectroscopies, Ng-physisorption, XRD, XPS, TEM and thermal analysis have been reported previously [5, 6, 14, 15]. 

NbOCl4] , and [NbOF4] have been prepared by Zn/acid reduction of NbCls plus acetylacetone, NbCIs, and NbF5, respectively. The acetylacetonate was extracted with chloroform and the ESR parameters are as expected for an axially symmetric niobyl complex. 

---