Europium (III) oxalate

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Crystal structure
No drawing available
General
Surname Europium (III) oxalate
Ratio formula Eu 2 (C 2 O 4 ) 3
Brief description

colorless solid

External identifiers / databases
CAS number 3269-12-3
PubChem 90472147
Wikidata Q15628196
properties
Molar mass
  • 567.985 g mol −1 (anhydrous)
  • 640.046 g mol −1 (tetrahydrate)
  • 676.077 g mol −1 (hexahydrate)
  • 748.138 g mol −1 (decahydrate)
Physical state

firmly

solubility

1.38 mg l −1

safety instructions
GHS hazard labeling
no classification available
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Europium (III) oxalate (Eu 2 (C 2 O 4 ) 3 ) is a chemical compound made of europium and oxalic acid . There are different types of hydrates , including decahydrate, hexahydrate and tetrahydrate. A europium (II) oxalate is also known.

Extraction and presentation

An excess of oxalate is added to a hot solution of Eu 3+ cations and the resulting precipitate of Eu 2 (C 2 O 4 ) 3  10H 2 O is dried over a drying agent in a desiccator .

properties

The dehydration of Eu 2 (C 2 O 4 ) 3  · 10H 2 O takes place below 200 ° C.

The decomposition of this compound takes place in two stages, the first at 350 ° C and the second at approx. 620 ° C.

Eu 2 (C 2 O 4 ) 3  · 10H 2 O shows in the Mössbauer spectrum an isomer shift of +0.26 mm / s with a line width of 2.38 mm / s, in reference to EuF 3 . The Debye temperature of Eu 2 (C 2 O 4 ) 3 is 166 ± 15 K. Eu 2 (C 2 O 4 ) 3  · 10H 2 O crystallizes monoclinically in the space group P 2 1 / c (space group no. 14 ) with the lattice parameters a  = 1098, b  = 961, c  = 1004 pm and β  = 114.2 ° with four formula units per unit cell. Nanoparticles show a line emission when excited by a light source of 393 nm, the transitions 5 D 0 → 7 F 1 (592 nm) and 5 D 0 → 7 F 2 (616 nm) can then be found in the spectrum. This can be used as a red phosphor for white LEDs . Template: room group / 14

use

In order to obtain europium (III) oxide (Eu 2 O 3 ) from the ores, this is ultimately obtained by burning up europium (III) oxalate.

Individual evidence

  1. ^ A b c d e John K. Gibson, Nathan A. Stum: Spectroscopic investigation of the thermal decomposition of europium oxalate . In: Thermochimica Acta . tape 226 , October 26, 1993, p. 301-310 , doi : 10.1016 / 0040-6031 (93) 80231-X .
  2. ↑ SS Berdonosov, DG Berdonosova, MA Prokofev, V. Ya. Lebedev: Study of europium oxalate decahydrate . In: Zh. Neorg. Khim. tape 21 , 1976, p. 1184-1189 .
  3. ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
  4. ↑ H. Pink: Europium (II) oxalate . In: Z. anorg. gen. Chem. Band 353 , no. 5-6 , September 1967, pp. 247-249 , doi : 10.1002 / zaac.19673530505 .
  5. ^ A b C. I. Wynter, FW Oliver, D. Hill, JJ Spijkerman, YP Bartlett: Mössbauer Effect of 151 Eu in Europium Chelates . In: Radiochim. Acta . tape 55 , no. 2 , August 1, 1991, pp. 111-112 , doi : 10.1524 / ract.1991.55.2.111 .
  6. ↑ A. Glasner, E. Levy, M. Steinberg: Thermogravimetric and Differentialthermoanalyse of europium (III) oxalate and unite europium (II) salt . In: Chem. Zentralblatt . tape 136 , no. 17 , 1965, p. 05296 .
  7. ↑ C. Wynter: Moessbauer effect of europium-151 in europium oxalate and fluorides . In: Nucl. Instrum. Methods Phys. Res . B76, no. 1-4 , April 1993, pp. 352-353 , doi : 10.1016 / 0168-583X (93) 95235-W .
  8. Jump up ↑ CI Wynter, DH Ryan, SP Taneja, L. May, FW Oliver, DE Brown, M. Iwunzie: Mössbauer studies of 151 Eu in europium oxalate, europium bissalen ammonium and europium benzoate . In: Hyperfine Interact. tape 166 , no. 1-4 , November 2005, pp. 499-503 , doi : 10.1007 / s10751-006-9315-4 .
  9. ↑ A. Dinu, Th. Kukku, J. Monu, PR Biju, NV Unnikrishnanaand, J. Cyriac: Structural and spectroscopic investigations on the quenching free luminescence of europium oxalatenanocrystals . In: Acta Cryst. C75, 2019, pp. 589-597 , doi : 10.1107 / S2053229619005059 .
  10. ↑ Wei Zhu, You-jin Zhang, Hong-mei He, Zhi-yong Fang: Synthesis and Luminescence Property of Hierarchical Europium Oxalate Micropaticles . In: Chinese Journal of Chemical Physics . tape 24 , 2011, p. 65-69 , doi : 10.1088 / 1674-0068 / 24/01 / 65-69 .
  11. ↑ Ginya Adachi, Nobuhito Imanaka, Zhen Chuan Kang: Binary rare earth oxides . Springer Netherlands, 2004, ISBN 978-1-4020-2568-6 , pp. 138 (( limited preview in Google Book search).