Europium(III) oxalate explained

Europium(III) oxalate (Eu2(C2O4)3) is a chemical compound of europium and oxalic acid. There are different hydrates including the decahydrate, hexahydrate and tetrahydrate.[1] Europium(II) oxalate is also known.[2]

Preparation

An excess of oxalate is added to a hot solution of Eu3+ cations. The resulting precipitate of Eu2(C2O4)3 ⋅ 10H2O is dried in a desiccator.[3]

Properties

Europium(III) oxide (Eu2O3) can be prepared by calcining europium(III) oxalate.[4]

The dehydration of Eu2(C2O4)3 · 10H2O occurs below 200 °C:

Eu2(C2O4)3*10H2O -> Eu2(C2O4)3*6H2O -> Eu2(C2O4)3*4H2O -> Eu2(C2O4)3

The decomposition of this compound takes place in two stages, the first at 350 °C and the second at about 620 °C.[5]

Eu2(C2O4)3 -> Eu2[CO3]3 + 3 CO -> Eu2O3 + 3 CO2 + 3 CO

In the Mössbauer spectrum, Eu2(C2O4)3 · 10H2O shows an isomer shift of +0,26 mm/s with a line width of 2,38 mm/s, in reference to EuF3.[6] The Debye temperature of Eu2(C2O4)3 is 166±15 K.[7]

Eu2(C2O4)3 · 10H2O crystallizes monoclinically in the space group of P21/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.[8]

Nanoparticles show a line emission when excited by a light source of 393 nm, the transitions 5D0→7F1 (592 nm) and 5D0→7F2 (616 nm) can then be found in the spectrum. This can be used as a red phosphor for white LEDs.[9]

Notes and References

  1. John K. Gibson, Nathan A. Stum. Spectroscopic investigation of the thermal decomposition of europium oxalate. Thermochimica Acta. 1993-10-26. 226 . 301–310. 10.1016/0040-6031(93)80231-X.
  2. H. Pink. Europium(II)-oxalat. Zeitschrift für Anorganische und Allgemeine Chemie. 1967-09-01. 353 . 5–6. 247–249. 10.1002/zaac.19673530505.
  3. 1991-08-01. 2. 111–112. 10.1524/ract.1991.55.2.111. 99690174 . Short Communication: Mössbauer Effect 151Eu of in Europium Chelates. Wynter. C. I.. Oliver. F. R.. Hill. Dana. Spijkerman. J. J.. Boyd-Bartlett. Y. P.. Radiochimica Acta. 55.
  4. Book: Ginya Adachi, Nobuhito Imanaka, Zhen Chuan Kang. Binary rare earth oxides. 2004. Springer Netherlands. 978-1-4020-2568-6. 138.
  5. A. Glasner, E. Levy, M. Steinberg. Thermogravimetric and Differentialthermoanalyse of europium(III)oxalat and unite europium(II)salzen. Chemisches Zentralblatt. 1965. 17. 05296.
  6. 10.1016/0168-583X(93)95235-W . Mössbauer effect of 151Eu in europium oxalate and fluorides . 1993 . Wynter . C.I. . Oliver . F.W. . Davis . Alfred . Spijkerman . J.J. . Stadelmaier . H. . Wolfe . E.A. . Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms . 76 . 1–4 . 352–353 . 1993NIMPB..76..352W .
  7. C. I. Wynter, D. H. Ryan, S. P. Taneja, L. May, F. W. Oliver, D. E. Brown, M. Iwunzie. Mössbauer studies of 151Eu in europium oxalate,europium bissalen ammonium and europium benzoate. Hyperfine Interactions. November 2005. 166 . 1–4. 499–503. 10.1007/s10751-006-9315-4. 2005HyInt.166..499W . 95479298 .
  8. A. Dinu, Th. Kukku, J. Monu, P. R. Biju, N. V. Unnikrishnanaand, J. Cyriac. Structural and spectroscopic investigations on thequenching free luminescence of europium oxalatenanocrystals. Acta Crystallographica Section C. 2019. 75 . 5 . 589–597. 10.1107/S2053229619005059. 31062717 . 146808653 .
  9. Wei Zhu, You-jin Zhang, Hong-mei He, Zhi-yong Fang . Synthesis and Luminescence Property of Hierarchical Europium Oxalate Micropaticles . . 2011 . 24 . 1 . 65–69 . 10.1088/1674-0068/24/01/65-69. 2011ChJCP..24...65Z .

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Europium(III) oxalate".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.