Europium acetate

Separation of Samarium and Europium. One hundred thirty-five grams of samarium-europium acetate in 450 ml. of solution at 60° was treated with 1.0 g. of sodium in 80 ml. of mercury. One-half milliliter of 30% sulfuric acid was added, and the precipitated europium (II) sulfate... 

When potassium amalgam is stirred with europium acetate-citrate solution for 30 to 60 minutes, europium amalgam is formed. 

Europium acetate monohydrate (99.9 %), samarium acetate tetrahydrate (99.9 %), acetone-i 6 (D, 99.9 %) and CDCI3 (D, 99.8 %) were purchased from Wako Pure Chemical Industries Ltd. l,l,l,5,5,5-hexafluoro-2,4-pentanedione, 4,5-bis(diphenyl-pho-sphino)-9,9-dimethylxanthene, 4,5-bis(di-ferf-butylphosphino)-9,9-dimethylx-anthene and bis[(2-diphenylphosphino)phenyl]ether were obtained from Tokyo Kasei... 

Europium acetate monohydrate (8.0 g, 23 mmol) was dissolved in distilled water (100 mL) in a 300 mL flask. A solution of 1,1,1,5,5,5-hexalluoro-2,4-pentanedi-one (16 g, 77 mmol) was added dropwise to the solution. The reaction mixture produced a precipitation of white yellow powder after stirring for 2 h at room temperature. The reaction mixture was filtered, and the resulting powder was recrystallized from methanol/water to afford colorless needle crystals of the titled compound. 

Fig. 4 C MAS-NMR spectra of tetrahydrate europium acetate Eu(02CCH3)3-4H20, in protonated (a) and deuterated (b) form, at a field of 4.7 T, at rotation rates of 4,650 Hz. Reprinted with permission from [23]. 1993 American Chemical Society...

Europium (III) acetate (2H2O) [62667-64-5] M 383.1, pKj 8.31 (for aquo Eu " ). Recrystd several times from water [Ganapathy et al. J Am Chem Soc 108 3159 1986]. For europium shift reagents see lanthanide shift reagents in Chapter 4. 

Bis(acrylonitrile)nickel(0), 2312 l,2-Bis(dichlorophosphino)ethane, 0797 Bis(trimethylsilyl) phosphonite, 2611 Bromodimethylborane, 0887 Calcium silicide, 3943 Cerium trisulfide, 3967 Chromium(II) acetate, 1493 Chromium(II) oxide, 4241 Cobalt(III) nitride, 4214 Cobalt(II) sulfide, 4218 Dicobalt boride, 0128 Dimethyl ethanephosphonite, 1732 Europium(II) sulfide, 4293 2-Furaldehyde, 1836 Indium(II) oxide, 4641... 

The monazite sand is heated with sulfuric acid at about 120 to 170°C. An exothermic reaction ensues raising the temperature to above 200°C. Samarium and other rare earths are converted to their water-soluble sulfates. The residue is extracted with water and the solution is treated with sodium pyrophosphate to precipitate thorium. After removing thorium, the solution is treated with sodium sulfate to precipitate rare earths as their double sulfates, that is, rare earth sulfates-sodium sulfate. The double sulfates are heated with sodium hydroxide to convert them into rare earth hydroxides. The hydroxides are treated with hydrochloric or nitric acid to solubihze all rare earths except cerium. The insoluble cerium(IV) hydroxide is filtered. Lanthanum and other rare earths are then separated by fractional crystallization after converting them to double salts with ammonium or magnesium nitrate. The samarium—europium fraction is converted to acetates and reduced with sodium amalgam to low valence states. The reduced metals are extracted with dilute acid. As mentioned above, this fractional crystallization process is very tedious, time-consuming, and currently rare earths are separated by relatively easier methods based on ion exchange and solvent extraction. 

Time-resolved data (Fig. 46) demonstrates the exchange very clearly. The compound is 0.005 M Eu—0.020 M Tb—0.004 M DMB in acetic acid. A burst of excitation is applied to the DMB while the red emission from the europium is monitored. As the exchange of energy from DMB to terbium is very fast, the buildup corresponds to the longer exchange times from terbium->europium. 

Figure 47. Time-resolved excitation spectra of the 613-m i europium emission. The compound is 0.005 M Eu 0.020 M Tb0.004 M DMB in acetic acid. The spectral resolution is 10 m the temporal resolution is 2.5 /nsec, [from Ref. (75i)].

Europium (III) acetate (2H2O) [101953-41-7] M 383.1. Recrystd several times from water... 

Europium (II) acetate, formation of, from europium amalgam, 2 68 Europium(III) acetate, 2 66 citrate solution of, 2 67 Europium amalgams, 2 65, 66, 68n. Europium (II) carbonate, 2 69, 71 Europium(II) chloride, 2 69, 71 formation of, from europium amalgam, 2 68 Europium (III) oxalate, 2 66 Europium (III) oxide, 2 66 Europium (II) salts, 2 69 Europium(II) sulfate, 2 69, 70... 

Gadolinite, extraction of, 2 44 Gadolinium, separation of europium from samarium and, as magnesium nitrate double salt, 2 57 separation of samarium from, in acetate solution with sodium amalgam, 5 36... 

Figure 3.9 Structures of (a) [CeL3(phen)]2 (HL = acetic acid) and (b) [EnL3(phen)]2 (HL = 2-furancarboxylic acid) [RE, black (large balls) O, grey N, black (small balls) C, white H, omitted]. (Redrawn from the CIF files of A. Panagiotopoulos et al., Molecular structure and magnetic properties of acetato-bridged lanthanide(III) dimers, Inorganic Chemistry, 34, 4918 920, 1995 [37] and X. Li et al., Synthesis, structure and luminescence property of the ternary and quaternary europium complexes with furoic acid, Journal of Molecular Structure, 604, 65-71, 2002 [48].)...

Fomina, LG, Kiskin, M.A., Martynov, A.G, Aleksandrov, GG, Dobrokhotova, Z.V., Gorbimova, Y.G et al. (2004) Lanthanum(III), samarium(III), europium(lll), and thuUum(lll) binuclear acetates and pivalates synthesis, structure, magnetic properties, and solid-phase thermolysis. Zhurrml NeorganJcheskoi Khimii, 49 (9), 1463-1474. 

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